SPORE Supported Publications

  • Expanded Basal Compartment and Disrupted Barrier in Vocal Fold Epithelium Infected with Mouse Papillomavirus MmuPV1
  • A Novel In Vivo Model of Laryngeal Papillomavirus-Associated Disease Using <em>Mus musculus</em> Papillomavirus
  • Stress Keratin 17 Expression in Head and Neck Cancer Contributes to Immune Evasion and Resistance to Immune-Checkpoint Blockade
  • Validation of Monte Carlo <sup>131</sup> I radiopharmaceutical dosimetry workflow using a 3D-printed anthropomorphic head and neck phantom
  • Merkel cell polyomavirus large T antigen binding to pRb promotes skin hyperplasia and tumor development
  • Activation of the CREB Coactivator CRTC2 by Aberrant Mitogen Signaling promotes oncogenic functions in HPV16 positive head and neck cancer
  • Prospective Study of PET/MRI Tumor Response During Chemoradiotherapy for Patients With Low-risk and Intermediate-risk p16-positive Oropharynx Cancer
  • Advances in Organ Preservation for Laryngeal Cancer
  • Bayes optimal informer sets for early-stage drug discovery
  • Network inference with Granger causality ensembles on single-cell transcriptomics
  • Sex and genetic background define the metabolic, physiologic, and molecular response to protein restriction
  • Branched, dendritic, and hyperbranched polymers in liquid biopsy device design
  • Hierarchically Multivalent Peptide-Nanoparticle Architectures: A Systematic Approach to Engineer Surface Adhesion
  • Radiation Augments the Local Anti-Tumor Effect of <em>In Situ</em> Vaccine With CpG-Oligodeoxynucleotides and Anti-OX40 in Immunologically Cold Tumor Models
  • Autophagy awakens-the myriad roles of autophagy in head and neck cancer development and therapeutic response
  • Syndecans and Their Synstatins: Targeting an Organizer of Receptor Tyrosine Kinase Signaling at the Cell-Matrix Interface
  • Defining high-risk elective contralateral neck radiation volumes for oropharynx cancer
  • Tri-modal liquid biopsy: Combinational analysis of circulating tumor cells, exosomes, and cell-free DNA using machine learning algorithm
  • Opioid use in patients undergoing treatment for oral cavity cancer
  • Biology of HPV Mediated Carcinogenesis and Tumor Progression
  • Role of IQGAP1 in Carcinogenesis
  • Dendrimers for cancer immunotherapy: Avidity-based drug delivery vehicles for effective anti-tumor immune response
  • Multiomic analysis reveals decidual-specific transcriptional programing of MAIT cells
  • Mouse papillomavirus type 1 (MmuPV1) DNA is frequently integrated in benign tumors by microhomology-mediated end-joining
  • Size-Dependent Drug Loading, Gene Complexation, Cell Uptake, and Transfection of a Novel Dendron-Lipid Nanoparticle for Drug/Gene Co-delivery
  • Low-dose targeted radionuclide therapy renders immunologically cold tumors responsive to immune checkpoint blockade
  • Quantification and molecular imaging of fatty acid isomers from complex biological samples by mass spectrometry
  • Combination of radiation therapy, bempegaldesleukin, and checkpoint blockade eradicates advanced solid tumors and metastases in mice
  • Respiratory-swallow coordination in a rat model of chemoradiation
  • Role of IQGAP1 in Papillomavirus-Associated Head and Neck Tumorigenesis
  • High-resolution magnetic resonance and mass spectrometry imaging of the human larynx
  • Impact of immediate cryopreservation on the establishment of patient derived xenografts from head and neck cancer patients
  • A multipurpose brachytherapy catheter to enable intratumoral injection
  • Structure-preserving integrated analysis for risk stratification with application to cancer staging
  • MixTwice: large-scale hypothesis testing for peptide arrays by variance mixing
  • Toward improved <em>in vitro</em> models of human cancer
  • Immunotherapy in Head and Neck Cancer-Ready for Prime Time or More Research Needed?
  • The Merkel Cell Polyomavirus T Antigens Function as Tumor Promoters in Murine Skin
  • Tumor-Specific Antibody, Cetuximab, Enhances the <em>In Situ</em> Vaccine Effect of Radiation in Immunologically Cold Head and Neck Squamous Cell Carcinoma
  • Enhanced detection of cell-free DNA (cfDNA) enables its use as a reliable biomarker for diagnosis and prognosis of gastric cancer
  • Activation of EPHA2-ROBO1 Heterodimer by SLIT2 Attenuates Non-canonical Signaling and Proliferation in Squamous Cell Carcinomas
  • Life Beyond COVID: Pay Attention to Viruses
  • On-Tissue Derivatization with Girard's Reagent P Enhances N-Glycan Signals for Formalin-Fixed Paraffin-Embedded Tissue Sections in MALDI Mass Spectrometry Imaging
  • Microfluidic lumen-based systems for advancing tubular organ modeling
  • An Avidity-Based PD-L1 Antagonist Using Nanoparticle-Antibody Conjugates for Enhanced Immunotherapy
  • AXL Mediates Cetuximab and Radiation Resistance Through Tyrosine 821 and the c-ABL Kinase Pathway in Head and Neck Cancer
  • Follow-Up and Management of Patients With Head and Neck Cancer During the 2019 Novel Coronavirus (SARS-CoV-2) Disease Pandemic
  • An Infection-Based Murine Model for Papillomavirus-Associated Head and Neck Cancer
  • Priming and Propagating Anti-tumor Immunity: Focal Hypofractionated Radiation for in Situ Vaccination and Systemic Targeted Radionuclide Theranostics for Immunomodulation of Tumor Microenvironments
  • FGFR Inhibition Enhances Sensitivity to Radiation in Non-Small Cell Lung Cancer
  • The Promise of Combining Radiation Therapy With Immunotherapy
  • A Mouse Model of Oropharyngeal Papillomavirus-Induced Neoplasia Using Novel Tools for Infection and Nasal Anesthesia
  • Fibroblast Growth Factor Receptors as Targets for Radiosensitization in Head and Neck Squamous Cell Carcinomas
  • Matrix density drives 3D organotypic lymphatic vessel activation in a microfluidic model of the breast tumor microenvironment
  • Targeting AKT/PKB to improve treatment outcomes for solid tumors
  • Interstitial diffuse optical probe with spectral fitting to measure dynamic tumor hypoxia
  • Patient Derived Models to Study Head and Neck Cancer Radiation Response
  • Clinical outcomes for larynx patients with cancer treated with refinement of high-dose radiation treatment volumes
  • Mus musculus Papillomavirus 1: a New Frontier in Animal Models of Papillomavirus Pathogenesis
  • Stress keratin 17 enhances papillomavirus infection-induced disease by downregulating T cell recruitment
  • Human Tumor-Lymphatic Microfluidic Model Reveals Differential Conditioning of Lymphatic Vessels by Breast Cancer Cells
  • A PI3K/AKT Scaffolding Protein, IQ Motif-Containing GTPase Associating Protein 1 (IQGAP1), Promotes Head and Neck Carcinogenesis
  • Cox regression with survival-time-dependent missing covariate values
  • Development of an In Situ Cancer Vaccine via Combinational Radiation and Bacterial-Membrane-Coated Nanoparticles
  • Effects of culture method on response to EGFR therapy in head and neck squamous cell carcinoma cells
  • Dendrimer-Based Platform for Effective Capture of Tumor Cells after TGFβ<sub>1</sub>-Induced Epithelial-Mesenchymal Transition
  • High-throughput quantitative detection of basal autophagy and autophagic flux using image cytometry
  • The Specificity of EGF-Stimulated IQGAP1 Scaffold Towards the PI3K-Akt Pathway is Defined by the IQ3 motif
  • De-Escalation Strategies in HPV-Associated Oropharynx Cancer-Are we Putting the Cart Before the Horse?
  • A Phase Ib Study of Axitinib in Combination with Crizotinib in Patients with Metastatic Renal Cell Cancer or Other Advanced Solid Tumors
  • Human organotypic lymphatic vessel model elucidates microenvironment-dependent signaling and barrier function
  • Reducing radiotherapy target volume expansion for patients with HPV-associated oropharyngeal cancer
  • Preclinical Pharmacokinetics and Dosimetry Studies of <sup>124</sup>I/<sup>131</sup>I-CLR1404 for Treatment of Pediatric Solid Tumors in Murine Xenograft Models
  • Personalized Treatment for Lacrimal Sac Adenoid Cystic Carcinoma: Case Report and Literature Review
  • Age-related alterations in swallowing biomechanics
  • Peptide-nanoparticle conjugates: a next generation of diagnostic and therapeutic platforms?
  • SLP-Perceived Technical and Patient-Centered Factors Associated with Pharyngeal High-Resolution Manometry
  • Pretreatment CLR 124 Positron Emission Tomography Accurately Predicts CLR 131 Three-Dimensional Dosimetry in a Triple-Negative Breast Cancer Patient
  • HPV impacts survival of stage IVC non-oropharyngeal HNSCC cancer patients
  • Expression pattern of androgen receptor and AR-V7 in androgen-deprivation therapy-naïve salivary duct carcinomas
  • Correlates of Early Pharyngeal High-Resolution Manometry Adoption in Expert Speech-Language Pathologists
  • Enhanced Radiosensitivity in Solid Tumors using a Tumor-selective Alkyl Phospholipid Ether Analog
  • MERTK Mediates Intrinsic and Adaptive Resistance to AXL-targeting Agents
  • Loss of Function of Canonical Notch Signaling Drives Head and Neck Carcinogenesis
  • Results From 10 Years of a Free Oral Cancer Screening Clinic at a Major Academic Health Center
  • Pharmacodynamic study using FLT PET/CT in advanced solid malignancies treated with a sequential combination of X-82 and docetaxel
  • Genomics Reloaded: Rise of the Expression Profiles
  • Toward improved in vitro models of human cancer. APL Bioeng
    Ayuso JM, Park KY, Virumbrales-Muñoz M, Beebe DJ
    2021 Mar; 5 (1): 010902
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      Cancer is a leading cause of death across the world and continues to increase in incidence. Despite years of research, multiple tumors (e.g., glioblastoma, pancreatic cancer) still have limited treatment options in the clinic. Additionally, the attrition rate and cost of drug development have continued to increase. This trend is partly explained by the poor predictive power of traditional in vitro tools and animal models. Moreover, multiple studies have highlighted that cell culture in traditional Petri dishes commonly fail to predict drug sensitivity. Conversely, animal models present differences in tumor biology compared with human pathologies, explaining why promising therapies tested in animal models often fail when tested in humans. The surging complexity of patient management with the advent of cancer vaccines, immunotherapy, and precision medicine demands more robust and patient-specific tools to better inform our understanding and treatment of human cancer. Advances in stem cell biology, microfluidics, and cell culture have led to the development of sophisticated bioengineered microscale organotypic models (BMOMs) that could fill this gap. In this Perspective, we discuss the advantages and limitations of patient-specific BMOMs to improve our understanding of cancer and how these tools can help to confer insight into predicting patient response to therapy.

