Hypermethylation of promoter region of RAS association domain family gene1A in esophageal squamous cell carcinoma and significance thereof

Abstract

To investigate the hypermethylation of the promoter region of RAS association domain family gene1A (RASSF1A) and its relationship with esophageal squamous cell carcinoma. Sixty-six patients with esophageal squamous carcinoma, 60 males and 6 females, aged 59 +/- 8 (44 - 76), underwent resection of the tumor. Methylation-specific PCR (MSP) was used to detect the hypermethylation of promoter region of RASSF1A in the carcinoma tissues and the adjacent normal tissues. The hypermethylation rate of RASSF1A promoter in the tumor tissues was 48. 5% (32/66), significantly higher than that in the adjacent normal tissues (6.1%, 4/66, P < 0.05). The hypermethylation rate of RASSF1A promoter of the patients with lymph node metastasis was 61.1%, significantly higher than that of the patients without lymph node metastasis (33.3%, chi(2) = 5.055, P = 0.025). The hypermethylation rate of RASSF1A promoter in the esophageal squamous cell carcinoma at advanced stages (stages III - IV) was 69.2%, significantly higher than that in the esophageal squamous cell carcinoma at early stages (stages I - II, 35.0%, chi(2) = 7.392, P = 0.007). The hypermethylation rates of RASSF1A promoter in the high, moderate, and low differentiation tumors were 61.5% (16/26), 46.2% (12/26), and 28.6% (4/14) respectively without significant differences among them (chi(2) = 4.053, P = 0.132). Abnormal methylation exists in the RASSF1A promoter in esophageal squamous cell carcinoma. The hypermethylation of RASSF1A promoter is related to lymph node metastasis and TNM stage.