title: The tumor suppressor gene RhoBTB1 is a novel target of miR-31 in human             colon cancer.
abstract: miRNAs are a class of endogenous non-coding RNA, which can regulate downstream             target genes through binding to the 3'UTR of those genes. Numerous studies have             indicated that abnormal expression of miRNAs is implicated in tumor development.             Aberrant expression of miR-31 has been found in various cancers, including colorectal             cancer. Here, we show that miR-31 is upregulated in human colon cancer tissues             and cell lines, and that repression of miR-31 inhibited colon cancer cell proliferation             and colony formation in soft agarose. To further elucidate the mechanism underlying             the role of miR-31 in promoting colon cancer, we used online miRNA target prediction             databases and found that the tumor suppressor RhoTBT1 may be a target of miR-31.             Imunohistochemistry assay revealed that RhoBTB1 was significantly decreased in             HT29 cells. In addition, ectopic expression of miR-31 reduced RhoBTB1 in the colon             cancer cell line HT29. The results suggested that suppression of RhoBTB1 may be             responsible for colon tumorigenesis, which was inhibited directly by miR-31. The             results of MTT and soft agarose colony-formation assays showed that knockdown             of RhoBTB1 by RNAi induced cell proliferation, and colony formation in soft agarose,             which mimicked the function of miR-31. This further suggested that suppression             of RhoBTB1 was responsible for colon tumorigenesis. In conclusion, we found that             miR-31 acts as an oncogene in colon cancer and identified RhoBTB1 as a new target             of miR-31 further study demonstrated that miR-31 contributed to the development             of colon cancer at least partly by targeting RhoBTB1.
authors.affiliation: Endoscopy Center, China-Japan Union Hospital, Jilin University,                     Changchun 130033, P.R. China.
authors.forename: Rui-Si
authors.initials: RS
authors.lastname: Xu
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Wu
authors.forename: Si-Qi
authors.initials: SQ
authors.lastname: Zhang
authors.forename: Chang-Feng
authors.initials: CF
authors.lastname: Li
authors.forename: Lei
authors.initials: L
authors.lastname: Yang
authors.forename: Dan-Dan
authors.initials: DD
authors.lastname: Li
authors.forename: Bao-Gang
authors.initials: BG
authors.lastname: Zhang
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jing-Peng
authors.initials: JP
authors.lastname: Jin
authors.forename: Bin
authors.initials: B
authors.lastname: Zhang
mesh_terms: D063646:Carcinogenesis / Q000235:genetics; D049109:Cell Proliferation; D003110:Colonic Neoplasms / Q000235:genetics* / Q000473:pathology; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D016147:Genes, Tumor Suppressor; D019073:HT29 Cells; D006801:Humans; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism; D013234:Stem Cells; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: C534612:MIRN31 microRNA, human; D035683:MicroRNAs; C497336:RHOBTB2 protein, human; D025521:Tumor Suppressor Proteins; D019204:GTP-Binding Proteins