Loss of p53 drives neuron reprogramming in head and neck cancer.

The solid tumour microenvironment includes nerve fibres that arise from the peripheral nervous system1,2. Recent work indicates that newly formed adrenergic nerve fibres promote tumour growth, but the origin of these nerves and the mechanism of their inception are unknown1,3. Here, by comparing the transcriptomes of cancer-associated trigeminal sensory neurons with those of endogenous neurons in mouse models of oral cancer, we identified an adrenergic differentiation signature. We show that loss of TP53 leads to adrenergic transdifferentiation of tumour-associated sensory nerves through loss of the microRNA miR-34a. Tumour growth was inhibited by sensory denervation or pharmacological blockade of adrenergic receptors, but not by chemical sympathectomy of pre-existing adrenergic nerves. A retrospective analysis of samples from oral cancer revealed that p53 status was associated with nerve density, which was in turn associated with poor clinical outcomes. This crosstalk between cancer cells and neurons represents mechanism by which tumour-associated neurons are reprogrammed towards an adrenergic phenotype that can stimulate tumour progression, and is a potential target for anticancer therapy.

A general calculus of fitness landscapes finds genes under selection in cancers.

Genetic variants drive the evolution of traits and diseases. We previously modeled these variants as small displacements in fitness landscapes and estimated their functional impact by differentiating the evolutionary relationship between genotype and phenotype. Conversely, here we integrate these derivatives to identify genes steering specific traits. Over cancer cohorts, integration identified 460 likely tumor-driving genes. Many have literature and experimental support but had eluded prior genomic searches for positive selection in tumors. Beyond providing cancer insights, these results introduce a general calculus of evolution to quantify the genotype-phenotype relationship and discover genes associated with complex traits and diseases.

Low doses of methylnaltrexone inhibits head and neck squamous cell carcinoma growth in vitro and in vivo by acting on the mu-opioid receptor.

The Mu-opioid receptor (MOR) has been implicated in tumorigenesis and metastasis. Methylnaltrexone (MNTX), an antagonist of MOR, has shown to inhibit tumor growth and metastasis in lung cancer cell lines. The effect of MNTX on other cell lines such as head and neck squamous cell carcinoma (HNSCC) has not been investigated. We measured the expression and activity of the receptor in different HNSCC cell lines. Then, we evaluated the impact of modulating the expression MOR and the effect of MNTX on the proliferation, clonogenic activity, invasion, and migration of two HNSCC (FaDu and MDA686Tu) cell lines expressing MOR and one cell line (UMSCC47) not expressing the receptor. We also evaluated the impact of MNTX on tumor growth and metastasis formation in vivo. Activation of the receptor with [d-Ala2,N-Me-Phe4, Gly5-ol] (DAMGO) caused a significant reduction in cyclic adenosine monophosphate levels in FaDu cells. Knockdown of MOR inhibited in vitro aggressive cell behaviors on FaDu and MDA686Tu cells and correlated with a reduction in markers of epithelial-mesenchymal transition. In vitro studies showed that MNTX strongly inhibited the proliferation, clonogenic activity, invasion, and migration of FaDu and MDA686Tu cells but has no effect on UMSCC47 cells. In vivo experiments demonstrated that MNTX suppresses tumor growth in HNSCC cell tumor-bearing mice. Our studies indicate that MOR could be considered as a therapeutic target to treat HNSCC.

The mutational landscape of early- and typical-onset oral tongue squamous cell carcinoma.

