Ars2 is overexpressed in human cholangiocarcinomas and its depletion increases PTEN and PDCD4 by decreasing microRNA-21.
Due to the lack of effective diagnostic tools, most patients with cholangiocarcinoma (CCA) have no chance of surgical resection. Ars2 is a protein that was reported to be important for microRNA (miR) biogenesis, and its depletion can reduce the levels of several miRs, including miR-21, which is overexpressed in CCAs. We hypothesized that Ars2 was also present in CCAs and could be an early diagnostic marker. In our experiments, Ars2, PTEN, PDCD4, and miR-21 were evaluated in 18 CCAs and paired normal tissues. ShArs2, miR-21 mimics, and Ars2 were transfected into CCA and bile duct epithelial cells either alone or together. Cell proliferation, tumorigenicity analysis and expression changes of Ars2, PTEN, PDCD4, and miR-21 were evaluated. We found that both Ars2 and miR-21 were overexpressed, with 95% sensitivity and 100% specificity, and an ROC of 0.995 in distinguishing between CCAs and paired normal tissues by qRT-PCR. PTEN and PDCD4 were reversed in immunohistochemistry, but no difference was observed using qRT-PCR. The knockdown of Ars2 in CCA cells decreased the level of miR-21, inhibited cell proliferation and prevented tumor formation in nude mice. Ars2 knockdown also led to an increase in both PTEN and PDCD4 protein levels. Both proteins decreased when the miR-21 mimic was con-transfected. However, the overexpression of Ars2 alone could not get the opposite results. Based on our data, we conclude that Ars2 is overexpressed in human CCA and may be a diagnostic marker. Ars2 depletion increases PTEN and PDCD4 protein levels via the reduction of miR-21.
Hepatobiliary Surgery Institute, Southwest Hospital, Third Military Medical University, Chongqing, People's Republic of China.
Qian
Q
He
Lei
L
Cai
Ling
L
Shuai
Dajiang
D
Li
Cheng
C
Wang
Yongkang
Y
Liu
Xiaowu
X
Li
Zhihua
Z
Li
Shuguang
S
Wang
D000368:Aged; D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D001650:Bile Duct Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D001653:Bile Ducts, Intrahepatic / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D018281:Cholangiocarcinoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D051379:Mice; D035683:MicroRNAs / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D008875:Middle Aged; D009687:Nuclear Proteins / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D051059:PTEN Phosphohydrolase / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D015854:Up-Regulation
D051017:Apoptosis Regulatory Proteins; C524940:MIRN21 microRNA, human; D035683:MicroRNAs; D009687:Nuclear Proteins; C114487:PDCD4 protein, human; D016601:RNA-Binding Proteins; C527299:SRRT protein, human; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human