喉鳞状细胞癌中RASSF1A基因启动子区甲基化及蛋白表达

目的：探讨RASSF1A基因启动子区甲基化与喉癌的关系。方法：运用甲基化特异性PCR，检测RASSF1A基因在48例喉癌组织、相对应癌旁组织及48例正常人外周血中的启动子区甲基化情况。用Western blotting方法检测喉癌组织、癌旁组织及正常人外周血中RASSF1A表达情况。结果：在48例喉癌组织、相对应的癌旁组织和48份正常人外周血中，RASSF1A基因启动子区分别有34例（70.83%）、11例（22.92%）和6例（12.50%）发生了甲基化, 喉癌组织甲基化程度明显高于癌旁组织和正常人外周血（P<0.05）。在48例喉癌组织中27例（56.25%）不能正常表达RASSF1A蛋白，而相对应癌旁组织中仅有8例（16.67%），喉癌组织中RASSF1A蛋白的表达程度明显低于癌旁组织(P<0.01)。启动子区发生甲基化的34例喉癌组织中共有25例（73.53%）呈弱阳性，而7例未发生甲基化的喉癌组织中为1例（14.29%），两组间比较差异具有显著性(P<0.05)。结论：RASSF1A基因启动子区甲基化与喉癌的发生有关，有望成为喉癌诊断的分子标志。

Promoter methylation of RASSF1A gene in laryngeal squamous cell carcinoma and protein expression

Objective To investigate the relationship between promoter methylation of RASSF1A gene and laryngeal squamous cell carcinoma.Methods A methylation-specific PCR was performed to detect the promoter methylation of RASSF1A gene in 48 tumor tissues,48 corresponding normal tissues and 48 normal blood plasma.The expression of RASSF1A protein was determined by means of Western blotting.Results The methylation in RASSF1A gene was detected in 34(70.83%) tumor tissue samples,11(22.92%) corresponding normal tissue samples and 6(12.50%) blood plasma samples,respectively.The methylation degree of tumor tissue was higher than that of corresponding normal tissues and normal blood plasma(P<0.05).27(56.25%)of 48 tumor tissue samples and(8(16.67%)of) 48 corresponding normal tissue samples expressed less RASSF1A protein.The level of expression of RASSF1A protein in tumor tissues was lower than that in corresponding normal tissues(P<0.01).25(73.53%)of 34 methylated tumor tissue samples expressed less RASSF1A protein, while only 1(14.29%) of 7 unmethylated tumor tissue samples expressed less RASSF1A protein(P<0.05).Conclusion The promoter methylation of RASSF1A is associated with the carcinogenesis of laryngeal squamous cell carcinoma.It may be a useful marker for diagnosis of laryngeal squamous cell carcinoma.