The role of protein p16INK4a in non-oropharyngeal head and neck squamous cell carcinoma in Southern China

Evaluation of p16 expression in oral and oropharyngeal squamous cell carcinoma

Introduction

Oral and oropharyngeal cancers together are the 6th most common cancers in the world and more than 90% are squamous cell carcinomas (OSCC, OPSCC). HPV is an important risk factor. p16 expression apart from indirectly assessing HPV infection, is an independent favorable prognostic marker. Lewis/Modified Lewis criteria of p16 grading identifies a subset of patients with improved overall survival.

Aims

(1) To evaluate p16 expression in these cancers. (2) To correlate p16 expression with age, gender, sub-site, histological type and grade. (3) To utilize the Lewis/modified Lewis criteria.

Methodology

The study included 70 cases of OSSC's and OPSCC's. Histological features were analyzed. p16 expression was determined and graded. Results were analyzed and evaluated using Chi-square test (value of P < 0.05 was taken significant).

Results

p16 positivity was seen in 46/70 (66%) cases (44 OSCC & 26 OPSCC). It was more frequent in younger patients and significantly higher in males. There was no correlation between degree of differentiation and p16 expression. In OSCC, 72.7% were p16 positive, mostly from tongue, buccal mucosa, and hard palate. p16 positivity was seen in 53.8% of OPSCCs, mostly from base of tongue and tonsil. Also, 30.4% of all cases could be included in Lewis criteria and 39.1% in modified Lewis criteria.

Conclusion

p16 is an inexpensive, easily available marker, it may be incorporated routinely in all histologically diagnosed cases of OSCC and OPSCC.

Clinicopathological Significance of FOXO4 Expression and Correlation with Prx1 in Head and Neck Squamous Cell Carcinoma

OBJECTIVE

Forkhead box O 4 (FOXO4), a key albumen in the forkhead box O (FOXOs) family, plays crucial roles as a tumor suppressor in the cancer development. In our previous study, Peroxiredoxin1 (Prx1) promoted the development of oral cancer and was predicted to bind to FOXO4. The aim of this study was to investigate the clinicopathological significance of FOXO4 expression and its potential mechanism in head and neck squamous cell carcinomas (HNSCC).

METHODS

The function of FOXO4 correlation with HNSCC prognosis was analyzed via ONCOMINE, UALCAN, Human Protein Atlas, and cBioPortal. The expression of FOXO4 was detected in Prx1 silenced CaL27 and SCC9 cell lines by Western blot. FOXO4 protein expression was observed via immunohistochemistry (IHC) and the binding of Prx1 to FOXO4 measured by Duolink analysis in a 4-nitro-quinoline-1-oxide- (4NQO-) induced tongue carcinogenesis model in Prx1+/+ and Prx1+/- mice.

RESULTS

By the analysis of Bioinformation Databases, there was a significant interaction of FOXO4 down expression to clinical tumor stages and pathological grades in the patients with HNSCC. Reduced mRNA and protein expression of FOXO4 were found to be significantly correlated with the poor overall survival (OS) of HNSCC patients. FOXO4 expression is negatively related to Prx1 significantly in HNSCC tissues. By employing a 4NQO-induced oral carcinogenesis mouse model, we confirmed that FOXO4 expression was reduced in 4NQO-induced squamous cell carcinoma (SCC) tongue tissues compared with those in normal tissues. Prx1 knockdown resulted in the upregulation of FOXO4 expression in the SCC tissues and CaL27 and SCC9 cell lines. Furthermore, the interaction of Prx1 with FOXO4 was observed in mouse tongue tissues by Duolink analysis.

CONCLUSION

FOXO4 plays an important role in the development of HNSCC. The lower expression of FOXO4 is significantly correlated with the shorter OS in patients with HNSCC. FOXO4 is negatively regulated via interaction with Prx1. FOXO4 could be a potential molecular target for the treatment and prognosis of HNSCC.

Clinical efficacy of an antibody-based detection system for human papilloma virus infection in oral squamous cell carcinoma

OBJECTIVES

There is an increasing number of oral squamous cell carcinoma (OSCC) associated with HPV-16. However, p16 expression by immunohistochemistry as the current gold standard for a surrogate marker for virus infection reveals unsatisfying diagnostic accuracy. The aim of this study was to investigate a new rapid test for L1 antibody detection (Prevocheck®) and to validate its diagnostic performance.

MATERIALS AND METHODS

In a prospective study, the HPV 16 association of all consecutive patients with an OSCC treated between 2015 and 2019 were analyzed by L1 seropositivity (via PrevoCheck®), p16 immunostaining, and partly multiplex PCR for subtype analysis.

RESULTS

Overall (n = 107), p16 expression was positive in 17 cases (15.9%), and L1 antibody seropositivity in 7 cases (6.5%). In PCR analysis, two cases of HPV35 and 50 were found. Total HPV prevalence was 8.4% overall and 6.5% for HPV-16. An inferior diagnostic accuracy for HPV-16-associated OSCC in comparison to PrevoCheck® was revealed.

CONCLUSION

The rapid test for L1 antibodies showed an optimal sensitivity and specificity, positive and negative predictive value, and an overall diagnostic accuracy of 100%. However, HPV prevalence seems low in OSCC.

CLINICAL RELEVANCE

L1 rapid test may represent an additional diagnostic staging method to detect HPV-16 association rather than p16 immunohistochemistry.