siRNA干扰BIRC6对肾癌786-O细胞凋亡和自噬的影响

目的 研究杆状病毒IAP重复序列蛋白6（BIRC6）在肾癌组织中的表达，并探讨BIRC6沉默对786-O细胞凋亡和自噬的影响。方法 收集2016年2月~2018年12月梅州市人民医院肾癌手术切除标本20例，通过免疫组化检测BIRC6蛋白在肾癌组织中的表达水平。将肾癌786-O细胞分为两组，对照siRNA组和BIRC6 siRNA组；通过lipofectamine 2000将BIRC6小干扰RNA（BIRC6-siRNA）及其对照siRNA（con-siRNA）转染到肾癌786-O细胞，Western blot检测转染后BIRC6蛋白表达水平，CCK8和流式细胞术分别检测BIRC6-siRNA和5-FU人肾癌786-O细胞活力和凋亡的影响，Western blot检测细胞自噬相关蛋白Beclin和LC3A/B的表达水平。结果 免疫组化结果显示BIRC6蛋白在肾癌组织中的表达显着高于正常肾组织，转染BIRC6-siRNA后786-O细胞的BIRC6蛋白表达水平显著降低。12.5、25、50、100和200 μg/mL的5-FU诱导786-O细胞后，BIRC6-siRNA组细胞增殖抑制率显著高于con-siRNA组，差异具有统计学意义（P<0.01）；流式检测结果显示，BIRC6-siRNA组肾癌786-O细胞凋亡率显著高于con-siRNA组，差异具有统计学意义（P<0.01）；BIRC6-siRNA组肾癌786-O细胞Beclin和LC3A/B蛋白表达显著低于con-siRNA组。结论 siRNA干扰BIRC6能够抑制肾癌786-O细胞自噬，促进5-FU诱导的细胞凋亡，促进肾癌786-O细胞对5-FU的敏感性。

Effect of small interfering RNA-mediated BIRC6 silencing on apoptosis and autophagy of renal cancer 786-O cells

Objective To study the expression of BIRC6 in renal cancer tissues and investigate the effect of BIRC6 silencing on apoptosis and autophagy of 786-O cells. Methods Twenty surgical specimens of renal cancer tissues and adjacent renal tissues were collected from Meizhou People's Hospital between February, 2016 and December, 2018 for detection of BIRC6 protein expression using immunohistochemistry. Renal cancer 786-O cells were transfected with a control small interfering RNA (siRNA) or BIRC6 siRNA via lipofectamine 2000, and the changes in cell proliferation and apoptosis following 5-FU treatment were assessed using CCK8 assay and flow cytometry; the expressions of autophagy-related proteins Beclin and LC3A/B were detected by Western blotting. Results The expression of BIRC6 protein was significantly higher in renal cancer tissues than in the adjacent renal tissues. Western blotting showed that siRNA-mediated silencing of BIRC6 significantly lowered the expression of BIRC6 in 786-O cells. In the cells with BIRC6 silencing, treatment with 12.5, 25, 50, 100 and 200 μg/mL 5-FU resulted in significantly higher proliferation inhibition rates than in the cells transfected with the control siRNA (P<0.01). BIRC6 silencing also significantly increased the apoptosis rate of 786-O cells following 5-FU treatment (P<0.01). The results of Western blotting showed that BIRC6 silencing significantly lowered the protein expressions of Beclin and LC3A/B in 786-O cells. Conclusion Interference of BIRC6 mediated by siRNA can inhibit autophagy and promote 5-FU-induced apoptosis to enhance the sensitivity of 786-O cells to 5-FU.