Abstract C194: Repression of tumor survival pathways by novel and selective inhibitors of MNK1 and MNK2 kinases in cancer

Herewith, we report development of small molecule inhibitors of MNK1 and MNK2 kinases and their cellular activity. MNK1 and 2 are MAP kinase-interacting kinases are activated by RAS and MAPK signaling pathways, and are involved in regulation of translation. Both kinases phosphorylate translation initiation factor eIF4e on a conserved serine 209. eIF4E can contribute to the oncogenic transformation both in vitro and in vivo and is highly expressed in diverse types of cancer. Interestingly, mice that lack both Mnk1 and Mnk2 do not have any apparent phenotype. Recently first dual MNK1/MNK2 inhibitors have entered clinical trials as a combinational therapy with docetaxel in NSCLC. SEL201 is a series of small molecule inhibitors which inhibit activity of both MNK1 and MNK2 in a low nM range and high selectivity confirmed in kinome panels. Analysis of SEL201 cellular activity indicated potent inhibition of eIF4e Ser209 in vitro in cancer cells and in vivo after oral administration in xenograft tumors. Repressed phosphorylation of eIF4e resulted in impaired translation of several proteins involved in metastasis and activation of immune cells. High potency, selectivity and favorable ADME/PK profile indicates that SEL201 inhibitors would be useful tools in probing molecular consequences of eIF4e Ser209 inhibition in cancer cells. SEL201 in vitro and in vivo activities on viability and metastasis will be presented in cellular and in vivo models of solid tumors and hematological malignancies. SEL201 series is further developed as a cancer therapy with a good therapeutic window. Citation Format: Tomasz Rzymski, Agnieszka Dreas, Ewelina Wincza, Charles-Henry Fabritius, Urszula Kulesza, Katarzyna Kucwaj- Brysz, Mariusz Milik, Aniela Gołas, Renata Windak, Eliza Żyłkiewicz, Anna Wróbel, Maciej Sułkowski, Krzysztof Brzózka. Repression of tumor survival pathways by novel and selective inhibitors of MNK1 and MNK2 kinases in cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr C194.