Role Of HMLH1hMSH2Promoter HyPermethylation Correlates With Platinum-Resistance In Cervical Cancer Cell SIHA、SIHA/DDP

Objective:The study aimed to investigate the role of hMLH1&hMSH2promoter hypermethylation correlates with platinum-resistance in cervical cancer cell SIHA and SIHA/DDP.Methods:1. Methylation-specific PCR(MSP) was carried out to determine the methylation status of hMLHl and hMSH2in SIHA and SIHA/DDP.2. Making use of RT-PCR to determine hMLH1and hMSH2expression in SIHA,SIHA/DDP.And in cell SIHA/DDP treated by different5-Aza-CdR,what is the concentration of5-Aza-CdR when hMLH1、 hMSH2expression at the most.3. After48h’s treatment of different cisplation’s concentration, selecting MTT to determine the change of the resistance index between SIHA/DDP and SIHA/DDP treated by5-Aza-CdR.4. The cycle of cell lines Was investigated by flow cytometry after treatment of DDP between SIHA/DDP and SIHA/DDP treated by5-Aza-CdR.Results:1. The partial methylation status of hMLH1was determined in SIHA cells,hypermethylation status of hMLH1was determined in SIHA/DDP cells. But we have found that there is no methylation status of hMSH2in SIHA cells and partial methylation status of hMSH2in SIHA/DDP cells.2. The expression of hMLH1and hMSH2in SIHA cells are more than in SIHA/DDP. And with the increase of concentration of5-Aza-CdR, the two genes’expression in SIHA/DDP cells are more. When the concentration of5-Aza-CdR is10μmol/L, the two genes’ expression are in the most.3. After treatment with cisplatin over48hours,the resistance index of SIHA/DDP、SIHA/DDP treated by pha5-Aza-CdR were12.82、6.93.And there is significant difference between them(P<0.05)4. By flow cytometry,we investigate that the cells of SIHA/DDP treated by5-Aza-CdR are noticeable reduction. And among them,the G2phase’s cells reduce most. Conclusion:The methylation of hMLH1and hMSH2may be involved in the process of resistance to platinum-based chemotherapy in the SIHA/DDP cell line.