Histone Demethylase Retinoblastoma Binding Protein 2 is Overexpressed in Hepatocellular Carcinoma and Negatively Regulated by hsa-miR-212
Histone Demethylase Retinoblastoma Binding Protein 2 is Overexpressed in Hepatocellular Carcinoma and Negatively Regulated by hsa-miR-212
复制标题
组蛋白去甲基酶视网膜母细胞瘤结合蛋白 2 在肝细胞癌中过表达并受 hsa-miR-212 负调控
DOI：
10.1371/journal.pone.0069784
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发表时间：
2013-07-29
期刊：
影响因子：
3.7
通讯作者：
Chen, Chunyan
中科院分区：
文献类型：
--
作者：
Liang, Xiuming;Zeng, Jiping;Chen, Chunyan
背景视网膜母细胞瘤结合蛋白2（retinoblastoma binding protein 2，RBP 2）与胃癌的发生有关，但其在肝细胞癌（hepatocellular carcinoma，HCC）中的作用及调控尚不清楚。我们在体外和人体组织中确定了RBP 2的功能及其在HCC中的调节。方法采用实时荧光定量PCR和免疫组化方法，对20例肝癌组织和20例正常肝组织中的基因表达进行分析。通过病灶形成分析增殖，通过β-半乳糖苷酶染色分析衰老。荧光素酶报告基因检测启动子活性。结果RBP 2在癌组织中的表达强于非癌组织，而其结合microRNA人miR-212（hsa-miR-212）的表达则相反。SiRNA敲除RBP 2显着上调细胞周期蛋白依赖性激酶抑制剂（CDKI），抑制肝癌细胞增殖并诱导衰老。hsa-miR-212过表达抑制RBP 2表达，抑制细胞增殖，诱导细胞衰老，与CDKIs表达上调一致; hsa-miR-212低表达时，CDKIs表达下调。抑制hsa-miR-212表达上调RBP 2表达。荧光素酶报告基因检测hsa-miR-212与RBP 2 3′ UTR的直接结合。结论RBP 2在HCC中过表达，并受hsa-miR-212负调控。hsa-miR-212-RBP 2-CDKI通路可能在HCC的发病机制中起重要作用。
Background The H3K4 demethylase retinoblastoma binding protein 2 (RBP2) is involved in the pathogenesis of gastric cancer, but its role and regulation in hepatocellular carcinoma (HCC) is unknown. We determined the function of RBP2 and its regulation in HCC in vitro and in human tissues. Methods We analyzed gene expression in 20 specimens each of human HCC and normal liver tissue by quantitative real-time PCR and immunohistochemistry. Proliferation was analyzed by foci formation and senescence by β-galactosidase staining. Promoter activity was detected by luciferase reporter assay. Results The expression of RBP2 was stronger in cancerous than non-cancerous tissues, but that of its binding microRNA, Homo sapiens miR-212 (hsa-miR-212), showed an opposite pattern. SiRNA knockdown of RBP2 significantly upregulated cyclin-dependent kinase inhibitors (CDKIs), with suppression of HCC cell proliferation and induction of senescence. Overexpression of hsa-miR-212 suppressed RBP2 expression, with inhibited cell proliferation and induced cellular senescence, which coincided with upregulated CDKIs; with low hsa-miR-212 expression, CDKIs were downregulated in HCC tissue. Inhibition of hsa-miR-212 expression upregulated RBP2 expression. Luciferase reporter assay detected the direct binding of hsa-miR-212 to the RBP2 3′ UTR. Conclusions RBP2 is overexpressed in HCC and negatively regulated by hsa-miR-212. The hsa-miR-212–RBP2–CDKI pathway may be important in the pathogenesis of HCC.