The Expression Of14-3-3σ In Chemoresistance Nasopharyngeal Carcinoma Cell

Objective:To study the expression of14-3-3σ in the nasopharyngeal carcinoma cell line HNE1and cisplatin resistance cell line HNEl-DDP and the methylation14-3-3σ gene,in order to primarily discuss the relationship between14-3-3σ and drug resistance.Methods:In this study, Western Blotting and Quantitative PCR were firstly used to detect the expression of14-3-3σ in HNE1-DDP cells and HNE1cells on protein and mRNA levels respectively.Then MTT assay and flow cytometric analysis were used to analyze HNE1-DDP cell proliferation activities and cell cycles,respectively,after intervention by5-aza-2’-dC.Western Blotting and qPCR were used again to detect the changes of14-3-3σ after the intervention.In addition,p53was detected too.To clear the relationship between methylation and drug resistance,Bisulfite Sequencing PCR was used to analyze methylation of14-3-3a CpG sites in HNE1cell line. HNE1-DDP cell line and HNE1-DDP cell lines intervented by5-aza-2’-dC.SPSS13.0statistical software was used for the data analysis.Results:Comparing with HNE1cells, the14-3-3σ protein and mRNA and p53protein levels were all decreased in HNE1-DDP cells. After treated with different concentrations of5-aza-2’-dC (0,1,5,10μmol/L), the HNE1-DDP cells were significantly inhibited and the cell cycles were arrested in S phase and G2-M phase. Meanwhile, the expressions of14-3-3σ protein and mRNA were increasing. Additionally,BSP showed that CpG sites of14-3-3σ promoter region were nearly non-methylation in HNE1cells,HNE1-DDP cells and the intervention groups.Conclusions:14-3-3σ may play an important role in nasopharyngeal carcinoma chemoresistance.5-aza-2’-dC could inhibite the growth of HNE1-DDP,block it’s cell cycles and increase the expression of14-3-3σ,at the same time,14-3-3σ may be involved in the inhibition affect. The lower expression of14-3-3σ in HNE1-DDP cell may not due to its methylation,but may be related wtih p53.A further study must be needed.