鞘氨醇激酶1通过ERK1/2信号通路促进非小细胞肺癌细胞的侵袭和迁移

Sphingosine kinase 1 enhances invasion and migration of non-small-cell lung cancer cells by ERK1/2 signaling pathway

目的:探讨鞘氨醇激酶1(SphK1)对非小细胞肺癌(NSCLC)细胞迁移和侵袭的影响及其作用机制。方法:选取31例外科手术切除并经常规组织学检查确诊为NSCLC的肿瘤组织标本和配对癌旁肺组织标本,应用免疫组织化学染色和RT-qPCR检测SphK1的表达。将pcDNA3.1-SphK1载体(SphK1组)、空白pcDNA3.1载体对照(NC组)、SphK1 siRNA(siSphK1组)和对照siRNA(siNC组)分别转染人肺腺癌A549细胞,Western blot法检测SphK1、E-cadherin、fibronectin和p-ERK1/2的表达;利用Transwell实验评估过表达SphK1和抑制ERK1/2对A549细胞迁移和侵袭的影响。结果:SphK1在NSCLC组织中高表达,并与肿瘤分期相关。SphK1过表达可显著促进A549细胞的迁移和侵袭,提高p-ERK1/2和fibronectin蛋白水平,减少E-cadherin蛋白表达(P<0.05),而干扰SphK1则呈现相反的结果。ERK1/2抑制剂U0126可显著抑制SphK1过表达诱导的p-ERK1/2和fibronectin上调及E-cadherin下调,也抑制了SphK1过表达增强的A549细胞侵袭和迁移能力(P<0.05)。结论:SphK1可能通过ERK1/2通路降低E-cadherin蛋白水平、提高fibronectin蛋白水平,并促进NSCLC细胞的侵袭和迁移。

AIM:To explore the effects of sphingosine kinase 1(SphK1)on the migration and invasion of nonsmall-cell lung cancer(NSCLC)cells and its mechanism.METHODS:Thirty-one tumor specimens,which were surgically resected and routinely histologically confirmed as NSCLC,and matched adjacent lung tissues were selected.Immunohistochemical staining and RT-qPCR were used to detect the expression of SphK1.The pcDNA3.1-SphK1 vector(SphK1 group),empty pcDNA3.1 vector control(NC group),SphK1 siRNA(siSphK1 group)or control siRNA(siNC group)was transfected into human lung adenocarcinoma A549 cells,and the protein levels of SphK1,E-cadherin,fibronectin and p-ERK1/2 were determined by Western blot.The effects of over-expression of SphK1 and inhibition of ERK1/2 on migration and invasion of A549 cells were evaluated by Transwell assays.RESULTS:SphK1 was highly expressed in the NSCLC tissues and was associated with tumor stage.SphK1 over-expression significantly promoted the migration and invasion of A549 cells,increased the protein levels of p-ERK1/2 and fibronectin,and decreased the protein expression of E-cadherin(P<0.05),but the opposite result was observed after SphK1 interference.The ERK1/2 inhibitor U0126 significantly inhibited the up-regulation of p-ERK1/2 and fibronectin levels and the down-regulation of E-cadherin expression induced by SphK1 over-expression,and also inhibited the invasion and migration of A549 cells promoted by SphK1 over-expression(P<0.05).CONCLUSION:SphK1 may reduce E-cadherin protein levels,increase fibronectin protein levels,and promote the invasion and migration of NSCLC cells through ERK1/2 signaling pathway.