Targeting Foxm1 Improves Cytotoxicity of Paclitaxel and Cisplatinum in Platinum-Resistant Ovarian Cancer.

Abstract

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 real-time 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, 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.

• Authors: Gina L Westhoff, Yi Chen, Nelson N H Teng
• Journal: International journal of gynecological cancer : official journal of the International Gynecological Cancer Society (Int J Gynecol Cancer) Vol. 27 Issue 5 Pg. 887-894 (06 2017) ISSN: 1525-1438 [Electronic] England
• PMID: 28498253 (Publication Type: Journal Article)

Chemical References

• FOXM1 protein, human
• Forkhead Box Protein M1
• RNA, Messenger
• Platinum
• Thiostrepton
• Cisplatin

Topics

• Antineoplastic Combined Chemotherapy Protocols (pharmacology)
• Ascites (drug therapy, metabolism)
• Carcinoma, Ovarian Epithelial
• Cell Line, Tumor
• Cisplatin (administration & dosage)
• Drug Resistance, Neoplasm
• Drug Synergism
• Female
• Forkhead Box Protein M1 (antagonists & inhibitors, biosynthesis, genetics)
• Humans
• Molecular Targeted Therapy
• Neoplasms, Glandular and Epithelial (drug therapy, metabolism)
• Ovarian Neoplasms (drug therapy, metabolism)
• Platinum (administration & dosage)
• RNA, Messenger (genetics, metabolism)
• Thiostrepton (administration & dosage)