异鼠李素对肺癌的作用及其抗肿瘤机制的初步探讨

Effects and Mechanisms of Isorhamnetin on Lung Carcinoma.

目的探讨异鼠李素体内外对肺癌增殖的影响及初步研究其抗肿瘤机制。方法将不同浓度异鼠李素加入体外培养的人A549细胞,用MTT法,3H-TdR掺入法等测定体外抗瘤活性,用流式细胞仪、彗星电泳、免疫组化等观察其对肿瘤细胞凋亡的诱导作用;采用Lewis细胞C57BL/6鼠移植瘤,观察药物对移植瘤的影响。结果异鼠李素处理A549细胞后,细胞形态出现典型凋亡特征,下调bcl-2基因,PCNA蛋白表达;上调抑癌基因P53、bax及caspase-3基因。实验观察到,异鼠李素在体内也具有明显的抗肿瘤作用,可显著降低癌细胞增殖指数,诱导Lewis肺癌凋亡,其机理可能与下调PCNA和bcl-2的表达,上调caspase-3、bax表达有关。结论异鼠李素抑制肿瘤细胞的生长增殖,诱导细胞凋亡是其抗肿瘤作用主要机制之一,是一种有较好前景的抗肿瘤的新型中药单体。

Objective To investigate the effect of isorhamnetin on lung cancers and the mechanism of its effect. Method A549 cells were treated with l0 - 320 μg/ml isorhamnetin ; morphologic characteristic were observed, and analyzed by light-microscope and electronic microscopy. Growth inhibition was analyzed by MTT, ^3H-TdR assay. Apoptosis and expression-associated gene peaks were detected by flow cytometry （FCM）. Tumor model was set up by transplantating Lewis lung cancinoma cells into C57BL/6 mice. Result Isorhamnetin markedly inhibited the growth of A549 cells, and apoptosis of those cells was observed. 20 μg/ml isorhamnetin could induce A549 cell apoptosis and up-regulate the expression of apoptosis genes Bax, Caspase-3, P53 and down-regulate the expression of the anti-apoptotic gene Bcl-2 and PCNA protein. The observation showed＇that the tumor weight was significantly lighter and the tumor size smaller compared to the control group. The results of apoptosis-related genes and proteins expression levels of transplanted Lewis cells were same as those of A549 cells in vitro. Conclusion Isorhamnetin can induce apoptosis in A549 cells, transplantes Lewis cells and plays a role in the down-regulation of oncogenes and the up-regulation of apoptotic genes.