title: Identification of chemosensitivity nodes for vinblastine through small interfering RNA high-throughput screens.
abstract: 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.
authors: Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors: Carolyn A
authors: CA
authors: Kitchens
authors: Peter R
authors: PR
authors: McDonald
authors: Tong Ying
authors: TY
authors: Shun
authors: Ian F
authors: IF
authors: Pollack
authors: John S
authors: JS
authors: Lazo
mesh_terms: D000814:Aniline Compounds / Q000494:pharmacology*; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy* / Q000235:genetics; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D019254:Genes, bcl-2; D005909:Glioblastoma / Q000188:drug therapy* / Q000235:genetics; D057166:High-Throughput Screening Assays; D006801:Humans; D008928:Mitochondria / Q000187:drug effects; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000037:antagonists & inhibitors*; D034741:RNA, Small Interfering; D013449:Sulfonamides / Q000494:pharmacology*; D014162:Transfection; D050257:Tubulin Modulators / Q000494:pharmacology; D014747:Vinblastine / Q000494:pharmacology*
chemical_list: D000814:Aniline Compounds; D000972:Antineoplastic Agents, Phytogenic; D019253:Proto-Oncogene Proteins c-bcl-2; D034741:RNA, Small Interfering; D013449:Sulfonamides; D050257:Tubulin Modulators; D014747:Vinblastine; C528561:navitoclax