      View details for PubMedID 33532672
  • A Novel In Vitro Culture Model System to Study Merkel Cell Polyomavirus-Associated MCC Using Three-Dimensional Organotypic Raft Equivalents of Human Skin. Viruses
    Loke ASW, Longley BJ, Lambert PF, Spurgeon ME
    2021 Jan 19; 13 (1):
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      Merkel cell polyomavirus (MCPyV) is a human polyomavirus causally linked to the development of Merkel cell carcinoma (MCC), an aggressive malignancy that largely arises within the dermis of the skin. In this study, we recapitulate the histopathology of human MCC tumors in vitro using an organotypic (raft) culture system that is traditionally used to recapitulate the dermal and epidermal equivalents of skin in three dimensions (3D). In the optimal culture condition, MCPyV+ MCC cells were embedded in collagen between the epidermal equivalent comprising human keratinocytes and a dermal equivalent containing fibroblasts, resulting in MCC-like lesions arising within the dermal equivalent. The presence and organization of MCC cells within these dermal lesions were characterized through biomarker analyses. Interestingly, co-culture of MCPyV+ MCC together with keratinocytes specifically within the epidermal equivalent of the raft did not reproduce human MCC morphology, nor were any keratinocytes necessary for MCC-like lesions to develop in the dermal equivalent. This 3D tissue culture system provides a novel in vitro platform for studying the role of MCPyV T antigens in MCC oncogenesis, identifying additional factors involved in this process, and for screening potential MCPyV+ MCC therapeutic strategies.

      View details for PubMedID 33478104
  • The Merkel Cell Polyomavirus T Antigens Function as Tumor Promoters in Murine Skin. Cancers (Basel)
    Spurgeon ME, Liem A, Buehler D, Cheng J, DeCaprio JA, Lambert PF
    2021 Jan 09; 13 (2):
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      Merkel cell polyomavirus (MCPyV) causes the majority of human Merkel cell carcinomas (MCC), a rare but highly aggressive form of skin cancer. We recently reported that constitutive expression of MCC tumor-derived MCPyV tumor (T) antigens in the skin of transgenic mice leads to hyperplasia, increased proliferation, and spontaneous epithelial tumor development. We sought to evaluate how the MCPyV T antigens contribute to tumor formation in vivo using a classical, multi-stage model for squamous cell carcinoma development. In this model, two chemical carcinogens, DMBA and TPA, contribute to two distinct phases of carcinogenesis-initiation and promotion, respectively-that are required for tumors to develop. By treating the MCPyV transgenic mice with each chemical carcinogen, we determined how the viral oncogenes contributed to carcinogenesis. We observed that the MCPyV T antigens synergized with the tumor initiator DMBA, but not with the tumor promoter TPA, cause tumors. Therefore, the MCPyV tumor antigens function primarily as tumor promoters, similar to that seen with human papillomavirus (HPV) oncoproteins. These studies provide insight into the role of MCPyV T antigen expression in tumor formation in vivo and contribute to our understanding of how MCPyV may function as a human DNA tumor virus.

      View details for PubMedID 33435392
  • Enhanced detection of cell-free DNA (cfDNA) enables its use as a reliable biomarker for diagnosis and prognosis of gastric cancer. PLoS One
    Bu J, Lee TH, Jeong WJ, Poellmann MJ, Mudd K, Eun HS, Liu EW, Hong S, Hyun SH
    2020; 15 (12): e0242145
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      Although circulating cell-free DNA (cfDNA) is a promising biomarker for the diagnosis and prognosis of various tumors, clinical correlation of cfDNA with gastric cancer has not been fully understood. To address this, we developed a highly sensitive cfDNA capture system by integrating polydopamine (PDA) and silica. PDA-silica hybrids incorporated different molecular interactions to a single system, enhancing cfDNA capture by 1.34-fold compared to the conventional silica-based approach (p = 0.001), which was confirmed using cell culture supernatants. A clinical study using human plasma samples revealed that the diagnostic accuracy of the new system to be superior than the commercially available cfDNA kit, as well as other serum antigen tests. Among the cancer patients, plasma cfDNA levels exhibited a good correlation with the size of a tumor. cfDNA was also predicative of distant metastasis, as the median cfDNA levels of metastatic cancer patients were ~60-fold higher than those without metastasis (p = 0.008). Furthermore, high concordance between tissue biopsy and cfDNA genomic analysis was found, as HER2 expression in cfDNA demonstrated an area under ROC curve (AUC) of 0.976 (p <0.001) for detecting patients with HER2-positive tumors. The new system also revealed high prognostic capability of cfDNA, as the concentration of cfDNA was highly associated with the survival outcomes. Our novel technology demonstrates the potential to achieve efficient detection of cfDNA that may serve as a reliable biomarker for gastric tumor.

      View details for PubMedID 33264292
  • Activation of EPHA2-ROBO1 Heterodimer by SLIT2 Attenuates Non-canonical Signaling and Proliferation in Squamous Cell Carcinomas. iScience
    Srivastava S, Pang KM, Iida M, Nelson MS, Liu J, Nam A, Wang J, Mambetsariev I, Pillai R, Mohanty A, McDaniel N, Behal A, Kulkarni P, Wheeler DL, Salgia R
    2020 Nov 20; 23 (11): 101692
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      The tyrosine kinase receptor ephrin receptor A2 (EPHA2) is overexpressed in lung (LSCC) and head and neck (HNSCC) squamous cell carcinomas. Although EPHA2 can inhibit tumorigenesis in a ligand-dependent fashion via phosphorylation of Y588 and Y772, it can promote tumorigenesis in a ligand-independent manner via phosphorylation of S897. Here, we show that EPHA2 and Roundabout Guidance Receptor 1 (ROBO1) interact to form a functional heterodimer. Furthermore, we show that the ROBO1 ligand Slit Guidance Ligand 2 (SLIT2) and ensartinib, an inhibitor of EPHA2, can attenuate growth of HNSCC cells and act synergistically in LSCC cells. Our results suggest that patients with LSCC and HNSCC may be stratified and treated based on their EPHA2 and ROBO1 expression patterns. Although ~73% of patients with LSCC could benefit from SLIT2+ensartinib treatment, ~41% of patients with HNSCC could be treated with either SLIT2 or ensartinib. Thus, EPHA2 and ROBO1 represent potential LSCC and HNSCC theranostics.

      View details for PubMedID 33196021
  • Life Beyond COVID: Pay Attention to Viruses. Int J Radiat Oncol Biol Phys
    Harari PM, Lambert PF
    2020 Oct 01; 108 (2): 348-350
  • On-Tissue Derivatization with Girard's Reagent P Enhances N-Glycan Signals for Formalin-Fixed Paraffin-Embedded Tissue Sections in MALDI Mass Spectrometry Imaging. Anal Chem
    Zhang H, Shi X, Vu NQ, Li G, Li Z, Shi Y, Li M, Wang B, Welham NV, Patankar MS, Weisman P, Li L
    2020 10 06; 92 (19): 13361-13368
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      Glycosylation is a major protein post-translational modification whose dysregulation has been associated with many diseases. Herein, an on-tissue chemical derivatization strategy based on positively charged hydrazine reagent (Girard's reagent P) coupled with matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) was developed for analysis of N-glycans from FFPE treated tissue sections. The performance of the proposed approach was evaluated by analysis of monosaccharides, oligosaccharides, N-glycans released from glycoproteins, as well as MS imaging of N-glycans from human cancer tissue sections. The results demonstrated that the signal-to-noise ratios for target saccharides were notably improved after chemical derivatization, in which signals were enhanced by 230-fold for glucose and over 28-fold for maltooctaose. Improved glycome coverage was obtained for N-glycans derived from glycoproteins and tissue samples after chemical derivatization. Furthermore, on-tissue derivatization was applied for MALDI-MSI of N-glycans from human laryngeal cancer and ovarian cancer tissues. Differentially expressed N-glycans among the tumor region, adjacent normal tissue region, and tumor proximal collagen stroma region were imaged, revealing that high-mannose type N-glycans were predominantly expressed in the tumor region. Overall, our results indicate that the on-tissue labeling strategy coupled with MALDI-MSI shows great potential to spatially characterize N-glycan expression within heterogeneous tissue samples with enhanced sensitivity. This study provides a promising approach to better understand the pathogenesis of cancer related aberrant glycosylation, which is beneficial to the design of improved clinical diagnosis and therapeutic strategies.

