The Anti-Tumor Effects of Destruxin B on L5178Y Lymphoma Cell

• Main Authors: Pei-Chi Li, 黎培琪
• Other Authors: Cheng-Ming Liu
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/97839797524641320488

碩士 === 臺北醫學大學 === 生物醫學技術研究所 === 92 === Destruxin is a substance which secrete from entoenous fungi, Metarhizium. This substance is toxic to insect and has been used as an insecticide for decades. Over thirty species of destruxins have been isolated from different investigators. In this study, the purified destruxin B (DB) was tested for its in vitro and in vivo anti-tumor activities by using L5178Y lymphoma cells which was induced by methylcholanthrene from T lymphocytes of DBA/2 mice. The results indicated that DB suppresses L5178Y lymphoma growth dramatically even in the dose as low as 1.29 μM . When doses of DB over 5.17 μM , the dead tumor cells were found.The same doses range has no growth suppression or tumoricidal effect on either mouse spleen cells primary culture or NIH3T3 fibroblast cells. The results from flow cytometric analyses indicated that DB induced cell cycle arrest at G2/M phase, consequently, caused cell apoptosis. The further elucidate the mechanisms of apoptosis, some regulatory or signal proteins for cell cycle and apoptosis were analyzed by Western blot. The results indicated that under DB treatment, the CDK1 (cdc2) protein expression was suppressed, p53 protein was increased and caspase-3 was activated. These results confirmed the previous growth suppression and flow cytometric results. The in vivo experiment was performed by implanting L5178Y lymphoma cells into DBA/2 mouse peritoneal cavity i.p. at dose of 230 μg/kg. The results showed that the treated group of mice my extent their survival days at least for 2 weeks longer than that of control group. From both in vitro and in vivo experiment results, it has proven that DB may be as a potential candidate for future anti-tumor drug.