灵芝多糖对顺铂抑制荷膀胱癌T24细胞裸鼠肿瘤生长及血管生成作用的影响

Influence of Ganoderma lucidum polysaccharide on the inhibitory effects of cisplatin on the tumor growth and angiogenesis in bladder cancer(T24) cells-bearing nude mice

目的探讨灵芝多糖对膀胱癌的化疗增敏效应和对肿瘤血管生成的抑制作用。方法应用MTS法测定灵芝多糖联合顺铂对人膀胱癌T24细胞体外增殖的影响。采用Chou-Talalay联合指数法(即中效原理)判定两药合用时的相互作用关系。建立T24荷瘤裸鼠模型,观察灵芝多糖和顺铂的联合治疗效应,采用免疫组化染色检测荷瘤裸鼠肿瘤组织的微血管密度(MVD)及血管内皮生长因子(VEGF)、碱性成纤维细胞生长因子(bFGF)的表达水平,采用实时荧光定量PCR(real-time PCR)法和Western blotting检测荷瘤裸鼠肿瘤组织中VEGF和bFGF的表达情况。结果灵芝多糖在体外能有效抑制T24细胞的增殖,且与顺铂联用具有协同效应(CI<1)。免疫组化染色显示,灵芝多糖可显著增强顺铂对荷瘤裸鼠肿瘤生长的抑制作用(P<0.05),并可抑制肿瘤组织的血管生成及VEGF、bFGF的表达。实时荧光定量PCR和Western blotting检测也显示与单用顺铂比较,灵芝多糖联合顺铂治疗后荷瘤裸鼠肿瘤组织中VEGF和bFGF的表达显著下降。结论灵芝多糖和顺铂能协同抑制T24细胞的体外增殖;灵芝多糖可增强顺铂对T24荷瘤裸鼠肿瘤生长及血管生成的抑制作用,其机制可能与下调VEGF和bFGF的表达有关。

Objective To explore the chemo-sensitizing effect and inhibitory effect of Ganoderma lucidum polysaccharide （GLP） on tumor angiogenesis of bladder cancer. Methods The effect of GLP combined with cisplatin on the in vitro proliferation of human bladder cancer cell lines T24 was determined by MTS assay. The interaction between the two drugs was evaluated using the Chou-Talalay method. A T24 （bladder cancer）-bearing nude mouse model was established, and then the therapeutic effect of GLP combined with cisplatin was evaluated. The microvessel density （MVD） and the expressions of vascular endothelial growth factor （VEGF） and basic fibroblast growth factor （bFGF） in the tumor tissue were determined by immunohistochemical staining, and the expression levels of VEGF and bFGF in tumor tissue were determined by real-time fluorescence quantitative PCR and Western blotting. Results GLP combined with cisplatin markedly inhibited T24 cells proliferation in vitro showing a synergistic effect （CI〈 1）. Immunohistochemical staining showed that GLP could enhance the inhibitory effect of cisplatin on the tumor growth in the tumor- bearing nude mice （P〈0.05）, and it could also inhibit the angiogenesis and expressions of VEGF and bFGF in the tumor tissue. The real-time fluorescence quantitative PCR and Western blotting showed that the expression levels of VEGF and bFGF in tumor tissue significantly decreased in the tumor-bearing nude mice after being treated with GLP combined with cisplatin as compared with those treated by cisplatin alone. Conclusions GLP combined with cisplatin could inhibit the proliferation ofT24 cells in vitro synergically. GLP could enhance the inhibitory effect of cisplatin on tumor growth and angiogenesis in T24 tumor-bearing nude mice, and the mechanism may be related to the down-regulation of VEGF and bFGF expressions.