BACKGROUND: The incidence of oral tongue squamous cell carcinoma (OTSCC) is increasing among younger birth cohorts. The etiology of early-onset OTSCC (diagnosed before the age of 50 years) and cancer driver genes remain largely unknown. METHODS: The Sequencing Consortium of Oral Tongue Cancer was established through the pooling of somatic mutation data of oral tongue cancer specimens (n = 227 [107 early-onset cases]) from 7 studies and The Cancer Genome Atlas. Somatic mutations at microsatellite loci and Catalog of Somatic Mutations in Cancer mutation signatures were identified. Cancer driver genes were identified with the MutSigCV and WITER algorithms. Mutation comparisons between early- and typical-onset OTSCC were evaluated via linear regression with adjustments for patient-related factors. RESULTS: Two novel driver genes (ATXN1 and CDC42EP1) and 5 previously reported driver genes (TP53, CDKN2A, CASP8, NOTCH1, and FAT1) were identified. Six recurrent mutations were identified, with 4 occurring in TP53. Early-onset OTSCC had significantly fewer nonsilent mutations even after adjustments for tobacco use. No associations of microsatellite locus mutations and mutation signatures with the age of OTSCC onset were observed. CONCLUSIONS: This international, multicenter consortium is the largest study to characterize the somatic mutational landscape of OTSCC and the first to suggest differences by age of onset. This study validates multiple previously identified OTSCC driver genes and proposes 2 novel cancer driver genes. In analyses by age, early-onset OTSCC had a significantly smaller somatic mutational burden that was not explained by differences in tobacco use. LAY SUMMARY: This study identifies 7 specific areas in the human genetic code that could be responsible for promoting the development of tongue cancer. Tongue cancer in young patients (under the age of 50 years) has fewer overall changes to the genetic code in comparison with tongue cancer in older patients, but the authors do not think that this is due to differences in smoking rates between the 2 groups. The cause of increasing cases of tongue cancer in young patients remains unclear.

Literature-based automated discovery of tumor suppressor p53 phosphorylation and inhibition by NEK2.

Scientific progress depends on formulating testable hypotheses informed by the literature. In many domains, however, this model is strained because the number of research papers exceeds human readability. Here, we developed computational assistance to analyze the biomedical literature by reading PubMed abstracts to suggest new hypotheses. The approach was tested experimentally on the tumor suppressor p53 by ranking its most likely kinases, based on all available abstracts. Many of the best-ranked kinases were found to bind and phosphorylate p53 (P value = 0.005), suggesting six likely p53 kinases so far. One of these, NEK2, was studied in detail. A known mitosis promoter, NEK2 was shown to phosphorylate p53 at Ser315 in vitro and in vivo and to functionally inhibit p53. These bona fide validations of text-based predictions of p53 phosphorylation, and the discovery of an inhibitory p53 kinase of pharmaceutical interest, suggest that automated reasoning using a large body of literature can generate valuable molecular hypotheses and has the potential to accelerate scientific discovery.

Identifying predictors of HPV-related head and neck squamous cell carcinoma progression and survival through patient-derived models.

Therapeutic innovation for human papilloma virus-related (HPV+) head and neck squamous cell carcinomas (HNSCCs) is impaired by inadequate preclinical models and the absence of accurate biomarkers. Our study establishes the first well-characterized panel of patient-derived xenografts (PDXs) and organoids from HPV+ HNSCCs while determining fidelity of the models to the distinguishing genetic features of this cancer type. Despite low engraftment rates, whole exome sequencing showed that PDXs retain multiple distinguishing features of HPV+ HNSCC lost in existing cell lines, including PIK3CA mutations, TRAF3 deletion and the absence of EGFR amplifications. Engrafted HPV+ tumors frequently contained NOTCH1 mutations, thus providing new models for a negatively prognostic alteration in this disease. Genotype-phenotype associations in the models were then tested for prediction of tumor progression and survival in published clinical cohorts. Observation of high tumor mutational burdens (TMBs) in the faster-growing models facilitated identification of a novel association between TMB and local progression in both HPV+ and HPV- patients that was prognostic in HPV- cases. In addition, reduced E7 and p16INK4A levels found in a PDX from an outlier case with lethal outcome led to detection of similar profiles among recurrent HPV+ HNSCCs. Transcriptional data from the Cancer Genome Atlas was used to demonstrate that the lower E2F target gene expression predicted by reduced E7 levels has potential as a biomarker of disease recurrence risk. Our findings bridge a critical gap in preclinical models for HPV+ HNSCCs and simultaneously reveal novel potential applications of quantifying mutational burden and viral oncogene functions for biomarker development.

Functionally impactful TP53 mutations are associated with increased risk of extranodal extension in clinically advanced oral squamous cell carcinoma.