      View details for PubMedID 32865977
  • Follow-up and management of head and neck cancer patients during the 2019 novel coronavirus (SARS-CoV-2) disease pandemic. Adv Radiat Oncol
    Chua MLK, Ma DJ, Anderson CM, Karam SD, Margalit DN, Kimple RJ
    2020 May 15; :
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      The SARS-CoV-2 pandemic has significantly impacted healthcare delivery around the world. Elective procedures and routine follow-ups have been cancelled and/or converted to tele-health visits by many systems. In this article, we focus on recommendations for the surveillance of head and neck cancer patients during and following radiotherapy treatment. We synthesized information from clinical evidence, existing recommendations from the NCCN, and variations in practice between multiple academic tertiary cancer centers to develop the proposed guidance.

      View details for PubMedID 32426556
  • A Mouse Model of Oropharyngeal Papillomavirus-Induced Neoplasia Using Novel Tools for Infection and Nasal Anesthesia. Viruses
    Bilger A, King RE, Schroeder JP, Piette JT, Hinshaw LA, Kurth AD, AlRamahi RW, Barthel MV, Ward-Shaw ET, Buehler D, Masters KS, Thibeault SL, Lambert PF
    2020 04 16; 12 (4):
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      Human head and neck cancers that develop from the squamous cells of the oropharynx (Oropharyngeal Squamous Cell Carcinomas or OPSCC) are commonly associated with the papillomavirus infection. A papillomavirus infection-based mouse model of oropharyngeal tumorigenesis would be valuable for studying the development and treatment of these tumors. We have developed an efficient system using the mouse papillomavirus (MmuPV1) to generate dysplastic oropharyngeal lesions, including tumors, in the soft palate and the base of the tongue of two immune-deficient strains of mice. To maximize efficiency and safety during infection and endoscopy, we have designed a nose cone for isoflurane-induced anesthesia that takes advantage of a mouse's need to breathe nasally and has a large window for oral manipulations. To reach and infect the oropharynx efficiently, we have repurposed the Greer Pick allergy testing device as a virus delivery tool. We show that the Pick can be used to infect the epithelium of the soft palate and the base of the tongue of mice directly, without prior scarification. The ability to induce and track oropharyngeal papillomavirus-induced tumors in the mouse, easily and robustly, will facilitate the study of oropharyngeal tumorigenesis and potential treatments.

      View details for PubMedID 32316091
  • Fibroblast Growth Factor Receptors as Targets for Radiosensitization in Head and Neck Squamous Cell Carcinomas. Int J Radiat Oncol Biol Phys
    Fisher MM, SenthilKumar G, Hu R, Goldstein S, Ong IM, Miller MC, Brennan SR, Kaushik S, Abel L, Nickel KP, Iyer G, Harari PM, Kimple RJ, Baschnagel AM
    2020 07 15; 107 (4): 793-803
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      PURPOSE: We examined the capacity of the pan-fibroblast growth factor receptor (FGFR) inhibitor AZD4547 to augment radiation response across a panel of head and neck squamous cell carcinoma (HNSCC) cell lines and xenografts.

      METHODS AND MATERIALS: FGFR1, FGFR2, and FGFR3 RNA in situ hybridization expression was assessed in a cohort of HNSCC patient samples, cell lines, and patient-derived xenografts (PDXs). In vitro effects of AZD4547 and radiation on cell survival, FGFR signaling, apoptosis, autophagy, cell cycle, and DNA damage repair were evaluated. Reverse phase protein array was used to identify differentially phosphorylated proteins in cells treated with AZD4547. In vivo tumor responses were evaluated in cell lines and PDX models.

      RESULTS: FGFR1, FGFR2, and FGFR3 RNA in situ hybridization were expressed in 41%, 81%, and 89% of 107 oropharynx patient samples. Sensitivity to AZD4547 did not directly correlate with FGFR protein or RNA expression. In sensitive cell lines, AZD4547 inhibited p-MAPK in a time-dependent manner. Significant radiosensitization with AZD4547 was observed in cell lines that were sensitive to AZD4547. The mechanism underlying these effects appears to be multifactorial, involving inhibition of the MTOR pathway and subsequent enhancement of autophagy and activation of apoptotic pathways. Significant tumor growth delay was observed when AZD4547 was combined with radiation compared with radiation or drug alone in an FGFR-expressing HNSCC cell line xenograft and PDX.

      CONCLUSIONS: These findings suggest that AZD4547 can augment the response of radiation in FGFR-expressing HNSCC in vivo model systems. FGFR1 and FGFR2 may prove worthy targets for radiosensitization in HNSCC clinical investigations.

      View details for PubMedID 32298810
  • Matrix density drives 3D organotypic lymphatic vessel activation in a microfluidic model of the breast tumor microenvironment. Lab Chip
    Lugo-Cintrón KM, Ayuso JM, White BR, Harari PM, Ponik SM, Beebe DJ, Gong MM, Virumbrales-Muñoz M
    2020 05 07; 20 (9): 1586-1600
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      Lymphatic vessels (LVs) have been suggested as a preferential conduit for metastatic progression in breast cancer, where a correlation between the occurrence of lymph node metastasis and an increased extracellular matrix (ECM) density has been reported. However, the effect of ECM density on LV function is largely unknown. To better understand these effects, we used a microfluidic device to recreate tubular LVs in a collagen type I matrix. The density of the matrix was tailored to mimic normal breast tissue using a low-density collagen (LD-3 mg mL-1) and cancerous breast tissue using a high-density collagen (HD-6 mg mL-1). We investigated the effect of ECM density on LV morphology, growth, cytokine secretion, and barrier function. LVs cultured in HD matrices showed morphological changes as compared to LVs cultured in a LD matrix. Specifically, LVs cultured in HD matrices had a 3-fold higher secretion of the pro-inflammatory cytokine, IL-6, and a leakier phenotype, suggesting LVs acquired characteristics of activated vessels. Interestingly, LV leakiness was mitigated by blocking the IL-6 receptor on the lymphatic ECs, maintaining endothelium permeability at similar levels of LV cultured in a LD matrix. To recreate a more in vivo microenvironment, we incorporated metastatic breast cancer cells (MDA-MB-231) into the LD and HD matrices. For HD matrices, co-culture with MDA-MB-231 cells exacerbated vessel leakiness and secretion of IL-6. In summary, our data suggest that (1) ECM density is an important microenvironmental cue that affects LV function in the breast tumor microenvironment (TME), (2) dense matrices condition LVs towards an activated phenotype and (3) blockade of IL-6 signaling may be a potential therapeutic target to mitigate LV dysfunction. Overall, modeling LVs and their interactions with the TME can help identify novel therapeutic targets and, in turn, advance therapeutic discovery.

      View details for PubMedID 32297896
  • Targeting AKT/PKB to improve treatment outcomes for solid tumors. Mutat Res
    Iida M, Harari PM, Wheeler DL, Toulany M
    2020 Jan - Apr; 819-820: 111690
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      The serine/threonine kinase AKT, also known as protein kinase B (PKB), is the major substrate to phosphoinositide 3-kinase (PI3K) and consists of three paralogs: AKT1 (PKBα), AKT2 (PKBβ) and AKT3 (PKBγ). The PI3K/AKT pathway is normally activated by binding of ligands to membrane-bound receptor tyrosine kinases (RTKs) as well as downstream to G-protein coupled receptors and integrin-linked kinase. Through multiple downstream substrates, activated AKT controls a wide variety of cellular functions including cell proliferation, survival, metabolism, and angiogenesis in both normal and malignant cells. In human cancers, the PI3K/AKT pathway is most frequently hyperactivated due to mutations and/or overexpression of upstream components. Aberrant expression of RTKs, gain of function mutations in PIK3CA, RAS, PDPK1, and AKT itself, as well as loss of function mutation in AKT phosphatases are genetic lesions that confer hyperactivation of AKT. Activated AKT stimulates DNA repair, e.g. double strand break repair after radiotherapy. Likewise, AKT attenuates chemotherapy-induced apoptosis. These observations suggest that a crucial link exists between AKT and DNA damage. Thus, AKT could be a major predictive marker of conventional cancer therapy, molecularly targeted therapy, and immunotherapy for solid tumors. In this review, we summarize the current understanding by which activated AKT mediates resistance to cancer treatment modalities, i.e. radiotherapy, chemotherapy, and RTK targeted therapy. Next, the effect of AKT on response of tumor cells to RTK targeted strategies will be discussed. Finally, we will provide a brief summary on the clinical trials of AKT inhibitors in combination with radiochemotherapy, RTK targeted therapy, and immunotherapy.

