p16(INK4a)/CDKN2 expression and its relationship with oral squamous cell carcinoma is our current knowledge enough?

Using formalin fixed paraffin embedded tissue to characterize the microbiota in p16-positive and p16-negative tongue squamous cell carcinoma: a pilot study

BACKGROUND

Tongue squamous cell carcinoma (TSCC) is the most common oral cavity cancer, and p16 immunohistochemistry is an exact and available tool in the prognostic and predictive characterization of squamous cell cancers in the head and neck. Microorganisms have a close relationship with the development of TSCC. However, the association between oral bacteria and p16 status has not been well defined in the case of TSCC. Compared with traditional clinical microbial collection methods, formalin-fixed paraffin-embedded (FFPE) tissue samples have several advantages.

METHODS

To compare the microbiota compositions between p16-positive and p16-negative patients with TSCC, we performed a small pilot study of microbiological studies of TSCC by paraffin tissue. DNA from FFPE tissue blocks were extracted and microbiomes were profiled by sequencing the 16 S-rRNA-encoding gene (V1-V2/V3-V4/V4 regions). Alterations in the functional potential of the microbiome were predicted using PICRUSt, Tax4Fun, and BugBase.

RESULTS

A total of 60 patients with TSCC were enrolled in the study, however, some challenges associated with DNA damage in FFPE tissues existed, and only 27 (15 p16-positive and 12 p16-negative) passed DNA quality control. Nevertheless, we have tentatively found some meaningful results. The p16 status is associated with microbiota diversity, which is significantly increased in p16-positive patients compared with p16-negative patients. Desulfobacteria, Limnochordia, Phycisphaerae, Anaerolineae, Saccharimonadia and Kapabacteria had higher abundances among participants with p16-positive. Moreover, functional prediction revealed that the increase of these bacteria may enhance viral carcinogenesis in p16-positive TSCC.

CONCLUSIONS

Bacterial profiles showed a significant difference between p16-positive TSCC and p16-negative TSCC. These findings may provide insights into the relationship between p16 status and the microbial taxa in TSCC, and these bacteria may provide new clues for developing therapeutic targets for TSCC.

Predictive value of CDKN2A/p16INK4a expression in the malignant transformation of oral potentially malignant disorders: Systematic review and meta-analysis

BACKGROUND

Management of oral potentially malignant disorders (OPMDs) is still challenging. Despite the diagnostic ascertainment by bioptic examination, this method is poorly informative of the prognosis and subsequent malignant transformation. Prognosis is based on histological findings by grading of dysplasia. Immunohistochemical expression of p16INK4a has been investigated in different studies, with controversial results. In this scenario, we systematically revised the current evidence about p16INK4a immunohistochemical expression and the risk of malignization of OPMDs.

MATERIAL AND METHODS

After a proper set of keywords combination, 5 databases were accessed and screened to select eligible studies. The protocol was previously registered on PROSPERO (Protocol ID: CRD42022355931). Data were obtained directly from the primary studies as a measure to determine the relationship between CDKN2A/P16INK4a expression and the malignant transformation of OPMDs. Heterogeneity and publication bias were investigated by different tools, such as Cochran's Q test, Galbraith plot and Egger and Begg Mazumdar's rank tests.

RESULTS

Meta-analysis revealed a twofold increased risk to malignant development (RR = 2.01, 95% CI = 1.36-2.96 - I2 = 0%). Subgroup analysis did not highlight any relevant heterogeneity. Galbraith plot showed that no individual study could be considered as an important outlier.

CONCLUSION

Pooled analysis showed that p16INK4a assessment may arise adjunct tool to dysplasia grading, leading to an optimized determination of the potential progression to cancer of OPMDs. The p16INK4a overexpression analysis by immunohistochemistry techniques has a multitude of virtues that may facilitate its incorporation in the day-to-day prognostic study of OPMDs.

