pyrimidinones and Carcinoma--Ovarian-Epithelial

WEE1 has emerged as an attractive target in epithelial ovarian cancer (EOC), but how EOC cells may alter their sensitivity to WEE1 inhibition remains unclear. Here, through a cell cycle machinery-related gene RNAi screen, we found that targeting outer dense fiber of sperm tails 2-like (ODF2L) was a synthetic lethal partner with WEE1 kinase inhibition in EOC cells. Knockdown of ODF2L robustly sensitized cells to treatment with the WEE1 inhibitor AZD1775 in EOC cell lines in vitro as well as in xenografts in vivo. Mechanistically, the increased sensitivity to WEE1 inhibition upon ODF2L loss was accompanied by accumulated DNA damage. ODF2L licensed the recruitment of PKMYT1, a functionally redundant kinase of WEE1, to the CDK1-cyclin B complex and thus restricted the activity of CDK1 when WEE1 was inhibited. Clinically, upregulation of ODF2L correlated with CDK1 activity, DNA damage levels, and sensitivity to WEE1 inhibition in patient-derived EOC cells. Moreover, ODF2L levels predicted the response to WEE1 inhibition in an EOC patient-derived xenograft model. Combination treatment with tumor-targeted lipid nanoparticles that packaged ODF2L siRNA and AZD1775 led to the synergistic attenuation of tumor growth in the ID8 ovarian cancer syngeneic mouse model. These data suggest that WEE1 inhibition is a promising precision therapeutic strategy for EOC cells expressing low levels of ODF2L.

Topics: Animals; Carcinoma, Ovarian Epithelial; Cell Cycle Proteins; Cell Line, Tumor; DNA Damage; Female; Humans; Membrane Proteins; Mice; Ovarian Neoplasms; Protein Serine-Threonine Kinases; Protein-Tyrosine Kinases; Pyrimidinones; Semen

The development of resistance to platinum-based chemotherapy remains the unsurmountable obstacle in cancer treatment and consequently leads to tumor relapse. This study aims to investigate the mechanism by which loss of RBMS3 induced chemoresistance in epithelial ovarian cancer (EOC).. Our results demonstrate that genetic ablation of RBMS3 contributes to chemoresistance and PRI-724 may serve as a potential tailored treatment for patients with RBMS3-deleted EOC.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; beta Catenin; Bridged Bicyclo Compounds, Heterocyclic; Carcinoma, Ovarian Epithelial; Cisplatin; Drug Resistance, Neoplasm; Female; Gene Deletion; Gene Expression Regulation, Neoplastic; Humans; Kaplan-Meier Estimate; Mice, Inbred NOD; Mice, Knockout; Mice, SCID; MicroRNAs; Peptide Fragments; Pyrimidinones; RNA-Binding Proteins; Sialoglycoproteins; Signal Transduction; Trans-Activators; Xenograft Model Antitumor Assays

In the last 40 years ovarian cancer mortality rates have slightly declined and, consequently, it continues to be the fifth cause of cancer death in women. In the present study, we showed that β-catenin signaling is involved in the functions of ovarian cancer cells and interacts with the Notch system. Wnt and Notch systems showed to be prosurvival for ovarian cancer cells and their inhibition impaired cell proliferation and migration. We also demonstrated that the inhibition of β-catenin by means of two molecules, XAV939 and ICG-001, decreased the proliferation of the IGROV1 and SKOV3 ovarian cancer cell lines and that ICG-001 increased the percentage of IGROV1 cells undergoing apoptosis. The simultaneous inhibition of β-catenin and Notch signaling, by using the DAPT inhibitor, decreased ovarian cancer cell proliferation to the same extent as targeting only the Wnt/β-catenin pathway. A similar effect was observed in IGROV1 cell migration with ICG-001 and DAPT. ICG-001 increased the Notch target genes Hes-1 and Hey-1 and increased Jagged1 expression. However, no changes were observed in Dll4 or Notch 1 and 4 expressions. Our results suggest that Notch and β-catenin signaling co-operate in ovarian cancer to ensure the proliferation and migration of cells and that this could be achieved, at least partly, by the upregulation of Notch Jagged1 ligand in the absence of Wnt signaling. We showed that the Wnt pathway crosstalks with Notch in ovarian cancer cell functions, which may have implications in ovarian cancer therapeutics.

