Antitumor activityand mechanism of JD20,a newly synthetic analog of natural ent-kaurane diterpenoid / 中国药理学与毒理学杂志

ABSTRACT

OBJECTIVE To study the anti-tumor activity and molecular mechanism of natural diter-pene derivative JD20 in vitro. METHODS Screening the sensitive of gastric carcinoma cell lines to JD20 by cytotoxicity test for 24 h.Cell morphology was evaluated by using DAPI.After staining of can-cer cells with PI or annexin V-FITC/PI respectively,the cell cycle and apoptosis induced by JD20 were detectded by flow cytometry. The change in cell membrane potential was detected by JC-1 test kit. Western blot method was used to detect the apoptosis-related protein. RESULTS The novel natural kaurane diterpene derivative JD20 had a significant inhibitory effect on tumor cells and was particularly active on gastric cancer cell lines HGC-27 (IC50=4.72 ± 1.37 μmol·L- 1) and MGC-803 (IC50=7.36 ± 0.86 μmol·L-1).Further studies found that JD20 resulted in thecell cycle arrest in the G2/M phase,and induced a significant apoptosis in HGC-27. In addition, JD20 also caused the drop of mitochondrial membrane potential of HGC-27 within a short time (3 h). Furthermore, the Western blotting analysis showed that JD20 could induce the up-regulation of p53,Bax and Bim protein expression in gastric can-cer cells,and the releasing of cytochrome c from the mitochondria into the cytoplasm,as well as the ac-tivation of casepase-9/3.CONCLUSION The natural kaurane diterpene derivative JD20 can inhibit the proliferation of various human cancer cells by blocking the cell cycle and inducing apoptosis, and its mechanism of inducing apoptosis may be related to the mitochondria-mediated apoptosis pathway.