HPVTIMER: A shiny web application for tumor immune estimation in human papillomavirus-associated cancers

The tumor immune microenvironment (TIME) is closely associated with tumor formation, particularly linked to the human papillomavirus (HPV), and regulates tumor initiation, proliferation, infiltration, and metastasis. With the rise of immunotherapy, an increasing amount of sample data used for TIME exploration is available in databases. However, no currently available web tool enables a comprehensive exploration of the TIME of HPV-associated cancers by leveraging these data. We have developed a web tool called HPV-associated Tumor Immune MicroEnvironment ExploreR (HPVTIMER), which provides a comprehensive analysis platform that integrates over 10,000 genes and 2290 tumor samples from 65 transcriptome data sets across 8 cancer types sourced from the Gene Expression Omnibus (GEO) database. The tool features four built-in analysis modules, namely, the differential expression analysis module, correlation analysis module, immune infiltration analysis module, and pathway analysis module. These modules enable users to perform systematic and vertical analyses. We used several analytical modules in HPVTIMER to briefly explore the role of CDKN2A in head and neck squamous cell carcinomas. We expect that HPVTIMER will help users explore the immune microenvironment of HPV-associated cancers and uncover potential immune regulatory mechanisms and immunotherapeutic targets. HPVTIMER is available at http://www.hpvtimer.com/.

A novel EZH2/NXPH4/CDKN2A axis is involved in regulating the proliferation and migration of non-small cell lung cancer cells

NXPH4 is discovered to be a neuropeptide-like glycoprotein, belonging to the Neurexophilins (Nxphs) family. NXPH4 shares a similar domain structure with NXPH1, which, however, is poorly understood in terms of its function. Bioinformatics analysis and experimental verification in this study confirmed the abnormal high expression of NXPH4 in non-small cell lung cancer (NSCLC) tissues and cells. Knockdown of NXPH4 by siRNA can inhibit the proliferation and migration of cells, resulting in significant cell cycle arrest in S1 phase. Furthermore, in NSCLC cells, NXPH4 was regulated by transcriptional activation of Enhancer of zeste homolog 2 (EZH2) in its upstream. While downstream, NXPH4 could interact with CDKN2A and downregulate its protein stability, thus participating in the cell cycle regulation through interacting with cyclinD-CDK4/6-pRB-E2F signaling pathway. To sum up, the present study reveals a regulatory pathway of EZH2/NXPH4/CDKN2A in NSCLC, providing possible reference for understanding the function of NXPH4 in tumors.

Molecular Pathways and Druggable Targets in Head and Neck Squamous Cell Carcinoma

Head and neck cancers are a heterogeneous group of neoplasms, affecting an ever increasing global population. Despite advances in diagnostic technology and surgical approaches to manage these conditions, survival rates have only marginally improved and this has occurred mainly in developed countries. Some improvements in survival, however, have been a result of new management and treatment approaches made possible because of our ever-increasing understanding of the molecular pathways triggered in head and neck oncogenesis, and the growing understanding of the abundant heterogeneity of this group of cancers. Some important pathways are common to other solid tumours, but their impact on reducing the burden of head and neck disease has been less than impressive. Other less known and little-explored pathways may hold the key to the development of potential druggable targets. The extensive work carried out over the last decade, mostly utilising next generation sequencing has opened up the development of many novel approaches to head and neck cancer treatment. This paper explores our current understanding of the molecular pathways of this group of tumours and outlines associated druggable targets which are deployed as therapeutic approaches in head and neck oncology with the ultimate aim of improving patient outcomes and controlling the personal and economic burden of head and neck cancer.

Feasibility of p16 surrogate biomarker as adjunct diagnosis of oral and oropharyngeal malignancy in a resource-constrained country

BACKGROUND

Cases of Human papillomavirus (HPV)-associated oral and oropharyngeal cancer are increasing. Proper diagnostic tools are required to detect HPV among patients, especially in areas where high technology is lacking.

AIMS

To provide mapping of HPV prevalence in Southeast Asia and to determine the effectivity of p16 as a surrogate biomarker for HPV infection in oral and oropharyngeal cancer.

