Li-Dong Liu1,2, Ying-Xin Pang1,2, Xin-Rui Zhao1,2, Rui Li1,2, Cheng-Juan Jin1,2, Jing Xue1,2, Rui-Ying Dong3,4, Pei-Shu Liu5,6. 1. Department of Obstetrics and Gynecology, Qilu Hospital of Shandong University, 107 Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China. 2. Gynecology Oncology Key Laboratory, Qilu Hospital, Shandong University, Jinan, Shandong, People's Republic of China. 3. Department of Obstetrics and Gynecology, Qilu Hospital of Shandong University, 107 Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China. dongry0709@sina.com. 4. Gynecology Oncology Key Laboratory, Qilu Hospital, Shandong University, Jinan, Shandong, People's Republic of China. dongry0709@sina.com. 5. Department of Obstetrics and Gynecology, Qilu Hospital of Shandong University, 107 Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China. peishuliu@126.com. 6. Gynecology Oncology Key Laboratory, Qilu Hospital, Shandong University, Jinan, Shandong, People's Republic of China. peishuliu@126.com.
Abstract
PURPOSE: Curcumin (Cur), a yellow-colored dietary flavor from the plant (Curcuma longa), has been demonstrated to potentially resist diverse diseases, including ovarian cancer, but drug resistance becomes a major limitation of its success clinically. The key molecule or mechanism associated with curcumin resistance in ovarian cancer still remains unclear. The aim of our study was to investigate the effects of curcumin on autophagy in ovarian cancer cells and elucidate the underlying mechanism. METHODS: In our study, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), EdU proliferation assay and colony-forming assay were used to assess cell viability. Apoptosis was detected by western blot and flow cytometric analysis of apoptosis. Autophagy was defined by both electron microscopy and immunofluorescence staining markers such as microtubule-associated protein 1 light chain 3 (LC3). Plasmid construction and shRNA transfection helped us to confirm the function of curcumin. RESULTS: Curcumin reduced cell viability and induced apoptotic cell death by MTT assay in human ovarian cancer cell lines SK-OV-3 and A2780 significantly. Electron microscopy, western blot and immunofluorescence staining proved that curcumin could induce protective autophagy. Moreover, treatment with autophagy-specific inhibitors or stable knockdown of LC3B by shRNA could markedly enhance curcumin-induced apoptosis. Finally, the cells transiently transfected with AKT1 overexpression plasmid demonstrated that autophagy had a direct relationship with the AKT/mTOR/p70S6K pathway. CONCLUSIONS: Curcumin can induce protective autophagy of human ovarian cancer cells by inhibiting the AKT/mTOR/p70S6K pathway, indicating the synergistic effects of curcumin and autophagy inhibition as a possible strategy to overcome the limits of current therapies in the eradication of epithelial ovarian cancer.
PURPOSE:Curcumin (Cur), a yellow-colored dietary flavor from the plant (Curcuma longa), has been demonstrated to potentially resist diverse diseases, including ovarian cancer, but drug resistance becomes a major limitation of its success clinically. The key molecule or mechanism associated with curcumin resistance in ovarian cancer still remains unclear. The aim of our study was to investigate the effects of curcumin on autophagy in ovarian cancer cells and elucidate the underlying mechanism. METHODS: In our study, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), EdU proliferation assay and colony-forming assay were used to assess cell viability. Apoptosis was detected by western blot and flow cytometric analysis of apoptosis. Autophagy was defined by both electron microscopy and immunofluorescence staining markers such as microtubule-associated protein 1 light chain 3 (LC3). Plasmid construction and shRNA transfection helped us to confirm the function of curcumin. RESULTS:Curcumin reduced cell viability and induced apoptotic cell death by MTT assay in humanovarian cancer cell lines SK-OV-3 and A2780 significantly. Electron microscopy, western blot and immunofluorescence staining proved that curcumin could induce protective autophagy. Moreover, treatment with autophagy-specific inhibitors or stable knockdown of LC3B by shRNA could markedly enhance curcumin-induced apoptosis. Finally, the cells transiently transfected with AKT1 overexpression plasmid demonstrated that autophagy had a direct relationship with the AKT/mTOR/p70S6K pathway. CONCLUSIONS:Curcumin can induce protective autophagy of humanovarian cancer cells by inhibiting the AKT/mTOR/p70S6K pathway, indicating the synergistic effects of curcumin and autophagy inhibition as a possible strategy to overcome the limits of current therapies in the eradication of epithelial ovarian cancer.
Entities:
Keywords:
AKT/mTOR/p70S6K; Apoptotic cell death; Autophagy; Curcumin; Ovarian cancer
Authors: Monica Benvenuto; Loredana Albonici; Chiara Focaccetti; Sara Ciuffa; Sara Fazi; Loredana Cifaldi; Martino Tony Miele; Fernando De Maio; Ilaria Tresoldi; Vittorio Manzari; Andrea Modesti; Laura Masuelli; Roberto Bei Journal: Int J Mol Sci Date: 2020-09-10 Impact factor: 5.923