Histone methylation antagonism drives tumor immune evasion in squamous cell carcinomas.

How cancer-associated chromatin abnormalities shape tumor-immune interaction remains incompletely understood. Recent studies have linked DNA hypomethylation and de-repression of retrotransposons to anti-tumor immunity through the induction of interferon response. Here, we report that inactivation of the histone H3K36 methyltransferase NSD1, which is frequently found in squamous cell carcinomas (SCCs) and induces DNA hypomethylation, unexpectedly results in diminished tumor immune infiltration. In syngeneic and genetically engineered mouse models of head and neck SCCs, NSD1-deficient tumors exhibit immune exclusion and reduced interferon response despite high retrotransposon expression. Mechanistically, NSD1 loss results in silencing of innate immunity genes, including the type III interferon receptor IFNLR1, through depletion of H3K36 di-methylation (H3K36me2) and gain of H3K27 tri-methylation (H3K27me3). Inhibition of EZH2 restores immune infiltration and impairs the growth of Nsd1-mutant tumors. Thus, our work uncovers a druggable chromatin cross talk that regulates the viral mimicry response and enables immune evasion of DNA hypomethylated tumors.

Mucosal Soft Tissue Lesions.

Mucosal soft tissue lesions are fairly common in the pediatric population. However, the precise prevalence is unknown. This is the result of the limited number of studies, the use of various diagnostic criteria in those studies, and the transient nature of commonly encountered lesions in this population. In this section, we seek to familiarize the pediatric pathologist with a sampling of mucosal soft tissue lesions encountered in pediatric patients, highlight key diagnostic features and correlations with systemic diseases should they exist.

Evaluation of compounded cidofovir, famciclovir, and ganciclovir for the treatment of feline herpesvirus ocular surface disease in shelter-housed cats.

OBJECTIVE: To assess the efficacy of compounded cidofovir, famciclovir, and ganciclovir for the treatment of feline herpesvirus type 1 (FHV-1) ocular surface disease. ANIMALS STUDIED: 132 shelter-housed cats qPCR positive for FHV-1. PROCEDURES: A masked placebo-controlled study design was utilized. Animals were enrolled in one of four treatment groups: topical ocular placebo + oral placebo (n = 32), compounded cidofovir 0.5% ophthalmic solution + oral placebo (n = 32), compounded famciclovir oral solution (90 mg/kg) + topical ocular placebo (n = 32), and compounded ganciclovir 0.15% ophthalmic solution + oral placebo (n = 36). Cats were treated with each medication twice daily for 7 days and were evaluated on Day 1 and Day 8 using an ocular scoring system, body weight, and qPCR for FHV-1 viral load. RESULTS: Cidofovir significantly decreased viral load from Day 1 to Day 8 compared with placebo (p = .024). Neither famciclovir nor ganciclovir decreased viral load compared with placebo (p = .14, p = .41). There was no significant improvement of ocular scores for any drug group compared with placebo (p = .62). In all groups, 65%-75% of cats improved from Day 1 to Day 8. Juvenile cats had a significant increase in weight gain compared with placebo for cidofovir (p = .025) and ganciclovir (p = .023). All corneal ulcers in placebo animals failed to heal whereas 77% of ulcers in antiviral group animals healed. CONCLUSIONS: Topical ophthalmic cidofovir significantly decreased ocular FHV-1 viral shedding and increased weight gain in juvenile cats. Ganciclovir increased weight gain in juvenile cats. Compounded famciclovir demonstrated limited efficacy for the treatment of FHV-1 ocular surface disease in shelter-housed cats.

Environmental relative humidity affects Schirmer tear test results in normal dogs.

