The effect of human papillomavirus 16 E6 gene silenced by small interfering RNA on the expression and the promoter hypermethylation status of E-cadherin in cervical cancer SiHa cell line / 肿瘤研究与临床

ABSTRACT

Objective To investigate the influence of human papillomavirus (HPV) 16 E6 gene silencing by small interfering RNA (siRNA) on the expression and the promoter hypermethylation status of E-cadherin (E-cad) in cervical cancer SiHa cell line. Methods siRNA which used lentivirus as the vector was used to knock down the HPV16E6 gene in cervical cancer SiHa cell line. The expression levels of HPV16E6 mRNA, E-cad mRNA and protein in siRNA-HPV16E6 SiHa cell line were detected by RT-qPCR and Western blot, respectively. Methylation specific PCR (MSP) method was used to detect the methylation status of E-cad gene (CDH1) promoter in siRNA-HPV16E6 SiHa cell line. Results The E-cad mRNA expression levels in siRNA E6 group, empty vector group and blank control group were 4.755±1.085, 1.224± 0.840, 1.327±1.221, respectively. The protein expression levels were 0.616±0.019, 0.325±0.016, 0.299±0.015, respectively. The expressions of E-cad mRNA and protein in siRNA E6 group were significantly higher than those in the empty vector group and blank control group (F = 21.346, P 0.05). After knocking down HPV16E6 gene, the methylation status of E-cad gene was weakly positive, and the intensity of the amplified products was significantly weaker than that in the empty vector group and blank control group, while the unmethylation amplification was positive. Conclusions Knocking down the HPV16E6 gene increases the expression of E-cad in cervical cancer SiHa cell line, and decreases the level of CDH1 promoter methylation. To a certain extent, it partly reverses the hypermethylation status of CDH1 promoter, and causes E-cad to be re-expressed.