Heteronemin影響蛋白酪氨酸磷酸酶活性藉以調節氧化及內質網壓力對於前列腺癌細胞造成細胞毒殺的效果
李懿倫1,2、徐先炤3、阮雍順2,4、李建輝5、呂美津6,7
1衛生福利部屏東醫院泌尿科；2高雄醫學大學醫學研究所；3衛生福利部新營醫院泌尿科；4高雄市立大同醫院泌尿科；5衛生福利部旗山醫院復健科；6國立東華大學海洋生物研究所；7屏東海洋生物博物館
Heteronemin exhibited cytotoxic effects in prostate cancer cells via oxidative and ER stress involved by protein tyrosine phosphatases activation
Yi-Lun Lee1,2, Chen-Chau Shie1, Yung-Shun Juan2,3, Chien-Hui Li4, Mei-Chin Lu,5,6
1Department of Urology, Pingtung Hospital, Ministry of Health and Welfare, Pingtung, Taiwan; 2Graduate Institute of Medicine, Kaohsiung Medical University; 3Department of Urology, Sinying Hospital, Ministry of Health and Welfare, Tainan, Taiwan; 4Department of Urology, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung, Taiwan; 5Department of Rehabilitation Medicine, Cishan Hospital, Ministry of Health and Welfare, Kaohsiung, Taiwan; 6Graduate Institute of Marine Biology, National Dong Hwa University; 7National Museum of Marine Biology & Aquarium, Pingtung, Taiwan,
Purpose: The incidence of prostate cancer is growing in Taiwan males. Heteronemin, extracted from the marine sponge, exhibited potent cytotoxic effects in many cancer cell lines. Accumulating evidence shows that heteronemin promotes autophage and apoptosis in cancer cells. The aim of this study is to investigate the molecular mechanisms of heteronemin involving oxidative and endoplasmic reticulum(ER) stress in prostate cancer cells.
Materials and Methods: The cytotoxic activity of heteronemin was evaluated by MTT assay. Human prostate cell lines including LNcap and PC3 were incubated for in Vitro studies. Xenograft was established in nude mice as in Vivo animal model. Markers of apoptosis, autophage, oxidative and ER stress- related proteins were evaluated by Western blotting analysis. The apoptotic cells were measured via annexin V/PI staining. Mitochondrial membrane potential(MMP), reactive oxygen species(ROS) and calcium release were determined by flow cytometery with specific fluorescent dyes. The expressions of protein tyrosine phosphateases(PTPs) activation were assessed by Western blots.
Results: Heteronemin exhibited potent cytotoxic effect against LNcap and PC3 prostate cancer cells with IC50 1.4 and 2.7 μM after 24 h, respectively. In the xenograft animal model, the tumor size was significantly suppressed to about 51.9% in the heteronemin-treated group in comparison with the control group with no significant difference in the mice body weights. We found that the use of heteronemin-triggered apoptosis by 20.1–68.3%, caused disruption of mitochondrial membrane potential (MMP) by 66.9–99.1% and promoted calcium release by 1.8-, 2.0-, and 2.1-fold compared with the control group in a dose-dependent manner, as demonstrated by annexin-V/PI, rhodamine 123 and Fluo-3 staining assays, respectively. Moreover, our findings indicated that the pretreatment of LNcap cells with an inhibitor of protein tyrosine phosphatase (PTPi) diminished growth inhibition, oxidative and endoplasmic reticulum (ER) stress.
Conclusions: Heteronemin significantly exhibited cytotoxic effects in prostate cancer cells. Our results suggested PTP activation plays a crucial rule in the cytotoxic activity of heteronemin. Heteronemin promoted autophagy and apoptosis involving oxidative and ER stress through PTP activation in prostate cancer cells. Heteronemin, a marine sesterterpenoid-type natural product, presented as an interesting candidate as a potential anti-prostate cancer agent in the future.