OBJECTIVE: To investigate the effects of environmental temperature and relative humidity on tear test results in dogs. ANIMALS STUDIED: 22 normal dogs. PROCEDURES: Routine Schirmer tear tests (STT1) and phenol red thread tests (PRTT) were administered to normal dogs in four environmental conditions with different relative humidity (RH) and temperature (T). Environmental conditions (mean ± SD) included the following: normal indoor (RH = 49 ± 4%, T = 72 ± 2°F), outdoor (RH = 62 ± 11%, T = 85 ± 6°F), indoor high humidity (RH = 85 ± 6%, T = 71 ± 1°F), and indoor low humidity (RH = 39 ± 2%, T = 76 ± 1°F). ANCOVA models were used to assess for significant associations between tear test readings and RH/T (P < .05). RESULTS: A significant, direct positive relationship between RH and STT1 results was detected (y = 0.04909*X + 19.11, P = .006) but not between T and STT1. There was no significant relationship between PRTT and RH or T. CONCLUSIONS: These results suggest that STT1 but not PRTT is affected by RH and that T does not influence STT1 or PRTT results in normal dogs. RH is unlikely, however, to cause clinically significant effects on STT1 readings in normal dogs when performed in average indoor conditions. Future studies should investigate the influence of RH on STT1 readings obtained in dogs with keratoconjunctivitis sicca.

Schirmer strip wetting length varies by commercial manufacturer.

OBJECTIVE: To determine whether wetting length of Schirmer tear test (STT) strips varies by commercial manufacturer of test. ANIMALS STUDIED: Ten normal female beagle cross-breed dogs. PROCEDURES: Schirmer tear test strips from four commercial manufacturers were used to assess wetting lengths in-vitro when exposed to a set volume of water over 1 minute. Digital photography was used to assess the total surface area of Schirmer strips from each manufacturer. Schirmer tear test type 1 was performed on normal dogs over 1 minute with STT strips from the same four commercial manufacturers in a randomized crossover design. ANOVA was used to detect differences between strips from different manufacturers. RESULTS: Significant differences in wetting length were found between STT strips from different manufacturers in-vitro (P < .0001) and in-vivo (P < .0001). STT wetting lengths for the in-vitro experiments (mean ± SD) were 21.2 ± 0.8 mm (Amcon Laboratories), 27.8 ± 2.7 mm (Merck Animal Health), 30.0 ± 1.7 mm (HUB pharmaceuticals), and 31.5 ± 2.3 mm (Gulden Ophthalmics). STT wetting lengths for the experiments in live dogs (mean ± SD) were 17.5 ± 3.4 mm (Amcon Laboratories), 24.8 ± 3.9 mm (Merck Animal Health), 26.5 ± 3.7 mm (HUB pharmaceuticals), and 24.0 ± 3.9 mm (Gulden Ophthalmics). The surface area of STT strips were found to vary between different manufacturers. CONCLUSIONS: Schirmer tear test type 1 results in dogs are affected by choice of STT strip commercial manufacturer. It is proposed that guidelines are created for the standardization of future STT strip production.

Stafne Bone Defect Involving the Ascending Ramus.

The Stafne bone defect (SBD) classically presents as a well-defined, radiolucent lesion in the molar-mandibular angle region beneath the level of the mandibular canal. Due in large part to this prototypical appearance, most cases of SBDs are radiographically diagnostic without the need for tissue biopsy. A diagnostic challenge may arise, however, when the SBD occurs in other locations in the mandible. The authors report a case of a 57-year-old male who presented with a SBD of the left ascending ramus. The lesion was found incidentally on a panoramic radiograph. Additional imaging studies confirmed a lingual concavity of the mandibular bone consistent with a SBD, and a retrospective study of the patient's records revealed the presence of the lesion 5 years prior without any radiographic alterations. To date, only 10 documented cases of an SBD involving the ascending ramus have been reported. The rarity of such a presentation may obscure the diagnosis and lead to unwarranted surgical procedures. It is important to recognize atypically located SBDs, because unlike other radiolucent lesions, imaging studies are diagnostic. With proper diagnosis, additional surgical procedures and any associated morbidities can be avoided.

Ameloblastic Fibro-Odontoma in an Adolescent: A Case Report and Review of Literature.

