title: Defective Intestinal Mucin-Type O-Glycosylation Causes Spontaneous Colitis-Associated Cancer in Mice.
abstract: Core 1- and core 3-derived mucin-type O-linked oligosaccharides (O-glycans) are major components of the colonic mucus layer. Defective forms of colonic O-glycans, such as the Thomsen-nouveau (Tn) antigen, frequently are observed in patients with ulcerative colitis and colorectal cancer, but it is not clear if they contribute to their pathogenesis. We investigated whether and how impaired O-glycosylation contributes to the development of colitis-associated colorectal cancer using mice lacking intestinal core 1- and core 3-derived O-glycans.
  
  
  
  We generated mice that lack core 1- and core 3-derived intestinal O-glycans (DKO mice) and analyzed them, along with mice that singly lack intestinal epithelial core 1 O-glycans (IEC C1galt1(-/-) mice) or core 3 O-glycans (C3Gnt(-/-) mice). Intestinal tissues were collected at different time points and analyzed for levels of mucin and Tn antigen, development of colitis, and tumor formation using imaging, quantitative polymerase chain reaction, immunoblot, and enzyme-linked immunosorbent assay techniques. We also used cellular and genetic approaches, as well as intestinal microbiota depletion, to identify inflammatory mediators and pathways that contribute to disease in DKO and wild-type littermates (controls).
  
  
  
  Intestinal tissues from DKO mice contained higher levels of Tn antigen and had more severe spontaneous chronic colitis than tissues from IEC C1galt1(-/-) mice, whereas spontaneous colitis was absent in C3GnT(-/-) and control mice. IEC C1galt1(-/-) mice and DKO mice developed spontaneous colorectal tumors, although the onset of tumors in the DKO mice occurred earlier (age, 8-9 months) than that in IEC C1galt1(-/-) mice (15 months old). Antibiotic depletion of the microbiota did not cause loss of Tn antigen but did reduce the development of colitis and cancer formation in DKO mice. Colon tissues from DKO mice, but not control mice, contained active forms of caspase 1 and increased caspase 11, which were reduced after antibiotic administration. Supernatants from colon tissues of DKO mice contained increased levels of interleukin-1β and interleukin-18, compared with those from control mice. Disruption of the caspase 1 and caspase 11 genes in DKO mice (DKO/Casp1/11(-/-) mice) decreased the development of colitis and cancer, characterized by reduced colonic thickening, hyperplasia, inflammatory infiltrate, and tumors compared with DKO mice.
  
  
  
  Impaired expression of O-glycans causes colonic mucus barrier breach and subsequent microbiota-mediated activation of caspase 1-dependent inflammasomes in colonic epithelial cells of mice. These processes could contribute to colitis-associated colon cancer in humans.
authors.affiliation: Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma.
authors.forename: Kirk
authors.initials: K
authors.lastname: Bergstrom
authors.affiliation: Division of Digestive Disease, The 2nd Xiangya Hospital of Central South University, Changsha, Hunan, China.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Liu
authors.affiliation: Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma; Jiangsu Institute of Hematology, Collaborative Innovation Center of Hematology, Key Laboratory of Thrombosis and Hemostasis of Ministry of Health, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China.
authors.forename: Yiming
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma; The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Gao
authors.affiliation: Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma; Department of Biochemistry and Molecular Biology, School of Basic Medical Science, Fudan University, Shanghai, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Wu
authors.affiliation: Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma.
authors.forename: Kai
authors.initials: K
authors.lastname: Song
authors.affiliation: Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma.
authors.forename: Yi
authors.initials: Y
authors.lastname: Cui
authors.affiliation: Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma; Jiangsu Institute of Hematology, Collaborative Innovation Center of Hematology, Key Laboratory of Thrombosis and Hemostasis of Ministry of Health, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Li
authors.affiliation: Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma.
authors.forename: J Michael
authors.initials: JM
authors.lastname: McDaniel
authors.affiliation: Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma.
authors.forename: Samuel
authors.initials: S
authors.lastname: McGee
authors.affiliation: The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China.
authors.forename: Weichang
authors.initials: W
authors.lastname: Chen
authors.affiliation: The Muchmore Laboratories for Infectious Diseases Research, Department of Veterans Affairs Medical Center, Oklahoma City, Oklahoma; Department of Internal Medicine, Oklahoma Center for Medical Glycobiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
authors.forename: Mark M
authors.initials: MM
authors.lastname: Huycke
authors.affiliation: Department of Internal Medicine, Oklahoma Center for Medical Glycobiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
authors.forename: Courtney W
authors.initials: CW
authors.lastname: Houchen
authors.affiliation: Department of Microbiology and Immunology, Oklahoma Center for Medical Glycobiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
authors.forename: Lauren A
authors.initials: LA
authors.lastname: Zenewicz
authors.affiliation: Department of Biochemistry and Molecular Biology, Oklahoma Center for Medical Glycobiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: West
authors.affiliation: Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma.
authors.forename: Hong
authors.initials: H
authors.lastname: Chen
authors.affiliation: Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California, Los Angeles, California.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Braun
authors.affiliation: Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma; Jiangsu Institute of Hematology, Collaborative Innovation Center of Hematology, Key Laboratory of Thrombosis and Hemostasis of Ministry of Health, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China. Electronic address: Jianxin-Fu@omrf.org.
authors.forename: Jianxin
authors.initials: J
authors.lastname: Fu
authors.affiliation: Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma; Jiangsu Institute of Hematology, Collaborative Innovation Center of Hematology, Key Laboratory of Thrombosis and Hemostasis of Ministry of Health, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China; Department of Biochemistry and Molecular Biology, Oklahoma Center for Medical Glycobiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma. Electronic address: Lijun-Xia@omrf.org.
authors.forename: Lijun
authors.initials: L
authors.lastname: Xia
mesh_terms: D000818:Animals; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000378:metabolism*; D003092:Colitis / Q000139:chemically induced / Q000150:complications* / Q000378:metabolism; D015179:Colorectal Neoplasms / Q000209:etiology*; D000069196:Gastrointestinal Microbiome / Q000502:physiology; D006031:Glycosylation; D007413:Intestinal Mucosa / Q000378:metabolism / Q000382:microbiology; D051379:Mice; D018345:Mice, Knockout; D009077:Mucins / Q000378:metabolism*; D011134:Polysaccharides / Q000378:metabolism*
chemical_list: D015295:Antigens, Tumor-Associated, Carbohydrate; D009077:Mucins; D011134:Polysaccharides; C040286:Tn antigen
keywords: Mouse Model; Mucin-Type O-Glycans; Mucus Barrier; Ulcerative Colitis