Abstract 1935: Antitumor effect mechanism of statin in PCa cells focusing on autophagy

Abstract Antitumor effect mechanism of statin in prostate cancer cells focusing on autophagy Background:Statins have recently been studied for their proapoptotic and antimetastatic effects. However, the exact mechanisms of their anticancer actions remain unclear. We have studied the novel castration resistant prostate cancer (CRPC) treatment with statins. Using microarrays, we discovered up-regulation of ATG4B (Autophagy related 4 homolog B) in PC-3 cells after simvastatin treatment. In this study, we evaluated the effects of simvastatin focusing on androgen-independent prostate cancer cells. Methods:PC-3, LNCaP-LA, 22RV-1-LA (taht were derived from LNCaP and 22RV1 cells and cultured in 10% charcoal-stripped fetal bovine serum for 3 months), and DU145 human prostate cancer cell lines were used. Microarrays were performed using PC-3 untreated or administered with simvastatin (0 uM versus 5 uM). Proliferation, migration, and invasion were evaluated using MTS assay, Migration assay, and Invasion assay, respectively. The increases of autophagy were detected by western blot using microtubule associated protein 1 light chain 3 (LC-3) antibody and confirmed by a fluorescence microscope with staining autophagosomes by autophagy detection kit (abcam, Cambridge, UK). Results:Using microarrays, we discovered up-regulation of ATG4B in PC-3 cells after simvastatin treatment. Simvastatin inhibited the proliferation, migration, and invasion of PC-3, LNCaP-LA, 22RV1-LA and DU145 cells. The expression level of LC-3 was up-regulated by simvastatin in PC-3, LNCaP-LA, 22RV1-LA and DU145 cells. In PC-3 cells treated with statin, a significant increase in autophagosomes was confirmed by fluorescence microscopy. The expression of LC-3 and autophagosomes were increased in a concentration-dependent manner. Conclusions:It was found that statin administration enhances autophagy induction in a prostate cell line. We plan to study the combined effect with other drugs that induce autophagy. We would like to develop CRPC treatment by inducing autophagy cell death. Citation Format: Yoshiyuki Miyazawa, Daisuke Oka, Hiroshi Nakayama, Yoshitaka Sekine, Seiji Arai, Kazuhiro Suzuki. Antitumor effect mechanism of statin in PCa cells focusing on autophagy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1935.