Dan Ma1, Yingying Cao1, Zhenhua Wang1, Jie He2, Huimin Chen1, Hua Xiong1, Linlin Ren3, Chaoqin Shen1, Xinyu Zhang1, Yuqing Yan1, Tingting Yan1, Fangfang Guo1, Baoqin Xuan1, Zhe Cui4, Guangyao Ye4, Jing-Yuan Fang1, Haoyan Chen1, Jie Hong1. 1. State Key Laboratory for Oncogenes and Related Genes, Key Laboratory of Gastroenterology & Hepatology, Ministry of Health, Division of Gastroenterology and Hepatology, Shanghai Cancer Institute, Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China. 2. Department of Gastroenterology and Guangzhou Key Laboratory of Digestive Disease, Guangzhou Digestive Disease Center, Guangzhou First People's Hospital, School of Medicine, South China University of Technology, Guangdong, China. 3. Department of Gastroenterology, the Affiliated Hospital of Qingdao University, Qingdao, China. 4. Department of Gastrointestinal Surgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
Abstract
BACKGROUND: The long noncoding RNA (lncRNA) colon cancer-associated transcript-1 (CCAT1) has been reported to play a vital role in the development of cancer. Although the link between inflammation and cancer initiation is well established, whether CCAT1 is involved in inflammation and promotes inflammatory bowel disease (IBD) malignancy remains undetermined. We aimed to investigate the expression of CCAT1 in IBD and the effect of CCAT1 overexpression on intestinal epithelial barrier function. METHODS: The relationship between CCAT1 and the inflammation-related pathway was analyzed in both colorectal cancer (CRC) and IBD patients. Gene expression was detected by real-time polymerase chain reaction and Western blot. Transepithelial electrical resistance (TEER) and FD-4 flux measurement were used to test the effect of CCAT1 and miR-185-3p on intestinal epithelial barrier function. Luciferase assay was performed to validate the target site of miR-185-3p on 3'-UTR of MLCK mRNA. RESULTS: Gene set enrichment analysis revealed that several inflammation-related genes were enriched in the CCAT1 high-expressed group of CRC patients. The relationship between CCAT1 and inflammation activation in IBD patients was further confirmed. CCAT1 expression positively correlated with MLCK, which acts as a protein kinase to phosphorylate myosin light chain and induces tight junction protein distribution, whereas it was negatively correlated with miR-185-3p in IBD tissues. We also determined that CCAT1 overexpression increased Caco-2 monolayer permeability and upregulated MLCK. Furthermore, CCAT1-induced MLCK overexpression and IBD disease progression were significantly attenuated by miR-185-3p. CONCLUSIONS: The CCAT1/miR-185-3p/MLCK signaling pathway is strongly activated to destroy barrier function and promotes the pathogenesis of IBD.
BACKGROUND: The long noncoding RNA (lncRNA) colon cancer-associated transcript-1 (CCAT1) has been reported to play a vital role in the development of cancer. Although the link between inflammation and cancer initiation is well established, whether CCAT1 is involved in inflammation and promotes inflammatory bowel disease (IBD) malignancy remains undetermined. We aimed to investigate the expression of CCAT1 in IBD and the effect of CCAT1 overexpression on intestinal epithelial barrier function. METHODS: The relationship between CCAT1 and the inflammation-related pathway was analyzed in both colorectal cancer (CRC) and IBD patients. Gene expression was detected by real-time polymerase chain reaction and Western blot. Transepithelial electrical resistance (TEER) and FD-4 flux measurement were used to test the effect of CCAT1 and miR-185-3p on intestinal epithelial barrier function. Luciferase assay was performed to validate the target site of miR-185-3p on 3'-UTR of MLCK mRNA. RESULTS: Gene set enrichment analysis revealed that several inflammation-related genes were enriched in the CCAT1 high-expressed group of CRCpatients. The relationship between CCAT1 and inflammation activation in IBD patients was further confirmed. CCAT1 expression positively correlated with MLCK, which acts as a protein kinase to phosphorylate myosin light chain and induces tight junction protein distribution, whereas it was negatively correlated with miR-185-3p in IBD tissues. We also determined that CCAT1 overexpression increased Caco-2 monolayer permeability and upregulated MLCK. Furthermore, CCAT1-induced MLCK overexpression and IBD disease progression were significantly attenuated by miR-185-3p. CONCLUSIONS: The CCAT1/miR-185-3p/MLCK signaling pathway is strongly activated to destroy barrier function and promotes the pathogenesis of IBD.