Schmidt Friederike, Knobbe Christiane B, Frank Brigitte, Wolburg Hartwig, Weller Michael
Department of General Neurology, Hertie Institute for Clinical Brain Research, University of Tuebingen, Medical School, D-72076 Tuebingen, Germany.
Oncol Rep. 2008 Apr;19(4):1061-6.
The protein tyrosine kinase inhibitor, genistein, has been reported to inhibit proliferation and to induce cell death in various non-solid and solid cancer cell lines. Herein, we examined the effects of genistein in several human malignant glioma cell lines. We found that genistein inhibited the proliferation of LN-18, LNT-229, LN-308 and T98G cells at EC50 concentrations of 25-80 microM (72 h of exposure). The growth of a non-neoplastic immortalized human astrocyte cell line, SV-FHAS, was inhibited at similar concentrations. There was a reduction in [3H]-methylthymidine incorporation and a moderate lactate dehydrogenase release as a sign of cell death in genistein-treated glioma cells. Electron microscopy showed morphological changes with mitochondrial swelling and apoptosis in glioma cells treated with high concentrations of genistein. Genistein-induced cytotoxicity was associated with an increased DNA/topoisomerase II complex formation. Furthermore, genistein induced cell cycle arrest in G2/M. There was an increase in the p53 and p21 levels in response to genistein. However, there was no difference in genistein sensitivity between p21-deficient colon carcinoma cells and isogenic control cells. Genistein-induced cell death in LN-18 and LNT-229 was unaffected by the ectopic expression of the preferential caspase 1/8 inhibitor, crm-A, or co-exposure to the pan-specific pseudosubstrate caspase inhibitor, zVAD-fmk. The ectopic expression of the anti-apoptotic BCL-2 protein attenuated the cytotoxic effects of genistein. Moreover, the ectopic expression of temperature-sensitive p53V135A, which acts as a dominant-negative p53 mutant at 38.5 degrees C but assumes p53 wild-type properties at 32.5 degrees C, in LN-18 or LNT-229 cells, had no effect on genistein cytotoxicity at either temperature. Genistein did not act in synergy with CD95 ligand-induced apoptosis or various cancer chemotherapy drugs in cytotoxic or clonogenic cell death assays. Thus, genistein-like protein kinase inhibitors are promising agents for the experimental treatment of malignant gliomas.
蛋白质酪氨酸激酶抑制剂染料木黄酮已被报道可抑制多种非实体和实体癌细胞系的增殖并诱导细胞死亡。在此，我们研究了染料木黄酮对几种人恶性胶质瘤细胞系的影响。我们发现，染料木黄酮在25 - 80微摩尔的EC50浓度下（暴露72小时）可抑制LN - 18、LNT - 229、LN - 308和T98G细胞的增殖。一种非肿瘤性永生化人星形胶质细胞系SV - FHAS在相似浓度下生长也受到抑制。在经染料木黄酮处理的胶质瘤细胞中，[3H] - 甲基胸苷掺入减少，乳酸脱氢酶适度释放，这是细胞死亡的迹象。电子显微镜显示，高浓度染料木黄酮处理的胶质瘤细胞出现线粒体肿胀和凋亡的形态学变化。染料木黄酮诱导的细胞毒性与DNA /拓扑异构酶II复合物形成增加有关。此外，染料木黄酮诱导细胞周期停滞在G2 / M期。响应染料木黄酮，p53和p21水平升高。然而，p21缺陷的结肠癌细胞和同基因对照细胞对染料木黄酮的敏感性没有差异。染料木黄酮诱导的LN - 18和LNT - 229细胞死亡不受优先的半胱天冬酶1/8抑制剂crm - A的异位表达或与泛特异性假底物半胱天冬酶抑制剂zVAD - fmk共同暴露的影响。抗凋亡BCL - 2蛋白的异位表达减弱了染料木黄酮的细胞毒性作用。此外，温度敏感的p53V135A（在38.5摄氏度时作为显性负性p53突变体起作用，但在32.5摄氏度时具有p53野生型特性）在LN - 18或LNT - 229细胞中的异位表达，在这两个温度下对染料木黄酮的细胞毒性均无影响。在细胞毒性或克隆形成细胞死亡试验中，染料木黄酮与CD95配体诱导的凋亡或各种癌症化疗药物没有协同作用。因此，类似染料木黄酮的蛋白激酶抑制剂是恶性胶质瘤实验性治疗的有前景的药物。