Ameloblastic fibro-odontoma (AFO) is a rare benign odontogenic tumor with the histologic features of ameloblastic fibroma (AF) but also contains enamel and dentin. It is most commonly observed in the pediatric population. Distinction between AFO and AF becomes important as ameloblastic fibromas are associated with higher recurrence rates of up to 18%, and 35% of these recurrent lesions can undergo malignant transformation to ameloblastic fibrosarcoma. Hence, for amelobastic fibroma, conservative curettage is recommended for the initial lesion and marginal resection is considered for recurrent cases. In contrast, AFO can be treated with simple curettage and the recurrence rate is approximately seven percent. Malignant transformation of AFO is exceedingly rare. Therefore, the treatment and prognosis differs for these two histologically similar neoplasms. We present a case of a 17-year-old boy who was initially diagnosed with ameloblastic fibroma upon biopsy, with subsequent curettage specimen showing AFO, which carries a better prognosis.

Pyogenic Granuloma in the Tongue in a Five Year Old: A Case Report.

Pyogenic granuloma, also called lobular capillary hemangioma, is a benign vascular lesion of the skin and mucous membranes. While the majority of pyogenic granulomas in the oral cavity involve the gingiva, they also infrequently present at other sites including lips, oral mucosa, palate, and tongue. We report a case of a pyogenic granuloma of the tongue in a five-year old female patient.

Idiopathic Gingival Fibromatosis: Case Report and Review of the Literature.

Gingival fibromatosis (GF) is a condition characterized by a progressive, normal colored enlargement of the gingiva caused by an increase in the size of submucosal connective tissue. Both familial and idiopathic variants of the condition exist. The authors present a case report of a 38-year-old African American man who presented with an impressive overgrowth of the maxillary and mandibular gingivae, subsequently diagnosed as idiopathic GF. In this report, the authors will review the etiologies, treatment, and clinical and histological findings of GF, review similar cases found in the literature, and discuss the differential diagnosis for diffuse gingival enlargements.

Molecular Subtypes of Head and Neck Cancer in Patients of African Ancestry.

PURPOSE: The purpose of this study was to better understand the complex molecular biomarkers and signatures of head and neck cancer (HNC) among Black patients and identify possible molecular changes associated with HNC disparities. EXPERIMENTAL DESIGN: Molecular subtypes and genomic changes in HNC samples from patients of African and European ancestry in The Cancer Genome Atlas, Memorial Sloan Kettering Cancer Center, Broad Institute, MD Anderson Cancer Center, and John Hopkins University were identified. Molecular features (genomic, proteomic, transcriptomic) associated with race and genomic alterations associated with clinical outcomes were determined. An independent cohort of HNC tumor specimens was used to validate the primary findings using IHC. RESULTS: Black patients were found to have a younger age at diagnosis, more aggressive tumor types, higher rates of metastasis, and worse survival compared with White patients. Black patients had fewer human papillomavirus-positive tumor types and higher frequencies of laryngeal subtype tumors. Higher frequencies of TP53, MYO18B, KMT2D, and UNC13C mutations and a lower frequency of PIK3CA mutations were observed in Black patients. Tumors of Black patients showed significant enrichment of c-MYC and RET-tyrosine signaling and amplifications. A significant increase in tumor expression of c-MYC in Black patients was observed and was associated with poor survival outcomes in the independent cohort. CONCLUSIONS: Novel genomic modifications and molecular signatures may be related to environmental, social, and behavioral factors associated with racial disparities in HNC. Unique tumor mutations and biological pathways have potential clinical utility in providing more targeted and individualized screening, diagnostic, and treatment modalities to improve health outcomes.

Inflammatory biomarkers in saliva: assessing the strength of association of diabetes mellitus and periodontal status with the oral inflammatory burden.

AIM: To determine the strength of association of type 2 diabetes mellitus and periodontal disease with the oral inflammatory burden, as assessed by markers of inflammation in saliva. MATERIAL AND METHODS: Unstimulated saliva samples were collected from 192 subjects with or without type 2 diabetes. ß-glucuronidase (ßG) was measured via a fluorometric array and interlukin-1ß (IL-1ß) via enzyme-linked immunosorbent assay. The concentration of both mediators was evaluated in relationship to clinical parameters, severity of periodontal disease and diabetes status. RESULTS: Regression analysis demonstrated that diabetes and periodontal disease was independently and positively correlated with increased concentration of ßG in saliva (p < 0.001). Moreover, the relative association of periodontal disease with the level of ßG in saliva was greater than the strength of association of the diabetic status. IL-1ß concentration in saliva was primarily associated with the severity of periodontal disease (p < 0.01), but not the presence of diabetes (p = 0.50). CONCLUSIONS: This study examined the nature of the inflammatory response in the oral cavity as assessed by inflammatory markers in saliva. Both periodontal disease and diabetes mellitus were independently associated with the oral inflammatory burden, in which the effect of periodontal disease was more pronounced.

