低水平CUL1通过上调结直肠癌细胞中P21的表达抑制结直肠癌增殖和血管生成

Low Expression of CUL1 Inhibits Proliferation and Angiogenesis of Colorectal Cancer by Upregulating P21 Expression in HCT116 and SW480 cells

目的探讨CUL1在结直肠癌(CRC)细胞周期调控中的作用并初步探索其相关机制。方法采用Western blotting和PCR检测人CRC组织及细胞系HCT116、SW480中CUL1、P21以及细胞周期相关蛋白Cyclin D1的表达水平;采用流式细胞术和CCK-8细胞活性实验分析sh-CUL1及P21抑制剂(Frax597)对HCT116细胞周期和增殖的影响;采用体外内皮细胞成管实验检测sh-CUL1及Frax597对体外肿瘤血管生成的影响。结果人CRC组织和CRC细胞系HCT116、SW480细胞中CUL1均呈高表达(P>0.05);sh-CUL1可显著抑制HCT116细胞增殖及细胞周期G1/S期转换(P<0.05),但不会引起细胞凋亡(P>0.05);sh-CUL1可显著抑制HCT116细胞的体外血管生成(P<0.05);CUL1调节HCT116细胞增殖及体外血管生成是通过P21蛋白介导的。结论低水平CUL1能显著上调结直肠癌细胞内P21的表达,进而发挥调节细胞周期并抑制血管生成的作用。

Objective To investigate the role of CUL1 in the regulation of cell cycle in colorectal cancer(CRC)cells and to initially explore the related mechanisms.Methods Western blotting and PCR were used to detect the expression levels of CUL1,P21 and Cyclin D1 in human CRC tissues and HCT116 and SW480 cells.Flow cytometry and CCK-8 cell activity assay were applied to analyze the effects of sh-CUL1 and P21 inhibitor(Frax597)on cell cycle and proliferation of HCT116.The in vitro endothelial cell tube formation assays were performed to detect the effects of sh-CUL1 and Frax597 on angiogenesis.Results CUL1 was highly expressed in human CRC tissues and cell lines HCT116 and SW480.sh-CUL1 significantly inhibited cell cycle G1/S conversion and cell proliferation without causing apoptosis in HCT116 cells.It also inhibited angiogenesis of HCT116 cells in vitro.CUL1 regulated cell proliferation activity and angiogenesis in vitro via P21 protein.Conclusion Low expression of CUL1 can significantly up-regulate the expression of P21 in CRC cells,and play a role in regulating cell cycle and inhibiting angiogenesis.