APC and P53 mutations synergize to create a therapeutic vulnerability to NOTUM inhibition in advanced colorectal cancer [bulk RNA-seq]

We report that inactivation of the APC tumor suppressor results in dramatic activation of the NOTUM carboxylesterase, which has potent tumor suppressive activity in APC-null adenomatous epithelium. During progression to adenocarcinoma, APC and TP53 mutations (usually coincident in advanced CRC) synergize, converting NOTUM to an obligate oncoprotein. We provide evidence that the Jekyll-and-Hyde behavior of NOTUM results from its differential activity upon enzymatic targets Glypicans 1 and 4 in early vs. late-stage disease, respectively. Ultimately, we demonstrate that small molecule inhibition of NOTUM activity in a mouse model of metastatic colon cancer is sufficient to arrest primary tumor growth and metastatic colonization. Thus, the extracellular carboxylesterase NOTUM represents a novel therapeutic vulnerability in advanced colorectal adenocarcinomas. Overall design: Infected A and AP organoid with sh-Ctrl or sh-Notum virus and puro selected for 3 days and do bulk RNA sequencing