Abstract 5729: Imiqualines for pancreatic cancer: first-in-class potent and synergistic inhibitors of microtubule polymerisation

Abstract

Abstract Background: The survival rate for patients with Pancreatic Ductal Adenocarcinoma (PDAC) is dramatically poor with a five-year survival rate less than 10%. The research of new treatments, which could complement the current therapeutic arsenal constituted by Gemcitabine, FOLFIRINOX (fluorouracile, leucovorin, irinotecan, oxaliplatin) and nab-paclitaxel, is a major challenge. Imiqualines are new original small heterocyclic chemical molecules based on the quinoxalinic moiety. Among these first in class compounds, the lead EAPB02303 (1) displays outstanding nanomolar activities comparable to those of the current best anticancer agents on a panel of human cancer cell lines, notably on poorly sensitive cancer like PDAC and melanoma. We tested here if EAPB02303 could be an attractive first in class molecule in PDAC and we conducted in-deep molecular characterization and bioinformatics studies to decipher its mechanism of action. Methods: We characterized EAPB02303 effect on tumor growth in-vitro by conducting sulforhodamine B assay on a panel of PDAC cells including cells derived from PDX (Patient Derived Xenograft) and 3D models with Cancer Associated Fibroblasts. We assessed in-vivo activity on subcutaneous PDAC xenografts mouse models. We then studied EAPB02303 effect on cell cycle, apoptosis and microtubule polymerisation by flow cytometry and immunofluorescence. We analyzed mRNAseq and Reverse Phase Protein Assay (RPPA) data of PDAC cell lines treated with EAPB02303 at multiple time points and concentrations to identify signaling pathways and key proteins implicated in EAPB02303 effect. We performed differential gene expression and gene set enrichment analysis by using EdgeR, Deseq2 and fgsea packages. We also used PharmacoGx package to seek for similar transcriptomic profiles among the CMAP perturbational database. Results: We showed that EAPB02303 exerts activity at low nanomolar concentrations in-vitro in PDAC cell lines and 3D models, and is able to reduce tumor growth in our xenografts in-vivo mouse models. We also found a potent synergy with Paclitaxel at lower concentrations of both compounds. Furthermore, we found that EAPB02303 induces mitosis arrest and impairment of spindle assembly after 24h treatment. Cells also underwent apoptosis after 48h treatment. mRNAseq and RPPA data showed activation of several signaling pathways including MAPK kinases. CMAP database mining revealed a high connectivity score of transcriptomic signatures between EAPB02303 and inhibitors of microtubule polymerization. All these data suggest that EAPB02303 is a new microtubule-disrupting agent with in-vivo activity in PDAC and in-vitro synergy with Paclitaxel, showing potential for future clinical investigations. (1) Imidazo[1,2a]quinoxalines and derivatives thereof for treating cancers. WO 2009 043934A1. Deleuze-Masqeufa C. et al. Citation Format: Kevin Bigot, Véronique Garambois, Nadia Vie, Marine Bruciamacchie, Pierre-Emmanuel Colombo, Diego Tosi, Cindy Patinote, Yann Maggipinto, Pierre-Antoine Bonnet, Céline Gongora, Carine Deleuze-Masquefa, Christel Larbouret. Imiqualines for pancreatic cancer: first-in-class potent and synergistic inhibitors of microtubule polymerisation. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5729.