肝癌组织中胰岛素样生长因子-Ⅱ异常表达及mRNA转录干预对HepG2细胞凋亡的影响

Abnormal expression of insulin-like growth factor-Ⅱ and intervening of its mRNA transcription in the promotion of HepG2 cell apoptosis

目的观察肝癌组织及血胰岛素样生长因子（IGF）-Ⅱ表达与病理学特征的关系，以及小干扰RNA干预IGF-ⅡmRNA转录，对HepG2细胞的影响。方法以自身配对法收集南通大学附属医院2009年12月-2010年8月肝癌、癌周和远癌组织，分析IGF-Ⅱ表达，肝病患者血IGF-Ⅱ浓度和病理学特征；以siRNA转染HepG2细胞，干预IGF-ⅡmRNA转录，以反转录PCR、定量PCR和ELISA法，分别从转录及蛋白水平分析；以EdU和Hoechst33342染色分析HepG2细胞增殖与凋亡。结果肝癌组织IGF-Ⅱ基因（100％，30／30）和蛋白（83．3％，25／30）高表达，均明显高于癌周（46．7％，53．3％）及远癌组织（0，0）（均P〈0．01）；肝癌患者血IGF-Ⅱ水平（3．74±0．67）ng／L明显高于肝硬化（3．10±0．63）ng／L、慢性肝炎（1．93±0．17）ng／L及健康对照（1．14±0．14）ng／L（P〈0．001），与性别、年龄、肿瘤大小和AFP浓度间未见明显相关，但与HBV感染有关（t=5．390，P〈0．001）。体外研究显示IGF-ⅡsiRNA成功转染HepG2细胞后，IGF-Ⅱ表达在转录和蛋白水平上明显受抑，呈剂量和时间依赖；抑制IGF-ⅡmRNA转录，HepG2细胞凋亡和对阿霉素敏感性均明显增加。结论IGF-Ⅱ表达与HCC进展密切相关，干预其mRNA转录可促进癌细胞凋亡，增强化疗药物敏感性。

Objective To explore the expression and pathological features of insulin-like growth factor-Ⅱ （IGF-Ⅱ ） in tissues and sera of hepatoeellular carcinoma （HCC） patients and the siRNA-mediated inhibition of IGF-Ⅱ mRNA transcription in human HepG2 cells. Methods From December 2009 to August 2010, the self-control HCC, paraeaneerous and distal cancerous tissues were collected to analyze the expression of IGF-Ⅱ. The serum levels of IGF-Ⅱ expression were detected for pathological features. IGF-Ⅱ expression in HepG2 cells was intervened by siRNA. IGF-Ⅱ mRNA or IGF-Ⅱ level and analyzed by reverse transcription-polymerase chain reaction （ RT-PCR）, real-time PCR or enzyme-linked immunosorbent assay （ELISA）. And the ratio of cell apoptosis was analyzed by EdU/Hoechst33342. Results The levels of IGF-Ⅱ expression in HCC tissues at mRNA （100%, 30/30） or protein （83.3%, 25/30） were significantly higher （ P 〈 0. 01） than those in para-cancerous （46. 7% , 53.3% ） or distal cancerous tissues （0, 0）. The serum level of IGF-Ⅱ was significantly higher in HCC patients（3.74 ±0. 67） ng/L than that in cases with benign liver diseases（ 1.93 ±0. 17）ng/L and controls（ 1.14 ± 0. 14 ）ng/L （P 〈 0. 001 ）. The expression of IGF-Ⅱ in the HCC group was associated with HBV infection （ t = 5. 390, P 〈 0. 001 ）. After siRNA transfection, the expression of IGF-Ⅱ decreased significantly in HepG2 cells at mRNA or protein levels. The down-regulated expression of IGF-Ⅱwas dependent on the dose and time of IGF-Ⅱ siRNA. And the apoptotie index of HepG2 cells and the sensitivity to adriamyein both increased. Conclusion The expression of IGF-Ⅱ is closely associated with the progression of HCC. And the intervening of its transcription may promote apoptosis and sensitize to adriamycin.