title: Epothilone B induces human ovarian cancer OV-90 cell apoptosis via external pathway.
abstract: We evaluated molecular events associated with apoptosis induced by Epothilone B (EpoB, Patupilone) and paclitaxel (PTX) in human ovarian papillary serous adenocarcinoma cell line (OV-90). Epothilones are compounds of natural origin with mechanisms of action similar to taxanes, but with more potent antiproliferative activity. Apoptosis was one of the major forms of cell death induced by EpoB. The mode of cell death was assessed colorimetrically, fluorimetrically, cytometry, and by immunoblot analyses through measuring DNA fragmentation, the level of TRAIL, the cleavage of poly(ADP-ribose) polymerase (PARP) and the activation of caspase-9, -8 and -3. We measured also additional markers of apoptosis, like phosphatidylserine externalization and morphological changes. Moreover, we estimated glycoprotein P (P-gp) activity in OV-90 ovarian cancer cell line. The studies indicated that the extrinsic pathway of apoptosis, which is triggered by certain TNF family members and engages their respective receptors on the surface of the target cell, was predominant. We were the first to have demonstrated (using immunoassay) the release of TNF-related apoptosis-inducing ligand (TRAIL) after treatment with EpoB. EpoB and PTX mediate activation of both initiator caspases-8 and -9, leading to the appearance of caspase-3. In EpoB treated cells, DNA fragmentation was also detected. EpoB leads to the reduction in DNA repair capacity. In summary, we report that Epothilone B induces apoptosis in OV-90 cells via a TRAIL and caspase 8-dependent pathway. PTX leads to smaller apoptotic events in comparison to EpoB.
authors.affiliation: Department of Thermobiology, Institute of Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland. Electronic address: zychan@biol.uni.lodz.pl.
authors.forename: Aneta
authors.initials: A
authors.lastname: Rogalska
authors.affiliation: Department of Thermobiology, Institute of Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Marczak
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B / Q000378:metabolism; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D020169:Caspases / Q000378:metabolism*; D045744:Cell Line, Tumor; D020552:Comet Assay; D004249:DNA Damage; D034261:Epothilones / Q000494:pharmacology*; D005260:Female; D006801:Humans; D010051:Ovarian Neoplasms; D017239:Paclitaxel / Q000494:pharmacology; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000378:metabolism*
chemical_list: C513055:ABCB1 protein, human; D018435:ATP Binding Cassette Transporter, Subfamily B; D000970:Antineoplastic Agents; D034261:Epothilones; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D011065:Poly(ADP-ribose) Polymerases; D020169:Caspases; D017239:Paclitaxel; C093788:epothilone B
keywords: Apoptosis; Epothilone B; PARP; Paclitaxel; TRAIL; TUNEL