Studies On The Function And Probable Underlying Mechanism Of MiRNA-206Ectopic Overexpression In Human Hepatocellular Carcinoma

With regard to miR-206, a member of the muscle-specific miR-1family ofmyomiRs, and early studies identified miR-206as a skeletal muscle-specific miRNAinvolved in muscle development. However, subsequent studies revealed thatmiR-206was closely related to various tumours., and is involved in cell proliferation,apoptosis and migration. Recent studies show that miR-206can act as a tumorsupressor. Studies have shown that miR-206can target Notch3is one of theimportant mechanisms to suppress tumor development.Objective:In this study,we aimed to investigate the potential function and probableunderlying mechanism of miR-206in the development and progression of HCCfrom both molecular and cellular levels, and simulated gene therapy for cancer toprovide it with some reference theory and experimental basis.Methods:1. The expression of Notch3in HCC and matched non-neoplastic tissue wereimmunohistochemically assessed on formalin-fixed, paraffin-embedded sections.2. The role of miR-206overexpression on human hepatocellular carcinomacells HepG2in vitro.miR-206mimics were transiently transfected into HepG2cells usingLipofectamineTM2000. Then, we evaluated the role of miR-206in cell proliferation,apoptosis, cycle arrest, and migration using MTS assay, Hoechst33342staining,Annexin V-FITC/PI assay, flow cytometry analysis, and wound healing in HepG2cells.Using quantitative real-time PCR (qRT-PCR) and Western blot, we detectedthe expression of Notch3,Bax,Bcl-2,Hes1,P57and MMP-9both at mRNA andprotein levels,miR-206at mRNA level,Caspase-3at protein level, respectively.Results:1. miR-206overexpression could inhibit cell proliferation and activateapoptotic cell death in HepG2cells. 2. miR-206overexpression could induce cell cycle arrest and inhibite migrationof HepG2cells.3. After miR-206was upregulated in HepG2cells, Notch3,Hes1, Bcl-2andMMP-9were downregulated both at mRNA and protein levels,but P57and Bax wereupregulated.cleaved Caspase-3was dramatically increased at protein level as well.4. Immunostaining showed high Notch3protein expression in the cytoplasmof neoplastic hepatocytes compared with occasional weak hepatocytic staining intheir corresponding adjacent non-neoplastic tissues samples.5. The probable underlying mechanism that miR-206inhibits cell growth andmigration is at least partially dependent on Notch3signaling in HepG2cells.Conclusion:miR-206involves in the regulation of cell growth,apoptosis,cell cycle andmigration in HepG2cells, and the probable underlying mechanism that miR-206inhibits cell growth and migration is at least partially dependent on Notch3signalingin HepG2cells. miR-206as a potential regulatory factor may become a new targetfor the treatment of liver cancer.