METHODS

Medical records of 56 patients diagnosed with oral and oropharyngeal squamous cell carcinomas (SCC) were reviewed. HPV PCR DNA and p16 immunohistochemistry (IHC) examination were performed to detect HPV positivity.

RESULTS

HPV PCR prevalence in oropharyngeal SCC is 42.9% and 28.6% in oral SCC. P16 IHC has 67% sensitivity and 75% specificity in detecting HPV in oropharyngeal cancer, and 33% and 72% in oral cancer.

CONCLUSION

We conclude that p16 IHC with a 5% cut-off can be used as a surrogate biomarker for oropharyngeal SCC, but not oral SCC, in areas where resources are restricted. However, further diagnostic tools may be needed.

Trop2 inhibition of P16 expression and the cell cycle promotes intracellular calcium release in OSCC

Trop2 is an intracellular calcium signal transducer and a prognostic biomarker in many cancers. P16 is a cell cycle gene that negatively regulates cell proliferation and division in most human cancers. Oral squamous cell carcinoma (OSCC) is a common malignant tumor subgroup of head and neck squamous cell carcinoma worldwide. Both Ca²⁺-dependent and cell cycle signaling pathways play vital roles in OSCC, although the molecular mechanisms remain to be elucidated. We aimed to examine the function of Trop2 and P16 in regulating intracellular calcium ions and the cell cycle in OSCC cell lines. Furtherly, the mRNA and protein expression levels of Trop2 and P16 in OSCC tissue samples were assessed, and their function was evaluated as potential clinical prognostic biomarkers. Trop2 promoted intracellular calcium ion release in OSCC and induced S phase of the cell cycle. Moreover, Trop2-mediated Ca²⁺ inhibited P16 expression through the AMP-activated protein kinase pathway in OSCC. Interestingly, P16 overexpression could not reverse these phenomena in vitro. We also demonstrated that human OSCC tissues showed high Trop2 mRNA and protein expression, and Trop2+/P16- expression is an independent prognostic marker for OSCC patients. Our data suggest that Trop2+/P16- may be a valuable prognostic marker for OSCC and that Trop2 inhibits P16 expression and induces S phase by promoting intracellular calcium release in OSCC.

Integrative analysis of gene alterations and immunoexpression profiles of cell cycle checkpoints in oral squamous cell carcinoma

BACKGROUND

Oral squamous cell carcinoma (OSCC) represents 95% of all cancers of the head and neck region. The five-year survival rate of OSCC patients is about 60% and has not gone throw significant improvements despite recent advances in molecular biology, or the identification of key pathways in its pathophysiology such as cell cycle.

OBJECTIVE

1) to analyse the inmunoexpression of cell cycle checkpoints (CPs) in an OSCC institutional cohort and to relate it to clinicopathological features and survival, and 2) to study CPs-related genes in the OSCC subset of the TCGA database.

METHODS

Immunohistochemistry (IHC) for p16INK4a, p21CIP1, cyclin D1 and p27KIP1 protein expression was quantified by tissue microarray analysis in 68 samples from OSCC patients. In order to analyse its correlation with genetic information, a cohort belonging to The Cancer Genome Atlas (TCGA) database was analysed.

RESULTS

Of 68 patients, 34 (50%) developed recurrence, and 36 (52.09%) died as a result of disease progression (mean survival 34.09 months). IHC staining for nuclear cyclin D1 was associated with worse staging and tobacco use. p16INK4a, p21CIP1, cyclin D1, and p27KIP1 expression was unrelated to overall survival. No statistically significant correlation linked the CPs-related genes mutations to OSCC overall survival in the TCGA database.

CONCLUSIONS

CPs variations at a phenotype and genotype level seem not to affect significantly clinicopathological features and survival in the studied OSCC cohorts.

