OBJECTIVE:To study the effects of tamoxifen on lipid metabolism of hepatocellular carcinoma HepG2 cells.METHODS:HepG2 cells were cultured in vitro.MTT assay was used to measure the effects of 0.5,1,5,15 and 30 μmol/L tamoxifen on the proliferation of HepG2 cells.The effects of 0.5,1,5 μmol/L tamoxifen and 200 μmoUL cetylic acid (positive controd on the lipid accumulation of HepG2 cells were detected by oil red O staining.Fluorescence quantitative PCR was applied to determine the effects of 5 μmol/L tamoxifen on the expression of FAS,Srebp-lc and ACC in HepG2 cells and the expression of fatty acid oxidation related genes such as PPAR-α and UCP-2 were also determined.The effects of 5 μmol/L tamoxifen on protein expression and the phosphorylation of ACC were examined with Western blotting assay.AU results above were compared with blank control group.RESULTS:Compared with blank control group,0.5,1 and 5 μmol/L tamoxifen had no significant effects on the proliferation of HepG2 cells (P＞0.05),while 15 and 30 μmol/L tamoxifen could inhibit the proliferation of HepG2 cells significantly (P＜0.05) ; 5 μmol/L tamoxifen could increase lipid accumulation significantly,which was similar to positive control; 0.5 and 1 μmol/L tamoxifen had no significant effect on it (P＞0.05).The expression of FAS mRNA was increased by tamoxifen treatment while the protein levels of P-ACC were decreased (P＜0.05).No change was found in other gene and protein expression (P＞0.05).CONCLUSIONS:Tamoxifen can induce the lipid accumulation of HepG2 cells,which may be associated with the decrease of P-ACC level and the increase of FAS mRNA expression.%目的:研究他莫昔芬对肝癌HepG2细胞脂质代谢的影响.方法:体外培养HepG2细胞,MTT法检测0.5、1、5、15、30μmo]/L他莫昔芬对HepG2细胞增殖的影响;油红O染色检测0.5、1、5μmol/L他莫昔芬和200 μmol/棕榈酸(阳性对照)对HepG2细胞内脂质沉积的影响;荧光定量聚合酶链式反应法检测5 μmol/L他莫昔芬对HepG2细胞内脂肪酸(FA)合成酶(FAS)、固醇调节元件结合蛋白1c (Srebp-1c)、乙酰辅酶A羧化酶(ACC)的表达和FA氧化相关基因过氧化物酶体增殖物激活受体α(PPAR-α)、解偶联蛋白2(UCP-2)表达的影响;蛋白印迹法检测5μmol/L他莫昔芬对HepG2细胞内ACC蛋白表达及其磷酸化(P-ACC)水平的影响.以上检测结果均与空白对照组进行比较.结果:与空白对照组比较,0.5、1、5μmol/L他莫昔芬对HepG2细胞增殖无明显影响(P＞0.05),15、30 μmol/他莫昔芬能明显抑制HepG2细胞的增殖(P＜0.05);5μmol他莫昔芬能明显增加细胞内脂质沉积,且与阳性对照相似,0.5、1μmol/L他莫昔芬对细胞内脂质沉积无明显影响(P＞0.05);细胞内FAS mRNA表达明显增强、P-ACC水平明显降低(P＜0.05),其余基因和蛋白表达无明显变化(P＞0.05).结论:他莫昔芬能诱导HepG2细胞脂质沉积增加,可能与细胞内P-ACC水平降低、FAS mRNA表达上调有关.
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