Topics: Animals; Bridged Bicyclo Compounds, Heterocyclic; Carcinoma, Ovarian Epithelial; Cell Movement; Cell Proliferation; Cell Survival; Diamines; Female; Humans; Mice; Mice, Nude; Ovarian Neoplasms; Pyrimidinones; Receptors, Notch; Signal Transduction; Thiazoles; Wnt Signaling Pathway; Xenograft Model Antitumor Assays

Low-grade serous ovarian cancer (LGSOC) constitutes 5-8% of epithelial ovarian cancers and is refractory to chemotherapy. We and others have shown metformin to cause significant growth inhibition in high-grade ovarian cancer both in vitro and in vivo. Here, we aimed to analyze if metformin was effective in inhibiting proliferation of LGSOC alone and in combination with MEK inhibitor.. Three LGSOC lines (VOA1056, VOA1312 and VOA5646) were treated with metformin, trametinib or 2-deoxyglucose (2DG) alone or in combination with metformin. Proliferation was measured by MTT assay over a period of four days. Protein expression was measured by western blotting. Seahorse Analyzer was used to measure effect of metformin on glycolysis and mitochondrial respiration.. All LGSOC cell lines showed significant inhibition with metformin in a dose- and time-dependent manner. Trametinib significantly inhibited the growth of Ras mutated LGSOC lines (VOA1312 and VOA1056), while VOA5646 cells without RAS mutation did not show any response. Metformin and trametinib combination showed synergistic inhibition of RAS mutated VOA1312 and VOA1056 cells, but not for non-Ras mutated VOA5646 cells. Metformin and trametinib increased phosphorylated AMPK expression in LGSOC lines with combination showing stronger expression. Trametinib decreased 42/44 mitogen activated kinase phosphorylation in all cell lines, while metformin and combination had no significant effect. 2-DG significantly inhibited glycolysis in all LGSOC lines and combination with metformin showed synergistic inhibitory effect.. Metformin alone or in combination with MEK and glycolytic inhibitors may be a potential therapy for LGSOC, a cancer that is indolent but chemo-resistant.

Topics: AMP-Activated Protein Kinases; Antimetabolites; Blotting, Western; Carcinoma, Ovarian Epithelial; Cell Line, Tumor; Cell Proliferation; Deoxyglucose; Drug Synergism; Drug Therapy, Combination; Female; Humans; Hypoglycemic Agents; Metformin; Neoplasm Grading; Neoplasms, Cystic, Mucinous, and Serous; Neoplasms, Glandular and Epithelial; Ovarian Neoplasms; Protein Kinase Inhibitors; Pyridones; Pyrimidinones; ras Proteins; Signal Transduction

Resistance to platinum-based chemotherapy is the major barrier to treating epithelial ovarian cancer. To improve patient outcomes, it is critical to identify the underlying mechanisms that promote platinum resistance. Emerging evidence supports the concept that platinum-based therapies are able to eliminate the bulk of differentiated cancer cells, but are unable to eliminate cancer initiating cells (CIC). To date, the relevant pathways that regulate ovarian CICs remain elusive. Several correlative studies have shown that Wnt/β-catenin pathway activation is associated with poor outcomes in patients with high-grade serous ovarian cancer (HGSOC). However, the functional relevance of these findings remain to be delineated. We have uncovered that Wnt/β-catenin pathway activation is a critical driver of HGSOC chemotherapy resistance, and targeted inhibition of this pathway, which eliminates CICs, represents a novel and effective treatment for chemoresistant HGSOC. Here we show that Wnt/β-catenin signaling is activated in ovarian CICs, and targeted inhibition of β-catenin potently sensitized cells to cisplatin and decreased CIC tumor sphere formation. Furthermore, the Wnt/β-catenin specific inhibitor iCG-001 potently sensitized cells to cisplatin and decreased stem-cell frequency in platinum resistant cells. Taken together, our data is the first report providing evidence that the Wnt/β-catenin signaling pathway maintains stem-like properties and drug resistance of primary HGSOC PDX derived platinum resistant models, and therapeutic targeting of this pathway with iCG-001/PRI-724, which has been shown to be well tolerated in Phase I trials, may be an effective treatment option.

Topics: Animals; Antineoplastic Agents; beta Catenin; Bridged Bicyclo Compounds, Heterocyclic; Carcinoma, Ovarian Epithelial; Cisplatin; Drug Resistance, Neoplasm; Humans; Mice; Mice, Nude; Neoplasms, Glandular and Epithelial; Neoplastic Stem Cells; Ovarian Neoplasms; Pyrimidinones; Spheroids, Cellular; Tumor Cells, Cultured; Wnt Proteins; Wnt Signaling Pathway; Xenograft Model Antitumor Assays