ABSTRACT
PURPOSE: To identify microRNAs (miRNAs) directly regulating the proto-oncogene Bmi-1 expression in the development of hepatocellular carcinoma (HCC) and to explore the underlying molecular mechanisms. METHODS: Four HCC cell lines, including HepG2, Bel7404, Huh7, and PLC5, the normal hepatocellular cell line MIHA, and 30 HCC biopsies were included in this study. Potential miRNAs, which interact with Bmi-1 and are involved in the development of HCC were identified through bioinformatic analyses. The expression of miRNA and Bmi-1 in HCC cell lines and HCC tissues was analyzed using fluorescence protein analysis, real-time quantitative PCR (RT-qPCR), and Western blotting. RESULTS: Bioinformatic analysis suggested that miR-218 is a potential miRNA regulating Bmi-1 expression. Fluorescence protein analysis, RT-qPCR, and Western blotting confirmed the direct interaction between miR-218 and Bmi-1. In addition, increased expression of Bmi-1 was detected in HCC cell lines and HCC tissues. In most HCC tissues, the expression of miR-218 was decreased and was associated with increased expression of Bmi-1. CONCLUSION: miR-p218 downregulates the expression of the proto-oncogene Bmi-1 in HCC, and it may be an effective target for the treatment of this disease.
Subject(s)
Carcinoma, Hepatocellular/genetics , Liver Neoplasms/genetics , MicroRNAs/metabolism , Mitogen-Activated Protein Kinase 7/antagonists & inhibitors , Carcinoma, Hepatocellular/metabolism , Carcinoma, Hepatocellular/pathology , Cell Line, Tumor , Humans , Liver Neoplasms/metabolism , Liver Neoplasms/pathology , MicroRNAs/genetics , Mitogen-Activated Protein Kinase 7/biosynthesis , Mitogen-Activated Protein Kinase 7/genetics , Proto-Oncogene Mas , Proto-Oncogenes , TransfectionABSTRACT
OBJECTIVE: Titanium, by far one of the oldest materials in medical implants used for hard tissue replacement and rehabilitation, was used widely as implant material. The objective of the present study was to fabricate the TiN modified layer on the surface of medical pure titanium and improve its surface properties. Thus the wear resistance, biocompatibility and antisepsis were improved. METHODS: A continuous-wave 2 kW Nd: YAG laser was used to irradiate the sample in the environment of N2 with concentration of 99.995%. Titanium nitride surface coatings had been extensively used as corrosion resistant and biocompatible layers on titanium and its alloys. The microstructure and composition of the laser nitrided coating were studied by scanning electron microscopy and X-ray diffraction. Microhardness of the modified sample was also analyzed by micro-hardmeter. RESULTS: TiN modified layer with the thickness of about 400 microm was obtained. TiN distributed gradually from surface to the substrate. There was a good metallurgical bonding between the nitrided layer and the substrate. The hardness of the modified layer was reduced from the surface to the inside. CONCLUSION: With optimum process parameters, a compact laser modified gradient coating reinforced with fine TiN was achieved on the surface of medical titanium.
