Frequent promoter hypermethylation of tumor-related genes in head and neck squamous cell carcinoma

• Published in: Oncology reports Vol. 22; no. 6; pp. 1519 - 1526
• Main Authors: STEINMANN, Katrin, SANDNER, Annett, SCHAGDARSURENGIN, Undraga, DAMMANN, Reinhard H
• Format: Journal Article
• Language: English
• Published: Athens Spandidos 01-12-2009
• Subjects: Adult; Aged; Biological and medical sciences; Carcinoma, Squamous Cell - genetics; Carcinoma, Squamous Cell - metabolism; Cell Line, Tumor; DNA Methylation; Epigenesis, Genetic; Female; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Gene Silencing; Head and Neck Neoplasms - genetics; Head and Neck Neoplasms - metabolism; Humans; Male; Medical sciences; Middle Aged; Otorhinolaryngology (head neck, general aspects and miscellaneous); Otorhinolaryngology. Stomatology; Promoter Regions, Genetic; Tumors; Transcription promoter; Biological marker; Malignant tumor; biomarker; Cancerology; DNA; Epigenetics; DNA methylation; ENT disease; Head and neck cancer; Head and neck squamous cell carcinoma; Frequency; Genetics; Methylation; Tumor promoter; Cancer; Tumor suppressor gene
• ISSN: 1021-335X; 1791-2431
• DOI: 10.3892/or_00000596

Squamous cell carcinomas of head and neck (HNSCC) are a result of multiple genetic and epigenetic alterations. Epigenetic inactivation of tumor suppressor genes is an important event in head and neck carcinogenesis. Here we analyzed the promoter methylation of 15 genes (RASSF1A, p16, MGMT, DAPK, RARbeta, MLH1, CDH1, GSTP1, RASSF2, RASSF4, RASSF5, MST1, MST2, LATS1, LATS2) in 54 HNSCC and in matching 23 normal tissues. Methylation of these tumor-related genes (TRG) was significantly more frequent in HNSCC (42%) compared to normal samples (23%; p<0.05). Particularly, methylation of p16 (60%), MGMT (53%), DAPK (67%), RARbeta (75%), MLH1 (69%), CDH1 (43%), RASSF5 and MST1 (96%) was often found in HNSCC. Methylation of RASSF1A (18%), GSTP1 (4%), RASSF4 (13%), MST2 (4%), LATS1 (24%) and LATS2 (8%) was less frequently detected. A trend of increased TRG methylation in more advanced tumor stages and less differentiated HNSCC was observed. Methylation of p16 was significantly higher in poorly differentiated HNSCC (p=0.037) and RASSF5 methylation occurred preferentially in advanced tumor stages (p<0.05). Methylation of RASSF4 was higher in patients with recurrent HNSCC (23%) than patients without relapse (0%; p=0.033). Methylation of TRG in head and neck cancer cell lines was observed at similar frequency as in primary HNSCC. In summary, frequent hyper-methylation of tumor-related genes in HNSCC was detected and this epigenetic silencing event may have an essential role in head and neck carcinogenesis.