      View details for PubMedID 32120136
  • Interstitial diffuse optical probe with spectral fitting to measure dynamic tumor hypoxia. Biomed Phys Eng Express
    Fru LC, Jacques SL, Nickel KP, Varghese T, Kissick MW, DeWerd LA, Kimple RJ
    2020 Jan; 6 (1):
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      Understanding the dynamic nature of tumor hypoxia is vital for cancer therapy. The presence of oxygen within a tumor during radiation therapy increases the likelihood of local control. We used a novel interstitial diffuse optical probe to make real-time measurements of blood volume fraction and hemoglobin oxygen saturation within a tumor at a high temporal resolution. This device was initially characterized and benchmarked using a customized vessel designed to control hemoglobin oxygen saturation and blood volume in a solution of blood with different concentrations of an oxygen scavenger, tetrakis (hydroxymethyl) phosphonium chloride. The optical device was found to consistently monitor the changes in oxygen saturation and these changes correlated to the concentration of the oxygen scavenger added. In near-simultaneous measurements of blood volume and oxygen saturation in tumor-bearing mice, the changes in blood volume fraction and oxygen saturation measured with the interstitial diffuse optical probe were benchmarked against photoacoustic imaging system to track and compare temporal dynamics of oxygen saturation and blood volume in a patient-derived xenograft model of hypopharyngeal carcinoma. Positive correlations between our device and photoacoustic imaging in measuring blood volume and oxygen saturation were observed.

      View details for PubMedID 32095273
  • Patient Derived Models to Study Head and Neck Cancer Radiation Response. Cancers (Basel)
    Cosper PF, Abel L, Lee YS, Paz C, Kaushik S, Nickel KP, Alexandridis R, Scott JG, Bruce JY, Kimple RJ
    2020 Feb 12; 12 (2):
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      Patient-derived model systems are important tools for studying novel anti-cancer therapies. Patient-derived xenografts (PDXs) have gained favor over the last 10 years as newer mouse strains have improved the success rate of establishing PDXs from patient biopsies. PDXs can be engrafted from head and neck cancer (HNC) samples across a wide range of cancer stages, retain the genetic features of their human source, and can be treated with both chemotherapy and radiation, allowing for clinically relevant studies. Not only do PDXs allow for the study of patient tissues in an in vivo model, they can also provide a renewable source of cancer cells for organoid cultures. Herein, we review the uses of HNC patient-derived models for radiation research, including approaches to establishing both orthotopic and heterotopic PDXs, approaches and potential pitfalls to delivering chemotherapy and radiation to these animal models, biological advantages and limitations, and alternatives to animal studies that still use patient-derived tissues.

      View details for PubMedID 32059418
  • Clinical outcomes for larynx patients with cancer treated with refinement of high-dose radiation treatment volumes. Head Neck
    Burr AR, Harari PM, Haasl AM, Wieland AM, Bruce JY, Kimple RJ, Hartig GK, McCulloch TM, Witek ME
    2020 Feb 14; :
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      BACKGROUND: To evaluate disease control, toxicities, and dose to dysphagia/aspiration risk structures (DARS) using a direct gross tumor volume (GTV70Gy ) to planning target volume expansion (dPTV70Gy ) for patients with squamous cell carcinoma of the larynx (LSCC).

      METHODS: A retrospective review was performed on patients with LSCC treated between 2003 and 2018. Clinical outcomes, toxicities, and dosimetric data were analyzed.

      RESULTS: Seventy-three patients were identified. Overall survival at 5-years was 57.8%. Five-year local and regional control was 79.8% and 88.2%, respectively. Distant metastatic-only failure was 2.7%. Eighty percent of failures were 95% contained within the dPTV70Gy . Mean dose and the volume of DARS receiving 70 Gy was significantly lower for dPTV70Gy compared to a consensus-defined PTV70Gy .

      DISCUSSION: Judicious reduction in high-dose target volumes can preserve high tumor control rates while reducing dose to normal surrounding structures underscoring the potential benefit of this approach in enabling local therapy intensification to improve locoregional control.

      View details for PubMedID 32057151
  • Mus musculus Papillomavirus 1: a New Frontier in Animal Models of Papillomavirus Pathogenesis. J Virol
    Spurgeon ME, Lambert PF
    2020 04 16; 94 (9):
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      Animal models of viral pathogenesis are essential tools in human disease research. Human papillomaviruses (HPVs) are a significant public health issue due to their widespread sexual transmission and oncogenic potential. Infection-based models of papillomavirus pathogenesis have been complicated by their strict species and tissue specificity. In this Gem, we discuss the discovery of a murine papillomavirus, Mus musculus papillomavirus 1 (MmuPV1), and how its experimental use represents a major advancement in models of papillomavirus-induced pathogenesis/carcinogenesis, and their transmission.

      View details for PubMedID 32051276
  • Stress keratin 17 enhances papillomavirus infection-induced disease by downregulating T cell recruitment. PLoS Pathog
    Wang W, Uberoi A, Spurgeon M, Gronski E, Majerciak V, Lobanov A, Hayes M, Loke A, Zheng ZM, Lambert PF
    2020 01; 16 (1): e1008206
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      High-risk human papillomaviruses (HPVs) cause 5% of human cancers. Despite the availability of HPV vaccines, there remains a strong urgency to find ways to treat persistent HPV infections, as current HPV vaccines are not therapeutic for individuals already infected. We used a mouse papillomavirus infection model to characterize virus-host interactions. We found that mouse papillomavirus (MmuPV1) suppresses host immune responses via overexpression of stress keratins. In mice deficient for stress keratin K17 (K17KO), we observed rapid regression of papillomas dependent on T cells. Cellular genes involved in immune response were differentially expressed in the papillomas arising on the K17KO mice correlating with increased numbers of infiltrating CD8+ T cells and upregulation of IFNγ-related genes, including CXCL9 and CXCL10, prior to complete regression. Blocking the receptor for CXCL9/CXCL10 prevented early regression. Our data provide a novel mechanism by which papillomavirus-infected cells evade host immunity and defines new therapeutic targets for treating persistent papillomavirus infections.

      View details for PubMedID 31968015
  • Human Tumor-Lymphatic Microfluidic Model Reveals Differential Conditioning of Lymphatic Vessels by Breast Cancer Cells. Adv Healthc Mater
    Ayuso JM, Gong MM, Skala MC, Harari PM, Beebe DJ
    2020 02; 9 (3): e1900925
    • More

      Breast tumor progression is a complex process involving intricate crosstalk between the primary tumor and its microenvironment. In the context of breast tumor-lymphatic interactions, it is unclear how breast cancer cells alter the gene expression of lymphatic endothelial cells and how these transcriptional changes potentiate lymphatic dysfunction. Thus, there is a need for in vitro lymphatic vessel models to study these interactions. In this work, a tumor-lymphatic microfluidic model is developed to study the differential conditioning of lymphatic vessels by estrogen receptor-positive (i.e., MCF7) and triple-negative (i.e., MDA-MB-231) breast cancer cells. The model consists of a lymphatic endothelial vessel cultured adjacently to either MCF7 or MDA-MB-231 cells. Quantitative transcriptional analysis reveals expression changes in genes related to vessel growth, permeability, metabolism, hypoxia, and apoptosis in lymphatic endothelial cells cocultured with breast cancer cells. Interestingly, these changes are different in the MCF7-lymphatic cocultures as compared to the 231-lymphatic cocultures. Importantly, these changes in gene expression correlate to functional responses, such as endothelial barrier dysfunction. These results collectively demonstrate the utility of this model for studying breast tumor-lymphatic crosstalk for multiple breast cancer subtypes.

      View details for PubMedID 31894641
  • A PI3K/AKT Scaffolding Protein, IQ Motif-Containing GTPase Associating Protein 1 (IQGAP1), Promotes Head and Neck Carcinogenesis. Clin Cancer Res
    Wei T, Choi S, Buehler D, Anderson RA, Lambert PF
    2020 01 01; 26 (1): 301-311
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      PURPOSE: Head and neck cancer (HNC) is the sixth most common cancer worldwide with a 5-year survival rate of less than 50%. The PI3K/AKT/mTOR signaling pathway is frequently implicated in HNC. Recently, IQ motif-containing GTPase-activating protein 1 (IQGAP1) was discovered to scaffold the PI3K/AKT signaling pathway. IQGAP1 gene expression is increased in HNC, raising the hypothesis that IQGAP1 contributes to HNC.

      EXPERIMENTAL DESIGN: We performed a combination of in vitro studies using human cancer cell lines treated with a cell-permeable peptide that interferes with IQGAP1's ability to bind to PI3K, and in vivo studies utilizing mice genetically knocked out for the Iqgap1 (Iqgap1 -/-). In vivo EGF stimulation assays were used to evaluate PI3K signaling. To study the role of IQGAP1 in HNC, we used a well-validated mouse model that drives HNC via a synthetic oral carcinogen, 4-nitroquinoline 1-oxide (4NQO).

      RESULTS: IQGAP1 is necessary for efficient PI3K signaling in vitro and in vivo. Disruption of IQGAP1-scaffolded PI3K/AKT signaling reduced HNC cell survival. Iqgap1 -/- mice had significantly lower cancer incidences, lesser disease severity, and fewer cancer foci. IQGAP1 protein levels were increased in HNC arising in Iqgap1+/+ mice. The level of PI3K signaling in 4NQO-induced HNC arising in Iqgap1 -/- mice was significantly reduced, consistent with the hypothesis that IQGAP1 contributes to HNC at least partly through PI3K signaling. High IQGAP1 expression correlated with reduced survival, and high pS6 levels correlated with high IQGAP1 levels in patients with HNC.

      CONCLUSIONS: These data demonstrate that IQGAP1 contributes to head and neck carcinogenesis.

