Objective: Maternal embryonic leucine zipper kinase (MELK) is receiving an attention as a therapeutic target in various types of cancers. In this study, we aimed to evaluate the prognostic significance of MELK expression in ovarian cancer using clinical samples, and assessed the efficacy of a small molecule MELK inhibitor, OTS167, using patient-derived ovarian cancer cells as well as cell lines. Methods: Expression levels of MELK in 11 ovarian cancer cell lines were confirmed by western blotting. Inhibitory concentration of OTS167 was determined by colorimetric assay.MELK messenger RNA (mRNA) expression was evaluated in 228 ovarian cancer patients by quantitative polymerase chain reaction. Growth inhibition of OTS167 was also evaluated using freshly-isolated primary ovarian cancer cells including spheroid formation condition. Results: MELK mRNA expression was significantly higher in ovarian cancer than in normal ovaries (p<0.001), and high MELK mRNA expression was observed in patients with advanced stage, positive ascites cytology and residual tumor size. Patients with high MELK mRNA expression showed shorter progression-free survival (p=0.001). Expression of MELK was also confirmed in 10 of 11 ovarian cancer cell lines tested, and the half maximal inhibitory concentration of MELK inhibitor, OTS167, ranged from 9.3 to 60 nM. Additionally, OTS167 showed significant growth inhibitory effect against patient-derived ovarian cancer cells, regardless of their tumor locations, histologic subtypes and stages. Conclusions We demonstrated MELK as both a prognostic marker and a therapeutic target for ovarian cancer using clinical ovarian cancer samples. MELK inhibition by OTS167 may be an effective approach to treat ovarian cancer patients.

Objective: In Japan, perioperative prophylaxis of pulmonary embolism (PE) in gynecologic cancer patients with preoperative asymptomatic venous thromboembolism (VTE) has not been well established yet. The GOTIC-VTE trial was a prospective, multi-center, single-arm clinical trial to investigate the prevention of postoperative symptomatic PE onset by seamless anticoagulant therapy from the preoperative period to 4 weeks after surgery instead of using intermittent pneumatic compression. Methods: Anticoagulant therapy was started immediately after asymptomatic VTE diagnosis and stopped preoperatively according to the rules of each institution. Unfractionated heparin administration was resumed within 12 hours postoperatively, and this was followed by the switch to low-molecular-weight heparin and subsequently, edoxaban; this cycle was continued for 28 days. Primary outcome was the occurrence of symptomatic PE in 28 days postoperatively. Secondary outcomes were the incidence of VTE-related events in 28 days and 6 months postoperatively and protocol-related adverse events. Results: Between February 2018 and September 2020, 99 patients were enrolled; of these, 82patients were assessed as the full analysis set, including 58 for ovarian cancer, fallopian tube, or peritoneal cancer; 21 for endometrial cancer; and 3 for cervical cancer. No symptomatic PE was observed within 28 days postoperatively; two patients had bleeding events (major bleeding and clinically relevant nonmajor bleeding) and three had grade 3 adverse events (increased alanine transaminase, aspartate aminotransferase, or gamma-glutamyl transferase). Conclusion The multifaceted perioperative management for gynecologic malignancies with asymptomatic VTE effectively prevented postoperative symptomatic PE.Trial Registration: JRCT Identifier: jRCTs031180124

Objective: In Japan, perioperative prophylaxis of pulmonary embolism (PE) in gynecologic cancer patients with preoperative asymptomatic venous thromboembolism (VTE) has not been well established yet. The GOTIC-VTE trial was a prospective, multi-center, single-arm clinical trial to investigate the prevention of postoperative symptomatic PE onset by seamless anticoagulant therapy from the preoperative period to 4 weeks after surgery instead of using intermittent pneumatic compression. Methods: Anticoagulant therapy was started immediately after asymptomatic VTE diagnosis and stopped preoperatively according to the rules of each institution. Unfractionated heparin administration was resumed within 12 hours postoperatively, and this was followed by the switch to low-molecular-weight heparin and subsequently, edoxaban; this cycle was continued for 28 days. Primary outcome was the occurrence of symptomatic PE in 28 days postoperatively. Secondary outcomes were the incidence of VTE-related events in 28 days and 6 months postoperatively and protocol-related adverse events. Results: Between February 2018 and September 2020, 99 patients were enrolled; of these, 82patients were assessed as the full analysis set, including 58 for ovarian cancer, fallopian tube, or peritoneal cancer; 21 for endometrial cancer; and 3 for cervical cancer. No symptomatic PE was observed within 28 days postoperatively; two patients had bleeding events (major bleeding and clinically relevant nonmajor bleeding) and three had grade 3 adverse events (increased alanine transaminase, aspartate aminotransferase, or gamma-glutamyl transferase). Conclusion The multifaceted perioperative management for gynecologic malignancies with asymptomatic VTE effectively prevented postoperative symptomatic PE.Trial Registration: JRCT Identifier: jRCTs031180124

Objective: In Japan, perioperative prophylaxis of pulmonary embolism (PE) in gynecologic cancer patients with preoperative asymptomatic venous thromboembolism (VTE) has not been well established yet. The GOTIC-VTE trial was a prospective, multi-center, single-arm clinical trial to investigate the prevention of postoperative symptomatic PE onset by seamless anticoagulant therapy from the preoperative period to 4 weeks after surgery instead of using intermittent pneumatic compression. Methods: Anticoagulant therapy was started immediately after asymptomatic VTE diagnosis and stopped preoperatively according to the rules of each institution. Unfractionated heparin administration was resumed within 12 hours postoperatively, and this was followed by the switch to low-molecular-weight heparin and subsequently, edoxaban; this cycle was continued for 28 days. Primary outcome was the occurrence of symptomatic PE in 28 days postoperatively. Secondary outcomes were the incidence of VTE-related events in 28 days and 6 months postoperatively and protocol-related adverse events. Results: Between February 2018 and September 2020, 99 patients were enrolled; of these, 82patients were assessed as the full analysis set, including 58 for ovarian cancer, fallopian tube, or peritoneal cancer; 21 for endometrial cancer; and 3 for cervical cancer. No symptomatic PE was observed within 28 days postoperatively; two patients had bleeding events (major bleeding and clinically relevant nonmajor bleeding) and three had grade 3 adverse events (increased alanine transaminase, aspartate aminotransferase, or gamma-glutamyl transferase). Conclusion The multifaceted perioperative management for gynecologic malignancies with asymptomatic VTE effectively prevented postoperative symptomatic PE.Trial Registration: JRCT Identifier: jRCTs031180124