甘珀酸增强RSL3对耐顺铂睾丸癌细胞增殖、侵袭和迁移的抑制作用

目的 探讨铁死亡诱导剂RSL3对耐顺铂睾丸癌细胞（I-10/DDP）增殖、侵袭和迁移能力的影响以及甘珀酸对RSL3抗耐药睾丸癌活性的作用。方法 MTT法检测不同浓度RSL3（0、1、2、4、8、16、32 μmol/L）及合用甘珀酸（100 μmol/L）作用后I-10/DDP细胞的存活率、铁死亡抑制剂Fer-1（2 μmol/L）的作用下RSL3（4 μmol/L）及甘珀酸（100 μmol/L）合用RSL3（4 μmol/L）处理后I-10/DDP细胞的存活率。后续实验分为Control组、甘珀酸（100 μmol/L）组、RSL3（2 μmol/L）组、甘珀酸（100 μmol/L）合用RSL3（2 μmol/L）组，采用集落克隆实验检测细胞增殖能力、划痕实验和Transwell实验检测细胞侵袭与迁移能力。Western blot检测GPX4水平、C11 BODIPY 581/591荧光探针检测lipid 活性氧（ROS）水平、FerroOrange荧光探针检测Fe2+水平。结果 RSL3呈浓度依赖性降低I-10/DDP细胞存活率，且在RSL3浓度2、4、8 μmol/L 时，合用甘珀酸后细胞存活率显著降低（P<0.05）；与Control组相比，RSL3处理后I-10/DDP细胞的集落形成数减少、划痕愈合率减小（P=0.012）、侵袭和迁移细胞数减少（P<0.001）；与单用RSL3相比，甘珀酸合用RSL3处理后I-10/DDP细胞的集落形成数显著减少、划痕愈合率显著减小（P=0.005）、侵袭和迁移细胞数显著减少（P=0.001，P=0.002）。Fer-1降低单用RSL3、甘珀酸合用RSL3对I-10/DDP细胞增殖的抑制率（P<0.01）；与Control组相比，RSL3作用后细胞内GPX4水平降低（P=0.001）、lipid ROS 水平（P=0.001）和Fe2+水平升高；且与单用RSL3相比，甘珀酸合用RSL3处理后细胞内GPX4水平明显降低（P=0.01）、lipid ROS 水平（P=0.001）和Fe2+水平明显升高。结论 RSL3可诱导耐顺铂睾丸癌细胞发生铁死亡，并能抑制细胞增殖、侵袭和迁移能力；甘珀酸通过促进RSL3诱导的铁死亡从而增强RSL3的抑制作用。

Carbenoxolone enhances inhibitory effect of RSL3 against cisplatin-resistant testicular cancer cells by promoting ferroptosis

Objective To investigate the inhibitory effect of RSL3 on the proliferation, invasion and migration of cisplatinresistant testicular cancer cells (I-10/DDP) and the effect of carbenoxolone on the activity of RSL3 against testicular cancer. Methods MTT assay was used to evaluate the survival rate of I-10/DDP cells following treatment with RSL3 (1, 2, 4, 8, 16 or 32 μmol/L) alone or in combination with carbenoxolone (100 μmol/L) or after treatment with Fer-1 (2 μmol/L), RSL3 (4 μmol/L), RSL3+Fer-1, RSL3+carbenoxolone (100 μmol/L), or RSL3+Fer-1+carbenoxolone. Colony formation assay was used to assess the proliferation ability of the treated cells; wounding-healing assay and Transwell assay were used to assess the invasion and migration ability of the cells. The expression of GPX4 was detected using Western blotting, the levels of lipid ROS were detected using C11 BODIPY 581/591 fluorescent probe, and the levels of Fe2 + were determined with FerroOrange fluorescent probe. Results RSL3 dose-dependently decreased the survival rate of I-10/DDP cells, and the combined treatment with 2, 4, or 8 μmol/L RSL3 with carbenoxolone, as compared with RSL3 treatment alone, resulted in significant reduction of the cell survival rate. The combination with carbenoxolone significantly enhanced the inhibitory effect of RSL3 on colony formation, wound healing rate (P=0.005), invasion and migration of the cells (P<0.001). Fer-1 obviously attenuated the inhibitory effects of RSL3 alone and its combination with carbenoxolone on I-10/DDP cells (P<0.01). RSL3 treatment significantly decreased GPX4 expression (P=0.001) and increased lipid ROS level (P=0.001) and Fe2+ level in the cells, and these effects were further enhancedby the combined treatment with carbenoxolone (P<0.01). Conclusion Carbenoxolone enhances the inhibitory effect of RSL3 on the proliferation, invasion and migration of cisplatin-resistant testicular cancer cells by promoting RSL3-induced ferroptosis.