Progress in targeted therapeutic drugs for oral squamous cell carcinoma

With the rapid development of biomedicine, people have a deeper understanding with the biological characteristics of malignant tumors, and begin to notice that in most tumors, there are over-expression of several molecules such as epidermal growth factor receptor(EGFR), vascular endothelial growth factor (VEGF) and its receptors,mammalian target of rapamycin(mTOR),programmed cell death receptor-1(PD-1),cyclin-dependent kinases(CDKs) and so on, whose levels are closely related to the prognosis of tumors. It has been found that the drugs targeting the above molecules can significantly improve the survival rate of cancer patients, and have the advantages of high selectivity, low toxicity and high therapeutic index. Targeted drugs, as new ones in the field of cancer, have achieved good efficacy in most tumor treatments. Oral cancer is an aggressive malignant tumour that is prone to relapse and metastasis. More than 90% of them are squamous cell carcinoma, and the 5-year survival rate remains at about 50%-60%.The proposing of targeted therapy opens up a new way for the treatment of oral cancer and brings dawn to patients with advanced diseases. Currently,a variety of targeted therapeutic drugs are being tested in various clinical trials in patients with oral squamous cell carcinoma(OSCC)·In this paper, we discuss the research progress of targeted therapeutic drugs in the treatment of OSCC in recent years.

Rnf2 knockdown reduces cell viability and promotes cell cycle arrest in gastric cancer cells

Rnf2 is a fundamental component of the polycomb repressive complex 1and acts as the really interesting new gene finger E3 ligase, which is responsible for histone 2A modification. Previous studies have shown that the ring finger protein 2 (Rnf2) is overexpressed in various types of tumor and has a close association with tumor development. However, few studies have been carried out into the expression and biological function of Rnf2 in gastric cancer cells. The present study measured the expression of Rnf2 in gastric cancer cells and normal epithelial gastric cells. The results demonstrate that Rnf2 is upregulated in gastric cancer cells. In addition, the knockdown of Rnf2 inhibited the cell viability and induced increased G1 phase followed by a substantial reduction of the G2/M phase. The expression levels of p21 and p27 were also significantly elevated by the knockdown of Rnf2. These results provide evidence of the oncogenic function of Rnf2 in gastric cancer, possibly through an inhibition of cellular proliferation and a delay of the G2/M phase. Therefore, Rnf2 may be a novel target for the prognosis and therapy of gastric cancer.

p27Kip1 expression as a prognostic marker for squamous cell carcinoma of the head and neck

Regulation of the cell cycle is essential for carcinogenesis. The cell cycle is controlled by cyclin-dependent kinases (CDKs), which are upregulated by cyclins and downregulated by CDK inhibitors (CDKIs). Decreased p27^Kip1 expression has been associated with survival rate, tumor size, histological differentiation and the presence of lymph node metastasis in patients with various types of cancer. The aim of the current study is to provide a literature review on the association between p27^Kip1 expression and the clinical and pathological aspects of head and neck squamous cell carcinoma (HNSCC), and the expression of other CDKIs of the Cip/Kip family and cyclins. Throughout the literature, different methodologies were used to determine the immunohistochemical expression of p27^Kip1; thus, results concerning p27^Kip1 expression in HNSCC vary widely. However, it has now been confirmed that p27^Kip1 is underexpressed in SCC cells. p27 may be a promising marker for determining the prognosis of HNSCC, despite the marked variability of the results obtained. An association between p27 expression and survival rate, time to recurrence and tumor stage has been observed. Based on the information currently available, it is premature to recommend the analysis of p27^Kip1 expression in guiding HNSCC treatment planning. However, although relatively unstudied, the correlation between p27^Kip1 expression and other tumor suppressor genes may turn out to be important in determining the prognosis of HNSCC. Further prospective studies utilizing standardized laboratory methodologies and statistics that facilitate meta-analyses are required to confirm this proposal.

Unraveling the molecular genetics of head and neck cancer through genome-wide approaches

The past decade has seen an unprecedented increase in our understanding of the biology and etiology of head and neck squamous cell carcinomas (HNSCC). Genome-wide sequencing projects have identified a number of recurrently mutated genes, including unexpected alterations in the NOTCH pathway and chromatin related genes. Gene-expression profiling has identified 4 distinct genetic subtypes which show some parallels to lung squamous cell carcinoma biology. The identification of the human papilloma virus as one causative agent in a subset of oropharyngeal cancers and their association with a favorable prognosis has opened up avenues for new therapeutic strategies. The expanding knowledge of the underlying molecular abnormalities in this once very poorly understood cancer should allow for increasingly rational clinical trial design and improved patient outcomes.