SP140 inhibits STAT1 signaling, induces IFN-γ in tumor-associated macrophages, and is a predictive biomarker of immunotherapy response.

BACKGROUND: Understanding the role and potential therapeutic targeting of tumor-associated macrophages (TAMs) is crucial to developing new biomarkers and therapeutic strategies for cancer immunotherapies. The epigenetic reader SP140 has emerged as a master regulator of macrophage transcriptional programs; however, its role in the signaling of TAMs and response to immunotherapy has not been investigated. METHODS: We evaluated the correlation between SP140 expression in head and neck squamous cell carcinoma (HNSCC) TAMs and clinical outcomes. We also used complementary bioinformatics and experimental approaches to study the association of SP140 expression with tumor mutation burden, patient survival, immunogenic signature of tumors, and signaling of TAMs. SP140 overexpression or knockdown was implemented to identify the role of SP140 in downstream signaling and production of inflammatory cytokine and chemokines. Chromatin immunoprecipitation and analysis of assay of transposase accessible chromatin sequencing data were used to demonstrate the direct binding of SP140 on the promoters of STAT1. Finally, correlation of SP140 with immune cell infiltrates and response to immune-checkpoint blockade in independent cohorts of HNSCC, metastatic melanoma, and melanoma was assessed. RESULTS: We found that SP140 is highly expressed in TAMs across many cancer types, including HNSCCs. Interestingly, higher expression of SP140 in the tumors was associated with higher tumor mutation burden, improved survival, and a favorable response to immunotherapy. Tumors with high SP140 expression showed enrichment of inflammatory response and interferon-gamma (IFN-γ) pathways in both pan-cancer analysis and HNSCC-specific analysis. Mechanistically, SP140 negatively regulates transcription and phosphorylation of STAT1 and induces IFN-γ signaling. Activating SP140 in macrophages and TAMs induced the proinflammatory macrophage phenotype, increased the antitumor activity of macrophages, and increased the production of IFN-γ and antitumor cytokines and chemokines including interleukin-12 and CXCL10. SP140 expression provided higher sensitivity and specificity to predict antiprogrammed cell death protein 1 immunotherapy response compared with programmed death-ligand 1 in HNSCCs and lung cancer. In metastatic melanoma, higher levels of SP140 were associated with a durable response to immunotherapy, higher immune score estimates, high infiltrations of CD8+ T cells, and inflammatory TAMs. CONCLUSIONS: Our findings suggest that SP140 could serve as both a therapeutic target and a biomarker to identify immunotherapy responders.

High-speed light-sheet microscopy for the in-situ acquisition of volumetric histological images of living tissue.

Histological examinations typically require the excision of tissue, followed by its fixation, slicing, staining, mounting and imaging, with timeframes ranging from minutes to days. This process may remove functional tissue, may miss abnormalities through under-sampling, prevents rapid decision-making, and increases costs. Here, we report the feasibility of microscopes based on swept confocally aligned planar excitation technology for the volumetric histological imaging of intact living tissue in real time. The systems' single-objective, light-sheet geometry and 3D imaging speeds enable roving image acquisition, which combined with 3D stitching permits the contiguous analysis of large tissue areas, as well as the dynamic assessment of tissue perfusion and function. Implemented in benchtop and miniaturized form factors, the microscopes also have high sensitivity, even for weak intrinsic fluorescence, allowing for the label-free imaging of diagnostically relevant histoarchitectural structures, as we show for pancreatic disease in living mice, for chronic kidney disease in fresh human kidney tissues, and for oral mucosa in a healthy volunteer. Miniaturized high-speed light-sheet microscopes for in-situ volumetric histological imaging may facilitate the point-of-care detection of diverse cellular-level biomarkers.

