去泛素化酶 USP9X在 etoposide 促结肠癌细胞 SW620 凋亡中的作用研究

目的：探讨USP9X在etoposide促结肠癌细胞SW620凋亡中的作用和可能的机制。方法：设计并合成USP9X的shRNA和对照shcontrol，采用半定量RT-PCR和Western blot检测干扰效率。结肠癌细胞SW620分别转染USP9X-shRNA和shcontrol后用etoposide处理，检测MCL1的蛋白水平变化并通过c-PARP的水平检测细胞的凋亡水平。结果：半定量RT-PCR和Western blot检测显示在SW620细胞中USP9X-shRNA能够显著例氏USP9X的mRNA和蛋白的表达，抑制率达70％，该条shRNA可以作为有效干扰序列进行后续实验。20μg／mL etoposide处理24h后，经c-PARP的水平检测发现感染USP9X-shRNA的SW620细胞比对照组细胞的凋亡率显著增加。结论：以RNA干扰技术沉默USP9X基因可增加结肠癌细胞SW620对etoposide的敏感性，显著增加etoposide诱导的结肠癌SW620细胞的凋亡，推测USP9X基因可能成为结肠癌基因治疗的一个新靶点。

Effect of USP9X on apoptosis of colon cancer induced by etoposide

Objctives： To investigate the effect of USP9X on apoptosis of colon cancer induced by etoposide and its potential mechanism. Methods： USP9X small hairpin RNA（shRNA） sequence and control shRNA sequence were designed and synthesized, and the interference effective of USP9X-shRNA was detected by semi-quantitative RT-PCR and Western btotting. After transfected with USP9X-shRNA and shcontrol, SW620 cells were treated with etoposide, the detection of c-PARP were used to analysis the apoptosis of the celt. Results： Semi-quantitative RT-PCR and Western blot showed that the mRNA and protein level of USP9X were downregulated in SW620 cells transfected with USP9X-shRNA, and the inhibition rate reach to 70%. The shRNA sequence worked well for the following experiments. After treated with 20μg/ml etoposide for 24h, SW620 cells transfected with USP9X-shRNA showed an obvious higher apoptosis rate than the control cells. Conclusion： RNA interference of USP9X can enhance the sensitive of human colon cancer cell line SW620 to etoposide. The apoptosis of SW620 that induced by etoposide was severely increased. USP9X gene may become the new target of gene therapy for colorectal cancer.