Advances in the management of squamous cell carcinoma of the head and neck

Squamous cell carcinoma of the head and neck (SCCHN) is the sixth most common cancer worldwide. The main risk factors for cancers of the oral cavity, larynx, oropharynx, and hypopharynx are alcohol and tobacco use. In addition, the human papillomavirus (HPV) is an established cause of oropharyngeal cancer. An experienced multidisciplinary team is necessary for adequate management and optimal outcome. The treatment of locally advanced disease generally requires various combinations of radiotherapy, surgery, and systemic therapy, but despite this aggressive multimodal treatment, 40% to 60% of the patients will relapse. In this report, we will discuss recent advances in the management of SCCHN, including new developments in molecular biology, imaging, and treatment.

Promoter region hypermethylation and mRNA expression of MGMT and p16 genes in tissue and blood samples of human premalignant oral lesions and oral squamous cell carcinoma

Promoter methylation and relative gene expression of O(6)-methyguanine-DNA-methyltransferase (MGMT) and p16 genes were examined in tissue and blood samples of patients with premalignant oral lesions (PMOLs) and oral squamous cell carcinoma (OSCC). Methylation-specific PCR and reverse transcriptase PCR were performed in 146 tissue and blood samples from controls and patients with PMOLs and OSCC. In PMOL group, significant promoter methylation of MGMT and p16 genes was observed in 59% (P = 0.0010) and 57% (P = 0.0016) of tissue samples, respectively, and 39% (P = 0.0135) and 33% (P = 0.0074) of blood samples, respectively. Promoter methylation of both genes was more frequent in patients with OSCC, that is, 76% (P = 0.0001) and 82% (P = 0.0001) in tissue and 57% (P = 0.0002) and 70% (P = 0.0001) in blood, respectively. Significant downregulation of MGMT and p16 mRNA expression was observed in both tissue and blood samples from patients with PMOLs and OSCC. Hypermethylation-induced transcriptional silencing of MGMT and p16 genes in both precancer and cancer suggests important role of these changes in progression of premalignant state to malignancy. Results support use of blood as potential surrogate to tissue samples for screening or diagnosing PMOLs and early OSCC.

The mutational spectrum of squamous-cell carcinoma of the head and neck: targetable genetic events and clinical impact

Squamous-cell cancer of the head and neck (SCCHN) represents a heterogeneous disease entity, with various etiological factors implicated in the genesis of distinct molecular subsets of tumors, which exhibit different biological and clinical behavior. Treatment of SCCHN is expected to change in the next decade as targeted therapies continue to make strides. Recently, next-generation sequencing studies conducted on ∼190 SCCHN specimens shed light into the molecular pathogenesis of the disease. These studies discovered mutations in genes involved in the differentiation program of squamous epithelium and the Notch/p63 axis (such as NOTCH1, TP63 and FBXW7), and validated genetic alterations derived from previous studies (such as mutations in TP53, CDKN2A, PIK3CA, CCND1 and HRAS) as driver genetic events in SCCHN neoplastic transformation. More recently, comprehensive data from The Cancer Genome Atlas (TCGA) project on 306 SCCHN specimens provided further insight into SCCHN inherent molecular complexity, identifying novel significantly mutated genes, including FAT1, MLL2, TGFRBR2, HLA-A, NFE2l2 and CASP8. In this article, we provide an overview of the mutational spectrum of SCCHN, with emphasis on the clinical implementation of this knowledge. We also discuss the potential integration of new data within the framework of precision cancer medicine.

p16INK4A and p14ARF gene promoter hypermethylation as prognostic biomarker in oral and oropharyngeal squamous cell carcinoma: a review

