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Objective: Aberrantly activated FOXM1 (forkhead box protein M1) leading to uncontrolled cell proliferation and dysregulation of FOXM1 transcription network occurs in 84% of ovarian cancer cases. It was demonstrated that thiostrepton, a thiazole antibiotic, decreases FOXM1 expression. We aimed to determine if targeting the FOXM1 pathway with thiostrepton could improve the efficacy of paclitaxel and cisplatin in human ovarian cancer ascites cells ex vivo. Methods: Human ovarian cancer cell lines and patients' ascites cells were treated with paclitaxel, cisplatin, and thiostrepton or a combination for 48 hours, and cytotoxicity was assessed. Drug combination effects were determined by calculating the combination index values using the Chou and Talalay method. Quantitative reverse transcriptase-polymerase chain reaction was performed to determine changes in FOXM1 expression and its downstream targets. Results: Ovarian cancer cell lines and the patients' ascites cancer cells had an overexpression of FOXM1 expression levels. Targeting FOXM1 with thiostrepton decreased FOXM1 mRNA expression and its downstream targets such as CCNB1 and CDC25B, leading to cell death in both cell lines and patients' ascites cancer cells. Furthermore, addition of thiostrepton to paclitaxel and cisplatin showed synergistic effects in chemoresistant ovarian cancer patients' ascites cells ex vivo. Conclusion: Targeting FOXM1 may lead to novel therapeutics for chemoresistant epithelial ovarian cancer. [ABSTRACT FROM AUTHOR]

Combination therapy using gemcitabine with oxaliplatin (GEMOX) showed moderate activity in recurrent ovarian cancers. However, severe toxicities have been observed in patients who received full-dose therapy of GEMOX. On the other hand, bevacizumab enhances chemotherapeutic efficacy in various cancers. Here, we evaluated the effect of weekly low-dose administration of GEMOX in combination with bevacizumab (B-GEMOX) for patients with recurrent and refractory ovarian cancers (ROCs).A total of 19 patients with ROC were treated with B-GEMOX: 2 mg/kg of bevacizumab, 300 mg/m2 of gemcitabine, and 30 mg/m2 of oxaliplatin, 3 weeks on and 1 week off, q4weeks. The treatment was continued until development of severe toxicities or progressive disease. Tumor responses were assessed using the Response Evaluation Criteria in Solid Tumors and Gynecologic Cancer Intergroup criteria.Median number of the B-GEMOX therapy was 5 cycles. Response was observed in 4 (34%) cases by Response Evaluation Criteria in Solid Tumors, and in 2 (29%) cases by Gynecologic Cancer Intergroup criteria, resulting in overall response rate of 32%. Clinical benefit excluding progressive disease was obtained in 79% of the patients. Median progression-free survival was 4.5 months (range, 2-16+ months). Toxicities were mild and mainly consisted of hematologic, gastrointestinal, and neuropathy; however, there were no nonhematologic toxicities more than grade 1.Weekly administration of B-GEMOX was active for patients with ROC and showed mild toxicities. These results warrant further prospective studies for patients with ROC. [ABSTRACT FROM AUTHOR]

Based on the evidences showing that serum deprivation provokes apoptosis in a variety of cells, we have investigated the effect of serum deprivation on drug sensitivity.After human ovarian cancer cells were preincubated in 0.5 % serum containing medium for 12 hours, cellular drug sensitivities were determined by colony-forming assay.Serum deprivation treatment resulted in significant increase in paclitaxel sensitivity by factors of mean ± SD, 148.6 ± 28.1 and 10.1 ± 1.0 (n = 3; P < 0.001) fold in platinum-resistant C13 and CP70 cells, respectively. Similarly, serum deprivation induced significant docetaxel sensitivity in these cell lines. However, no enhancement effect of serum deprivation was observed in platinum-sensitive 2008 and A2780 cells. Serum deprivation did not have any effect on the sensitivities to cisplatin, vincristin, and doxorubicin in all of these cells. More than 7-fold increase of apoptotic cells were observed in C13 or CP70 cells when they were treated by serum deprivation followed by paclitaxel compared with the treatment of either serum deprivation or paclitaxel alone. Confocal laser microscopy using rhodamine 123 and flow cytometric analysis with 3,3′-dihexyloxacarbocyanine iodide revealed that serum deprivation decreased mitochondrial membrane potential in C13 or CP70 cells, whereas no change was observed in 2008 and A2780 cells. This indicates that serum deprivation induced depolarization specifically in platinum-resistant cells. Electron microscopy revealed that serum deprivation caused regeneration of mitochondrial matrix structure in C13 or CP70 cells where mitochondria were usually destructed and disappeared.These results indicate that serum deprivation confers taxane hypersensitivity specifically in platinum-resistant cells by recovering their impaired mitochondrial functions. The evidence might be clinically beneficial for the development of new chemotherapeutic technology, particularly for the patients with platinum-resistant ovarian cancer. [ABSTRACT FROM AUTHOR]

To evaluate the safety and efficacy of canfosfamide in combination with pegylated liposomal doxorubicin (PLD) in platinum-resistant ovarian cancer (OC).Patients with platinum-refractory or -resistant (primary or secondary) OC were randomized to receive canfosfamide at 1000 mg/m2 and PLD at 50 mg/m2 intravenously or PLD alone at 50 mg/m2 intravenously on day 1 every 28 days until tumor progression or unacceptable toxicity. The primary end point was progression-free survival (PFS). Other end points were objective response rate and safety. The study was originally planned for 244 patients. The trial was temporarily placed on hold after 125 patients were randomized while the results of another trial were being reviewed and the sponsor decided not to resume enrollment. The interim analysis became the final analysis.The median PFS was 5.6 months for canfosfamide + PLD (n = 65) versus 3.7 months for PLD (n = 60) (hazards ratio, 0.92; P = 0.7243). A preplanned subgroup analysis showed that 75 patients with platinum-refractory or primary platinum-resistant OC had a median PFS of 5.6 months for canfosfamide + PLD versus 2.9 months for PLD (hazards ratio, 0.55; P = 0.0425). Hematologic adverse events were 66% on the canfosfamide + PLD arm versus 44% on the PLD arm, manageable with dose reductions. Nonhematologic adverse events were similar for both arms. The incidence of palmar-plantar erythrodysesthesia and stomatitis was lower on canfosfamide + PLD (23%, 31%, respectively) versus (39%, 49%, respectively) on PLD.Overall median PFS showed a positive trend but was not statistically significant. The median PFS in the platinum-refractory and primary platinum-resistant OC patients was significantly longer for canfosfamide + PLD versus PLD. Canfosfamide may ameliorate the palmar-plantar erythrodysesthesia and stomatitis known to be associated with PLD. Further study of this active well-tolerated regimen in platinum-refractory and primary platinum-resistant OC is planned.This study was registered at www.clinicaltrials.gov: NCT00350948. [ABSTRACT FROM AUTHOR]