Effects of 5-Aza-CdR on the protein expression and promoter methylation of E-cadherin in the cervical cancer SiHa cells / 肿瘤研究与临床

ABSTRACT

Objective To investigate the effects of specific methyltransferase inhibitor of 5-Aza-2'-deoxycytidine (5-Aza-CdR) on the promoter methylation of E-cadherin (E-cad) gene, protein expression in human cervical cancer SiHa cells, and the cell biological behavior. Methods SiHa cells were treated with 5-Aza-CdR at different concentrations. Quantitative methylation-specific polymerase chain reaction (QMSP) was used to examine CpG island promoter methylation level of E-cad gene before and after treatment. The experimental group of the optimum concentration was selected. The expression levels of E-cad mRNA and its protein in SiHa cells line were detected by quantitative real-time polymerase chain reaction (RT-PCR) and western blot respectively. Cell adhesion test was used to measure cell adhesion ability and Transwell test was used to detect cell invasion and migration ability. Results E-cad gene promoter methylation index (PMR) of 5-Aza-CdR at 0, 1, 5, 10, 15 μmol/L level was (53.0 ±1.6) %, (50.0 ±1.2) %, (44.0 ±1.4) %, (27.0 ±1.7) %, (15.0±8.2) %respectively, and PMR value decreased gradually with the increase of 5-Aza-CdR concentration. Furthermore, PMR value was the lowest at 15μmol/L, and the difference was statistically significant compared with other 4 groups (P< 0.01). Then 5-Aza-CdR at 15 μmol/L was selected as the following experimental concentration. The expression of E-cad mRNA and its protein in the 5-Aza-CdR group were significantly higher than those in the blank control group (P<0.05). The rates of cell adhesion , cell invasion inhibition and migration inhibition were all increased with significant differences (P<0.05). Conclusions 5-Aza-CdR can upregulate E-cad mRNA and protein expression level in cervical cancer SiHa cells, reduce cell invasion and migration ability, and promote the adhesion of SiHa cells, which has reversed hypermethylation in the promoter region of E-cad gene partly.