Head and neck squamous cell carcinoma is a heterogeneous group of tumors with each subtype having a distinct histopathological and molecular profile. Most tumors share, to some extent, the same multistep carcinogenic pathways, which include a wide variety of genetic and epigenetic changes. Epigenetic alterations represent all changes in gene expression patterns that do not alter the actual DNA sequence. Recently, it has become clear that silencing of cancer related genes is not exclusively a result of genetic changes such as mutations or deletions, but it can also be regulated on epigenetic level, mostly by means of gene promoter hypermethylation. Results from recent studies have demonstrated that DNA methylation patterns contain tumor-type-specific signatures, which could serve as biomarkers for clinical outcome in the near future. The topic of this review discusses gene promoter hypermethylation in oral and oropharyngeal squamous cell carcinoma (OSCC). The main objective is to analyse the available data on gene promoter hypermethylation of the cell cycle regulatory proteins p16^INK4A and p14^ARF and to investigate their clinical significance as novel biomarkers in OSCC. Hypermethylation of both genes seems to possess predictive properties for several clinicopathological outcomes. We conclude that the methylation status of p16^INK4A is definitely a promising candidate biomarker for predicting clinical outcome of OSCC, especially for recurrence-free survival.

TP53 and CDKN2a mutations in never-smoker oral tongue squamous cell carcinoma

OBJECTIVES/HYPOTHESIS

To determine the incidence and clinical significance of TP53 and CDKN2a somatic mutations in never smokers with oral tongue squamous cell carcinoma (OTSCC).

STUDY DESIGN

Case series.

METHODS

Fifty-one paraffin-embedded tumors from never smokers with OTSCC were obtained. p53 and p16 expression was determined by immunohistochemical (IHC) staining. Tumor DNA was amplified by polymerase chain reaction, and direct sequencing and mutation analysis was performed. Statistical relationships among p53 and p16 IHC findings, TP53 and CDKN2a mutation status, and clinicopathologic characteristics were determined. Univariate and multivariate Cox models for survival were performed.

RESULTS

Sixteen tumors (31.4%) showed strong expression of p53 by IHC. There was no correlation between p53 status and clinicopathologic variables or survival outcomes. TP53 mutations were seen in 10 tumors (19.6%). Patients with TP53 mutations had higher tumor-node-metastasis (TNM) stage (P=0.049), worse tumor differentiation (P=0.025), earlier recurrence (P=0.024), and more often died from their disease (P=0.043) than those without mutations. Five tumors (9.8%) showed p16 positivity by IHC. There was no correlation between p16 status and clinicopathologic variables or survival. CDKN2a mutations were seen in four tumors (7.8%). Patients with CDKN2a mutations had earlier recurrence (P=0.019) and more often died from their disease (P=0.010) than those without mutations. Kaplan-Meier curves show worse disease-free survival (P=0.0162, P=0.0025) and overall survival (P=0.0095, P=0.0001) for TP53 and CDKN2a mutations, respectively. Multivariate analysis demonstrated that TP53 and CDKN2a mutations were independent predictors of disease-free survival (P=0.038 and P=0.039, respectively).

CONCLUSIONS

TP53 and CDKN2a mutations in never-smoker OTSCC are associated with worse clinicopathologic characteristics and poorer survival outcomes.

LEVEL OF EVIDENCE

N/A.

Immunohistochemical Detection of p16(INK4a) in Leukoplakia and Oral Squamous Cell Carcinoma

INTRODUCTION

Over-expression of p16(INK4a) has been reported in tissues of oral squamous cell carcinoma (SCC) associated with Human Papillomaviruses (HPVs). Immunohistochemical (IHC) detection of p16(INK4a) is an easy technique than molecular detection of HPVs, hence we investigated the presence of this protein in the most common pre-malignant and malignant oral lesions i.e. leukoplakia and SCC respectively.

MATERIAL AND METHODS

We performed IHC detection of p16(INK4a) in sections of paraffin embedded formalin fixed tissues of leukoplakia with or without dysplasia (n= 21) and SCC lesions (n= 69) and correlated with various patterns of p16(INK4a) positivity with respect to histological diagnosis.

