Objective: To investigate the effects and mechanisms of 5-aza-2'-deoxycytidine (5-Aza-CdR) on endometrial cancer cell.
Methods: In vitro experiments of 5-Aza-CdR were done using human endometrial cancer cell line HEC-1B. Evaluation of cellular proliferation and apoptosis was ascertained respectively using trypan blue exclusion and flow cytometry. RT-PCR and methylation specific PCR(MSP) was done to detect the expression of RASSF1A mRNA and methylation status of RASSF1A promoter of HEC-1B cell line.
Results: (1) The status of cellular growth and apoptosis of HEC-1B cell line: the growth inhibition effects of 5-Aza-CdR on HEC-1B cell line were both concentration-dependent (P < 0.01) and time-dependent (P < 0.01), as well as the apoptosis rate of HBC-1-B cell line depended on the dose of 5-Aza-CdR obviously (P < 0.01). (2) The expression of RASSF1A mRNA of HEC-1B cell line: RASSF1A mRNA was expressed in HEC-1B cell after 5-Aza-CdR treatment, but it was undetectable before the treatment. In the groups with different concentration of 5-Aza-CdR (0.05, 0.1, 1, 5, 10 nmol/ml), the expression of RASSF1A mRNA was respectively 0.074 +/- 0.004, 0.105 +/- 0.004, 0.167 +/- 0.006, 0.334 +/- 0.005, 0.484 +/- 0.007, which were remarkably different from the group without 5-Aza-CdR(the expression of RASSF1A mRNA was 0; P < 0.01). (3) The hypermethylation of RASSF1A promoter of HEC-1B cell line: the hypermethylation of RASSF1A promoter was detected in HEC-1B cell line. The status of hypermethylation was decreased after treatment with 5-Aza-CdR of 0.05, 0.1, 1, 5 nmol/ml, meanwhile, both methylation bands and demethylation bands were observed by methylation specific PCR. After the treatment with 5-Aza-CdR of 10 nmol/ml the hypermethylation was absent absolutely.
Conclusions: (1) In HEC-1B cell line, 5-Aza-CdR can inhibit cell proliferation and induce cell apopotosis. (2) 5-Aza-CdR can renew the expression of RASSF1A mRNA of HEC-1B cell line and reverse the hypermethylation of RASSF1A promoter.