BACKGROUND: The treatment of advanced oral squamous cell carcinoma (OSCC) is a clinical challenge because it is unclear which therapeutic approaches are the best for this highly heterogeneous group of patients. Because TP53 mutations are the most common genetic event in these tumors, the authors investigated whether they could represent an ancillary biomarker in the management of advanced OSCC. METHODS: The TP53 gene was sequenced in 78 samples from patients with advanced OSCC who received treatment at 2 institutions located in the United States and Brazil. TP53 mutations were classified according to an in-silico impact score (the evolutionary action score of p53 [EAp53]), which identifies mutations that have greater alterations of p53 protein function (high-risk). Associations between TP53 mutation status/characteristics and clinicopathologic characteristics were investigated. The relevant findings were validated in silico by analyzing 197 samples from patients with advanced OSCC from The Cancer Genome Atlas. RESULTS: No differences in clinical outcomes were detected between patients with TP53-mutant and wild-type TP53 disease. However, patients who had tumors carrying high-risk TP53 mutations had a significantly increased risk of developing extranodal extension (ENE) compared with those who had wild-type TP53-bearing tumors. The increased chances of detecting ENE among patients who had high-risk TP53 mutations was validated among patients with advanced OSCC from The Cancer Genome Atlas cohort. CONCLUSIONS: High-risk TP53 mutations are associated with an increased chance of detecting ENE in patients with advanced OSCC. Because ENE is 1 of the major factors considered for OSCC patient management, TP53 mutation status may represent a potential ancillary biomarker for treatment decisions regarding postoperative adjuvant therapy.

Genetics and penile cancer: recent developments and implications.

PURPOSE OF REVIEW: We summarize the recent developments in the molecular landscape of penile squamous cell carcinoma (PSCC). RECENT FINDINGS: Recent genomic studies have demonstrated a molecular convergence of PSCC with other squamous cell carcinomas (SCCs) from different organ sites. Similarly, human papillomavirus (HPV)-related PSCCs appear to have epigenetic and genomic similarities with other HPV-related cancers. This could have implications on future HPV-related cancer trial design. Growing efforts to characterize recurrent gene alterations in PSCC have expanded our understanding over the past years, showing a predominance of tumor suppressor gene alterations such as TP53 and NOTCH1. In addition, these studies have demonstrated that at least 30% of PSCC cases have targetable gene alterations. Further, the similar tumor mutational burden with other SCCs and the relatively high rates of programmed death-1 (PD-1) positive expression in PSCC constitute the rationale for investigation of PD-1 inhibition in ongoing clinical trials. Multiple studies have identified potential epigenetic and RNA signatures predictive of metastasis or survival, but these still require validation in larger cohorts. SUMMARY: PSCC appears to be genomicaly similar to other SCCs and HPV-related cancers. This provides the rationale and opportunity to include a rare tumor like PSCC in future 'basket type' trials using novel agents targeting multiple SCCs that may exhibit similar biology.

Distinct pattern of TP53 mutations in human immunodeficiency virus-related head and neck squamous cell carcinoma.

BACKGROUND: Human immunodeficiency virus-infected individuals (HIVIIs) have a higher incidence of head and neck squamous cell carcinoma (HNSCC), and clinical and histopathological differences have been observed in their tumors in comparison with those of HNSCC patients without a human immunodeficiency virus (HIV) infection. The reasons for these differences are not clear, and molecular differences between HIV-related HNSCC and non-HIV-related HNSCC may exist. This study compared the mutational patterns of HIV-related HNSCC and non-HIV-related HNSCC. METHODS: The DNA of 20 samples of HIV-related HNSCCs and 32 samples of non-HIV-related HNSCCs was sequenced. DNA libraries covering exons of 18 genes frequently mutated in HNSCC (AJUBA, CASP8, CCND1, CDKN2A, EGFR, FAT1, FBXW7, HLA-A, HRAS, KEAP1, NFE2L2, NOTCH1, NOTCH2, NSD1, PIK3CA, TGFBR2, TP53, and TP63) were prepared and sequenced on an Ion Personal Genome Machine sequencer. DNA sequencing data were analyzed with Ion Reporter software. The human papillomavirus (HPV) status of the tumor samples was assessed with in situ hybridization, the MassARRAY HPV multiplex polymerase chain reaction assay, and p16 immunostaining. Mutation calls were compared among the studied groups. RESULTS: HIV-related HNSCC revealed a distinct pattern of mutations in comparison with non-HIV-related HNSCC. TP53 mutation frequencies were significantly lower in HIV-related HNSCC. Mutations in HIV+ patients tended to be TpC>T nucleotide changes for all mutated genes but especially for TP53. CONCLUSIONS: HNSCC in HIVIIs presents a distinct pattern of genetic mutations, particularly in the TP53 gene. HIV-related HNSCC may have a distinct biology, and an effect of the HIV virus on the pathogenesis of these tumors should not be ruled out. Cancer 2018;124:84-94. © 2017 American Cancer Society.

