ABSTRACT
@# 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 proteinexpressionsofCDK1,CDK2andCaspase-3inHepG2cells. 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.