Effect of RASSF1A gene promoter methylation on its expression level in cervical cancer tissue and its clinical significance

Objective To research the promoter methylation level of RAS association domain family 1A (RASSF1A) and RASSF1A gene mRNA expression level in cervical cancer tissue, and to analyze their relationships with clinicopathological parameters of cervical cancer and the clinical significance. Methods The RASSF1A gene promoter methylation and RASSF1A gene mRNA were detected respectively by methylation specific PCR and quantitative real-time PCR method in 40 cases of cervical cancer tissues and corresponding adjacent tissues. Results RASSF1A mRNA expression level in cervical cancer (0.26±0.05) was significantly lower than that in adjacent tissues (0.28±0.03), and the difference was statistically significant (t=2.27, P=0.026). The methylation rate of RASSF1A gene promoter region (0.71%±0.04%) was significantly higher than that in adjacent tissues (0.66%± 0.03%), and the difference was statistically significant (t=6.78, P=0.000). The expression of RASSF1A mRNA was significantly correlated with pathological differentiation (t=3.31, P=0.002), International Federation of Gynecology and Obstetrics (FIGO) stage (t=2.13, P=0.040), lymphatic metastasis (t=2.56, P=0.015). The promoter methylation level of RASSF1A gene was significantly correlated with pathological differentiation (t=2.08, P=0.045), FIGO stage (t=2.66, P=0.011), lymphatic metastasis (t=2.22, P=0.033), depth of invasion (t=2.12, P=0.041). Conclusion The RASSF1A gene promoter region methylation level and the RASSF1A gene mRNA expression level are associated with the malignant degree of cervical carcinoma. The RASSF1A gene promoter region methylation level may be used as a reference indicator for predicting the risk of metastasis of cervical cancer. Key words: Cervical neoplasms; Methylation; RAS association domain family 1A gene