title: MicroRNA 301A Promotes Intestinal Inflammation and Colitis-Associated Cancer Development by Inhibiting BTG1.
abstract: Intestinal tissues from patients with inflammatory bowel disease (IBD) and colorectal cancer have increased expression of microRNA-301a (MIR301A) compared with tissues from patients without IBD. We studied the mechanisms of MIR301A in the progression of IBD in human tissues and mice.
  
  
  
  We isolated intestinal epithelial cells (IECs) from biopsy samples of the colon from 153 patients with different stages of IBD activity, 6 patients with colitis-associated cancer (CAC), and 35 healthy individuals (controls), enrolled in the study in Shanghai, China. We measured expression of MIR301A and BTG anti-proliferation factor 1 (BTG1) by IECs using quantitative reverse-transcription polymerase chain reaction. Human colon cancer cell lines (HCT-116 and SW480) were transfected with a lentivirus that expresses MIR301A; expression of cytokines and tight junction proteins were measured by quantitative reverse transcription polymerase chain reaction, flow cytometry, and immunofluorescence staining. We generated mice with disruption of the microRNA-301A gene (MIR301A-knockout mice), and also studied mice that express a transgene-encoding BTG1. Colitis was induced in knockout, transgenic, and control (C57BL/B6) mice by administration of dextran sulfate sodium (DSS), and mice were given azoxymethane to induce colorectal carcinogenesis. Colons were collected and analyzed histologically and by immunohistochemistry; tumor nodules were counted and tumor size was measured. SW480 cells expressing the MIR301A transgene were grown as xenograft tumors in nude mice.
  
  
  
  Expression of MIR301A increased in IECs from patients with IBD and CAC compared with controls. MIR301A-knockout mice were resistant to the development of colitis following administration of DSS; their colon tissues expressed lower levels of interleukin 1β (IL1β), IL6, IL8, and tumor necrosis factor than colons of control mice. Colon tissues from MIR301A-knockout mice had increased epithelial barrier integrity and formed fewer tumors following administration of azoxymethane than control mice. Human IECs expressing transgenic MIR301A down-regulated expression of cadherin 1 (also called E-cadherin or CDH1). We identified BTG1 mRNA as a target of MIR301A; levels of BTG1 mRNA were reduced in inflamed mucosa from patients with active IBD compared with controls. There was an inverse correlation between levels of BTG1 mRNA and levels of MIR301A in inflamed mucosal tissues from patients with active IBD. Human colon cancer cell lines that expressed a MIR301A transgene increased proliferation; they had increased permeability and decreased expression of CDH1 compared with cells transfected with a control vector, indicating reduced intestinal barrier function. BTG1 transgenic mice developed less severe colitis than control mice following administration of DSS. SW480 cells expressing anti-MIR301A formed fewer xenograft tumors in nude mice than cells expressing a control vector.
  
  
  
  Levels of MIR301A are increased in IECs from patients with active IBD. MIR301A reduces expression of BTG1 to reduce epithelial integrity and promote inflammation in mouse colon and promotes tumorigenesis. Strategies to decrease levels of MIR301A in colon tissues might be developed to treat patients with IBD and CAC.
authors.affiliation: Department of Gastroenterology, The Shanghai Tenth People's Hospital, Tongji University, Shanghai, China.
authors.forename: Chong
authors.initials: C
authors.lastname: He
authors.affiliation: Department of Gastroenterology, The Shanghai Tenth People's Hospital, Tongji University, Shanghai, China.
authors.forename: Tianming
authors.initials: T
authors.lastname: Yu
authors.affiliation: Department of Gastroenterology, The Shanghai Tenth People's Hospital, Tongji University, Shanghai, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Shi
authors.affiliation: Department of Gastroenterology, The Shanghai Tenth People's Hospital, Tongji University, Shanghai, China.
authors.forename: Caiyun
authors.initials: C
authors.lastname: Ma
authors.affiliation: Department of Gastroenterology, The Shanghai Tenth People's Hospital, Tongji University, Shanghai, China.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Yang
authors.affiliation: Department of Gastroenterology, The Shanghai Tenth People's Hospital, Tongji University, Shanghai, China.
authors.forename: Leilei
authors.initials: L
authors.lastname: Fang
authors.affiliation: Department of Gastroenterology, The Shanghai Tenth People's Hospital, Tongji University, Shanghai, China.
authors.forename: Mingming
authors.initials: M
authors.lastname: Sun
authors.affiliation: Department of Gastroenterology, The Shanghai Tenth People's Hospital, Tongji University, Shanghai, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wu
authors.affiliation: Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, the Graduate School of the Chinese Academy of Sciences, Shanghai, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Xiao
authors.affiliation: Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, the Graduate School of the Chinese Academy of Sciences, Shanghai, China.
authors.forename: Feifan
authors.initials: F
authors.lastname: Guo
authors.affiliation: Department of Gastroenterology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China.
authors.forename: Minhu
authors.initials: M
authors.lastname: Chen
authors.affiliation: Department of Gastroenterology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Yang
authors.affiliation: Department of Gastroenterology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Jiaming
authors.initials: J
authors.lastname: Qian
authors.affiliation: Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX. Electronic address: yicong@utmb.edu.
authors.forename: Yingzi
authors.initials: Y
authors.lastname: Cong
authors.affiliation: Department of Gastroenterology, The Shanghai Tenth People's Hospital, Tongji University, Shanghai, China. Electronic address: liuzhanju88@126.com.
authors.forename: Zhanju
authors.initials: Z
authors.lastname: Liu
mesh_terms: D000368:Aged; D000818:Animals; D001397:Azoxymethane; D015820:Cadherins / Q000235:genetics; D016022:Case-Control Studies; D049109:Cell Proliferation / Q000235:genetics; D003092:Colitis / Q000139:chemically induced / Q000235:genetics*; D003106:Colon / Q000473:pathology; D015179:Colorectal Neoplasms / Q000139:chemically induced / Q000209:etiology / Q000235:genetics* / Q000473:pathology; D016264:Dextran Sulfate; D015536:Down-Regulation; D004847:Epithelial Cells; D005260:Female; D015870:Gene Expression; D045325:HCT116 Cells; D006801:Humans; D058922:Inflammatory Breast Neoplasms / Q000150:complications / Q000235:genetics* / Q000378:metabolism; D053583:Interleukin-1beta / Q000235:genetics / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D008297:Male; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism; D009368:Neoplasm Transplantation; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics; D051996:Transcription Factor RelA / Q000235:genetics / Q000378:metabolism; D014162:Transfection; D047368:Tumor Burden; D015854:Up-Regulation
chemical_list: C489552:Btg1 protein, mouse; D015820:Cadherins; D053583:Interleukin-1beta; C550735:MIRN301A microRNA, human; C573832:MIRN301 microRNA, mouse; D035683:MicroRNAs; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D051996:Transcription Factor RelA; C074086:BTG1 protein, human; D016264:Dextran Sulfate; D048031:JNK Mitogen-Activated Protein Kinases; D001397:Azoxymethane
keywords: Crohn’s disease; Immune regulation; Mouse model; Ulcerative colitis