HSP90 regulation of ovarian cancer proliferation and survival. A) Ovarian cancer cell viability was determined by the CellTiter-Glo assay after 3 and 6 day treatment with HSP90 inhibitor, 17-AAG. The data were normalized to the DMSO control, and represent the mean values (± s.d.) of quadruplicate cultures (*p < 0.05, **P < 0.01, n = 3). B) Apoptosis was evaluated in ovarian cancer cell lines, at 24 h after treatment with 17-AAG. Caspase 3/7 activity was measured using a Caspase-Glo luminescence assay. The data were normalized to the DMSO control, and represent the mean values (± s.d.) from quadruplicate cultures (*p < 0.01, n = 3). C) Apoptosis analyses following 17-AAG (0.5 and 1 μM) treatment for 48 hours by using PE Annexin V Apoptosis Detection Kit I. D) Cell cycle analyses after 48 hours inhibitor treatment in serum-containing medium.