e. apoptosis vs. necrosis, by assessment of caspase 3 7 activity and cleaved more information PARP expression and lactate dehydrogenase activity. In addition to these markers of cell death, we looked at other apoptosis specific nuclear changes such as chromatin condensation as well as changes in mito chondrial potential. To further delineate the mechanism of action Inhibitors,Modulators,Libraries of BT, Inhibitors,Modulators,Libraries we focused on cell cycle, ROS generation, ATX inhib ition, and pro survival and pro apoptotic signalling markers. To assess whether BT induced growth inhibition of the cells is me diated via alterations in cell cycle regulation, we evalu ated the effect of BT on cell cycle distribution. Because the production of lethal levels of ROS has been sug gested as a mechanism of action of various cytotoxic agents in cancer cells, we assessed effect of BT on ROS generation in ovarian cancer cell lines.
To define the cel Inhibitors,Modulators,Libraries lular response of ovarian cancer cell lines to treatment with BT, we analysed the expression and or Inhibitors,Modulators,Libraries activation of cellular markers that are hallmarks of pro survival and pro apoptotic signalling in all cell lines. Finally, we studied the effect of BT on ATX secretion in ovarian cancer cell lines be cause BT has been shown to inhibit solid tumor growth in several preclinical cancer models by targeting auto taxin. Methods Cell lines and chemicals In order to assess the cytotoxic effects of BT, a panel of ovarian cancer cell lines exhibiting varying degrees of sensitivities to cisplatin was selected. OVACAR 3 and SKOV 3 are cisplatin resistant whereas A2780 and IGROV 1 represent cisplatin sensitive cell lines.
Addition ally, cisplatin resistant variants of A2780 and IGROV 1 derived by in vitro selection with cisplatin were also tested for BT cytotoxicity. A2780, A2780 CDDP and Inhibitors,Modulators,Libraries IGROV 1, IGROV 1CDDP represents isogenic ovarian cancer cell line pairs consisting of a cisplatin sensitive parental line and a stable cisplatin resistant sub line derived by in vitro selection with cisplatin. Human ovarian carcinoma cell lines, OVACAR 3, SKOV 3 were obtained from Dr. McAsey. Isogenic ovarian cancer cell lines pairs, e. g, A2780 A2780 CDDP and IGROV 1, IGROV 1CDDP were received as a generous gift from Dr. Brodsky. All cell lines were maintained in DMEM media supple mented with 10% heat inactivated FBS, 100 IU penicillin and 100 ug mL streptomycin. All cell lines were cultured at 37 C in a hu midified atmosphere at 5% CO2.
The cisplatin resistant variants A2780 CDDP and IGROV 1CDDP cells were treated with 3 uM cisplatin every 3rd passage to main tain cisplatin resistance. Bithionol, Rhodamine 123 and Calcitriol side effects propidium iodide were purchased from Sigma. Kinase inhibitors such as LY294002, SB203580 were purchased from Promega. All antibodies were purchased from Cell Signaling Technologies. PrestoBlue Cell Viability Reagent and ROS Dye carboxy H2DCFDA were pur chased from Invitrogen.