分離自海洋鏈絲菌之次級代謝物 Lu01-M 藉由誘導細胞週期停滯與 DNA 損傷在前列腺癌細胞中表現出細胞毒殺活性

李懿倫、李宗熹、江吉文¹、呂美津^2,3

衛生福利部屏東醫院泌尿科，¹藥劑科；²東華大學海洋生物研究所；³屏東海洋生物博物館

The secondary metabolite Lu01-M from the marine streptomyces sp. exhibited cytotoxic activity in prostate cancer cells by inducing cell cycle arrest

and DNA damage

Yi-Lun Lee, Tsung-Hsi Lee, Chi-Wen Chiang¹, Mei-Chin Lu^2,3

Department of Urology, ¹Department of Pharmacy, Pingtung Hospital, Ministry of Health and Welfare, Pingtung, Taiwan; ²Graduate Institute of Marine Biology, National Dong Hwa University; ³National Museum of Marine Biology & Aquarium, Pingtung, Taiwan

Purpose: The population of prostate cancer is in growth and then becomes the sixth leading casualty of cancer deaths in Taiwanese men in 2020. Taiwan is surrounded by one of the highest coral densities and diversities in the world. Such an circumstance led to significant advancements in research and technologies related to the marine environment. Our study screened the marine Streptomyces sp. by using ethyl acetate to extract the secondary metabolite, Lu01-M. The aim of this study is to investigate the cytotoxic mechanisms of Lu01-M in human prostate cancer cells.

Materials and Methods: Three prostate cancer cell lines, PC3, DU145, and LNCaP, were incubated in our experiments to evaluate the cytotoxic activity of Lu01-M. The viability of prostate cancer cells after Lu01-M treatment was evaluated by MTT assay. Lu01-M was treated in the human prostate cancer cells to process colony formation assay and wound healing assay studies. The cell cycle population was analyzed with flow cytometery. The expressions of biomarkers related to cell cycle arrest and DNA damage were assessed by Western blots.

Results: Lu01-M inhibited PC3, DU145, and LNCaP cell proliferation with IC₅₀ 1.03 ± 0.31, 2.12

± 0.38, and 1.27 ± 0.25 μg/mL, respectively after 72 h of treatment. The results indicated that PC3 cells were the most sensitive cancer cell line, and the cytotoxic activity demonstrated in a dose- and time-dependent manner. Thus, PC3 cells were subjected to further investigation. Lu01-M expressed the ability to inhibit prostate cancer cells colony formation and migration. Lu01-M (3.125 and 6.25 µg/mL) caused cell cycle G2/M phase accumulation. The expressions of the cell cycle-related proteins CDK4, CDK6, p-cdc2, CyclinB1, p-Rb, and E2F1 were decreased by Western blotting analysis. Our results also showed that the Lu01-M treatment significantly changed the phosphorylation of DNA damage target proteins ATR, ATM, Chk2, H2AX, and BRCA1.

Conclusions: We found that the treatment of Lu01-M could induce cell cycle arrest at the G2/M phase and DNA damage in human prostate cancer cells. These results suggested that the secondary metabolite Lu01-M from the marine Streptomyces sp. presented as an interesting candidate for its future therapeutic potential for the prostate cancer.