Mutation allele frequency threshold does not affect prognostic analysis using next-generation sequencing in oral squamous cell carcinoma.

BACKGROUND: With the development of sequencing technologies, there may be some disputes on sequencing analysis. The aim of this study was to investigate different allele frequency thresholds of mutations in targeted genes on prognostic analyses using a panel of cancer associated gene exons (CAGE) in oral squamous cell carcinoma (OSCC). METHODS: Forty-six patients were included in this study. Twelve genes were sequenced and analyzed using next-generation sequencing from formalin-fixed paraffin-embedded tissues. Allele frequency thresholds of 10, 5, and 3% were used for prognostic analyses. RESULTS: With a mean sequence depth of 3199-fold, 99% of CAGE were represented by at least 10 reads. Ninety-four non-synonymous (missense [70.2%], nonsense [11.7%], splice site [10.6%], and insertion/deletion [7.5%]) mutations were detected in 40 OSCC patients with an allele frequency threshold of 10%. TP53 (78.3%), NOTCH1 (30.4%), CASP8 (13.0%), CDKN2A (10.9%), and CDH1 (6.5%) were the most frequently mutated genes. Using allele frequency thresholds of 10, 5, and 3%, there were no significant differences in clinical outcomes between patients with non-synonymous mutations and wild type genotypes. CONCLUSIONS: TP53, NOTCH1, CASP8, CDKN2A, and CDH1 are the most frequently mutated genes in OSCC patients. The allele frequency threshold used in this study does not affect the results of clinical outcome analysis.

Mechanisms for the Generation of Two Quadruplications Associated with Split-Hand Malformation.

Germline copy-number variants (CNVs) involving quadruplications are rare and the mechanisms generating them are largely unknown. Previously, we reported a 20-week gestation fetus with split-hand malformation; clinical microarray detected two maternally inherited triplications separated by a copy-number neutral region at 17p13.3, involving BHLHA9 and part of YWHAE. Here, we describe an 18-month-old male sibling of the previously described fetus with split-hand malformation. Custom high-density microarray and digital droplet PCR revealed the copy-number gains were actually quadruplications in the mother, the fetus, and her later born son. This quadruplication-normal-quadruplication pattern was shown to be expanded from the triplication-normal-triplication CNV at the same loci in the maternal grandmother. We mapped two breakpoint junctions and demonstrated that both are mediated by Alu repetitive elements and identical in these four individuals. We propose a three-step process combining Alu-mediated replicative-repair-based mechanism(s) and intergenerational, intrachromosomal nonallelic homologous recombination to generate the quadruplications in this family.

How will we recruit, train, and retain physicians and scientists to conduct translational cancer research?

Advances in clinical medicine require effective translational research. Ideally, this research will be performed by multidisciplinary teams that include both physicians and basic scientists. However, the current system does not appropriately train either physicians or basic scientists for these careers. In addition, translational researchers are often not properly rewarded, and this creates a disincentive for pursuing this kind of research. The roles and challenges for physicians and basic researchers in the field of translational research are discussed along with proposed solutions for improving their recruitment, training, and retention. Cancer 2015;121:806-816. © 2014 American Cancer Society.

FXR silencing in human colon cancer by DNA methylation and KRAS signaling.

