Developing an AUTAC (AUtophagy-TArgeting Chimera) degrader tool to selectively target NKX3-2 to overcome chemoresistance in ovarian cancer

BACKGROUND NKX3-2 is a transcriptional repressor factor belonging to the NK family of homeobox-containing proteins that has been reported to promote metastasis and was found significantly upregulated in chemoresistant ovarian tumors. Targeted protein degradation (TPD) is a novel strategy that exploits heterobifunctional chimeric molecules to induce the selective degradation of specific targets. Autophagy-targeting chimera (AUTAC) promotes the turnover of a target protein of interest via autophagy-lysosome pathway. HYPOTHESIS AND AIMS Overall, our preliminary findings indicate that NKX3-2 seems to be a promising oncogenic factor, thus prompting further studies to prove its relevance as anti-cancer therapeutic target. We observed that NKX3-2 interacts with LC3, which in turn results in NKX3-2 clearance via autophagy. We aim to exploit this mechanism to develop a potent AUTAC degrader and to characterize its anti-cancer activities. EXPERIMENTAL PLAN We will set up a AUTAC degrader composed of a binding ligand for NKX3-2 and a nucleotide-based degradation tag recruiting autophagy machinery connected by a linker. In vitro biological validation will be carried out in three ovarian cancer cell lines (SKOV3, OVCAR3 and OAW42) differing for NKX3-2 levels and basal autophagy. Autophagy degradation will be confirmed by pharmacological inhibition and autophagy gene knockdown. Characterization of anti-cancer activity of NKX3-2 AUTAC degrader will be focused on cell proliferation, motility and response to chemotherapy. EXPECTED RESULTS The TPD approach provides several advantages in terms of selectivity, reduction of side effects and the need for a constant drug administration. We expect to design an efficient degrader tool that represents a new strategy to target oncogenic activities of NKX3-2, like sensitize cancer cells to chemotherapy and reduce their proliferative and invasive features