miR-483-5p promotes growth, migration and invasion of hepatocellular carcinoma cells by up-regulating IGF2 gene transcription / 中国病理生理杂志

ABSTRACT

AIM:To investigate the effect of miR-483-5p on P3 promoter-driven mRNA(P3 mRNA)expres-sion of human insulin-like growth factor 2(IGF2)gene and its role in the development of hepatocellular carcinoma (HCC).METHODS: The expression levels of miR-483-5p and P3 mRNA were analyzed by real-time PCR in human HCC cell lines Huh7,Hep3B,Bel-7402,HepG2 and SMMC-7721,normal human liver cell line HL-7702,83 cases of hu-man HCC tissues and their matched adjacent nontumorous tissues(MANT), and 22 cases of normal adult liver tissues (NALT).The association between P3 mRNA level and miR-483-5p level was evaluated by Pearson correlation analysis. The full-length sequences of 5'UTR of P3 mRNA containing wild-type and mutant miR-483-5p-binding sequences were cloned into pGL3 promoter vector, which were termed pGL3-P3-5'UTR-WT and pGL3-P3-5'UTR-MUT, respectively. These luciferase reporter constructs were transfected into HeLa,293T and Huh7 cells together with miR-483-5p mimic, miR-483-5p inhibitor or scrambled control,and the luciferase activity was measured using dual-luciferase reporter system. The miR-483-5p mimic,miR-483 inhibitor and scrambled control were also transfected into Huh 7 cells and Hep3B cells, and P3 mRNA level was detected by real-time PCR.The expression levels of miR-483-5p in the nuclear and cytoplasmic fractions of Hep3B cells and Huh7 cells were detected by real-time PCR.The effect of miR-483-5p on P3 mRNA transcrip-tion was evaluated by nuclear run-on assay.The effect of miR-483-5p on the stability of P3 mRNA was analyzed by RNA stability assay.Furthermore,the effects of miR-483-5p on the viability, apoptosis, migration and invasion of Huh7 cells were investigated.RESULTS:Significamtly high levels of miR-483-5p and P3 mRNA were detected in the 5 human HCC cell lines and the human HCC tissues as compared with the human normal liver cell line HL-7702, and the MANT and NALT,respectively.Linear correlation analysis revealed that P 3 mRNA level was positively correlated to miR-483-5p level in the 5 human HCC cell lines and the human HCC tissues.miR-483-5p directly recognized the P3 mRNA 5'UTR to pro-mote gene expression.Overexpression of miR-483-5p resulted in a significant increase in P3 mRNA expression in a dose-dependent manner in the Huh7 cells and Hep3B cells.The mature miR-483-5p was present in both cytoplasm and nucleus of Hep3B cells and Huh7 cells.miR-483-5p induced nascent P3 mRNA transcription in the nucleus of Huh7 cells.miR-483-5p did not alter P3 mRNA stability in Huh7 cells.Furthermore,miR-483-5p led to increased viability,apoptosis inhi-bition,and enhanced migration and invasion abilities in the Huh 7 cells.CONCLUSION:High expression of miR-483-5p promotes the growth,migration and invasion of HCC cells in part through up-regulating P3 mRNA transcription,and is con-sequently involved in the development of HCC.