Farnesoid X receptor (FXR) is a bile acid nuclear receptor described through mouse knockout studies as a tumor suppressor for the development of colon adenocarcinomas. This study investigates the regulation of FXR in the development of human colon cancer. We used immunohistochemistry of FXR in normal tissue (n = 238), polyps (n = 32), and adenocarcinomas, staged I-IV (n = 43, 39, 68, and 9), of the colon; RT-quantitative PCR, reverse-phase protein array, and Western blot analysis in 15 colon cancer cell lines; NR1H4 promoter methylation and mRNA expression in colon cancer samples from The Cancer Genome Atlas; DNA methyltransferase inhibition; methyl-DNA immunoprecipitation (MeDIP); bisulfite sequencing; and V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) knockdown assessment to investigate FXR regulation in colon cancer development. Immunohistochemistry and quantitative RT-PCR revealed that expression and function of FXR was reduced in precancerous lesions and silenced in a majority of stage I-IV tumors. FXR expression negatively correlated with phosphatidylinositol-4, 5-bisphosphate 3 kinase signaling and the epithelial-to-mesenchymal transition. The NR1H4 promoter is methylated in ~12% colon cancer The Cancer Genome Atlas samples, and methylation patterns segregate with tumor subtypes. Inhibition of DNA methylation and KRAS silencing both increased FXR expression. FXR expression is decreased early in human colon cancer progression, and both DNA methylation and KRAS signaling may be contributing factors to FXR silencing. FXR potentially suppresses epithelial-to-mesenchymal transition and other oncogenic signaling cascades, and restoration of FXR activity, by blocking silencing mechanisms or increasing residual FXR activity, represents promising therapeutic options for the treatment of colon cancer.

Novel non-invasive molecular signatures for oral cavity cancer, by whole transcriptome and small non-coding RNA sequencing analyses: Predicted association with PI3K/AKT/mTOR pathway.

INTRODUCTION: Identification of molecular biomarkers in the saliva and serum of oral cavity cancer patients represents a first step in the development of essential and efficient clinical tools for early detection and post-treatment monitoring. We hypothesized that molecular analyses of paired saliva and serum samples from an individual would likely yield better results than analyses of either serum or saliva alone. MATERIALS AND METHODS: We performed whole-transcriptome and small non-coding RNA sequencing analyses on 32 samples of saliva and serum collected from the same patients with oral squamous cell carcinoma (OSCC) and healthy controls (HC). RESULTS: We identified 12 novel saliva and serum miRNAs and a panel of unique miRNA and mRNA signatures, significantly differentially expressed in OSCC patients relative to HC (log2 fold change: 2.6-26.8; DE: 0.02-0.000001). We utilized a combined panel of the 10 top-deregulated miRNAs and mRNAs and evaluated their putative diagnostic potential (>87% sensitivity; 100% specificity), recommending seven of them for further validation. We also identified unique saliva and serum miRNAs associated with OSCC and smoking history (OSCC smokers vs. never-smokers or HC: log2 fold change: 22-23; DE: 0.00003-0.000000001). Functional and pathway analyses indicated interactions between the discovered OSCC-related non-invasive miRNAs and mRNAs and their targets, through PI3K/AKT/mTOR signaling. CONCLUSION: Our data support our hypothesis that using paired saliva and serum from the same individuals and deep sequencing analyses can provide unique combined mRNA and miRNA signatures associated with canonical pathways that may have a diagnostic advantage relative to saliva or serum alone and may be useful for clinical testing. We believe this data will contribute to effective preventive care by post-treatment monitoring of patients, as well as suggesting potential targets for therapeutic approaches.

Histologic and Genomic Analysis of Conjunctival SCC in African and American Cohorts Reveal UV Light and HPV Signatures and High Tumor Mutation Burden.

