摘要
目的观察γ线放射后FLCN缺失的肾癌细胞与高表达FLCN的肾癌细胞凋亡及自噬水平上的差别,并进一步确定γ线放射在FLCN缺失的肾癌细胞中诱导自噬的分子机制。方法本实验使用UOK257/UOK257-2及ACHN-sc/ACHN 5968两组细胞,通过Western blot、GFP-LC3及MDC荧光方法观察细胞内自噬现象,通过TUNEL方法测定细胞凋亡,通过克隆存活实验测定细胞对γ线放射的敏感性,并利用3-MA或Beclin 1 siRNA抑制自噬后,再次观察细胞内自噬、凋亡以及细胞对γ线放射敏感性的变化。结果相对于ACHN-sc/UOK257-2细胞,UOK257/ACHN 5968对γ线放射较敏感,且γ线放射可以在UOK257/ACHN 5968细胞中诱导更明显的自噬反应。应用自噬诱导剂雷帕霉素可以增强γ线放射对UOK257和ACHN 5968细胞的杀伤作用。Western blot结果表明,γ线放射通过激活MAPK信号通路并上调Beclin-1蛋白表达从而在UOK257/ACHN 5968细胞中激活自噬反应。结论 FLCN可以降低肾癌细胞对γ线放射的敏感性,无FLCN表达的UOK257肾癌细胞对γ线放射较敏感。与单独的γ线放射相比,联合应用自噬诱导剂和γ线放射对FLCN缺失或下调的肾癌细胞有更强的杀伤效果,而这可能为BHD伴发的肾癌或其它相关肿瘤的治疗提供一种更有效的治疗途径。
Objective Investigate the cellular and molecular mechanism of γ-irradiation-induced autoph-agy and apoptosis in renal cancer cells with and without FLCN expression. Methods Two pairs of cell lines were used:FLCN siRNA-silenced ACHN cell line (ACHN-5968)and scrambled ACHN cell line (ACHN-sc);FLCN-null UOK257 cell line and UOK257-2 cell line restored with ectopic expression of FLCN. Autophagy was examined by western blot,GFP-LC3,and MDC assay. Cell apoptosis was detected using TUNEL assay. cell radiosensitivity was measured by clonogenic assay. After inhibition of autophagy with 3-Methyladenine (3-MA)or Beclin 1 siRNA,cell radiosensitivity and apoptosis were measured again. Results Compared to FLCN -expressing counterparts,cancer cells without FLCN were more sensitive toγ-irradation,andγ-irradation in-duced more autophagy in FLCN-deficient UOK257 and ACHN-5968 cells. Rapamycin treatment significantly enhanced radiation-induced killing of these FLCN-deficient cells. The MAPK pathway was also identified as a key pathway for the activation of autophagy in these kidney cancer cells. Conclusions Our results suggest that FLCN-deficient renal cancer cells exhibited higher radiosensitivity. γ-irradation combined with an autophagy inducer might be a potentially more effective therapeutic approach for FLCN-deficient renal cancer.
出处
《泌尿外科杂志（电子版）》
2014年第1期13-20,共8页
Journal of Urology for Clinicians(Electronic Version)
