Background Abiraterone and MDV3100 are two effective anticancer agents for prostate cancer, however, the mechanism of their downstream action remains undefined. Methods A dual fluorescent biosensor plasmid was transfected in LNCaP cells to measure mitophagy. The DNA of LNCaP cells was extracted and performed with quantitative real-time PCR to detect mitochondrial DNA copy number. JC-1 staining was utilized to detect the mitochondrial membrane potential and electron microscope was performed to analyze mitochondrial morphology. Moreover, the protein levels of mitochondrial markers and apoptotic markers were detected by western blot. At last, the proliferation and apoptosis of LNCaP cells were analyzed with CCK-8 assay and flow cytometry after abiraterone or MDV3100 treatment. Results Mitophagy was induced by abiraterone and MDV3100 in LNCaP cells. The low expression level of mitochondrial DNA copy number and mitochondrial depolarization were further identified in the abiraterone or MDV3100 treatment groups compared with the control group. Besides, severe mitochondria swelling and substantial autophagy-lysosomes were observed in abiraterone- and MDV3100-treated LNCaP cells. The expression of mitochondria-related proteins, frataxin, ACO2 and Tom20 were significantly downregulated in abiraterone and MDV3100 treated LNCaP cells, whereas the expression level of inner membrane protein of mitochondria (Tim23) was significantly upregulated in the same condition. Moreover, the proliferation of LNCaP cells were drastically inhibited, and the apoptosis of LNCaP cells was increased in abiraterone or MDV3100 treatment groups. Meanwhile, the addition of mitophagy inhibitor Mdivi-1 (mitochondrial division inhibitor 1) could conversely elevate proliferation and constrain apoptosis of LNCaP cells. Conclusions Our results prove that both abiraterone and MDV3100 inhibit the proliferation, promote the apoptosis of prostate cancer cells through regulating mitophagy. The promotion of mitophagy might enhance the efficacy of abiraterone and MDV3100, which could be a potential strategy to improve chemotherapy with these two reagents.

中文翻译：

---

阿比特龙和 MDV3100 通过线粒体自噬抑制前列腺癌细胞的增殖并促进其凋亡。


背景 阿比特龙和 MDV3100 是两种有效的前列腺癌抗癌药物，但其下游作用机制仍不清楚。方法将双荧光生物传感器质粒转染LNCaP细胞以测量线粒体自噬。提取LNCaP细胞的DNA并进行实时定量PCR检测线粒体DNA拷贝数。 JC-1染色检测线粒体膜电位，电镜分析线粒体形态。此外，通过蛋白质印迹法检测线粒体标志物和凋亡标志物的蛋白水平。最后采用CCK-8法和流式细胞术分析阿比特龙或MDV3100处理后LNCaP细胞的增殖和凋亡情况。结果阿比特龙和MDV3100在LNCaP细胞中诱导线粒体自噬。与对照组相比，阿比特龙或MDV3100治疗组进一步发现线粒体DNA拷贝数和线粒体去极化的低表达水平。此外，在阿比特龙和 MDV3100 处理的 LNCaP 细胞中观察到严重的线粒体肿胀和大量的自噬溶酶体。在阿比特龙和MDV3100处理的LNCaP细胞中，线粒体相关蛋白frataxin、ACO2和Tom20的表达显着下调，而线粒体内膜蛋白（Tim23）的表达水平在相同条件下显着上调。此外，阿比特龙或MDV3100治疗组的LNCaP细胞增殖被显着抑制，LNCaP细胞凋亡增加。 同时，添加线粒体自噬抑制剂Mdivi-1（线粒体分裂抑制剂1）可以反过来促进LNCaP细胞的增殖并抑制细胞凋亡。结论我们的结果证明阿比特龙和MDV3100均通过调节线粒体自噬抑制前列腺癌细胞的增殖，促进其凋亡。促进线粒体自噬可能会增强阿比特龙和 MDV3100 的疗效，这可能是改善这两种试剂化疗的潜在策略。