Purpose: Conjunctival squamous cell carcinoma (conjSCC) is more prevalent and aggressive in sub-Saharan African countries compared with the rest of the world. This study aims to compare the genomic, immunophenotypic, and histologic features between patients from the United States and Ethiopia, to identify etiopathogenic mechanisms and unveil potential treatment strategies. Methods: We compared histologic features and mutational profiles using whole exome sequencing, high-risk human papillomavirus (HPV) status, PD-L1 expression, and tumor-infiltrating lymphocytes in conjSCC tumors of patients from Ethiopia (ETH; n = 25) and the United States (from MD Anderson [the MDA cohort]; n = 29). Genomic alterations were compared with SCCs from other anatomic sites using data from The Cancer Genome Atlas. Results: Solar elastosis was seen in 78% of ETH and 10% of MDA samples. Thicker tumors had higher density of CD8+ and CD3+ cells. HPV status was similar between the cohorts (ETH = 21% and MDA = 28%). The mean tumor mutation burden (TMB) was significantly higher in conjSCC (3.01/Mb, log10) and cutaneous SCC compared other SCC subtypes. ETH samples had higher TMB compared to the MDA cohort (3.34 vs. 2.73). Mutations in genes associated with ultraviolet light (UV) signature were most frequently encountered (SBS7b = 74% and SBS7a = 72%), with higher prevalence in the ETH cohort, whereas SBS2 and SBS13 signatures were more common among MDA HPV+ conjSCCs. Conclusions: Our findings suggest that UV exposure may play a major role in conjSCC, with a higher prevalence in the ETH cohort compared with the MDA cohort, where HPV also contributes.

Immune infiltration at the primary tumor is associated with clinical outcome of patients with extranodal extension of lymph node metastasis in oral cancer.

BACKGROUND: Extranodal extension (ENE) of lymph node metastasis is one of the most reliable prognostic indicators for patients with locally advanced oral cancer. Although multiple reports have found a close relationship between immune infiltration of tumors and patient clinical outcomes, its association with ENE is unknown. METHODS: We identified 234 human papillomavirus-negative (HPV-) oral cavity squamous cell carcinoma (OSCC) patients in The Cancer Genome Atlas and investigated the immune infiltration profiles of primary tumors and their association with survival. RESULTS: Hierarchical clustering analysis clearly classified the overall immune infiltration status in OSCC into high immune or low immune groups. The combination of ENE positivity and low immune infiltration was strongly associated with poor overall survival (OS) compared to the combination of ENE positivity and high immune infiltration [hazard ratio 2.04 (95 %CI, 1.08-3.83); p = 0.024]. The immune infiltration status was not associated with OS rates in patients with ENE-negative or node negative tumors. CONCLUSION: Overall Immune infiltration at the primary site was significantly associated with clinical outcome of OSCC patients with ENE.

Th2 Cells Are Associated with Tumor Recurrence Following Radiation.

The curative treatment of multiple solid tumors, including head and neck squamous cell carcinoma (HNSCC), utilizes radiation. The outcomes for HPV/p16-negative HNSCC are significantly worse than HPV/p16-positive tumors, with increased radiation resistance leading to worse locoregional recurrence (LRR) and ultimately death. This study analyzed the relationship between immune function and outcomes following radiation in HPV/p16-negative tumors to identify mechanisms of radiation resistance and prognostic immune biomarkers. A discovery cohort of 94 patients with HNSCC treated uniformly with surgery and adjuvant radiation and a validation cohort of 97 similarly treated patients were utilized. Tumor immune infiltrates were derived from RNAseq gene expression. The immune cell types significantly associated with outcomes in the discovery cohort were examined in the independent validation cohort. A positive association between high Th2 infiltration and LRR was identified in the discovery cohort and validated in the validation cohort. Tumor mutations in CREBBP/EP300 and CASP8 were significantly associated with Th2 infiltration. A pathway analysis of genes correlated with Th2 cells revealed the potential repression of the antitumor immune response and the activation of BRCA1-associated DNA damage repair in multiple cohorts. The Th2 infiltrates were enriched in the HPV/p16-negative HNSCC tumors and associated with LRR and mutations in CASP8, CREBBP/EP300, and pathways previously shown to impact the response to radiation.

FAK Drives Resistance to Therapy in HPV-Negative Head and Neck Cancer in a p53-Dependent Manner.

