Department of Orthopedics, The First Affiliated Hospital of China Medical University, Shenyang 110001, Liaoning, PR China.
Biochem Biophys Res Commun. 2013 Sep 20;439(2):179-86. doi: 10.1016/j.bbrc.2013.08.066. Epub 2013 Aug 29.
MG132 as a proteasome inhibitor could induce apoptosis in various cancer cells. This study aimed to discuss the effect of proteasome inhibitor MG132 on the TRAIL-induced apoptosis of human osteosarcoma OS732 cells. MG132 and TRAIL were applied on OS732 cells respectively or jointly. Cell survival rates, changes of cellular shape, cell apoptosis and cell invasion were analyzed, respectively, by 3-(4,5)-dimethylthiahiazo(-z-y1)-2,5-di-phenytetrazoliumromide (MTT) assay, inverted phase contrast microscope, flow cytometry, and transwell invasion chamber methods. The protein levels of DR5, caspase-3, caspase-8, p27(kip1) and MMP-9 were measured by Western blot analysis. The results indicated that combination of MG132 and TRAIL had the effect of up-regulating expression of DR5, caspase-3, caspase-8 and p27(kip1), down-regulating expression of MMP-9 and inducing apoptosis as well as suppressing the ability of invasion of OS732 cells. The survival rate of combined application of 10 μM MG132 and 100 ng/ml TRAIL on OS732 cells was significantly lower than that of the individual application (p<0.01). Changes of cellular shape and apoptotic rates also indicated the apoptosis-inducing effect of combined application was much stronger than that of individual application. Cell cycle analysis showed combination of MG132 and TRAIL mostly caused OS732 cells arrested at G2-M-phase. The invasion ability of OS732 cells was restrained significantly in the combined group compared with the individual group and control group.
MG132 作为一种蛋白酶体抑制剂，能够诱导多种癌细胞凋亡。本研究旨在探讨蛋白酶体抑制剂 MG132 对 TRAIL 诱导人骨肉瘤 OS732 细胞凋亡的影响。分别用 MG132 和 TRAIL 以及两者联合作用于 OS732 细胞，采用 MTT 法检测细胞存活率、倒置相差显微镜观察细胞形态学变化、流式细胞术检测细胞凋亡率、Transwell 小室法检测细胞侵袭能力，Western blot 检测 DR5、caspase-3、caspase-8、p27(kip1) 和 MMP-9 蛋白的表达。结果表明，MG132 与 TRAIL 联合应用具有上调 DR5、caspase-3、caspase-8 和 p27(kip1) 表达、下调 MMP-9 表达、诱导 OS732 细胞凋亡和抑制侵袭能力的作用。10 μM MG132 与 100 ng/ml TRAIL 联合应用对 OS732 细胞的存活率显著低于单独应用时（p<0.01）。细胞形态学变化和凋亡率也表明联合应用的诱导凋亡作用明显强于单独应用。细胞周期分析表明，MG132 与 TRAIL 联合应用主要使 OS732 细胞阻滞在 G2-M 期。与单独用药组和对照组相比，联合用药组 OS732 细胞的侵袭能力明显受到抑制。
