Methylation and protein expression of RASSF1A gene in cervical squamous cell carcinoma

Background and purpose:Ras associated domain family 1A (RASSF1A) is a candidate tumor suppressor gene. The methylation of the gene promoter is related to the occurrence of many human epithelial tumors. This study was designed to investigate the status of promoter methylation and protein expression of RASSF1A gene in cervical squamous cell carcinoma (CSCC). The correlation between methylation and gene inactivation of RASSF1A and its association with the occurrence of CSCC was analyzed. Methods:The promoter methylation and protein expression of RASSF1A in 15 normal cervical tissues and 46 CSCC were detected by methylation-specific polymerase chain reaction (MSP) and immunohistochemistry. Meanwhile, the relationship between methylation and protein expression of RASSF1A and clinicopathological characteristics was analyzed. Results:The methylation rate of RASSF1A promoter in CSCC was 43.5%, whereas methylation was completely abscent in normal cervical tissues (P0.05). At stageⅠ, stageⅡ and stageⅢ-Ⅳ in CSCC, the methylation rate of RASSF1A gradually increased (19.0%→58.8%→75.0%, P0.05). There were no significant associations between the methylation of RASSF1A and histological grade or lymphnode metastasis (P0.05). The methylation of RASSF1A was negatively correlated with its protein expression (r=-0.469, P0.05). Conclusion:The promoter methylation of RASSF1A plays an important role in the occurrence and development of CSCC and it is also associated with low expression of the RASSF1A protein.