pevonedistat and Ovarian-Neoplasms

Surgery and chemotherapy are the gold-standard treatments for ovarian cancer. The major cause of treatment failure in patients with ovarian cancer is tumoral heterogeneity and drug resistance. Paclitaxel (PTX) is one of the most commonly used first-line drugs for ovarian cancer chemotherapy. Unfortunately, the mechanisms of PTX chemoresistance remain unclear. Here, we examined the effects of post-translational neddylation on the sensitivity of ovarian cancer cells (OCCs) to PTX-induced apoptosis. Disruption of protein neddylation with the first-in-class inhibitor MLN4924 dramatically neutralized PTX-mediated antiproliferative, antimigration, and apoptotic effects in human OCCs. Moreover, MLN4924 treatment interrupted PTX-induced microtubule polymerization. Importantly, two neddylation conjugating E2 enzymes, UBE2M and UBE2F, were found to play essential roles in PTX-induced cytotoxicity and tubulin polymerization in OCCs. In summary, our findings demonstrated that disruption of protein neddylation by MLN4924 conferred resistance to PTX and provided insights into the potential mechanisms of PTX chemoresistance in ovarian cancer.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Cell Line, Tumor; Cell Proliferation; Cyclopentanes; Drug Resistance, Neoplasm; Female; Humans; Microtubules; NEDD8 Protein; Ovarian Neoplasms; Paclitaxel; Polymerization; Protein Processing, Post-Translational; Pyrimidines; Ubiquitin-Conjugating Enzymes

The use of carboplatin in cancer chemotherapy is limited by the emergence of drug resistance. To understand the molecular basis for this resistance, a chemogenomic screen was performed in 53 yeast mutants that had previously presented strong sensitivity to this widely used anticancer agent. Thirty-four mutants were responsive to carboplatin, and from these, 21 genes were selected for further studies because they have human homologues. Sixty percent of these yeast genes possessed human homologues which encoded proteins that interact with cullin scaffolds of ubiquitin ligases, or whose mRNA are under the regulation of Human antigen R (HuR) protein. Both HuR and cullin proteins are regulated through NEDDylation post-translational modification, and so our results indicate that inhibition of this process should sensitise resistant tumour cells to carboplatin. We showed that treatment of a tumour cell line with MLN4924, a NEDDylation inhibitor, overcame the resistance to carboplatin. Our data suggest that inhibition of NEDDylation may be a useful strategy to resensitise tumour cells in patients that have acquired carboplatin resistance.

Topics: Carboplatin; Cell Line, Tumor; Chromosomes, Human, Pair 1; Cullin Proteins; Cyclopentanes; Drug Resistance, Fungal; Drug Resistance, Neoplasm; ELAV-Like Protein 1; Female; Gene Expression Profiling; Humans; Mutation; Ovarian Neoplasms; Pyrimidines; Saccharomyces cerevisiae; Ubiquitin-Activating Enzymes

Ovarian cancer has the highest mortality rate of all female reproductive malignancies. Drug resistance is a major cause of treatment failure and novel therapeutic strategies are urgently needed. MLN4924 is a NEDDylation inhibitor currently under investigation in multiple phase I studies. We investigated its anticancer activity in cisplatin-sensitive and -resistant ovarian cancer models.. Cellular sensitivity to MLN4924/cisplatin was determined by measuring viability, clonogenic survival, and apoptosis. The effects of drug treatment on global protein expression, DNA damage, and reactive oxygen species generation were determined. RNA interference established natural born killer/bcl-2-interacting killer (NBK/BIK) as a regulator of therapeutic sensitivity. The in vivo effects of MLN4924/cisplatin on tumor burden and key pharmacodynamics were assessed in cisplatin-sensitive and -resistant xenograft models.. MLN4924 possessed significant activity against both cisplatin-sensitive and -resistant ovarian cancer cells and provoked the stabilization of key NEDD8 substrates and regulators of cellular redox status. Notably, MLN4924 significantly augmented the activity of cisplatin against cisplatin-resistant cells, suggesting that aberrant NEDDylation may contribute to drug resistance. MLN4924 and cisplatin cooperated to induce DNA damage, oxidative stress, and increased expression of the BH3-only protein NBK/BIK. Targeted NBK/BIK knockdown diminished the proapoptotic effects of the MLN4924/cisplatin combination. Administration of MLN4924 to mice bearing ovarian tumor xenografts significantly increased the efficacy of cisplatin against both cisplatin-sensitive and -resistant tumors.. Our collective data provide a rationale for the clinical investigation of NEDD8-activating enzyme (NAE) inhibition as a novel strategy to augment cisplatin efficacy in patients with ovarian cancer and other malignancies.