      View details for PubMedID 31597661
  • Effects of culture method on response to EGFR therapy in head and neck squamous cell carcinoma cells. Sci Rep
    Ayuso JM, Vitek R, Swick AD, Skala MC, Wisinski KB, Kimple RJ, Lambert PF, Beebe DJ
    2019 08 28; 9 (1): 12480
    • More

      The EGFR pathway plays a critical role in head and neck squamous cell carcinoma (HNSCC). Targeted therapies against the EGFR are utilized as a treatment for HNSCCC. However, patient response is heterogeneous and molecular biomarkers are lacking to predict patient response. Therefore, functional assays where drug response is directly evaluated in tumor cells are an interesting alternative. Previous studies have shown that experimental conditions modify the drug response observed in functional assays. Thus, in this work the influence of the culture environment on response to Cetuximab (EGFR monoclonal antibody) and AZD8055 (mTOR inhibitor) was evaluated. HNSCC UM-SCC-1 and UM-SCC-47 cells were cultured in 2D monoculture and compared with: 2D co-culture with cancer-associated fibroblasts (CAF); 3D culture in collagen hydrogels; and 3D culture in tumor spheroids. The results showed UM-SCC-1 drug response significantly changed in the different culture environments; leading to an increase in drug resistance in the CAF co-culture and the 3D spheroids. Conversely, UM-SCC-47 exhibited a more constant drug response across culture conditions. In conclusion, this work highlights the importance of culture conditions that modulate response to EGFR pathway inhibition.

      View details for PubMedID 31462653
  • Dendrimer-Based Platform for Effective Capture of Tumor Cells after TGFβ1-Induced Epithelial-Mesenchymal Transition. Anal Chem
    Myung JH, Cha A, Tam KA, Poellmann M, Borgeat A, Sharifi R, Molokie RE, Votta-Velis G, Hong S
    2019 07 02; 91 (13): 8374-8382
    • More

      Detection of circulating tumor cells (CTCs) relying on their expression of epithelial cell markers, such as epithelial cell adhesion molecule (EpCAM), has been commonly used. However, this approach unlikely captures CTCs that have undergone the process of epithelial-mesenchymal transition (EMT). In this study, we have induced EMT of in vitro prostate (PCa) and breast cancer (BCa) cell lines by treatment of transforming growth factor β 1 (TGFβ1), a pleiotropic cytokine with transition-regulating activities. We found that the TGFβ1-treated, post-EMT cells exhibited up to a 45% reduction in binding affinity to antibodies against EpCAM (aEpCAM). To overcome this limitation, we designed our capture platform that integrates a unique combination of biomimetic cell rolling, dendrimer-mediated multivalent binding, and antibody cocktails of aEpCAM/aEGFR/aHER-2. Our capture surfaces resulted in up to 98% capture efficiency of post-EMT cells from mixtures of TGFβ1-treated and untreated cancer cells spiked in culture media and human blood. In a clinical pilot study, our CTC device was also able to capture rare CTCs from PCa patients with significantly enhanced capture sensitivity and purity compared to the control surface with aEpCAM only, demonstrating its potential to provide a reliable detection solution for CTCs regardless of their EMT status.

      View details for PubMedID 31247718
  • High-throughput quantitative detection of basal autophagy and autophagic flux using image cytometry. Biotechniques
    SenthilKumar G, Skiba JH, Kimple RJ
    2019 08; 67 (2): 70-73
    • More

      Quantitative assessment of changes in macro-autophagy is often performed through manual quantification of the number of LC3B foci in immunofluorescence microscopy images. This method is highly laborious, subject to image-field selection and foci-counting bias, and is not sensitive for analyzing changes in basal autophagy. Alternative methods such as flow cytometry and transmission electron microscopy require highly specialized, expensive instruments and time-consuming sample preparation. Immunoblots are prone to exposure-related variations and noise that prevents accurate quantification. We report a high-throughput, inexpensive, reliable and objective method for studying basal level and flux changes in late-stage autophagy using image cytometry and acridine orange staining.

      View details for PubMedID 31238709
  • The Specificity of EGF-Stimulated IQGAP1 Scaffold Towards the PI3K-Akt Pathway is Defined by the IQ3 motif. Sci Rep
    Chen M, Choi S, Jung O, Wen T, Baum C, Thapa N, Lambert PF, Rapraeger AC, Anderson RA
    2019 06 24; 9 (1): 9126
    • More

      Epidermal growth factor receptor (EGFR) and its downstream phosphoinositide 3-kinase (PI3K) pathway are commonly deregulated in cancer. Recently, we have shown that the IQ motif-containing GTPase-activating protein 1 (IQGAP1) provides a molecular platform to scaffold all the components of the PI3K-Akt pathway and results in the sequential generation of phosphatidylinositol-3,4,5-trisphosphate (PI3,4,5P3). In addition to the PI3K-Akt pathway, IQGAP1 also scaffolds the Ras-ERK pathway. To define the specificity of IQGAP1 for the control of PI3K signaling, we have focused on the IQ3 motif in IQGAP1 as PIPKIα and PI3K enzymes bind this region. An IQ3 deletion mutant loses interactions with the PI3K-Akt components but retains binding to ERK and EGFR. Consistently, blocking the IQ3 motif of IQGAP1 using an IQ3 motif-derived peptide mirrors the effect of IQ3 deletion mutant by reducing Akt activation but has no impact on ERK activation. Also, the peptide disrupts the binding of IQGAP1 with PI3K-Akt pathway components, while IQGAP1 interactions with ERK and EGFR are not affected. Functionally, deleting or blocking the IQ3 motif inhibits cell proliferation, invasion, and migration in a non-additive manner to a PIPKIα inhibitor, establishing the functional specificity of IQ3 motif towards the PI3K-Akt pathway. Taken together, the IQ3 motif is a specific target for suppressing activation of the PI3K-Akt but not the Ras-ERK pathway. Although EGFR stimulates the IQGAP1-PI3K and -ERK pathways, here we show that IQGAP1-PI3K controls migration, invasion, and proliferation independent of ERK. These data illustrate that the IQ3 region of IQGAP1 is a promising therapeutic target for PI3K-driven cancer.

      View details for PubMedID 31235839
  • De-Escalation Strategies in HPV-Associated Oropharynx Cancer-Are we Putting the Cart Before the Horse? Int J Radiat Oncol Biol Phys
    Anderson CM, Kimple RJ, Lin A, Karam SD, Margalit DN, Chua MLK
    2019 07 15; 104 (4): 705-709
  • A Phase Ib Study of Axitinib in Combination with Crizotinib in Patients with Metastatic Renal Cell Cancer or Other Advanced Solid Tumors. Oncologist
    Michaelson MD, Gupta S, Agarwal N, Szmulewitz R, Powles T, Pili R, Bruce JY, Vaishampayan U, Larkin J, Rosbrook B, Wang E, Murphy D, Wang P, Lechuga MJ, Valota O, Shepard DR
    2019 09; 24 (9): 1151-e817
    • More

      LESSONS LEARNED: The combination of axitinib and crizotinib has a manageable safety and tolerability profile, consistent with the profiles of the individual agents when administered as monotherapy.The antitumor activity reported here for the combination axitinib/crizotinib does not support further study of this combination treatment in metastatic renal cell carcinoma given the current treatment landscape.

      BACKGROUND: Vascular endothelial growth factor (VEGF) inhibitors have been successfully used to treat metastatic renal cell carcinoma (mRCC); however, resistance eventually develops in most cases. Tyrosine protein kinase Met (MET) expression increases following VEGF inhibition, and inhibition of both has shown additive effects in controlling tumor growth and metastasis. We therefore conducted a study of axitinib plus crizotinib in advanced solid tumors and mRCC.

      METHODS: This phase Ib study included a dose-escalation phase (starting doses: axitinib 3 mg plus crizotinib 200 mg) to estimate maximum tolerated dose (MTD) in patients with solid tumors and a dose-expansion phase to examine preliminary efficacy in treatment-naïve patients with mRCC. Safety, pharmacokinetics, and biomarkers were also assessed.

      RESULTS: No patients in the dose-escalation phase (n = 22) experienced dose-limiting toxicity; MTD was estimated to be axitinib 5 mg plus crizotinib 250 mg. The most common grade ≥3 adverse events were hypertension (18.2%) and fatigue (9.1%). In the dose-expansion phase, overall response rate was 30% (95% confidence interval [CI], 11.9-54.3), and progression-free survival was 5.6 months (95% CI, 3.5-not reached).

      CONCLUSION: The combination of axitinib plus crizotinib, at estimated MTD, had a manageable safety profile and showed evidence of modest antitumor activity in mRCC.

      View details for PubMedID 31171735
  • Human organotypic lymphatic vessel model elucidates microenvironment-dependent signaling and barrier function. Biomaterials
    Gong MM, Lugo-Cintron KM, White BR, Kerr SC, Harari PM, Beebe DJ
    2019 09; 214: 119225
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      The lymphatic system is an active player in the pathogenesis of several human diseases, including lymphedema and cancer. Relevant models are needed to advance our understanding of lymphatic biology in disease progression to improve therapy and patient outcomes. Currently, there are few 3D in vitro lymphatic models that can recapitulate the physiological structure, function, and interactions of lymphatic vessels in normal and diseased microenvironments. Here, we developed a 3D microscale lymphatic vessel (μLYMPH) system for generating human lymphatic vessels with physiological tubular structure and function. Consistent with characteristics of lymphatic vessels in vivo, the endothelium of cultured vessels was leaky with an average permeability of 1.38 × 10-5 ± 0.29 × 10-5 cm/s as compared to 0.68 × 10-5 ± 0.13 × 10-5 cm/s for blood vessels. This leakiness also resulted in higher uptake of solute by the lymphatic vessels under interstitial flow, demonstrating recapitulation of their natural draining function. The vessels secreted appropriate growth factors and inflammatory mediators. Our system identified the follistatin/activin axis as a novel pathway in lymphatic vessel maintenance and inflammation. Moreover, the μLYMPH system provided a platform for examining crosstalk between lymphatic vessels and tumor microenvironmental components, such as breast cancer-associated fibroblasts (CAFs). In co-culture with CAFs, vessel barrier function was significantly impaired by CAF-secreted IL-6, a possible pro-metastatic mechanism of lymphatic metastasis. Targeted blocking of the IL-6/IL-6R signaling pathway with an IL-6 neutralizing antibody fully rescued the vessels, demonstrating the potential of our system for screening therapeutic targets. These results collectively demonstrate the μLYMPH system as a powerful model for advancing lymphatic biology in health and disease.

