HPV‐positive oropharyngeal squamous cell carcinoma is associated with TIMP3 and CADM1 promoter hypermethylation

Abstract

Oropharyngeal squamous cell carcinoma (OPSCC) is associated with human papillomavirus (HPV) in a proportion of tumors. HPV-positive OPSCC is considered a distinct molecular entity with a prognostic advantage compared to HPV-negative cases. Silencing of cancer-related genes by DNA promoter hypermethylation may play an important role in the development of OPSCC. Hence, we examined promoter methylation status in 24 common tumor suppressor genes in a group of 200 OPSCCs to determine differentially methylated genes in HPV-positive versus HPV-negative primary OPSCC. Methylation status was correlated with HPV status, clinical features, and patient survival using multivariate methods. Additionally, methylation status of 16 cervical squamous cell carcinomas (SCC) was compared with HPV-positive OPSCC. Using methylation-specific probe amplification, HPV-positive OPSCC showed a significantly higher cumulative methylation index (CMI) compared to HPV-negative OPSCC (P=0.008). For the genes CDH13, DAPK1, and RARB, both HPV-positive and HPV-negative OPSCC showed promoter hypermethylation in at least 20% of the tumors. HPV status was found to be an independent predictor of promoter hypermethylation of CADM1 (P < 0.001), CHFR (P = 0.027), and TIMP3 (P < 0.001). CADM1 and CHFR showed similar methylation patterns in OPSCC and cervical SCC, but TIMP3 showed no methylation in cervical SCC in contrast to OPSCC. Methylation status of neither individual gene nor CMI was associated with survival. These results suggest that HPV-positive tumors are to a greater extent driven by promotor hypermethylation in these tumor suppressor genes. Especially CADM1 and TIMP3 are significantly more frequently hypermethylated in HPV-positive OPSCC and CHFR in HPV-negative tumors.

Characterization of gene methylation in human papillomavirus associated-head and neck squamous cell carcinoma

“…In addition, significantly increased methylation of TIMP3 was observed in HPV-positive tumors. These results agreed with a previous study, which also showed that higher TIMP3 methylation frequency occurs in HPV 16-positive HNSCC as compared to HPV 16-negative tumors (van Kempen et al, 2014). Several other studies proposed that HPV infection may promote hypermethylation of tumor-related genes, such as DAPK (Flatley et al, 2014), p16 (Carestiato et al, 2013), and CCNA1 (Yanatatsaneejit et al, 2011).…”

FGFR1 Is a Potential Prognostic Biomarker and Therapeutic Target in Head and Neck Squamous Cell Carcinoma

“…Nine patients were excluded because HPV status was unknown and seven were excluded because TMA cores were absent for the tumor, leaving 436 patients for the analysis of FGFR1 protein expression (Table 1). This patient cohort was described previously (22,23).…”

“…"The Code for Proper Secondary Use of Human Tissue" and "The Code of Conduct for the Use of Data in Health Research", as stated by the Federation of Dutch Medical Scientific Societies, were followed for handling patient tissue and clinical data (Human Tissue and Medical Research: Code of Conduct for responsible use, 2011, Federa FMWV). The HPV status was determined for all tumors by a combination of p16 IHC and linear array genotyping assay as described previously (23).…”

Update on Head and Neck Cancer: Current Knowledge on Epidemiology, Risk Factors, Molecular Features and Novel Therapies

“…Moreover, they demonstrated that ectopic expression of the HPV oncogenes E6 and E7 genes, in an HPV-negative head and neck cell line, partially phenocopied the hypermethylation signature observed in HPV-positive tumors. In addition, van Kempen et al [43] analyzed the role of promoter hypermethylation of 24 tumor suppressor genes in 200 oropharyngeal SCCs and showed a significantly higher cumulative methylation index in HPV-positive compared to HPV-negative tumors. They also found CADM1 and TIMP3 genes significantly more frequently hypermethylated in HPV-positive oropharyngeal SCCs and CHFR specifically hypermethylated in HPV-negative tumors.…”