title: A study of cytotoxic synergy of UCN-01 and flavopiridol in syngeneic pair of cell lines.
abstract: Flavopiridol and UCN-01 are two novel protein kinase inhibitors with diverse cellular effects that may complement each other with regards to induction of apoptosis. HeLa cells engineered to overexpress human survivin (HeLa-S) were at least approximately 4.8-fold resistant to UCN-01 relative to proliferation observed in control HeLa cells (HeLa-V). Flavopiridol cytotoxicity as measured using the MTT assay was unaffected in HeLa-S cells when compared with HeLa-V cells. Similarly, simultaneous treatment of HeLa-V cells with flavopiridol and UCN-01 for 72 hours did not result in synergistic inhibition of proliferation; however, in HeLa-S cells, this combination resulted in synergistic inhibition of cell proliferation. Flavopiridol and UCN-01 augmented apoptosis in HeLa-S cells (as compared with HeLa-V cells) as measured by caspase-3 cellular activity assay, DNA fragmentation and PARP cleavage by western blot. In HeLa-V and -S cells, combination treatment resulted in caspase-8 cleavage. Caspase-9 was expressed in HeLa-V cells; however, there was a marked reduction of caspase-9 content in HeLa-S cells only. Combination treatment resulted in a significant reduction in survivin abundance in HeLa-S and SKBR3-UR cells, but not in their respective parental lines. The synergy of Flavopiridol and UCN-01 are selectively toxic to survivin-overexpressing cell lines and the mechanism of toxicity involves caspase-dependent cell death.
authors: Albert Einstein Comprehensive Cancer Center, Department of Medicine, Albert Einstein College of Medicine, Chanin 302, 1300 Morris Park Avenue, Bronx, NY 10461, USA.
authors: Kongming
authors: K
authors: Wu
authors: Mark
authors: M
authors: D'Amico
authors: Chenguang
authors: C
authors: Wang
authors: Chris
authors: C
authors: Albanese
authors: Richard G
authors: RG
authors: Pestell
authors: Sridhar
authors: S
authors: Mani
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases / Q000032:analysis / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D024161:Collagen Type XI / Q000032:analysis / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D005419:Flavonoids / Q000494:pharmacology*; D006367:HeLa Cells; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D009363:Neoplasm Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D010880:Piperidines / Q000494:pharmacology*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D019311:Staurosporine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000077022:Survivin; D014162:Transfection
chemical_list: D000970:Antineoplastic Agents; C107489:BIRC5 protein, human; D024161:Collagen Type XI; D005419:Flavonoids; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins; D009363:Neoplasm Proteins; C066455:PARP protein, Bos taurus; D010880:Piperidines; D047428:Protein Kinase Inhibitors; D000077022:Survivin; C077990:alvocidib; C054852:7-hydroxystaurosporine; C505530:CASP8 protein, human; C506433:CASP9 protein, human; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases; D019311:Staurosporine