      View details for PubMedID 31154151
  • Reducing radiotherapy target volume expansion for patients with HPV-associated oropharyngeal cancer. Oral Oncol
    Burr AR, Harari PM, Ko HC, Bruce JY, Kimple RJ, Witek ME
    2019 05; 92: 52-56
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      PURPOSE: To evaluate clinical outcomes and patterns of failure using a direct gross tumor volume to planning target volume expansion in patients with p16-positive oropharyngeal squamous cell carcinoma.

      METHODS AND MATERIALS: We performed a retrospective review of patients with p16-positive oropharyngeal squamous cell carcinomas treated between 2002 and 2017 with primary radiotherapy with or without concurrent systemic therapy. Patient and disease characteristics associated with disease control and clinical outcomes were analyzed by Cox proportional hazards regression and Kaplan-Meier analyses. Imaging at the time of first failure was used to categorize failure patterns.

      RESULTS: We identified 134 patients with a median follow-up of 56.2 months (range 8.2-160.2 months). Local and regional control at 5 years was 91.5% (95% CI: 86.8-96.4%), and 90.8% (95% CI: 85.6-96.2%), respectively. Of the 14 locoregional failures, there were 10 in-field (Type A), 3 marginal (Type B), and 1 geographic (Type E). Age >70 years (HR 5.42; 95% CI: 1.87-15.68) and T4 versus T1-3 (HR 4.09; 95% CI: 1.01-2.65) were associated with increased rates of locoregional failure on multivariate analysis. The rate of gastrostomy tube retention at one year was 6.0% (range 2.8-12.7%).

      CONCLUSIONS: Management of patients with p16-positive oropharyngeal squamous cell carcinoma using definitive radiotherapy and a high-dose planning target volume created without a gross tumor volume to clinical tumor volume expansion resulted in high locoregional control with the vast majority of failures occurring within the high-dose field. These data warrant prospective evaluation of this technique as a therapy de-intensification approach.

      View details for PubMedID 31010623
  • Age-related alterations in swallowing biomechanics. Exp Gerontol
    Kletzien H, Cullins MJ, Connor NP
    2019 04; 118: 45-50
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      BACKGROUND: Aging rodent models allow for the discovery of underlying mechanisms of cranial muscle dysfunction. Methods are needed to allow quantification of complex, multivariate biomechanical movements during swallowing. Videofluoroscopic swallow studies (VSS) are the standard of care in assessment of swallowing disorders in patients and validated quantitative, kinematic, and morphometric analysis methods have been developed. Our purpose was to adapt validated morphometric techniques to the rodent to computationally analyze swallowing dysfunction in the aging rodent.

      METHODS: VSS, quantitative analyses (bolus area, bolus velocity, mastication rate) and a rodent specific multivariate, morphometric computational analysis of swallowing biomechanics were performed on 20 swallows from 5 young adult and 5 old Fischer 344/Brown Norway rats. Eight anatomical landmarks were used to track the relative change in position of skeletal levers (cranial base, vertebral column, mandible) and soft tissue landmarks (upper esophageal sphincter, base of tongue).

      RESULTS: Bolus area significantly increased and mastication rate significantly decreased with age. Aging accounted for 77.1% of the variance in swallow biomechanics, and 18.7% of the variance was associated with swallow phase (oral vs pharyngeal). Post hoc analyses identified age-related alterations in tongue base retraction, mastication, and head posture during the swallow.

      CONCLUSION: Geometric morphometric analysis of rodent swallows suggests that swallow biomechanics are altered with age. When used in combination with biological assays of age-related adaptations in neuromuscular systems, this multivariate analysis may increase our understanding of underlying musculoskeletal dysfunction that contributes to swallowing disorders with aging.

      View details for PubMedID 30633957
  • Peptide-nanoparticle conjugates: a next generation of diagnostic and therapeutic platforms? Nano Converg
    Jeong WJ, Bu J, Kubiatowicz LJ, Chen SS, Kim Y, Hong S
    2018 Dec 12; 5 (1): 38
    • More

      Peptide-nanoparticle conjugates (PNCs) have recently emerged as a versatile tool for biomedical applications. Synergism between the two promising classes of materials allows enhanced control over their biological behaviors, overcoming intrinsic limitations of the individual materials. Over the past decades, a myriad of PNCs has been developed for various applications, such as drug delivery, inhibition of pathogenic biomolecular interactions, molecular imaging, and liquid biopsy. This paper provides a comprehensive overview of existing technologies that have been recently developed in the broad field of PNCs, offering a guideline especially for investigators who are new to this field.

      View details for PubMedID 30539365
  • HPV impacts survival of stage IVC non-oropharyngeal HNSCC cancer patients. Otorhinolaryngol Head Neck Surg
    Burr AR, Harari PM, Ko HC, Chen S, Yu M, Baschnagel AM, Kimple RJ, Witek ME
    2018; 3 (1):
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      Objectives: Human papillomavirus (HPV) status is a favorable prognostic marker for patients with oropharyngeal squamous cell carcinoma (OPSCC) and non-metastatic head and neck non-OPSCC. We evaluated the impact of HPV status on overall survival (OS) for patients with Stage IVC non-OPSCC.

      Materials and methods: Patients diagnosed with Stage IVC non-OPSCC and known HPV status between 2010-2013 were identified in the National Cancer Database. Univariate and multivariate analyses were performed to determine factors associated with OS. Propensity score-weighted Kaplan-Meier estimation was used to adjust for confounders in OS analyses. Multiple imputation method was used for sensitivity analysis.

      Results: We identified 708 patients with Stage IVC non-OPSCC with 30% being HPV-positive. Unadjusted median survival was 10.3 months for HPV-negative patients and 21.4 months for HPV-positive patients (p<0.0001). Age ≥ 65 and tumor diameter were associated with worse OS (p<0.05) while treatment versus no treatment and HPV-positive status were associated with improved OS on multivariate analysis (p<0.001). Adjusted median survival for patients with HPV-negative and HPV-positive disease was 11.1 months and 23.8 months, respectively (p<0.001). On unadjusted subgroup analysis, patients with HPV-positive oral cavity disease exhibited improved outcomes (p<0.0001) while HPV-positive hypopharynx (p<0.06) and larynx (p<0.12) patients exhibited a trend for improved OS compared to HPV-negative patients. The survival advantage associated with HPV positivity was maintained on sensitivity analysis (p<0.01).

      Conclusion: These data demonstrate a clinically meaningful association between HPV status and OS in patients with non-OSPCC presenting with Stage IVC disease. In the absence of randomized data, these findings support active consideration of HPV status in clinical decision making, clinical trial design, and patient counseling regarding prognosis.

      View details for PubMedID 30271885
  • Expression pattern of androgen receptor and AR-V7 in androgen-deprivation therapy-naïve salivary duct carcinomas. Hum Pathol
    Yang RK, Zhao P, Lu C, Luo J, Hu R
    2019 02; 84: 173-182
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      Androgen-deprivation therapy has been used to treat salivary duct carcinoma (SDC). The androgen receptor splice variant-7 (AR-V7) has been detected in castration-resistant prostate cancer and implicated in resistance to androgen receptor (AR)-targeted therapies. Given the potential role of AR/AR-V7 in SDC treatment, this study focuses on AR/AR-V7 expression in SDC specimens collected before androgen-deprivation therapy. RNA in situ hybridization (ISH) and immunohistochemistry (IHC) to detect total AR and AR-V7 were performed on formalin-fixed, paraffin-embedded SDC specimens from 23 patients. Full-length AR and AR-V7 transcripts were quantified in a subset of tumors by reverse-transcription polymerase chain reaction. Twenty SDCs were positive for total AR by ISH and IHC. Among AR-positive SDCs, 70% (14/20) were positive for AR-V7 messenger RNA by ISH, whereas 15% (3/20) were positive for AR-V7 protein by IHC. The 3 SDCs that expressed the highest levels of AR-V7 were all from female patients; one of them expressed a significant amount of AR-V7 and barely detectable full-length AR transcripts by reverse-transcription polymerase chain reaction. IHC expression of Forkhead box protein A1, prostate-specific antigen, prostatic acid phosphatase, and NKX3.1 was observed in some SDCs regardless of patient sex. Five SDCs demonstrated strong human epidermal growth factor receptor 2 expression. We conclude that treatment-naïve SDCs may express AR-V7 at levels comparable to or even exceeding the levels detected in castration-resistant prostate cancer. Our data support the feasibility to incorporate AR-V7 assessment via ISH and/or IHC in the ongoing clinical trials evaluating the therapeutic benefit of AR-targeted therapies in SDC patients.

