Laboratory for Tissue Engineering and Stem Cell Therapy, Department of Urology, University Hospital Zürich, Frauenklinikstrasse 10, 8091, Zurich, Switzerland.
Institute of Pharmacology, University of Bern, Inselspital, INO-F, 3010, Bern, Switzerland.
World J Urol. 2019 Feb;37(2):351-358. doi: 10.1007/s00345-018-2385-5. Epub 2018 Jun 27.
Abiraterone acetate (AA) plus prednisone is an approved treatment of advanced prostate cancer (PCa). Autophagy is linked to drug resistance in numerous types of cancers. We hypothesized, that upregulation of autophagy is one of the mechanisms by which PCa cells survive AA anti-tumor treatment and therefore evaluated the potential effect of a combination with autophagy inhibition.
Human PCa LNCaP cell lines were cultured in steroid-free medium and treated with AA. Autophagy was inhibited by 3-methyladenine, chloroquine and ATG5 siRNA knock-down. Cell viability and apoptosis was assessed by flow cytometry and fluorescence microscopy, and autophagy was monitored by immunohistochemistry, AUTOdot and Western blotting.
Western blot revealed upregulation of ATG5 and LC3 II with a reduction of p62 protein expression in AA-treated cells, indicating upregulation of autophagy. These data were supported by results obtained with immunocytochemistry and AUTOdot assays. Using flow cytometry, we showed that combining AA with autophagy inhibition significantly impaired cell viability (1.3-1.6-fold, p < 0.001) and increased apoptosis (1.4-1.5-fold, p < 0.001) compared to AA treatment alone.
AA activates autophagy as a cytoprotective mechanism in LNCaP prostate cancer cells and targeting of autophagy enhances the antitumor effect of the compound.
醋酸阿比特龙（AA）联合泼尼松是治疗晚期前列腺癌（PCa）的一种已被批准的疗法。自噬与多种类型癌症的耐药性有关。我们假设，自噬的上调是 PCa 细胞在 AA 抗肿瘤治疗中存活的机制之一，因此评估了与自噬抑制联合应用的潜在效果。
将人前列腺癌细胞系 LNCaP 在无类固醇的培养基中培养并进行 AA 处理。通过 3-甲基腺嘌呤、氯喹和 ATG5 siRNA 敲低来抑制自噬。通过流式细胞术和荧光显微镜评估细胞活力和细胞凋亡，通过免疫组化、AUTOdot 和 Western blot 监测自噬。
Western blot 显示，AA 处理的细胞中 ATG5 和 LC3 II 的表达上调，p62 蛋白表达减少，表明自噬上调。免疫细胞化学和 AUTOdot 检测的结果支持这些数据。通过流式细胞术，我们发现与单独使用 AA 相比，联合使用 AA 和自噬抑制显著降低了细胞活力（1.3-1.6 倍，p<0.001）并增加了细胞凋亡（1.4-1.5 倍，p<0.001）。
AA 在 LNCaP 前列腺癌细胞中激活自噬作为一种细胞保护机制，靶向自噬增强了该化合物的抗肿瘤作用。
