ABSTRACT
To investigate the effect of long noncoding RNA (LINC01419)/miR-485-5p/LSM4 on the malignant behavior of hepatocellular carcinoma (HCC) cells. The expressions of LINC01419, miR-485-5p, and LSM4 were determined in HCC at the cellular and clinical levels, and cell biological behavior was evaluated. The relationships between LINC01419, miR-485-5p, and LSM4 were predicted and verified. Additionally, the subcellular localization of LINC01419 in HCC cells was analyzed. Finally, an animal experiment was conducted to confirm the effect of LINC01419 silencing on tumor growth. in HCC tissues and cells, LINC01419 and LSM4 were increasingly expressed, but miR-485-5p was decreasingly expressed. LINC01419 negatively regulated miR-485-5p- and miR-485-5p-targeted LSM4. LINC01419 was localized in the cytoplasm of HCC cells. Downregulation of miR-485-5p or upregulation of LSM4 reversed the inhibition of HCC cell malignant behavior by LINC01419 interference. LINC01419 sponges miR-485-5p to upregulate LSM4 expression, thereby facilitating the biological behavior of HCC cells.
Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , MicroRNAs , RNA, Long Noncoding , Animals , Carcinoma, Hepatocellular/pathology , Cell Line, Tumor , Cell Movement , Cell Proliferation/genetics , Gene Expression Regulation, Neoplastic , Liver Neoplasms/pathology , MicroRNAs/genetics , MicroRNAs/metabolism , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolismABSTRACT
BACKGROUND: Long noncoding RNA (lncRNA) small nucleolar RNA host gene 3 (SNHG3) is an oncogenic lncRNA that has been reported in many cancers, but the role of SNHG3 in cholangiocarcinoma (CCA) remains largely unknown. Bioinformatic analysis revealed a regulatory relationship among SNHG3, miR-3173-5p, and ERG. miR-3173-5p is a tumour suppressive miRNA, while ERG is an oncogene. In the present study, we focused on the regulatory effects and molecular mechanisms of SNHG3 in CCA. METHOD: The expression of SNHG3 and miR-3173-5p was evaluated using qRT-PCR analysis. Knockdown of SNHG3 was achieved by shRNA. Cell viability was assessed by MTT assay. Migration and invasion were determined by Transwell assay. Flow cytometry was used to assess cell apoptosis. Western blots were applied to quantify protein levels. Furthermore, using RNA pulldown and dual luciferase assays, the interactions between SNHG3 and miR-3173-5p and between miR-3173-5p and ERG in CCA cells were validated. RESULTS: SNHG3 was significantly upregulated in CCA cells compared with normal human intrahepatic biliary epithelial cells. Knockdown of SNHG3 inhibited the proliferation and migration of CCA cells. Mechanistically, SNHG3-sponged miR-3173-5p, thus releasing the repression of ERG by miR-3173-5p. Rescue experiments showed that the miR-3173-5p/ERG axis mediated the oncogenic effect of SNHG3. CONCLUSION: Taken together, our data suggest that SNHG3 is a pleiotropic oncogenic lncRNA in CCA. Knockdown of SNHG3 expression suppressed malignant phenotypes in CCA cells via the miR-3173-5p/ERG axis.
Subject(s)
Bile Duct Neoplasms , Cholangiocarcinoma , MicroRNAs , RNA, Long Noncoding/genetics , Apoptosis , Bile Duct Neoplasms/pathology , Bile Ducts, Intrahepatic/pathology , Cell Line, Tumor , Cell Movement/genetics , Cell Proliferation/genetics , Cholangiocarcinoma/genetics , Cholangiocarcinoma/pathology , Gene Expression Regulation, Neoplastic , Humans , MicroRNAs/genetics , MicroRNAs/metabolism , Phenotype , RNA, Long Noncoding/metabolism , Transcriptional Regulator ERG/genetics , Transcriptional Regulator ERG/metabolismABSTRACT
Cholangiocarcinoma (CCA) is a highly aggressive and malignant tumor. In this study, the effect and molecular mechanism of nuclear enriched abundant transcript 1 (NEAT1) in CCA were elucidated. The expressions of NEAT1, microRNA-186-5p (miR-186-5p), and PTP4A1 were measured by quantitative real-time PCR. The protein levels were measured by Western blotting. Kaplan-Meier analysis was performed to create survival curves. The interactions between NEAT1, miR-186-5p, and PTP4A1 were assessed through the dual luciferase reporter assay. Additionally, the cell proliferation, apoptosis, migration, and invasion were measured by colony formation, flow cytometry, the Transwell assay, and the wound healing assay, respectively. NEAT1 and PTP4A1 were significantly upregulated in CCA tissues and cells, but miR-186-5p was downregulated. NEAT1 expression was negatively correlated with the survival of CCA patients and has remarkable correlation with serum CA199 levels and lymph node metastasis. Besides, NEAT1 could act as a molecular sponge for miR-186-5p to upregulate PTP4A1 expression. More importantly, the knockdown of NEAT1 or overexpression of miR-186-5p inhibited the proliferation, migration and invasion of CCA cells, and the inhibition of miR-186-5p reversed the effects of the knockdown of NEAT1. In addition, NEAT1 could also activate the PI3K/AKT signaling pathway and regulate the epithelial-mesenchymal transition (EMT) through the miR-186-5p/PTP4A1 axis. In conclusion, NEAT1 was involved in cell proliferation, migration and invasion in CCA, and the NEAT1/miR-186-5p/PTP4A1/PI3K/AKT axis indicated novel regulatory mechanisms and therapeutics for the treatment of CCA.