Treatment of recurrent mucosal melanoma of the oral cavity with topical imiquimod and pembrolizumab achieves complete histopathologic remission.

Mucosal melanomas constitute a subtype of melanoma with less effective treatments than cutaneous melanomas. We present a case of oral mucosal melanoma that recurred despite multiple resections and adjuvant temozolomide. Treatment with topical imiquimod combined with pembrolizumab achieved remission. A 56-year-old woman presented with a pigmented mass on her left anterior hard palate. Biopsy revealed malignant melanoma. The patient had resection with neck dissection with 3 months of adjuvant temozolomide due to positive margins. Malignant melanoma involving the hard palate recurred 1 year later requiring additional resection. Two years later, two additional pigmented lesions were found; further resections were deferred due to expected morbidity. Following 6 weeks of topical imiquimod treatment, the lesions shrunk significantly. Adjuvant pembrolizumab was added and complete histopathologic remission was observed in 6 months. The patient remained in remission for 4 years before new melanoma in situ was diagnosed, requiring five additional months of imiquimod. As of April 2021, there is no clinical evidence of melanoma. There are limited reports of oral melanoma treated with topical imiquimod. Here, imiquimod administered in combination with pembrolizumab achieved complete pathologic response.

Down-regulation of the tumor suppressor miR-34a contributes to head and neck cancer by up-regulating the MET oncogene and modulating tumor immune evasion.

BACKGROUND: MicroRNAs (miRs) have been shown to play an important role in tumorigenesis, including in head and neck squamous cell carcinoma (HNSCC). The miR-34 family is thought to play a role in tumor suppression, but the exact mechanism of their action in HNSCC is not well understood. Moreover, the impact of chromosomal changes and mutation status on miR-34a expression remains unknown. METHODS: Differential expression of miR-34a, MET, and genomic alterations were assessed in the Cancer Genome Atlas (TCGA) datasets as well as in primary HNSCC and adjacent normal tissue. The biological functions of miR-34a in HNSCC were investigated in samples derived from primary human tumors and HNSCC cell lines. The expression of MET was evaluated using immunohistochemistry, and the molecular interaction of miR-34a and MET were demonstrated by RNA pulldown, RNA immunoprecipitation, luciferase reporter assay, and rescue experiments. Lastly, locked nucleic acid (LNA) miRs in mouse xenograft models were used to evaluate the clinical relevance of miR-34a in HNSCC tumor growth and modulation of the tumor microenvironment in vivo. RESULTS: Chromosome arm 1p loss and P53 mutations are both associated with lower levels of miR-34a. In HNSCC, miR-34a acts as a tumor suppressor and physically interacts with and functionally targets the proto-oncogene MET. Our studies found that miR-34a suppresses HNSCC carcinogenesis, at least in part, by downregulating MET, consequently inhibiting HNSCC proliferation. Consistent with these findings, administration of LNA-miR-34a in an in vivo model of HNSCC leads to diminished HNSCC cell proliferation and tumor burden in vitro and in vivo, represses expression of genes involved in epithelial-mesenchymal transition, and negates the oncogenic effect of MET in mouse tumors. Consistently, LNA-miR-34a induced a decreased number of immunosuppressive PDL1-expressing tumor-associated macrophages in the tumor microenvironment. In HNSCC patient samples, higher levels of miR-34a are significantly associated with a higher frequency of Th1 cells and CD8 naïve T cells. CONCLUSIONS: Our results demonstrate that miR-34a directly targets MET and maintains anti-tumor immune activity. We propose miR-34a as a potential new therapeutic approach for HNSCC.

Alcohol Metabolism Enriches Squamous Cell Carcinoma Cancer Stem Cells That Survive Oxidative Stress via Autophagy.