Topics: Animals; Apoptosis; Apoptosis Regulatory Proteins; Cell Survival; Cisplatin; Cyclopentanes; DNA Damage; Drug Resistance, Neoplasm; Female; Humans; Membrane Proteins; Mice; Mitochondrial Proteins; NF-kappa B; Ovarian Neoplasms; Proteome; Pyrimidines; Reactive Oxygen Species; Tumor Burden; Tumor Stem Cell Assay; Xenograft Model Antitumor Assays

The nearly ubiquitous development of chemoresistant disease remains a major obstacle against improving outcomes for patients with ovarian cancer. In this investigation, we evaluated the preclinical activity of MLN4924, an investigational inhibitor of the NEDD8-activating enzyme, in ovarian cancer cells. Efficacy of MLN4924 both alone and in combination with platinum was assessed. Overall, single-agent MLN4924 exhibited moderate activity in ovarian cancer cell lines. However, the combination of MLN4924 with cisplatin or carboplatin produced synergistic effects in SKOV3 and ES2 cells, as well as in primary ovarian cancer cell lines established from high-grade serous, clear cell, and serous borderline ovarian tumors. The efficacy of cisplatin plus MLN4924 was also evident in several in vitro models of platinum-resistant ovarian cancer. Mechanistically, the combination of cisplatin and MLN4924 was not associated with DNA re-replication, altered platinum-DNA adduct formation, abrogation of FANCD2 monoubiquitination, or CHK1 phosphorylation. An siRNA screen was used to investigate the contribution of each member of the cullin RING ligase (CRL) family of E3 ubiquitin ligases, the best-characterized downstream mediators of MLN4924's biologic effects. Cisplatin-induced cytotoxicity was augmented by depletion of CUL3, and antagonized by siCUL1 in both ES2 and SKOV3 ovarian cancer cells. This investigation identifies inhibition of neddylation as a novel mechanism for overcoming platinum resistance in vitro, and provides a strong rationale for clinical investigations of platinum and MLN4924 combinations in ovarian cancer.

Topics: Apoptosis; Carboplatin; Cell Line, Tumor; Cisplatin; Cyclopentanes; Drug Resistance, Neoplasm; Drug Synergism; Fanconi Anemia Complementation Group D2 Protein; Female; Humans; Molecular Targeted Therapy; Ovarian Neoplasms; Pyrimidines; Ubiquitin-Activating Enzymes; Ubiquitination

Cullin-RING ubiquitin ligases (CRLs) are the largest family of E3 ligases and require cullin neddylation for their activation. The NEDD8-activating enzyme inhibitor MLN4924 reportedly blocked cullin neddylation and inactivated CRLs, which resulted in apoptosis induction and tumor suppression. However, CRL roles in ovarian cancer cell survival and the ovarian tumor repressing effects of MLN4924 are unknown. We show here that CRL4 components are highly expressed in human epithelial ovarian cancer tissues. MLN4924-induced DNA damage, cell cycle arrest, and apoptosis in ovarian cancer cells in a time- and dose-dependent manner. In addition, MLN4924 sensitized ovarian cancer cells to other chemotherapeutic drug treatments. Depletion of CRL4 components Roc1/2, Cul4a, and DDB1 had inhibitory effects on ovarian cancer cells similar to MLN4924 treatment, which suggested that CRL4 inhibition contributed to the chemotherapeutic effect of MLN4924 in ovarian cancers. We also investigated for key CRL4 substrate adaptors required for ovarian cancer cells. Depleting Vprbp/Dcaf1 did not significantly affect ovarian cancer cell growth, even though it was expressed by ovarian cancer tissues. However, depleting Cdt2/Dcaf2 mimicked the pharmacological effects of MLN4924 and caused the accumulation of its substrate, CDT1, both in vitro and in vivo. MLN4924-induced DNA damage and apoptosis were partially rescued by Cdt1 depletion, suggesting that CRL4(CDT2) repression and CDT1 accumulation were key biochemical events contributing to the genotoxic effects of MLN4924 in ovarian cancer cells. Taken together, these results indicate that CRL4(CDT2) is a potential drug target in ovarian cancers and that MLN4924 may be an effective anticancer agent for targeted ovarian cancer therapy.

Topics: Animals; Apoptosis; Blotting, Western; Carcinoma, Ovarian Epithelial; Cell Cycle Proteins; Cell Line, Tumor; Cell Survival; Cells, Cultured; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinase Inhibitor p27; Cyclopentanes; DNA Damage; Dose-Response Relationship, Drug; Female; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Mice; Mice, Nude; Neoplasms, Glandular and Epithelial; Nuclear Proteins; Ovarian Neoplasms; Pyrimidines; Reverse Transcriptase Polymerase Chain Reaction; RNA Interference; Ubiquitin-Protein Ligases; Xenograft Model Antitumor Assays