miR-26a对人肝癌HepG2蛋白表达的影响

The effect of miR-26a on the expression of protein in human hepatocarcinoma cell HepG2

目的分析mircoRNA-26a(miR-26a)转染对人肝癌HepG2细胞表达蛋白质组的影响,以确定miR-26a与肝癌发生发展的相关性。方法常规培养人肝癌HepG2细胞株,经miR-26a转染72 h后裂解并提取蛋白,双向电泳分离,匹配对比各蛋白斑点的表达量,筛选主要差异表达蛋白进行质谱鉴定。结果 HepG2细胞经miR-26a转染后表达蛋白谱呈现普遍下调的趋势,差异表达超过2倍及以上的蛋白斑点有10个。其中,有3个蛋白斑点为表达上调,有7个蛋白斑点为表达下调。质谱鉴定为:膜联蛋白A1、过氧化物酶4、增殖细胞核抗原、载脂蛋白A1、细胞色素C氧化酶5a、磷酸核糖焦磷酸激酶3、周期素依赖性蛋白激酶1和磷脂酰乙醇胺结合蛋白。结论 miR-26a可能通过调节HepG2肝癌细胞上述蛋白分子的表达,直接或间接发挥其抑癌作用。通过对这些差异表达蛋白分子机制的深入研究,将为阐明miR-26a的抗癌作用提供进一步的线索和依据。

【Objective】 To determine the effect of microRNA-26a（miR-26a） transfection on proteomic expression profile in human hepatocarcinoma cell HepG2.【Methods】 HepG2 cells were transfected with miR-26a mimics or negative control for 72h.The proteins of HepG2 cells with or without miR-26a mimic treatment were extracted following the lysis of cells and extraction of proteins,and the extracted protein was separated by two-dimensional electrophoresis.The proteomic expression profiles were analyzed by comparative proteomics technique to discover important protein spots with different expressions,and the protein with different expression with miR-26a was identified by MALDI-TOF-MS.【Results】 The proteomic expression profile of HepG2 cells with miR-26a mimics treatment showed a general down-regulation.Total of ten protein spots with over 2 times change were successfully identified,including 3 up-regulated protein（annexin A1,peroxiredoxin 4 and apolipoprotein A1） and 6 down-regulated protein（proliferating cell nuclear antigen,cytochrome c oxidase subunit 5A,ribose-phosphate pyrophosphokinase 3,cyclin-dependent kinase 1,phosphatidylethanolamine-binding protein 1 and one unknown protein）.【Conclusion】 MiR-26a could contribute its anti-cancer by regulating the expression of these proteins described above.Further investigation for the role of these proteins on pathogenesis of hepatocellular carcinoma is necessary.