Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
J Pharmacol Exp Ther. 2011 Dec;339(3):851-8. doi: 10.1124/jpet.111.184879. Epub 2011 Aug 31.
Discovering chemosensitivity pathways or nodes is an attractive strategy for formulating new drug combinations for cancer. Microtubules are among the most successful anticancer drug targets. Therefore, we implemented a small interfering RNA (siRNA) synthetic lethal screen targeting 5520 unique druggable genes to identify novel chemosensitivity nodes for vinblastine, a microtubule-destabilizing agent used clinically. We transiently transfected human glioblastoma cells with siRNAs for 48 h and then treated cells with a sublethal concentration of vinblastine. Forty-eight hours later, we analyzed cell viability and, using a series of statistical methods, identified 65 gene products that, when suppressed, sensitized glioblastoma cells to vinblastine. After completion of the secondary assays, we focused on one siRNA, B-cell lymphoma extra large (BCL-xL), because of its role in the intrinsic apoptosis signaling pathway as well as the availability of pharmacological inhibitors. We found that nontoxic concentrations of 4-[4-[[2-(4-chlorophenyl)-5,5-dimethylcyclohexen-1-yl]methyl]piperazin-1-yl]-N-[4-[[(2R)-4-morpholin-4-yl-1-phenylsulfanylbutan-2-yl]amino]-3-(trifluoromethylsulfonyl)phenyl]sulfonylbenzamide (ABT-263), an inhibitor of the BCL-2 family members (BCL-2, BCL-xL, and BCL-w), sensitized glioblastoma and non-small-cell lung cancer cells to vinblastine and induced apoptosis through the intrinsic cell death pathway. These results illustrate the usefulness of unbiased siRNA screens as a method for identifying potential novel anticancer therapeutic combinations.
发现化疗敏感性途径或节点是制定癌症新药组合的一种有吸引力的策略。微管是最成功的抗癌药物靶点之一。因此，我们针对 5520 个独特的可用药基因实施了小干扰 RNA(siRNA)合成致死筛选，以鉴定长春碱（一种临床上用于破坏微管的药物）的新化疗敏感性节点。我们将 siRNA 瞬时转染入人胶质母细胞瘤细胞 48 小时，然后用亚致死浓度的长春碱处理细胞。48 小时后，我们分析细胞活力，并使用一系列统计方法鉴定出 65 种基因产物，当这些基因产物被抑制时，可使胶质母细胞瘤细胞对长春碱敏感。完成二次测定后，我们专注于一种 siRNA，即 B 细胞淋巴瘤特大（BCL-xL），因为它在内在凋亡信号通路中起作用，并且有药理学抑制剂可用。我们发现，非毒性浓度的 4-[4-[[2-(4-氯苯基)-5,5-二甲基环己烯-1-基]甲基]哌嗪-1-基]-N-[4-[[(2R)-4-吗啉-4-基-1-苯硫基丁基]氨基]-3-(三氟甲基磺酰基)苯基]磺酰基苯甲酰胺（ABT-263），一种 BCL-2 家族成员（BCL-2、BCL-xL 和 BCL-w）的抑制剂，使胶质母细胞瘤和非小细胞肺癌细胞对长春碱敏感，并通过内在细胞死亡途径诱导细胞凋亡。这些结果说明了无偏 siRNA 筛选作为鉴定潜在新抗癌治疗组合的方法的有用性。