BACKGROUND: Alcohol (ethanol) consumption is a major risk factor for head and neck and esophageal squamous cell carcinomas (SCCs). However, how ethanol (EtOH) affects SCC homeostasis is incompletely understood. METHODS: We utilized three-dimensional (3D) organoids and xenograft tumor transplantation models to investigate how EtOH exposure influences intratumoral SCC cell populations including putative cancer stem cells defined by high CD44 expression (CD44H cells). RESULTS: Using 3D organoids generated from SCC cell lines, patient-derived xenograft tumors, and patient biopsies, we found that EtOH is metabolized via alcohol dehydrogenases to induce oxidative stress associated with mitochondrial superoxide generation and mitochondrial depolarization, resulting in apoptosis of the majority of SCC cells within organoids. However, CD44H cells underwent autophagy to negate EtOH-induced mitochondrial dysfunction and apoptosis and were subsequently enriched in organoids and xenograft tumors when exposed to EtOH. Importantly, inhibition of autophagy increased EtOH-mediated apoptosis and reduced CD44H cell enrichment, xenograft tumor growth, and organoid formation rate. CONCLUSIONS: This study provides mechanistic insights into how EtOH may influence SCC cells and establishes autophagy as a potential therapeutic target for the treatment of EtOH-associated SCC.

MicroRNA-Based Cancer Mortality Risk Scoring System and hTERT Expression in Early-Stage Oral Squamous Cell Carcinoma.

We have previously constructed a novel microRNA (miRNA)-based prognostic model and cancer-specific mortality risk score formula to predict survival outcome in oral squamous cell carcinoma (OSCC) patients who are already categorized into "early-stage" by the TNM staging system. A total of 836 early-stage OSCC patients were assigned the mortality risk scores. We evaluated the efficacy of various treatment regimens in terms of survival benefit compared to surgery only in patients stratified into high (risk score ≥0) versus low (risk score <0) mortality risk categories. For the high-risk group, surgery with neck dissection significantly improved the 5-year survival to 75% from 46% with surgery only (p < 0.001); a Cox proportional hazard model on time-to-death demonstrated a hazard ratio of 0.37 for surgery with neck dissection (95% CI: 0.2-0.6; p=0.0005). For the low-risk group, surgery only was the treatment of choice associated with 5-year survival benefit. Regardless of treatment selected, those with risk score ≥2 may benefit from additional therapy to prevent cancer relapse. We also identified hTERT (human telomerase reverse transcriptase) as a gene target common to the prognostic miRNAs. There was 22-fold increase in the hTERT expression level in patients with risk score ≥2 compared to healthy controls (p < 0.0005). Overexpression of hTERT was also observed in the patient-derived OSCC organoid compared to that of normal organoid. The DNA cancer vaccine that targets hTERT-expressing cells currently undergoing rigorous clinical evaluation for other tumors can be repurposed to prevent cancer recurrence in these high-risk early-stage oral cancer patients.

The REASON score: an epigenetic and clinicopathologic score to predict risk of poor survival in patients with early stage oral squamous cell carcinoma.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is a capricious cancer with poor survival rates, even for early-stage patients. There is a pressing need to develop more precise risk assessment methods to appropriately tailor clinical treatment. Genome-wide association studies have not produced a viable biomarker. However, these studies are limited by using heterogeneous cohorts, not focusing on methylation although OSCC is a heavily epigenetically-regulated cancer, and not combining molecular data with clinicopathologic data for risk prediction. In this study we focused on early-stage (I/II) OSCC and created a risk score called the REASON score, which combines clinicopathologic characteristics with a 12-gene methylation signature, to predict the risk of 5-year mortality. METHODS: We combined data from an internal cohort (n = 515) and The Cancer Genome Atlas (TCGA) cohort (n = 58). We collected clinicopathologic data from both cohorts to derive the non-molecular portion of the REASON score. We then analyzed the TCGA cohort DNA methylation data to derive the molecular portion of the risk score. RESULTS: 5-year disease specific survival was 63% for the internal cohort and 86% for the TCGA cohort. The clinicopathologic features with the highest predictive ability among the two the cohorts were age, race, sex, tobacco use, alcohol use, histologic grade, stage, perineural invasion (PNI), lymphovascular invasion (LVI), and margin status. This panel of 10 non-molecular features predicted 5-year mortality risk with a concordance (c)-index = 0.67. Our molecular panel consisted of a 12-gene methylation signature (i.e., HORMAD2, MYLK, GPR133, SOX8, TRPA1, ABCA2, HGFAC, MCPH1, WDR86, CACNA1H, RNF216, CCNJL), which had the most significant differential methylation between patients who survived vs. died by 5 years. All 12 genes have already been linked to survival in other cancers. Of the genes, only SOX8 was previously associated with OSCC; our study was the first to link the remaining 11 genes to OSCC survival. The combined molecular and non-molecular panel formed the REASON score, which predicted risk of death with a c-index = 0.915. CONCLUSIONS: The REASON score is a promising biomarker to predict risk of mortality in early-stage OSCC patients. Validation of the REASON score in a larger independent cohort is warranted.