PURPOSE: Radiation and platinum-based chemotherapy form the backbone of therapy in human papillomavirus (HPV)-negative head and neck squamous cell carcinoma (HNSCC). We have correlated focal adhesion kinase (FAK/PTK2) expression with radioresistance and worse outcomes in these patients. However, the importance of FAK in driving radioresistance and its effects on chemoresistance in these patients remains unclear. EXPERIMENTAL DESIGN: We performed an in vivo shRNA screen using targetable libraries to identify novel therapeutic sensitizers for radiation and chemotherapy. RESULTS: We identified FAK as an excellent target for both radio- and chemosensitization. Because TP53 is mutated in over 80% of HPV-negative HNSCC, we hypothesized that mutant TP53 may facilitate FAK-mediated therapy resistance. FAK inhibitor increased sensitivity to radiation, increased DNA damage, and repressed homologous recombination and nonhomologous end joining repair in mutant, but not wild-type, TP53 HPV-negative HNSCC cell lines. The mutant TP53 cisplatin-resistant cell line had increased FAK phosphorylation compared with wild-type, and FAK inhibition partially reversed cisplatin resistance. To validate these findings, we utilized an HNSCC cohort to show that FAK copy number and gene expression were associated with worse disease-free survival in mutant TP53, but not wild-type TP53, HPV-negative HNSCC tumors. CONCLUSIONS: FAK may represent a targetable therapeutic sensitizer linked to a known genomic marker of resistance.

Mutant p53 gains oncogenic functions through a chromosomal instability-induced cytosolic DNA response.

Inactivating TP53 mutations leads to a loss of function of p53, but can also often result in oncogenic gain-of-function (GOF) of mutant p53 (mutp53) proteins which promotes tumor development and progression. The GOF activities of TP53 mutations are well documented, but the mechanisms involved remain poorly understood. Here, we study the mutp53 interactome and find that by targeting minichromosome maintenance complex components (MCMs), GOF mutp53 predisposes cells to replication stress and chromosomal instability (CIN), leading to a tumor cell-autonomous and cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING)-dependent cytosolic DNA response that activates downstream non-canonical nuclear factor kappa light chain enhancer of activated B cell (NC-NF-κB) signaling. Consequently, GOF mutp53-MCMs-CIN-cytosolic DNA-cGAS-STING-NC-NF-κB signaling promotes tumor cell metastasis and an immunosuppressive tumor microenvironment through antagonizing interferon signaling and regulating genes associated with pro-tumorigenic inflammation. Our findings have important implications for understanding not only the GOF activities of TP53 mutations but also the genome-guardian role of p53 and its inactivation during tumor development and progression.

High intratumor genetic heterogeneity is related to worse outcome in patients with head and neck squamous cell carcinoma.

BACKGROUND: Although the presence of genetic heterogeneity within the tumors of individual patients is established, it is unclear whether greater heterogeneity predicts a worse outcome. A quantitative measure of genetic heterogeneity based on next-generation sequencing (NGS) data, mutant-allele tumor heterogeneity (MATH), was previously developed and applied to a data set on head and neck squamous cell carcinoma (HNSCC). Whether this measure correlates with clinical outcome was not previously assessed. METHODS: The authors examined the association between MATH and clinical, pathologic, and overall survival data for 74 patients with HNSCC for whom exome sequencing was completed. RESULTS: High MATH (a MATH value above the median) was found to be significantly associated with shorter overall survival (hazards ratio, 2.5; 95% confidence interval, 1.3-4.8). MATH was similarly found to be associated with adverse outcomes in clinically high-risk patients with an advanced stage of disease, and in those with tumors classified as high risk on the basis of validated biomarkers including those that were negative for human papillomavirus or having disruptive tumor protein p53 mutations. In patients who received chemotherapy, the hazards ratio for high MATH was 4.1 (95% confidence interval, 1.6-10.2). CONCLUSIONS: This novel measure of tumor genetic heterogeneity is significantly associated with tumor progression and adverse treatment outcomes, thereby supporting the hypothesis that higher genetic heterogeneity portends a worse clinical outcome in patients with HNSCC. The prognostic value of some known biomarkers may be the result of their association with high genetic heterogeneity. MATH provides a useful measure of that heterogeneity to be prospectively validated as NGS data from homogeneously treated patient cohorts become available.