thiostrepton and Ovarian-Neoplasms

Topics: Animals; Cell Line, Tumor; Cell Proliferation; Cell Survival; Disease Models, Animal; ErbB Receptors; Female; Forkhead Box Protein M1; Gene Knockdown Techniques; Humans; Lapatinib; Mice; Ovarian Neoplasms; Peritoneal Neoplasms; Receptor, ErbB-2; Signal Transduction; Thiostrepton; Transfection

High grade serous ovarian cancer (HGSOC) is the fifth leading cause of cancer deaths among women yet effective targeted therapies against this disease are limited. The heterogeneity of HGSOC, including few shared oncogenic drivers and origination from both the fallopian tube epithelium (FTE) and ovarian surface epithelium (OSE), has hampered development of targeted drug therapies. PAX8 is a lineage-specific transcription factor expressed in the FTE that is also ubiquitously expressed in HGSOC where it is an important driver of proliferation, migration, and cell survival. PAX8 is not normally expressed in the OSE, but it is turned on after malignant transformation. In this study, we use proteomic and transcriptomic analysis to examine the role of PAX8 leading to increased migratory capabilities in a human ovarian cancer model, as well as in tumor models derived from the OSE and FTE. We find that PAX8 is a master regulator of migration with unique downstream transcriptional targets that are dependent on the cell's site of origin. Importantly, we show that targeting PAX8, either through CRISPR genomic alteration or through drug treatment with micelle encapsulated thiostrepton, leads to a reduction in tumor burden. These findings suggest PAX8 is a unifying protein driving metastasis in ovarian tumors that could be developed as an effective drug target to treat HGSOC derived from both the OSE and FTE.

Topics: Animals; Cell Adhesion; Cell Movement; Cells, Cultured; Cystadenocarcinoma, Serous; Drug Compounding; Drug Delivery Systems; Fallopian Tubes; Female; Gene Expression Profiling; Mice; Mice, Nude; Micelles; Neoplasm Grading; Neoplasm Invasiveness; Neoplasm Metastasis; Ovarian Neoplasms; PAX8 Transcription Factor; Peritoneum; Proteome; Proteomics; Thiostrepton

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.. 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.. 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.. Targeting FOXM1 may lead to novel therapeutics for chemoresistant epithelial ovarian cancer.

Topics: Antineoplastic Combined Chemotherapy Protocols; Ascites; Carcinoma, Ovarian Epithelial; Cell Line, Tumor; Cisplatin; Drug Resistance, Neoplasm; Drug Synergism; Female; Forkhead Box Protein M1; Humans; Molecular Targeted Therapy; Neoplasms, Glandular and Epithelial; Ovarian Neoplasms; Platinum; RNA, Messenger; Thiostrepton

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.. 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.. 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.. Targeting FOXM1 may lead to novel therapeutics for chemoresistant epithelial ovarian cancer.

Topics: Antineoplastic Combined Chemotherapy Protocols; Ascites; Carcinoma, Ovarian Epithelial; Cell Line, Tumor; Cisplatin; Drug Resistance, Neoplasm; Drug Synergism; Female; Forkhead Box Protein M1; Humans; Molecular Targeted Therapy; Neoplasms, Glandular and Epithelial; Ovarian Neoplasms; Paclitaxel; Signal Transduction; Thiostrepton

Chemoresistance to anti-cancer drugs substantially reduces survival in epithelial ovarian cancer. In this study, we showed that chemoresistance to cisplatin and paclitaxel induced the epithelial-mesenchymal transition (EMT) and a stem cell phenotype in ovarian cancer cells. Chemoresistance was associated with the downregulation of epithelial markers and the upregulation of mesenchymal markers, EMT-related transcription factors, and cancer stem cell markers, which enhanced invasion and sphere formation ability. Overexpression of FOXM1 increased cisplatin-resistance and sphere formation in cisplatin-sensitive and low FOXM1-expressing ovarian cancer cells. Conversely, depletion of FOXM1 via RNA interference reduced cisplatin resistance and sphere formation in cisplatin-resistant and high FOXM1-expressing cells. Overexpression of FOXM1 also increased the expression, nuclear accumulation, and activity of β-CATENIN in chemoresistant cells, whereas downregulation of FOXM1 suppressed these events. The combination of cisplatin and the FOXM1 inhibitor thiostrepton inhibited the expression of stem cell markers in chemoresistant cells and subcutaneous ovarian tumor growth in mouse xenografts. In an analysis of 106 ovarian cancer patients, high FOXM1 levels in tumors were associated with cancer progression and short progression-free intervals. Collectively, our findings highlight the importance of FOXM1 in chemoresistance and suggest that FOXM1 inhibitors may be useful for treatment of ovarian cancer.

Topics: Animals; Antineoplastic Agents; Biomarkers, Tumor; Blotting, Western; Carcinoma, Ovarian Epithelial; Cell Line, Tumor; Cell Proliferation; Cisplatin; Disease Progression; Drug Resistance, Neoplasm; Epithelial-Mesenchymal Transition; Female; Forkhead Box Protein M1; Forkhead Transcription Factors; Humans; Immunohistochemistry; Mice, Inbred NOD; Mice, SCID; Neoplasms, Glandular and Epithelial; Neoplastic Stem Cells; Ovarian Neoplasms; Paclitaxel; RNA Interference; Survival Analysis; Thiostrepton; Tumor Burden; Xenograft Model Antitumor Assays