      View details for PubMedID 30267779
  • Correlates of Early Pharyngeal High-Resolution Manometry Adoption in Expert Speech-Language Pathologists. Dysphagia
    Jones CA, Forgues AL, Rogus-Pulia NM, Orne J, Macdonald CL, Connor NP, McCulloch TM
    2019 06; 34 (3): 325-332
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      Pharyngeal high-resolution manometry (HRM) is at a point of entry into speech-language pathologist (SLP) clinical practice. However, the demographic characteristics of SLPs who are early adopters of HRM are unclear; perspectives of early adopters may shape how the technology is received by the field at large. We hypothesized that younger SLPs, those working in outpatient settings, those with a strong knowledge base in HRM, and those with experience in other types of instrumentation are more likely to have interest in adopting HRM. We surveyed the population of board-certified SLPs (BCS-S; n = 262) with a 33% response rate (n = 78). Firth logistic regression was used to determine differences in those expressing interest in adopting HRM into future practice (n = 28) and those who did not (n = 45) from the analytic sample of 73 respondents. The best fitting model predicted that SLPs: (1) with training in more types of instrumentation; and (2) believing they could explain the HRM procedure to a patient were more likely to plan to adopt pharyngeal HRM into regular clinical practice. Experience with a variety of instrumentation techniques may encourage SLPs to use new forms of technology. Knowledge of early adopter demographics will allow for development of targeted trainings and determination of HRM implementation barriers. Identification of a clinician sub-group more likely to adopt other new technologies in the future may also be possible.

      View details for PubMedID 30232550
  • Enhanced Radiosensitivity in Solid Tumors using a Tumor-selective Alkyl Phospholipid Ether Analog. Mol Cancer Ther
    Elsaid MY, Shahi A, Wang AR, Baiu DC, Li C, Werner LR, Singhal S, Hall LT, Weichert JP, Armstrong EA, Bednarz BP, Harari PM, Iyer G, Otto M
    2018 11; 17 (11): 2320-2328
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      Antitumor alkyl phospholipid (APL) analogs comprise a group of structurally related molecules with remarkable tumor selectivity. Some of these compounds have shown radiosensitizing capabilities. CLR127 is a novel, clinical-grade antitumor APL ether analog, a subtype of synthetic APL broadly targeting cancer cells with limited uptake in normal tissues. The purpose of this study was to investigate the effect of CLR127 to modulate radiation response across several adult and pediatric cancer types in vitro as well as in murine xenograft models of human prostate adenocarcinoma, neuroblastoma, Ewing sarcoma, and rhabdomyosarcoma. In vitro, CLR127 demonstrated selective uptake in cancer cells compared to normal cells. In cancer cells, CLR127 treatment prior to radiation significantly decreased clonogenic survival in vitro, and led to increased radiation-induced double-stranded DNA (dsDNA) breakage compared with radiation alone, which was not observed in normal controls. In animal models, CLR127 effectively increased the antitumor response to fractionated radiotherapy and led to delayed tumor regrowth at potentially clinically achievable doses. In conclusion, our study highlights the ability of CLR127 to increase radiation response in several cancer types. Given almost universal uptake of CLR127 in malignant cells, future research should test whether the observed effects can be extended to other tumor types. Our data provide a strong rationale for clinical testing of CLR127 as a tumor-targeted radiosensitizing agent. Mol Cancer Ther; 17(11); 2320-8. ©2018 AACR.

      View details for PubMedID 30108133
  • MERTK Mediates Intrinsic and Adaptive Resistance to AXL-targeting Agents. Mol Cancer Ther
    McDaniel NK, Cummings CT, Iida M, Hülse J, Pearson HE, Vasileiadi E, Parker RE, Orbuch RA, Ondracek OJ, Welke NB, Kang GH, Davies KD, Wang X, Frye SV, Earp HS, Harari PM, Kimple RJ, DeRyckere D, Graham DK, Wheeler DL
    2018 11; 17 (11): 2297-2308
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      The TAM (TYRO3, AXL, MERTK) family receptor tyrosine kinases (RTK) play an important role in promoting growth, survival, and metastatic spread of several tumor types. AXL and MERTK are overexpressed in head and neck squamous cell carcinoma (HNSCC), triple-negative breast cancer (TNBC), and non-small cell lung cancer (NSCLC), malignancies that are highly metastatic and lethal. AXL is the most well-characterized TAM receptor and mediates resistance to both conventional and targeted cancer therapies. AXL is highly expressed in aggressive tumor types, and patients with cancer are currently being enrolled in clinical trials testing AXL inhibitors. In this study, we analyzed the effects of AXL inhibition using a small-molecule AXL inhibitor, a monoclonal antibody (mAb), and siRNA in HNSCC, TNBC, and NSCLC preclinical models. Anti-AXL-targeting strategies had limited efficacy across these different models that, our data suggest, could be attributed to upregulation of MERTK. MERTK expression was increased in cell lines and patient-derived xenografts treated with AXL inhibitors and inhibition of MERTK sensitized HNSCC, TNBC, and NSCLC preclinical models to AXL inhibition. Dual targeting of AXL and MERTK led to a more potent blockade of downstream signaling, synergistic inhibition of tumor cell expansion in culture, and reduced tumor growth in vivo Furthermore, ectopic overexpression of MERTK in AXL inhibitor-sensitive models resulted in resistance to AXL-targeting strategies. These observations suggest that therapeutic strategies cotargeting both AXL and MERTK could be highly beneficial in a variety of tumor types where both receptors are expressed, leading to improved survival for patients with lethal malignancies. Mol Cancer Ther; 17(11); 2297-308. ©2018 AACR.

      View details for PubMedID 30093568
  • Loss of Function of Canonical Notch Signaling Drives Head and Neck Carcinogenesis. Clin Cancer Res
    Nyman PE, Buehler D, Lambert PF
    2018 12 15; 24 (24): 6308-6318
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      PURPOSE: Head and neck squamous cell carcinoma (HNSCC), a common cancer worldwide, is etiologically associated with tobacco use, high alcohol consumption, and high-risk human papillomaviruses (HPV). The Notch signaling pathway, which is involved in cell differentiation decisions with differential downstream targets and effects depending on tissue type and developmental stage, has been implicated in human HNSCC. NOTCH1 is among the most frequently mutated genes in both HPV-positive and HPV-negative HNSCC. These mutations are predicted to inactivate the function of Notch. Other studies have argued the opposite-Notch signaling is increased in HNSCC.

      EXPERIMENTAL DESIGN: To assess the role of Notch signaling in HPV-positive and HPV-negative HNSCC, we utilized genetically engineered mouse (GEM) models for conventional keratinizing HNSCC, in which either HPV16 E6 and E7 oncoproteins or a gain-of-function mutant p53 are expressed, and in which we inactivated canonical Notch signaling via expression of a dominant negative form of MAML1 (DNMAML1), a required transcriptional coactivator of Notch signaling.

      RESULTS: Loss of canonical Notch signaling increased tumorigenesis in both contexts and also caused an increase in nuclear β-catenin, a marker for increased tumorigenic potential. When combined with loss of canonical Notch signaling, HPV oncogenes led to the highest frequency of cancers overall and the largest number of poorly differentiated (high-grade) cancers.

      CONCLUSIONS: These findings inform on the contribution of loss of canonical Notch signaling in head and neck carcinogenesis.

      View details for PubMedID 30087145
  • Results From 10 Years of a Free Oral Cancer Screening Clinic at a Major Academic Health Center. Int J Radiat Oncol Biol Phys
    Blitzer GC, Rosenberg SA, Anderson BM, McCulloch TM, Wieland AM, Hartig GK, Bruce JY, Witek ME, Kimple RJ, Harari PM
    2018 09 01; 102 (1): 146-148
  • Comparison Between Patient-Perceived Voice Changes and Quantitative Voice Measures in the First Postoperative Year After Thyroidectomy: A Secondary Analysis of a Randomized Clinical Trial. JAMA Otolaryngol Head Neck Surg
    Kletzien H, Macdonald CL, Orne J, Francis DO, Leverson G, Wendt E, Sippel RS, Connor NP
    2018 11 01; 144 (11): 995-1003
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      Importance: Voice changes after thyroidectomy are typically attributed to recurrent laryngeal nerve injury. However, most postoperative voice changes occur in the absence of clinically evident vocal fold paralysis. To date, no study has compared the prevalence, duration, and consequences of voice-related disability from the patient perspective with use of quantitative vocal measures.

      Objectives: To assess the quality-of-life consequences of postthyroidectomy voice change from the perspective of patients with thyroid cancer and to compare patient-perceived voice changes with changes in quantitative vocal variables at 5 time points in the first postoperative year.

      Design, Setting, and Participants: This prospective mixed methods observational study within a randomized clinical trial occurred at the University of Wisconsin Hospital and Clinics. Participants were 42 patients with clinically node-negative papillary thyroid cancer without a preexisting vocal cord paralysis who were recruited and enrolled from outpatient clinics between June 6, 2014, and March 6, 2017, as part of the ongoing randomized clinical trial.

      Intervention: Total thyroidectomy.

      Main Outcomes and Measures: Semistructured interviews, symptom prevalence, and instrumental voice evaluations (laryngoscopy, phonation threshold pressure, Dysphonia Severity Index, and Voice Handicap Index) occurred at baseline (n = 42) and 2-week (n = 42), 6-week (n = 39), 6-month (n = 35), and 1-year (n = 30) postoperative time points.

      Results: Participants had a mean age of 48 years (interquartile range, 38-58 years; age range, 22-70 years) and were mostly female (74% [31 of 42]) and of white race/ethnicity (98% [41 of 42]). Impaired communication was the primary theme derived from patient interviews from before thyroidectomy to after thyroidectomy. Voice changes were perceived by 24 participants at 2 weeks after thyroidectomy. After surgery, voice symptoms were prevalent and persisted for 50% (21 of 42) of participants out to at least 1 year of follow-up. Quantitative vocal perturbations were detected in the Dysphonia Severity Index and Voice Handicap Index at the 2-week follow-up but returned to baseline levels by the 6-week follow-up visit.

