Hippo通路靶向Ascl2调节结直肠肿瘤转移分子机制  

The molecular mechanism of Hippo pathway regulating colorectal tumor metastasis via targeting Ascl2

作　　者：布力布·吉力斯汉[1] 尹哲[1] 王薇[1] 唐勇[1] Bulibu·Jilisihan;YIN Zhe;WANG Wei;TANG Yong(Department of Gastroenterology,Affiliated Cancer Hospital of Xinjiang Medical University,Urumqi 830011,China)

机构地区：[1]新疆医科大学附属肿瘤医院消化内科

出　　处：《河北医科大学学报》2019年第11期1255-1260,共6页Journal of Hebei Medical University

基　　金：新疆维吾尔自治区自然科学基金(2016D01C334)

摘　　要：目的探讨Hippo通路调节结直肠肿瘤转移的分子机制。方法下载TCGA数据库中276例结直肠癌患者的临床资料及YAP1、TAZ和Ascl2的表达值,分析三者在结直肠癌组织、对应癌旁组织、不同M分期、T分期的结直肠癌组织的表达模式,以及患者总生存率(overall survival,OS)和无病生存率(disease-free survival,DFS)。构建Hippo通路激活因子MST1和MST2的过表达载体,转染SW480细胞,采用免疫印迹(Western blot)和实时荧光定量PCR(quantitative real-time polymerase chain reaction,QPCR)检测Hippo通路靶基因YAP1和TAZ,以及上皮-间充质转化(epithelial-mesenchymal transition,EMT)相关因子Ascl2、E-cadherin、N-cadherin的表达,荧光素酶报告系统检测Ascl2启动子的转录活性。采用Transwell方法检测过表达MST1/2的SW480的迁移和侵袭能力。结果YAP1、TAZ和Ascl2三者在结直肠癌中的表达明显高于癌旁组织,且表达水平随着肿瘤的远处转移和浸润程度增强而增加。高表达YAP1、TAZ和Ascl2的结直肠癌患者的5年OS和DFS明显低于低表达患者。过表达Hippo通路激酶MST1和MST2导致YAP1/TAZ磷酸化增加,非磷酸化YAP1/TAZ表达减少,抑制EMT相关因子Ascl2、N-cadherin表达,增加E-cadherin表达。Transwell实验证实过表达MST1/2抑制结肠癌细胞的迁移和侵袭能力。荧光素酶报告系统结果发现过表达MST1/2抑制Ascl2启动子的转录活性,表明Ascl2的转录调控受到Hippo通路的抑制。结论Ascl2是Hippo通路的下游靶基因,激活Hippo通路能够抑制结直肠癌的EMT过程,进一步阻碍肿瘤转移的发生,为结直肠癌转移的机制研究提供新的依据。Objective To investigate the molecular mechanism of Hippo pathway regulating colorectal tumor metastasis.Methods Download the clinical data and the expression values of YAP1,TAZ and Ascl2 of 276 colorectal cancer patients in the TCGA database,the expression patterns in colorectal cancer tissues,corresponding adjacent tissues,different M and T stages of colorectal cancer tissues,overall survival(OS)and disease-free survival(disease-free survival,DFS)were analyzed.The overexpression vector of Hippo pathway activating factor MST1 and MST2 was constructed and transfected into SW480 cells.The target genes YAP1 and TAZ of the Hippo pathway and the epithelial-mesenchymal transition(EMT)related factors Ascl2 were detected by Western blot and quantitative real-time polymerase chain reaction(qPCR).Results The expression of YAP1,TAZ and Ascl2 in colorectal cancer was significantly higher than that in paracancerous tissues,and the expression level of YAP1,TAZ and Ascl2 was increased with the distant metastasis and infiltration of tumor.The 5-year OS and DFS of patients with high expression of YAP1,TAZ and Ascl2 were significantly lower than those of patients with low expression.Overexpression of Hippo pathway kinase MST1 and MST2 resulted in increased phosphorylation of YAP1/TAZ,decreased expression of non-phosphorylated YAP1/TAZ,inhibition of EMT-related factors Ascl2 and N-cadherin,and increased E-cadherin expression.Transwell experiments confirmed that MST1/2 overexpression inhibited colon cancer cell migration and invasion.Luciferase reporter system showed that overexpression of MST1/2 inhibited the transcriptional activity of Ascl2 promoter,indicating that transcriptional regulation of Ascl2 is inhibited by Hippo pathway.Conclusion Ascl2 is a downstream target of Hippo pathway,Activation of Hippo pathway can inhibit the EMT of colorectal cancer and further hinder the occurrence of tumor metastasis,and the study provided a new basis for the mechanism of colorectal cancer metastasis.

关 键 词：结直肠肿瘤 肿瘤转移 Hippo通路 Ascl2 

分 类 号：R735[医药卫生—肿瘤]