RESULTS

In the present study, 71% cases of oral SCC cases were positive for p16(INK4a), of which the most common pattern was diffuse nuclear and cytoplasmic staining. Among the cases with leukoplakia, 57.1% were positive for overexpression of p16(INK4a), wherein diffuse and sporadic pattern was observed among 23.8 percent each.

CONCLUSION

In the present study, significant number of oral SCC cases observed overexpressing p16(INK4a) . However HPV DNA detection based studies are needed to validate the utility of IHC detection of p16(INK4a) as a surrogate marker for HPV associated oral SCC.

Immunohistochemical expression of p16 in Carcinoma Ex-pleomorphic Adenoma (undifferentiated and Adenocarcinoma Types)

OBJECTIVE

This study was aimed at characterizing alterations in the immunohistochemical expression of p16 in carcinoma ex-pleomorphic adenomas.

STUDY DESIGN

A selected series of 27 cases of carcinoma ex-pleomorphic adenomas were examined.

RESULTS

The results showed that p16 expression in non tumour duct cells was strongly positive nuclear staining in 23 (85%) cases out of 27 cases, that 3 (11.1%) had moderate staining, and that 1 (3.7%) had weak staining. p16 expression in carcinoma ex-pleomorphic adenomas was indicated as a negative nuclear staining in 22 (81.4%) cases out of 27cases, and 5 (18.5%) cases expressed moderate staining.

CONCLUSION

This study suggests that alteration of p16 expression is detected in carcinoma ex-pleomorphic adenomas. p16 has a role in development of carcinoma ex-pleomorphic adenomas.

Genetic alterations in head and neck squamous cell carcinoma: The next-gen sequencing era

Head and neck squamous cell carcinoma is the sixth most common cancer in the world with approximately 650000 new cases diagnosed annually. Next-generation molecular techniques and results from phase 2 of the Cancer Genome Atlas becoming available have drastically improved our current knowledge on the genetics basis of head and neck squamous cell carcinoma. New insights and new perspectives on the mutational landscape implicated in head and neck squamous cell carcinoma provide improved tools for prognostication. More importantly, depend on the patient’s tumor subtypes and prognosis, deescalated or more aggressive therapy maybe chosen to achieve greater potency while minimizing the toxicity of therapy. This paper aims to review our current knowledge on the genetic mutations and altered molecular pathways in head and neck squamous cell carcinoma. Some of the most common mutations in head and neck squamous cell carcinoma reported by the cancer genome atlas including TP53, NOTCH1, Rb, CDKN2A, Ras, PIK3CA and EGFR are described here. Additionally, the emerging role of epigenetics and the role of human papilloma virus in head and neck squamous cell carcinoma are also discussed in this review. The molecular pathways, clinical applications, actionable molecular targets and potential therapeutic strategies are highlighted and discussed in details.

Interleukin-32 expression is associated with a poorer prognosis in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) represent the sixth most common malignancy diagnosed worldwide. Patient's survival is low due the high frequency of tumor recurrence. Inflammation promotes carcinogenesis as well as the formation of metastasis. Indeed, proinflammatory mediators are known to stimulate the expression of specific transcription factors such as Snai1 and to increase the ability of tumor cells to migrate into distant organs. The atypical interleukin-32 (IL32) was mainly described to exacerbate inflammatory responses in rheumatoid arthritis and inflammatory bowel diseases. IL32 is expressed in various cancers but its role in HNSCC physiology is still unexplored. Here, we analyzed the expression of IL32 and its implication on HNSCC aggressiveness. We showed that patients with tumor expressing high amounts of IL32 exhibit decreased disease-free periods (20.5 mo vs. 41 mo, P = 0.0041) and overall survival (P = 0.0359) in comparison with individuals with weak IL32 tumor expression. This overexpression was negatively correlated with gender (P = 0.0292) and p53 expression (P = 0.0307). In addition, in vitro data linked IL32 expression to metastasis formation since IL32 inhibition decreased Snai1 expression and tumor cell migration in a Boyden chamber assay. Our data provide new insight into the role of IL32 in HNSCC aggressiveness.