PIK3CA and p53 Mutations Promote 4NQO-Initated Head and Neck Tumor Progression and Metastasis in Mice.

The PI3K signaling pathway is frequently mutated in head and neck squamous cell carcinoma (HNSCC), often via gain-of-function (GOF) mutations in the PIK3CA gene. Here, we present novel genetically engineered mouse models (GEMM) carrying a GOF allele Loxp-STOP-Loxp(LSL)-PIK3CAH1047R (E20) alone or in combination with heterozygous LSL-p53+/R172H (p53) mutation with tissue-specific expression to interrogate the role of oncogenic PIK3CA in transformation of upper aerodigestive track epithelium. We demonstrated that the GOF PIK3CA mutation promoted progression of 4-nitroquinoline 1-oxide-induced oral squamous cell carcinoma (OSCC) in both E20 single mutant and E20/p53 double mutant mice, with frequent distal metastasis detected only in E20/p53 GEMM. Similar to in human OSCC, loss of p16 was associated with progression of OSCC in these mice. RNA-seq analyses revealed that among the common genes differentially expressed in primary OSCC cell lines derived from E20, p53, and E20/p53 GEMMs compared with those from the wild-type mice, genes associated with proliferation and cell cycle were predominantly represented, which is consistent with the progressive loss of p16 detected in these GEMMs. Importantly, all of these OSCC primary cell lines exhibited enhanced sensitivity to BYL719 and cisplatin combination treatment in comparison with cisplatin alone in vitro and in vivo, regardless of p53 and/or p16 status. Given the prevalence of mutations in p53 and the PI3K pathways in HNSCC in conjunction with loss of p16 genetically or epigenetically, this universal increased sensitivity to cisplatin and BYL719 combination therapy in cancer cells with PIK3CA mutation represents an opportunity to a subset of patients with HNSCC. IMPLICATIONS: Our results suggest that combination therapy of cisplatin and PI3K inhibitor may be worthy of consideration in patients with HNSCC with PIK3CA mutation.

MicroRNA-based risk scoring system to identify early-stage oral squamous cell carcinoma patients at high-risk for cancer-specific mortality.

BACKGROUND: For early-stage oral squamous cell carcinoma (OSCC), there is no existing risk-stratification modality beyond conventional TNM staging system to identify patients at high risk for cancer-specific mortality. METHODS: A total of 568 early-stage OSCC patients who had surgery only and also with available 5-year clinical outcomes data were identified. Signature microRNAs (miRNAs) were discovered using deep sequencing analysis and validated by qRT-PCR. The final 5-plex prognostic marker panel was utilized to generate a cancer-specific mortality risk score using the multivariate Cox regression analyses. The prognostic markers were validated in the internal and external validation cohorts. RESULTS: The risk score from the 5-plex marker panel consisting of miRNAs-127-3p, 4736, 655-3p, TNM stage and histologic grading stratified patients into four risk categories. Compared to the low-risk group, the high-risk group had 23-fold increased mortality risk (hazard ratio 23, 95% confidence interval 13-42), with a median time-to-recurrence of 6 months and time-to-death of 11 months (vs >60 months for each among low-risk patient; p < .001). CONCLUSION: The miRNA-based 5-plex marker panel driven mortality risk score formula provides clinically practical and reliable measures to assess the prognosis of patients assigned to an early-stage OSCC.