丙戊酸钠对肺癌细胞MICA蛋白表达的影响及其信号转导机制  

Effect of Sodium Valproate on Expression of MICA Protein in Lung Cancer Cell Line A549 and Its Mechanism of Signaling Pathway

作　　者：梅花[1] 周向东[1] 陈贵华[1] 蒋幼凡[1] 

机构地区：[1]重庆医科大学附属第二医院呼吸内科,重庆400010

出　　处：《华中科技大学学报（医学版）》2014年第6期679-683,共5页Acta Medicinae Universitatis Scientiae et Technologiae Huazhong

基　　金：重庆市卫生局资助项目(No.2009-2-176)

摘　　要：目的研究丙戊酸钠(sodium valproate,VPA)作为组蛋白去乙酰酶抑制剂对肺癌A549细胞人类MHCⅠ类分子链相关基因A(human MHC classⅠchain-related A,MICA)蛋白表达的影响,并初步探讨其信号转导机制。方法使用不同浓度的VPA刺激处于对数生长期的肺癌A549细胞,培养24h后使用RT-PCR法检测肺癌A549细胞MICA mRNA水平,Western blot法检测MICA蛋白水平,得出最佳VPA刺激浓度。分别以丝裂素活化蛋白激酶(mitogen-activated protein kinase,MAPK)通路的3条主要通路抑制剂即ERK1/2抑制剂(PD98059)、p38蛋白激酶抑制剂(SB203580)、JNK抑制剂(SP600125)预处理A549细胞,再将VPA依照预定最适浓度分别加入培养24h。使用RTPCR法检测A549细胞MICA mRNA水平,Western blot法检测MICA蛋白水平。使用ELISA法检测上述各组A549细胞培养上清液中分泌型MICA(sMICA)蛋白水平。结果 RT-PCR及Western blot检测结果显示加入VPA后A549细胞中MICA mRNA转录水平、MICA蛋白水平均显著升高(均P<0.05);使用p38蛋白激酶抑制剂SB203580、ERK1/2抑制剂PD98059预处理,均能显著减弱VPA诱导的A549细胞MICA mRNA及蛋白水平的提高(P<0.05);各组细胞培养上清液中sMICA浓度无差异。结论 VPA能增强肺癌A549细胞MICA蛋白的表达,其机制可能与ERK、p38信号通路有关。Objective To investigate the effects of histone deacetylase inhibitor sodium valproate（VPA ）on the expression of human MHC classⅠchain‐related A（MICA）protein in lung cancer A549 cells and explore its possible mechanisms of signa‐ling pathway.Methods Lung cancer A549 cells were cultured with different concentrations of VPA.The expression levels of MICA mRNA were detected by RT‐PCR and the MICA protein synthesis was judged by Western blot after cultivation for 24 h , and then optimum stimulation concentration of VPA was obtained.A549 cells were pretreated by three inhibitors of MAPK sig‐nal pathway（ERK1/2 inhibitor PD98059 ,p38 protein kinase inhibitor SB203580 ,and JNK inhibitor SP600125）. Then A549 cells were stimulated with the optimum stimulation concentration of VPA.The MICA mRNA levels were analyzed by RT‐PCR ,MI‐CA protein levels assessed by Western blot ,and secreted MICA（sMICA）levels of cultural supernatants detected by ELISA after cultivation for 24 h.Results The results of RT‐PCR and Western blot showed that VPA could enhance both the mRNA and protein level of MICA in human lung cancer cell line A549（P〈0.05）. The ERK1/2 inhibitor PD98059 and p38 protein kinase inhibitor SB203580 could lessen the increased expression of MICA induced by VPA（P〈0.05）. However ,the levels of sMICA in cultural supernatants were not significantly different among the groups.Conclusion Histone deacetylase inhibitor VPA can enhance the expression of MICA in human lung cancer A549 cells via an ERK1/2 and p38 protein kinase signal related mecha‐nism.

关 键 词：丙戊酸钠 肺癌 人类MHCI类分子链相关基因A 丝裂素活化蛋白激酶 

分 类 号：R734.2[医药卫生—肿瘤]