蛋白磷酸酯酶2A通过MAPK信号通路抑制宫颈癌细胞侵袭

Protein Phosphatase 2A Inhibits the Invasion of Cervical Cancer Cells Through MAPK Signaling Pathway

目的:探讨蛋白磷酸酯酶2A(PP2A)在宫颈癌细胞侵袭中的作用及其可能机制。方法:常规培养Hela细胞,通过药物或基因调节PP2A水平,药物实验中将Hela细胞分为3组,即正常对照组(DMSO处理,n=6)、DES组(10nM PP2A激动剂DES处理,n=6)和OA组(10nM PP2A抑制剂OA处理,n=6);质粒转染组中将Hela细胞分为对照组(DsRed组,n=6)、wtPP2A组(n=6)和siPP2A组(n=6),按分组要求转染相应质粒。采用小室穿孔实验观察其对Hela细胞侵袭的影响;蛋白免疫印迹实验(Western Blot)观察其对MAPK信号通路的作用。结果:研究发现上调PP2A可显著抑制Hela细胞侵袭,而下调PP2A则显著促进Hela细胞侵袭;激活PP2A可去磷酸化丝裂原激活的蛋白激酶家族(p-JNK, p-p38和p-ERK MAPK)及金属蛋白酶9(MMP-9)。结论:PP2A可能通过去磷酸化MAPK信号通路下调MMP-9起调节宫颈癌细胞侵袭的作用。

Objective:To explore the role of protein phosphatase 2A(PP2A)in the invasion of cervical cancer and its mechanism.Method:Hela cells were cultured and transfected with PP2A plasmids to regulate the activity of PP2A.In the drug experiment,Hela cells were divided into three groups namely normal control group(DMSO trentment,n=6),DES group(10nM PP2A agonist DES treatment,n=6)and OA group(10nM PP2A inhibitor OA treatment,n=6).Hela cell were divided into DsRed group(n=6),wtPP2A group(n=6)and siPP2A group(n=6)in plasmid transfection expriments,and the corresponding plasmids were transfected according to grouping requirements.The invasion of Hela cells was detected by transwell assay.Western blotting was used to observe its effect of PP2A on MAPK signaling pathway.Results:Upregulation of PP2A pharmacologically and genetically could inhibit Hela cells invasion by using transwell assay.Activation of PP2A also inhibited p-JNK,p-p38 and p-ERK activity.Meanwhile,we found activation of PP2A could downregulate MMP-9 levels,which further inhibited Hela cells migration and invasion.Conclusion:Activation of PP2A by drug or gene significantly inhibitrs the invasion of cervical cancer cells,which acts by dephosphorylation of p-JNK,p-p38 and p-ERK/MAPK signaling pathways and down regulation of MMP-9 protein levels.