Open AccessThe tumor suppressor gene RhoBTB1 is a novel target of miR-31 in human colon cancer
Author(s) -
Ruisi Xu,
Xiaodong Wu,
Siqi Zhang,
LI Chang-feng,
Lei Yang,
Dandan Li,
Baogang Zhang,
Ying Zhang,
Jingpeng Jin,
Bin Zhang
Publication year - 2012
Publication title -
international journal of oncology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.405
H-Index - 122
ISSN - 1019-6439
DOI - 10.3892/ijo.2012.1746
Subject(s) - oncogene , carcinogenesis , biology , cancer research , microrna , gene knockdown , colorectal cancer , ectopic expression , cancer , cell growth , rna interference , tumor suppressor gene , cell cycle , microbiology and biotechnology , cell culture , gene , rna , genetics
miRNAs are a class of endogenous non-coding RNA, which can regulate downstreamtarget genes through binding to the 3'UTR of those genes. Numerous studies haveindicated that abnormal expression of miRNAs is implicated in tumor development.Aberrant expression of miR-31 has been found in various cancers, including colorectalcancer. Here, we show that miR-31 is upregulated in human colon cancer tissuesand cell lines, and that repression of miR-31 inhibited colon cancer cell proliferationand colony formation in soft agarose. To further elucidate the mechanism underlyingthe role of miR-31 in promoting colon cancer, we used online miRNA target predictiondatabases and found that the tumor suppressor RhoTBT1 may be a target of miR-31.Imunohistochemistry assay revealed that RhoBTB1 was significantly decreased inHT29 cells. In addition, ectopic expression of miR-31 reduced RhoBTB1 in the coloncancer cell line HT29. The results suggested that suppression of RhoBTB1 may beresponsible for colon tumorigenesis, which was inhibited directly by miR-31. Theresults of MTT and soft agarose colony-formation assays showed that knockdownof RhoBTB1 by RNAi induced cell proliferation, and colony formation in soft agarose,which mimicked the function of miR-31. This further suggested that suppressionof RhoBTB1 was responsible for colon tumorigenesis. In conclusion, we found thatmiR-31 acts as an oncogene in colon cancer and identified RhoBTB1 as a new targetof miR-31 further study demonstrated that miR-31 contributed to the developmentof colon cancer at least partly by targeting RhoBTB1.