目的：探讨siRNA技术干扰胰岛素样生长因子-1受体（insulin-like growth factors-1 receptors, IGF-1R）表达对缺氧环境下肝癌HepG2 细胞周期和凋亡的影响。方法：采用氯化钴处理制备实验所需的肝癌缺氧细胞模型。设计并合成3 对siRNA序列和1 对阴性对照序列，转染缺氧的肝癌HepG2 细胞24 h 后以荧光显微镜观察转染效果，采用WB法检测IGF-1R蛋白表达筛选出干扰效率最高的siRNA序列。选用该序列再次转染缺氧肝癌细胞，以流式细胞术、MTT法检测细胞的周期、凋亡和增殖变化，以WB法检测HepG2 细胞中CDK1、CDK2 和Caspase-3 蛋白的表达。结果：成功建立缺氧HepG2 细胞模型，siRNA转染缺氧HepG2 细胞后以IGF-1R-siRNA-2 转染效率最高且敲减IGF-1R表达最明显（均P<0.01）。IGF-1R-siRNA-2 转染的HepG2 细胞的增殖被明显抑制（P<0.05 或P<0.01）、细胞周期被阻滞在G0/G1（P<0.05）、细胞凋亡率明显增加至（25.3±1.3）%（P<0.01），同时发现敲减IGF-1R后缺氧HepG2 细胞中CDK1、CDK2 蛋白表达明显降低而Caspase-3 表达则明显增加（P<0.05或P<0.01）。结论：siRNA干扰IGF-1R表达通过调控细胞周期和凋亡相关蛋白而抑制缺氧环境中HepG2细胞的恶性生物学行为，IGF-1R可能是HCC潜在的治疗靶点。

Objective: To explore the effect of interfering insulin-like growth factors-1 receptors (IGF-1R) by small interfering RNA (siRNA) on cell cycle and apoptosis of hypoxic hepatocellular carcinoma HepG2 cells. Methods: The hypoxic hepatocellular carcinoma model was established via cobalt chloride treatment. Three siRNAs targeting IGF1R gene and one negative control siRNA were designed and synthesized. They were transfected into hypoxic HepG2 cells, and 24 h later, the transfection efficiency was detected by fluorescent microscopy. The protein expression of IFG-1R was detected with Western blotting (WB) to screen the siRNA with highest transfection efficacy. The selected siRNA was used to transfect hypoxic HepG2 cells. The proliferation of hypoxic HepG2 cells was determined by MTT assay. Cell cycle distribution and apoptosis were analyzed by Flow cytometry. WB was performed to detect the protein expressions of CDK1, CDK2 and Caspase-3 in HepG2 cells. Results: The hypoxic hepatocellular carcinoma model was successfully established. IGF-1R-siRNA-2 showed the most effective interference efficiency and the most significant knockdown of IGF-1R (all P<0.01). The proliferation of HepG2 cells transfected with IGF-1R siRNA-2 was significantly suppressed (P<0.05 or P<0.01), the cell cycle was blocked at G0/G1 phase (P<0.05), and the apoptosis rate was increased up to (25.3±1.3)% P<0.01). In the meanwhile,the expressions of CDK1 and CDK2 were decreased and the expression of Caspase-3 was increased in hypoxic HepG2 cells after IGF-1R knockdown (P<0.05). Conclusion: Interfering IGF-1R by siRNA inhibits the malignant biological behaviors of hypoxic HepG2 cells via regulating cell cycle and apoptosis-related proteins. IGF-1R may be a potential target for the treatment of HCC.

福建省卫计委青年课题资助项目（No. 2016-1-65）；福建医科大学附属第二医院苗圃基金资助项目（No. 2017MP10）