【摘要】 目的探讨重组转化生长因子α绿脓杆菌外毒素融合蛋白(TP40)对膀胱癌细胞生长的抑制作用。方法采用蛋白印迹(Westernblot)法检测人膀胱癌T24细胞表皮生长因子受体(EGFR)的表达。用浓度为5～1000μg/L的TP40处理T24细胞,甲基噻唑基四唑(MTT)法检测细胞生长24、48、72和96h时的生长情况。氚胸腺嘧啶核苷([3H]TdR)掺入法检测TP40对T24细胞蛋白质合成的抑制作用。用浓度为1～7500μg/L的表皮生长因子(EGF)竞争拮抗TP40的细胞毒作用。结果T24细胞表达EGFR强阳性。浓度为5、50、100、250、500、750和1000μg/L的TP40处理T24细胞96h,细胞生长抑制率分别为10%、19%、27%、41%、47%、53%和61%。用750μg/L的TP40处理T24细胞24、48、72和96h,[3H]TdR掺入率分别为80%,69%,48%和51%。浓度为1～7500μg/L的EGF对TP40有竞争抑制作用。结论人膀胱癌T24细胞能高水平地表达EGFR;重组TP40对T24细胞的生长具有剂量、时间依赖性抑制作用,该作用是通过EGFR进行的。更多还原

【Abstract】 Objective To study inhibitory effect of recombinant transforming growth factor alpha Pseudomonas exotoxin fusion protein (TP40) on proliferation of the human bladder cancer T24 cells. Methods Expression of epidermal growth factor receptor (EGFR) in cultured T24 cells was analyzed with Western blot assay. Human bladder cancer T24 cells were exposed to TP40 at 5-1 000 μg/L. Methyl thiazolyl tetrazolium assay was applied to evaluate the cell proliferation by measuring the absorbance ( A ) at 570 nm with a microplate reader. Tritium labeled thymine deoxyriboside ([ 3H] TdR) uptake was measured to observe DNA synthesis. Competition assays were performed by the EGF at 1-7 500 μg/L. Results Expression of EGFR was high in human bladder cancer T24 cells. Cell growth was suppressed by 10%, 19%, 27%, 41%, 47%, 53% and 61% after 96 h treatment with TP40 at 5, 50, 100, 250, 500, 750 and 1 000 μg/L, respectively. [ 3H] TdR incorporation was 80%, 69%, 48% and 51% after 24 h, 48 h, 72 h, 96 h treatment with TP40 at 750 μg/L, respectively. When the concentration was 1-7 500 μg/L, EGF could block the inhibitory effect of TP40 to some extent. Conclusions Human bladder cancer T24 cells express EGFR at a high level. TP40 could inhibit the growth of T24 cells effectively in a dose and time dependent manner. The cytotoxic effects of TP40 were specifically mediated by EGFR.更多还原