AIM:To study the effects of Se-methylselenocysteine(MSC) on the growth and apoptosis of human liver carcinoma cell line,HepG_2 cells and the molecular mechanism of effects.METHODS: After HepG_2 cells treated with various concentrations of MSC,survival and apoptosis were determined by MTT assay and light microscope,apoptosis and cell cycle were determined by flow cytometry.Malignant phenotype was determined by soft agarose growth assay.Cyclin D1 mRNA expression was determined by RT-PCR and Caspase-3 activity was measured by Caspase-3 activity assay kit.RESULTS: After being treated with 25(?mol?L~(-1)) MSC for 24 h,the survival of HepG_2 cells was decreased,a marked apoptosis and S phase arrest characteristic was observed in time-and dose-dependent manner.Soft agatose growth assay showed MSC inhibited HepG_2 cells growth in soft agarose.RT-PCR and Caspase-3 assay showed that HepG_2 cells treated with 25(?mol?L~(-1)) MSC for 24 and 48 hours,the expression of Cyclin D1 mRNA was down-regulated by 38% and 47%,while Caspase-3 activity was up-regulated by((39.61)?(6.65))%and((118.73)?(6.48))%.HepG_2 cells treated with 50(?mol?L~(-1)) MSC for 24 and 48 h,the expression of Cyclin D1 mRNA was down-regulated by 53% and 82%, whereas Caspase-3 activity was up-regulated by((80.66)?(9.31))% and((152.67)?(7.95))%.CONCLUSION: MSC can inhibit the growth of HepG_2 cells,and induce apoptosis and S phase arrest of HepG_2 cells.The phenotype alterations of HepG_2 cells might relate with inhibition of Cyclin D1 expression and Caspase-3 activity by MSC in the cells.

BACKGROUND: A large amount of in vivo and in vitro experiments have confirmed that, basic fibroblast growth factor (bFGF) has been widely utilized in various tissues and cells, it can facilitate the wound healing.OBJECTIVE: To observe the efficacy and feasibility of gene gun-mediate delivery of human bFGF on the healing of deep partial thickness bum wounds.DESIGN, TIME AND SETTING: Randomized design,an observational trial was performed at the Military Central Laboratory of Changhai Hospital in the Second Military Medical University of Chinese PLA between December 2007 and October 2008.MATERIALS: SD rats of clean grade, weighing 200-250 g, irrespective of genders, ware involved in this study.METHODS: Natural human bFGF gene was recombined and optimized, then eukaryotic expression vector pCI-neo-bFGF was constructed taking pCI-neo as a vector, and transfeoted with human embryonic kidney cells 293 T cells. Dot blot and Western blot methods were utilized to determine the bFGF expression. Rat model of deep partial thickness burn wounds was processed into transgene process using gene gun technique, pCI-neo-bFGF-transfected ones served as experiment group while pCI-neo-transfected ones served as controls.MAIN OUTCOME MEASURES:Wound healing time was recorded and the efficacy was evaluated. The contents of hydroxyproline and collaganase Ⅰ in burn wound tissues were determined at 24 hours, 48 hours, 96 hours, 7 days, 10 days and 14 days following transgene process.RESULTS: the recombinant pCI-neo-bFGF was transfected with human embryonic kidney 293T cells. Dot blot and Western blot analysis have showed that, the constructed pCI-neo-bFGF expression vector could express human bFGF, and the expression of synthesized gene was remarkably higher than that of natural gene under fluorescence microscope; gene gun-mediated transgene experiment have showed that, the wound healing time was (13.00+1.31) days in the experiment group and (14.75±1.28) days in the control group, with significant differences (P＜0.05). The contents of hydroxyproline and collagenase Ⅰ reached a peak at 5 days after the injury, that is 48 hours after transfection, and then gradually decreased and maintained at a certain level. The experiment group had higher hydroxyproline levels compared with control group at different time points (P＜0.05, P＜0.01); the collagenase Ⅰ in the experiment group was notably higher than that in the control group at 48 hours and 96 hours after transfection (P＜0.01).CONCLUSION: Gene gun-mediated delivery of human bFGF can short the time of wound healing, increase the contents of hydroxyproline and collagenase Ⅰ during the healing period, accelerate the healing of deep partial thickness burn wounds.