RT Journal Article SR Electronic T1 Paneth cell–derived growth factors support tumorigenesis in the small intestine JF Life Science Alliance JO Life Sci. Alliance FD Life Science Alliance LLC SP e202000934 DO 10.26508/lsa.202000934 VO 4 IS 3 A1 Qing Chen A1 Kohei Suzuki A1 Luis Sifuentes-Dominguez A1 Naoteru Miyata A1 Jie Song A1 Adam Lopez A1 Petro Starokadomskyy A1 Purva Gopal A1 Igor Dozmorov A1 Shuai Tan A1 Bujun Ge A1 Ezra Burstein YR 2021 UL https://www.life-science-alliance.org/content/4/3/e202000934.abstract AB Paneth cells (PCs) are small intestinal epithelial cells that secrete antimicrobial peptides and growth factors, such as Wnt ligands. Intriguingly, the context in which PC-derived Wnt secretion is relevant in vivo remains unknown as intestinal epithelial ablation of Wnt does not affect homeostatic proliferation or restitution after irradiation injury. Considering the importance of growth factors in tumor development, we explored here the role of PCs in intestinal carcinogenesis using a genetic model of PC depletion through conditional expression of diphtheria toxin-α subunit. PC depletion in ApcMin mice impaired adenoma development in the small intestine and led to decreased Wnt3 expression in small bowel adenomas. To determine if PC-derived Wnt3 was required for adenoma development, we examined tumor formation after PC-specific ablation of Wnt3. We found that this was sufficient to decrease small intestinal adenoma formation; moreover, organoids derived from these tumors displayed slower growth capacity. Overall, we report that PC-derived Wnt3 is required to sustain early tumorigenesis in the small bowel and identify a clear role for PC-derived Wnt production in intestinal pathology.