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目的研究和探讨力达霉素对碱性成纤维细胞生长因子(bFGF)诱导的癌细胞中信号转导的抑制作用。方法MTT法检测LDM和阿霉素(ADR)对3种人癌细胞系的增殖抑制作用。受体结合实验检测LDM对bFGF与其受体结合的作用。W estern b lotting检测bFGF受体复合物的形成,流式细胞测定细胞内Ca2+的流动,免疫印迹法测定bFGF所诱导的3种PKC亚型的活性。结果MTT法实验结果,LDM在体外对3种人癌细胞均显示出强烈的增殖抑制作用。按IC50值进行比较表明,LDM的活性比ADR强1 000倍以上。LDM抑制[125I]-bFGF对大鼠肺细胞膜受体的IC50为2.0×10-4nmol.L-1。LDM能阻碍bFGF与其受体复合物的形成,LDM(10 nmol.L-1)预孵育2 h可阻止bFGF诱导的细胞内Ca2+效应。免疫印迹法证明,LDM可抑制bFGF诱导的癌细胞的3种PKC亚型的活性。结论力达霉素抗肿瘤作用的机制之一可能是通过阻断bFGF受体的信号转导途径。
Objective To study and investigate the inhibitory effect of lidamycin on signal transduction induced by basic fibroblast growth factor (bFGF) in cancer cells. Methods MTT assay was used to detect the inhibitory effects of LDM and ADR on the proliferation of three human cancer cell lines. Receptor binding assay was used to detect the effect of LDM on bFGF binding to its receptor. Western Blotting was used to detect the formation of bFGF receptor complex. Flow cytometry was used to measure intracellular Ca2 + flux. The activities of three PKC isoforms induced by bFGF were determined by Western blotting. Results The results of MTT assay showed that LDM showed a strong inhibitory effect on proliferation of all three kinds of human cancer cells in vitro. The comparison of IC50 values shows that LDM is more than 1000 times more active than ADR. LDM inhibited [125I] -bFGF on rat lung cell membrane receptor IC50 of 2.0 × 10-4nmol.L-1. LDM blocked the formation of bFGF complex with its receptor, and preincubation with LDM (10 nmol.L-1) for 2 h prevented the bFGF-induced intracellular Ca2 + effect. Immunoblotting demonstrated that LDM inhibited the activity of 3 PKC isoforms of bFGF-induced cancer cells. Conclusions One of the mechanisms of the anti-tumor effect of lidamycin may be through blocking the signal transduction pathway of bFGF receptor.