Vasohibin 2 reduces chemosensitivity to gemcitabine in pancreatic cancer cells via Jun proto-oncogene dependent transactivation of ribonucleotide reductase regulatory subunit M2.
Vasohibin 2 reduces chemosensitivity to gemcitabine in pancreatic cancer cells via Jun proto-oncogene dependent transactivation of ribonucleotide reductase regulatory subunit M2.
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Vasohibin 2 通过核糖核苷酸还原酶调节亚基 M2 的 Jun 原癌基因依赖性反式激活降低胰腺癌细胞对吉西他滨的化疗敏感性
DOI：
10.1186/s12943-017-0619-6
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发表时间：
2017-03-21
期刊：
影响因子：
37.3
通讯作者：
Miao Y
中科院分区：
文献类型：
--
作者：
Tu M;Li H;Lv N;Xi C;Lu Z;Wei J;Chen J;Guo F;Jiang K;Song G;Gao W;Miao Y
VASH2 （dvasohibin 2）此前已被确定为一种促衰老因子和一种癌症相关蛋白。我们研究了胰腺癌中VASH2表达与化疗耐药的关系。方法对102例人胰腺癌标本进行VASH2免疫组化染色。构建VASH2过表达或低表达的胰腺癌细胞系模型。通过基因表达分析确定VASH2差异调控的基因。通过生物信息学的方法查询了VASH2调控的下游基因表达的转录因子。采用双荧光素酶报告基因测定和ChIP测定来证实VASH2过表达或敲低后靶基因的转激活。结果VASH2蛋白在人胰腺癌中的表达高于配对癌旁组织，且VASH2水平升高与吉西他滨化疗耐药相关。在胰腺癌细胞系模型中，VASH2表达诱导吉西他滨在体内和体外耐药。发现核糖核苷酸还原酶调控亚基M2 （RRM2）的表达受VASH2调控；免疫组化分析显示VASH2和RRM2在人胰腺癌组织中的表达呈正相关。生物信息学分析显示VASH2诱导Jun原癌基因（Jun）上调RRM2的表达；通过染色质免疫沉淀和双荧光素酶报告基因检测证实了VASH2对RRM2的这种JUN依赖性调控，这表明JUN直接结合RRM2启动子激活转录。结论VASH2通过jun依赖性RRM2的转激活降低胰腺癌细胞对吉西他滨的化疗敏感性。
BackgroundVasohibin 2 (VASH2) has previously been identified as an agiogenenic factor and a cancer related protein. Here we investigated the association of VASH2 expression and chemoresistance in pancreatic cancer.MethodsImmunohistochemical staining for VASH2 was performed on 102 human pancreatic cancer samples. Pancreatic cancer cell line models exhibiting overexpression or knockdown of VASH2 were generated. Gene expression analyses were carried out to determine genes differentially regulated by VASH2. Putative transcription factors that are downstream mediators of gene expression regulated by VASH2 were queried bioinformatically. Dual-luciferase reporter assays and ChIP assays were performed to confirm transactivation of target genes following VASH2 overexpression or knockdown.ResultsVASH2 protein expression was higher in human pancreatic cancer than in paired adjacent tissues and elevated VASH2 levels were associated with gemcitabine chemoresistance. In cell line models of pancreatic cancer, VASH2 expression induced gemcitabine chemoresistance in vitro and in vivo. It was discovered that expression of ribonucleotide reductase regulatory subunit M2 (RRM2) is regulated by VASH2; immunohistochemical analysis demonstrated a positive association of VASH2 expression and RRM2 expression in human pancreatic cancer tissues. Bioinformatics analyses revealed that induction of the Jun proto-oncogene (JUN) by VASH2 is responsible for upregulation of RRM2 expression; this JUN-dependent regulation of RRM2 by VASH2 was confirmed by chromatin immunoprecipitation and dual luciferase reporter assays, which demonstrated that JUN directly binds with the RRM2 promoter to activate transcription.ConclusionsThese data suggest that VASH2 reduces the chemosensitivity to gemcitabine in pancreatic cancer cells via JUN-dependent transactivation of RRM2.