Aldehyde dehydrogenase 1 (ALDH1) is a cancer stem-like cell (CSC) marker in human cancers; however, the specific ALDH1-regulated function and its underlying signalling pathways have not been fully demonstrated. Here, we investigated the ALDH1-regulated function and its underlying signalling and tested whether all-trans retinoic acid (ATRA) can suppress ALDH1-regulated tumour behaviour in ovarian cancer cells. By modulating ALDH1 expression using flow cytometry enrichment and exogenous overexpression or knockdown, we showed that the ALDH1 activity is positively correlated with stemness in ovarian cancer cells according to measures such as sphere formation and CSC marker expression as well as tumourigenesis in a mouse xenograft model. The findings indicate that the ALDH1 directly regulates the functions of ovarian cancer cells. We also showed that ALDH1 can regulate the expression of FoxM1 and Notch 1, which are involved in the downstream signalling of ALDH1-mediated biofunctions. Inhibition of FoxM1 by Thiostrepton and of Notch1 by DAPT downregulated the sphere formation ability of cells. ATRA reduced ALDH1 expression, suppressed tumour formation and inhibited sphere formation, cell migration and invasion in ALDH1-abundant ovarian cancer cells. We conclude that ATRA downregulates ALDH1/FoxM1/Notch1 signalling and suppresses tumour formation in ovarian cancer cells.

Topics: Aldehyde Dehydrogenase 1 Family; Animals; Antineoplastic Agents; Cell Movement; Cell Transformation, Neoplastic; Dipeptides; Down-Regulation; Female; Forkhead Box Protein M1; Forkhead Transcription Factors; Humans; Isoenzymes; Mice; Mice, Inbred NOD; Mice, SCID; Neoplasm Invasiveness; Neoplasm Transplantation; Neoplastic Stem Cells; Ovarian Neoplasms; Receptor, Notch1; Retinal Dehydrogenase; RNA Interference; RNA, Small Interfering; Spheroids, Cellular; Thiostrepton; Transplantation, Heterologous; Tretinoin; Tumor Cells, Cultured

FoxM1 is an oncogenic Forkhead transcription factor that is overexpressed in ovarian cancer. However, the mechanisms by which FoxM1 is deregulated in ovarian cancer and the extent to which FoxM1 can be targeted in ovarian cancer have not been reported previously. In this study, we showed that MDM2 inhibitor Nutlin-3 upregulated p53 protein and downregulated FoxM1 expression in several cancer cell lines with wild type TP53 but not in cell lines with mutant TP53. FoxM1 downregulation was partially blocked by cycloheximide or actinomycin D, and pulse-chase studies indicate Nutlin-3 enhances FoxM1 mRNA decay. Knockdown of p53 using shRNAs abrogated the FoxM1 downregulation by Nutlin-3, indicating a p53-dependent mechanism. FoxM1 inhibitor, thiostrepton, induces apoptosis in cancer cell lines and enhances sensitivity to cisplatin in these cells. Thiostrepton downregulates FoxM1 expression in several cancer cell lines and enhances sensitivity to carboplatin in vivo. Finally, FoxM1 expression is elevated in nearly all (48/49) ovarian tumors, indicating that thiostrepton target gene is highly expressed in ovarian cancer. In summary, the present study provides novel evidence that both amorphic and neomorphic mutations in TP53 contribute to FoxM1 overexpression and that FoxM1 may be targeted for therapeutic benefits in cancers.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Carboplatin; Cell Line, Tumor; Drug Synergism; Female; Forkhead Box Protein M1; Forkhead Transcription Factors; HEK293 Cells; Humans; Imidazoles; Mice; Mice, Nude; Molecular Targeted Therapy; Mutation; Ovarian Neoplasms; Piperazines; Thiostrepton; Tumor Suppressor Protein p53; Xenograft Model Antitumor Assays

Forkhead box M1 (FOXM1) is a proliferation-associated transcription factor essential for cell cycle progression. Numerous studies have documented that FOXM1 has multiple functions in tumorigenesis and its elevated levels are frequently associated with cancer progression. Here, we characterized the role of ERK/FOXM1 signaling in mediating the metastatic potential of ovarian cancer cells. Immunohistochemical (IHC), immunoblotting and semi-quantitative RT-PCR analyses found that both phospho-ERK and FOXM1 were frequently upregulated in ovarian cancers. Intriguingly, the overexpressed phospho-ERK (p<0.001) and FOXM1 (p<0.001) were significantly correlated to high-grade ovarian tumors with aggressive behavior such as metastasized lymph node (5 out of 6). Moreover, the expressions of phospho-ERK and FOXM1 had significantly positive correlation (p<0.001). Functionally, ectopic expression of FOXM1B remarkably enhanced cell migration/invasion, while FOXM1C not only increased cell proliferation but also promoted cell migration/invasion. Conversely, inhibition of FOXM1 expression by either thiostrepton or U0126 could significantly impair FOXM1 mediated oncogenic capacities. However, the down-regulation of FOXM1 by either thiostrepton or U0126 required the presence of p53 in ovarian cancer cells. Collectively, our data suggest that over-expression of FOXM1 might stem from the constitutively active ERK which confers the metastatic capabilities to ovarian cancer cells. The impairment of metastatic potential of cancer cells by FOXM1 inhibitors underscores its therapeutic value in advanced ovarian tumors.

Topics: Blotting, Western; Butadienes; Cell Line; Cell Line, Tumor; Cell Movement; Cell Proliferation; Dose-Response Relationship, Drug; Enzyme Inhibitors; Extracellular Signal-Regulated MAP Kinases; Female; Forkhead Box Protein M1; Forkhead Transcription Factors; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Matrix Metalloproteinase 9; Neoplasm Invasiveness; Nitriles; Ovarian Neoplasms; Phosphoproteins; Protein Isoforms; Receptors, Urokinase Plasminogen Activator; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Thiostrepton; Tumor Suppressor Protein p53