Methylation Of ASC Gene In Promotor Region Is Related With The Genesis Of Ovarian Carcinomas

Objective:To investigate the correlation between methylation of ASC gene in promotor region and the genesis of ovarian cancer.Methods: Genomic DNA was isolated from 7 ovarian cancer cell lines(A2780,SKOV3,Anglne,CAOV3,OVCAR3,SW626,COC1),18 primary ovarian cancer specimens and 10 normal ovary specimens. Methylation-specific PCR was used to detect methylation of ASC promotor region. Expression of ASC mRNA and protein was examined by RT-PCR and Western Blot.Results: Methylation of ASC gene was observed in 4/7 (SKOV3,SW626,Angle,A2780)ovarian cancer cell lines and 7/18 primary ovarian cancer tissues,but in none of the 10 normal ovary specimens,there was a significant different between them(P <0.05).The expression of ASC gene in cancers with methylation was lower than that in cancers without methylation.Conclusions: Methylation of ASC are frequent events in ovarian cancer and are important mechanisms for the loss of expression of this gene. Aberrant methylation of ASC may play a role in the pathogenesis of ovarian cancer. Objective : To explore the transcription regulation of DNA 5'CpG island demethylation on ASC gene and effects of growth on human ovarian cancer cell line SKOV3.Methods: SKOV3 cell line was exposed to the specific demethylating agent, 5'-Aza-2'-deoxycytidine(5-Aza-CdR) ,for seventy-two hours to detect whether the silencing of ASC gene could be reversed . Methylation status was evaluated by Methylation-specific PCR (MSP).Growthspeed,expression of ASC mRNA and protein were determined by MTT assay,reverse transcription polymerase chain reaction(RT-PCR) and western blot respectively.Results:(1)The methylated DNA 5'CpG island on ASC gene in untreated SKOV3 cells was reversed by 5'-Aza-2'-deoxycytidine treatment.(2) SKOV3 cell line after treatment with three different concentration 5'-Aza-2'-deoxycytidine grew slowly and double time increased to 1.14,1.31 and 1.43 times respectively.(3)The expression of SKOV3 cell ASC gene mRNA and protein treated with 5'-Aza-2'-deoxycytidine were increased significantly.Conclusion: 5'-Aza-2'-deoxycytidine may effectively cause demethylation of DNA 5'CpG island of ASC and inhibit the growth of SKOV3 cell by reactivating the gene transcription silenced by abrreant hypermethylation.