小RNA技术干扰p21联合环磷酰胺对HepG2细胞增殖及凋亡的影响

目的探讨小RNA干扰p21表达联合环磷酰胺对HepG2细胞增殖和凋亡的影响及相关作用机制。方法将化学合成的针对p21的siRNA序列转染至HepG2细胞，将HepG2细胞分为5组：空白对照组、阴性对照组、RNA抑制组、环磷酰胺组、联合组（RNA抑制＋环磷酰胺）。采用Mrrr比色法、流式细胞术和分光光度法分别检测HepG：细胞增殖、细胞凋亡及半胱氨酸天冬氨酸蛋白酶家族成员caspase-9、caspase．3和caspase-6的活化程度。结果p21 siRNA转染后，相对于环磷酰胺单独处理组，联合处理组HepG，细胞增殖率显著降低，而细胞凋亡率则率明显升高（P〈0．01）；caspase-9、caspase-3和caspase-6的活化程度显著升高（P〈0．01）。结论p21靶向RNA抑制作用联合环磷酰胺处理显著促进了HepG2细胞凋亡，p21可作为肝癌基因治疗的后选新靶点。

Influence of small interfering RNA inhibiting p21 combined with cyclophosphamide on proliferation and apoptosis of HepG2 cells

Objective To explore the influence of small interfering RNA inhibitiing p21 combined with cyclophosphamide （CTX） on proliferation and apoptosis of HepG2 cells and its related mechanism. Methods The siRNA sequence targeting p21 which was synthesized by chemical method was transfected into HepG2 cells. The HepG2 cells were divided into five groups ： blank control group, negative control group, siRNA group, CTX group and combination group （siRNA combined with CTX）. MTr assay, flow cytometry and spectrophotometry were employed to detect the cell proliferation, apoptosis and caspase-9, caspase-3 and caspase-6 activities. Results The apoptosis of HepG2 cells and activities of caspase-9, caspase-3 and caspase-6 were significantly higher in combination group than those in CTX group after transfection（ P 〈 0.01 ） ,while the proliferation of HepG2 cells decreased （P 〈 0.01 ）. Conclusion The siRNA combined with CTX can significantly induce cell apoptosis, and p21 gene may be a candidate target in the gent therapy of hepatoma.