MTG16 is a tumor suppressor in colitis-associated carcinoma

Authors

McDonough EM Elizabeth M , Barrett CW Caitlyn W , Parang B Bobak , Mittal MK Mukul K , Smith JJ J Joshua , Bradley AM Amber M , Choksi YA Yash A , Coburn LA Lori A , Short SP Sarah P , Thompson JJ Joshua J , Zhang B Baolin , Poindexter SV Shenika V , Fischer MA Melissa A , Chen X Xi , Li J Jiang , Revetta FL Frank L , Naik R Rishi , Washington MK M Kay , Rosen MJ Michael J , Hiebert SW Scott W , Wilson KT Keith T , Williams CS Christopher S .
JCI insight. 2017 08 17; 2(16).

Abstract

MTG16 is a member of the myeloid translocation gene (MTG) family of transcriptional corepressors. While MTGs were originally identified in chromosomal translocations in acute myeloid leukemia, recent studies have uncovered a role in intestinal biology. For example, Mtg16-/- mice have increased intestinal proliferation and are more sensitive to intestinal injury in colitis models. MTG16 is also underexpressed in patients with moderate/severe ulcerative colitis. Based on these findings, we postulated that MTG16 might protect against colitis-associated carcinogenesis. MTG16 was downregulated at the protein and RNA levels in patients with inflammatory bowel disease and in those with colitis-associated carcinoma. Mtg16-/- mice subjected to inflammatory carcinogenesis modeling exhibited worse colitis and increased tumor multiplicity and size. Loss of MTG16 also increased severity of dysplasia, apoptosis, proliferation, DNA damage, and WNT signaling. Moreover, transplantation of WT marrow into Mtg16-/- mice failed to rescue the Mtg16-/- protumorigenic phenotypes, indicating an epithelium-specific role for MTG16. While MTG dysfunction is widely appreciated in hematopoietic malignancies, the role of this gene family in epithelial homeostasis, and in colon cancer, was unrealized. This report identifies MTG16 as an important modulator of colitis and tumor development in inflammatory carcinogenesis.