101. 1955-P: GLP-1R Activation Attenuates Prostate Cancer Growth via Inhibiting Cell Cycle Progression
- Author
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Toru Shigeoka, Shinichiro Irie, Toshihiko Yanase, Tomoko Tanaka, Takako Kawanami, Masatoshi Tanaka, Yuriko Hamaguchi, Takashi Nomiyama, and Kazuki Nabeshima
- Subjects
Gleason grading system ,endocrine system ,medicine.diagnostic_test ,Cell growth ,business.industry ,Endocrinology, Diabetes and Metabolism ,digestive, oral, and skin physiology ,Cancer ,medicine.disease ,Flow cytometry ,Prostate cancer ,In vivo ,Internal Medicine ,medicine ,Cancer research ,SKP2 ,business ,hormones, hormone substitutes, and hormone antagonists ,Intracellular - Abstract
Incretin therapy is one of the most popular treatment for type 2 diabetes. We have previously reported anti-prostate cancer effect of GLP-1R agonist Exendin-4(Ex-4) (Diabetes 2014, PLOS ONE 2015), and LEADER trial suggested that GLP-1R agonist could reduce prostate cancer. In our previous report, the attenuation of prostate cancer cell proliferation was depending on GLP-1R expression, and Ex-4 did not attenuate cell proliferation in ALVA-41, a prostate cancer cell without intrinsic GLP-1R expression. Then, we next examined anti-prostate cancer effect in ALVA-41 forced expressed GLP-1R using lentivirus vector (ALVA-41-GLP-1R). We confirmed abundant GLP-1R expression in ALVA-41-GLP-1R using RT-PCR and immunohistochemistry, and intracellular cAMP level was increased by Ex-4 in ALVA-41-GLP-1R. Ex-4 significantly decreased the proliferation of ALVA-41-GLP-1R in a dose dependent manner, but not in ALVA-41-control. BrdU assay revealed that DNA synthesis was attenuated in ALVA-41-GLP-1R, and G1 to S phase entry was inhibited in cell cycle distribution in flow cytometry analysis. Further, p27kip protein was increased and Skp2, ubiquitin ligase for p27kip, expression was decreased in ALVA-41-GLP-1R treated by Ex-4. In vivo experiments using xenograft model mice transplanting ALVA-41-GLP-1R revealed that Ex-4 decreased prostate cancer growth via activation of GLP-1R forced expressed in ALVA41. Further, GLP-1R expression level in human prostate cancer tissues was inversely associated with Gleason grading system of human prostate cancer. These data suggested that forced expressed GLP-1R attenuated prostate cancer cell proliferation via inhibiting cell cycle progression in vivo and in vitro, and GLP-1R activation could be one of optional therapy for prostate cancer. Disclosure T. Shigeoka: None. T. Nomiyama: None. T. Kawanami: None. Y. Hamaguchi: None. T. Tanaka: None. S. Irie: None. K. Nabeshima: None. M. Tanaka: None. T. Yanase: None. Funding Japan Society for the Promotion of Science
- Published
- 2019
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