The Expression And Methylation Status Of The Gene P16/PTEN/XAF1 In Pancreatic Carcinoma

Objectives:To observe the transcription,expression and methylation status of gene P16,PTEN and XAF1 in pancreatic cancer tissues and cell lines.Methods:Collect pancreatic tumor(n=30),ajacent(n=10),normal(n=10) tissues andthree pancreatic cancer cell lines.Add in demethylation drug 5-aza-2′-deoxycytidine toact on cell lines.Perform RT-PCR,WesternBlot,immunohistochemistry andimmunofluorescence tests to detect the expression of mRNA and protein in pancreatictissues and cell lines.The MSP method is used to investigate the methylation status intissues and cell lines.Flow cytometry is carried out to analyse the cell cycle.Results:The expressions of gene P16,PTEN and XAF1 are down-regulated in tumortissues while the methylation status of these genes are up-regulated,which showscertain statistical signification(p＜0.05).The expression and methylation status of P16,PTEN and XAF1 genes are closely related with tumor differentiation,lymph nodemetastasis and clinical stages(p＜0.05).The methylation status of P16,PTEN andXAF1 are related with the pancreatic tumor marker CA19-9 with greatsignification(p＜0.05).Through adding 5-aza-2′-deoxycytidine to induce the pancreaticcell lines,improvement of expression of gene P16,PTEN and XAF1 can be acquired,with the demethylation status and blocked proliferation in G1 phase.Conclusions:The reduction of expressions of P16,PTEN and XAF1 and increase ofmethylation status of these genes in pancreatic cancer can be considered as the biological marker to distinguish it from normal pancreas.The transcription,expressionand methylation status of gene P16,PTEN and XAF1 are closely related with severalclinical factors,such as the differentiation,lymph node metastasis and clinical stages.Thus the methylation level of P16,PTEN and XAF1 could be expected as an indicatorof early diagnosis of pancreatic cancer.5-aza-2′-deoxycytidine can reverse abnormalgene methylation,as well as induce the transcription and expression of gene P16,PTENand XAF1.Moreover,this drug can inhibit tumor cell proliferation.It implies the5-aza-2′-deoxycytidine can be used as a antineoplastic drug.