Validation of methods for oropharyngeal cancer HPV status determination in US cooperative group trials

Tumor human papillomavirus (HPV) status is a prognostic factor for oropharyngeal cancer, but classification methods are not standardized. Here we validate the HPV classification methods used in US cooperative group trials. Tumor DNA and RNA purified from 240 paraffin-embedded oropharyngeal cancers diagnosed from 2000 to 2009 were scored as evaluable if positive for DNA and mRNA controls by quantitative polymerase chain reaction (PCR). Eighteen high-risk (HR) HPV types were detected in tumors by consensus PCR, followed by HR-HPV E6/7 oncogene expression analysis by quantitative reverse transcriptase PCR. The sensitivity (S), specificity (SP), and positive (PPV) and negative predictive values (NPV) of p16 expression detected by immunohistochemistry (IHC) and HPV16 detected by in situ hybridization (ISH) were evaluated in comparison with HR-HPV E6/7 oncogene expression. Interrater agreement among 3 pathologists was evaluated by κ statistics. Of 235 evaluable tumors, 158 (67%; 95% confidence interval, 61.2-73.3) were positive for HR-HPV E6/7 oncogene expression [HPV type 16 (92%), 18 (3%), 33 (3%), 35 (1%), or 58 (1%)]. p16 IHC had high sensitivity (S 96.8%, SP 83.8%, PPV 92.7%, and NPV 92.5%), whereas HPV16 ISH had high specificity (S 88.0%, SP 94.7%, PPV 97.2%, and NPV 78.9%) for HR-HPV oncogene expression. Interrater agreement was excellent for p16 (κ=0.95 to 0.98) and HPV16 ISH (κ=0.83 to 0.91). Receiver operating curve analysis determined the cross-product of p16 intensity score and percentage of tumor staining to optimally discriminate HR-HPV E6/7-positive and HR-HPV E6/7-negative tumors. p16 IHC and HPV16 ISH assays show excellent performance, with high sensitivity and specificity, respectively. A new validated H-score for p16 IHC assessment is proposed. Appropriate assay choice depends on clinical implications of a false-positive or false-negative test.

Lessons learned from next-generation sequencing in head and neck cancer

Scientific innovation has enabled whole exome capture and massively parallel sequencing of cancer genomes. In head and neck cancer, next-generation sequencing has granted us further understanding of the mutational spectrum of squamous cell carcinoma. As a result of these new technologies, frequently occurring mutations were identified in NOTCH1, a gene that had not previously been implicated in head and neck cancer. The current review describes the most common mutations in head and neck cancer: TP53, NOTCH1, HRAS, PIK3CA, and CDKN2A. Emphasis is placed on the involved cellular pathways, clinical correlations, and potential therapeutic interventions. Additionally, the implications of human papillomavirus on mutation patterns are discussed.

The molecular pathogenesis of head and neck squamous cell carcinoma

Squamous cell carcinoma of the head and neck (HNSCC) is a relatively common human cancer characterized by high morbidity, high mortality, and few therapeutic options outside of surgery, standard cytotoxic chemotherapy, and radiation. Although the most important risk factors are tobacco use and alcohol consumption, the disease is also linked to infection with high-risk types of human papilloma viruses (HPVs). Recent genetic analyses have yielded new insights into the molecular pathogenesis of this disease. Overall, while somatic activating mutations within classical oncogenes including PIK3CA and RAS occur in HNSCC, they are relatively uncommon. Instead genetic data point to a contribution of multiple tumor suppressor pathways, including p53, Rb/INK4/ARF, and Notch, in tumor initiation, progression, and maintenance. The increasingly refined knowledge of HNSCC genetics, combined with ever-more-sophisticated animal models and newer drug targeting strategies, should promote novel therapeutic approaches and improved disease outcomes.