高迁移率族蛋白1促进原发性肝癌细胞增殖

HMGB1 promotes cell proliferation of primary hepatocellular carcinoma

目的探讨高迁移率族蛋白1(HMGB1)及晚期糖基化终产物受体(RAGE)在原发性肝癌中的表达,研究HMGB1促进肝癌细胞增殖的作用以及相关的分子机制。方法取肝癌组织及癌旁组织各25例,免疫组化法观察组织样本中HMGB1及RAGE的表达;体外培养肝癌细胞系HepG2和正常肝细胞系L02,用Western blot检测细胞系中HMGB1及RAGE的表达。向HepG2肝癌细胞系中加入外源性重组人HMGB1蛋白(rhHMGB1),用MTT法检测处于不同浓度rhHMGB1(0、10、50和100μg/L)以及不同处理时间(0、12、24和36 h)作用下HepG2细胞的增殖率;用Western blot检测细胞中RAGE和NF-κB的表达。结果 HMGB1和RAGE蛋白在肝癌组织的阳性表达率为64%和72%,分别高于癌旁组织的20%和28%(P<0.05)。随着细胞培养时间的延长,HMGB1及RAGE的表达呈上升趋势;随着rhHMGB1浓度的升高或处理时间的延长,HepG2细胞的增殖率显著提高(P<0.05),细胞中RAGE和NF-κB的表达显著上调(P<0.05)。结论 HMGB1和RAGE蛋白在肝癌组织及肝癌细胞中高表达。HMGB1可能通过与其受体RAGE结合,进一步激活NF-κB信号通路,从而促进肝癌细胞增殖。

Objective To investigate the expression of the high-mobility group box-B1 （HMGB1） and the receptor for advanced glycation endproduct （RAGE） in primary hepatocellular carcinoma and to study the effect of HMGB1 on the proliferation of hepatocarcinoma cells and the related molecular mechanism. Methods Twenty-five cases of hepatocellular carcinoma tissues and corresponding normal liver tissues were collected and the expression of HMGB1 and RAGE in the tissue samples was observed by immunohistochemistry. HepG2 cells and normal L02 hepatocytes were cultured in vitro , and Western blot was used to detect the expression of HMGB1 and RAGE. HepG2 cells was pretreated with recombinant human HMGB1 （rhHMGB1） at different concentrations （0, 10, 50 and 100 μg/L） and for different time （0, 12, 24 and 36 h）, and then MTT assay was used to detect the proliferation of HepG2 cells. The expression of RAGE and NF-κB in HepG2 cells was detected by Western blot. Results The positive expression rates of HMGB1 and RAGE protein in hepatocellular carcinoma tissues were 64% and 72%, and much higher than corresponding normal liver tissues of 20% and 28% （ P 〈0.05）. With the prolongation of cell culture time, the expression of HMGB1 and RAGE increased. With the increase of rhHMGB1 concentration or the prolongation of treatment time, the proliferation rate of HepG2 cells was significantly increased （ P 〈0.05）, and the expression of RAGE and NF-κB was up-regulated （ P 〈0.05）. Conclusions HMGB1 and RAGE protein are highly expressed in hepatocellular carcinoma tissues and hepatocarcinoma cells. HMGB1 may activate NF-κB signaling pathway by binding to its receptor RAGE, thereby promoting the proliferation of hepatocellular carcinoma cells.