      Conclusions and Relevance: Voice changes are common after surgery for papillary thyroid cancer and affect quality of life for many patients out to 1 year of follow-up. Directly querying patients about postoperative voice changes and questioning whether commonly used aerodynamic and acoustic variables detect meaningful voice changes are important in identifying patients whose quality of life has been affected by postthyroidectomy dysphonia.

      Trial Registration: ClinicalTrials.gov Identifier: NCT02138214.

      View details for PubMedID 29710208
  • Genomics Reloaded: Rise of the Expression Profiles. Int J Radiat Oncol Biol Phys
    Gan GN, Kimple RJ
    2018 05 01; 101 (1): 1-3
  • Impact of HPV Status on the Prognostic Potential of the AJCC Staging System for Larynx Cancer. Otolaryngol Head Neck Surg
    Davidson SM, Ko HC, Harari PM, Wieland AM, Chen S, Baschnagel AM, Kimple RJ, Witek ME
    2018 09; 159 (3): 456-465
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      Objective We evaluated the ability of the American Joint Committee on Cancer (AJCC) seventh edition staging system to prognosticate the overall survival of patients with human papillomavirus (HPV)-positive laryngeal squamous cell carcinoma. Study Design Retrospective analysis. Setting National Cancer Database. Subjects and Methods Patients diagnosed with laryngeal squamous cell carcinoma who were treated with curative intent were identified in the National Cancer Database. Multivariate analysis was utilized to determine factors correlated with overall survival in the HPV-negative and HPV-positive cohorts. Unadjusted and propensity score-weighted Kaplan-Meier estimation was used to determine overall survival of HPV-negative and HPV-positive patients across AJCC stage groupings. Results We identified 3238 patients with laryngeal squamous cell carcinoma, of which 2812 were HPV negative and 426 were HPV positive. Overall survival adjusted for age, sex, and comorbidity status confirmed significant differences among all consecutive stage groupings (I vs II, P < .001; II vs III, P < .05; III vs IVA, P < .001; IVA vs IVB, P < .05) in the HPV-negative cohort, whereas only stages IVAs and IVB ( P < .01) exhibited a significant difference in overall survival for HPV-positive patients. Conclusion The current AJCC staging system does not accurately distinguish risk of mortality for patients with HPV-positive disease. These data support the consideration of HPV status in estimating prognosis as well as clinical trial design and clinical decision making for patients with laryngeal squamous cell carcinoma.

      View details for PubMedID 29611770
  • Transcriptional-mediated effects of radiation on the expression of immune susceptibility markers in melanoma. Radiother Oncol
    Werner LR, Kler JS, Gressett MM, Riegert M, Werner LK, Heinze CM, Kern JG, Abbariki M, Erbe AK, Patel RB, Sriramaneni RN, Harari PM, Morris ZS
    2017 09; 124 (3): 418-426
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      BACKGROUND AND PURPOSE: We recently reported a time-sensitive, cooperative, anti-tumor effect elicited by radiation (RT) and intra-tumoral-immunocytokine injection in vivo. We hypothesized that RT triggers transcriptional-mediated changes in tumor expression of immune susceptibility markers at delayed time points, which may explain these previously observed time-dependent effects.

      MATERIALS AND METHODS: We examined the time course of changes in expression of immune susceptibility markers following in vitro or in vivo RT in B78 murine melanoma and A375 human melanoma using flow cytometry, immunoblotting, and qPCR.

      RESULTS: Flow cytometry and immunoblot revealed time-dependent increases in expression of death receptors and T cell co-stimulatory/co-inhibitory ligands following RT in murine and human melanoma. Using high-throughput qPCR, we observed comparable time courses of RT-induced transcriptional upregulation for multiple immune susceptibility markers. We confirmed analogous changes in B78 tumors irradiated in vivo. We observed upregulated expression of DNA damage response markers days prior to changes in immune markers, whereas phosphorylation of the STAT1 transcription factor occurred concurrently with changes following RT.

      CONCLUSION: This study highlights time-dependent, transcription-mediated changes in tumor immune susceptibility marker expression following RT. These findings may help in the design of strategies to optimize sequencing of RT and immunotherapy in translational and clinical studies.

      View details for PubMedID 28893414
  • Clinical outcomes for patients presenting with N3 head and neck squamous cell carcinoma: Analysis of the National Cancer Database. Head Neck
    Ko HC, Chen S, Wieland AM, Yu M, Baschnagel AM, Hartig GK, Harari PM, Witek ME
    2017 Nov; 39 (11): 2159-2170
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      BACKGROUND: There is a paucity of data regarding head and neck squamous cell carcinomas (HNSCCs) and N3 nodal disease.

      METHODS: Retrospective analysis of patients with N3 HNSCC identified in the National Cancer Database (NCDB) was performed.

      RESULTS: We identified 4867 patients with N3 HNSCC treated with primary surgery or chemoradiotherapy (CRT). Propensity-adjusted median survival was 54.2 and 44.8 months for surgery and CRT, respectively (P = .06). Oropharyngeal primary subsite demonstrated a survival advantage with surgery versus CRT with propensity-adjusted median survivals of 86.0 and 61.9 months, respectively (P < .05).

      CONCLUSION: Management of N3 HNSCC relies largely on CRT. Patients with N3 nodal disease with nonoropharyngeal primary tumors exhibit 5-year overall survival approaching 30% independent of initial treatment modality. Patients with oropharyngeal primaries exhibit improved outcomes with surgery largely influenced by the human papillomavirus (HPV)-negative subset. These data represent the most comprehensive analysis of N3 HNSCC outcomes and serves as a foundation for future research and clinical management.

      View details for PubMedID 28737019
  • Radiosensitization of Adenoid Cystic Carcinoma with MDM2 Inhibition. Clin Cancer Res
    Prabakaran PJ, Javaid AM, Swick AD, Werner LR, Nickel KP, Sampene E, Hu R, Ong IM, Bruce JY, Hartig GK, Wieland AM, Canon J, Harari PM, Kimple RJ
    2017 Oct 15; 23 (20): 6044-6053
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      Purpose: Adenoid cystic carcinoma (ACC) is a rare cancer arising from the major or minor salivary gland tissues of the head and neck. There are currently no approved systemic agents or known radiosensitizers for ACC. Unlike the more common head and neck squamous cell carcinomas that frequently harbor TP53 mutations, ACCs contain TP53 mutations at a rate of <5%, rendering them an attractive target for MDM2 inhibition.Experimental Design: We report the successful establishment and detailed characterization of a TP53-WT ACC patient-derived xenograft (PDX), which retained the histologic features of the original patient tumor. We evaluated this model for response to the MDM2 inhibitor AMG 232 as monotherapy and in combination with radiotherapy.Results: AMG 232 monotherapy induced modest tumor growth inhibition, and radiation monotherapy induced a transient tumor growth delay in a dose-dependent fashion. Strikingly, combination treatment of AMG 232 with radiotherapy (including low-dose radiotherapy of 2 Gy/fraction) induced dramatic tumor response and high local tumor control rates 3 months following treatment. Posttreatment analysis revealed that although both AMG 232 and radiotherapy alone induced TP53 tumor-suppressive activities, combination therapy amplified this response with potent induction of apoptosis after combination treatment.Conclusions: These data identify that MDM2 inhibition can provide potent radiosensitization in TP53-WT ACC. In light of the absence of effective systemic agents for ACC, the powerful response profile observed here suggests that clinical trial evaluation of this drug/radiotherapy combination may be warranted to improve local control in this challenging malignancy. Clin Cancer Res; 23(20); 6044-53. ©2017 AACR.

      View details for PubMedID 28659312
  • Cotargeting mTORC and EGFR Signaling as a Therapeutic Strategy in HNSCC. Mol Cancer Ther
    Swick AD, Prabakaran PJ, Miller MC, Javaid AM, Fisher MM, Sampene E, Ong IM, Hu R, Iida M, Nickel KP, Bruce JY, Wheeler DL, Kimple RJ
    2017 Jul; 16 (7): 1257-1268
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      Head and neck squamous cell carcinomas (HNSCC) are frequently altered along the PI3K/AKT/mTORC signaling axis. Despite excellent preclinical data, the use of compounds targeting this pathway as monotherapy has been underwhelming in initial clinical trials, and identification of predictive biomarkers remains challenging. To investigate mTORC-specific inhibition, we tested catalytic mTORC (AZD8055) and PI3K/mTORC (NVP-BEZ-235) inhibitors ± cetuximab in a panel of HNSCC cell lines and patient-derived xenografts (PDX). Cell lines were assayed for response to all agents and siRNA knockdown of targets by multiple approaches. All cell lines showed similar response to both drug and siRNA inhibition of both PI3K and mTORC pathways, with anti-EGFR combination producing modest additive effect. Five PDX models that presented PIK3CA mutation or intrinsic cetuximab resistance were treated with a combination of cetuximab and AZD8055. In vivo single-agent mTORC inhibition inhibited growth of one PIK3CA-mutant cancer, but had little effect on any PIK3CAWT or a second PIK3CA-mutant model. In all models, the combination therapy showed greater growth delay than monotherapy. The uniform ability of PI3K and mTORC inhibition to suppress the growth of HNSCC cells highlights the pathway's role in driving proliferation. Although single-agent therapy was largely ineffective in vivo, improved response of combination treatment in an array of PDXs suggests the potential for adding a catalytic mTORC inhibitor to cetuximab therapy. Overall, these results add to a growing body of evidence, suggesting that approaches that attempt to match biomarkers to the optimal therapy in HNSCC remain complex and challenging. Mol Cancer Ther; 16(7); 1257-68. ©2017 AACR.

      View details for PubMedID 28446642