title: DNA methylation is involved in the aberrant expression of miR-133b in colorectal cancer cells.
abstract: The dysregulation of microRNA (miRNA) expression is highly involved in cancer. Recently, a number of studies have demonstrated that the silencing of specific miRNAs is associated with DNA methylation. The muscle-specific miRNA-113b (miR-133b) is markedly downregulated in human colorectal cancer (CRC) compared with healthy colon cells, and is critical in the regulation of CRC cell proliferation and apoptosis. However, the mechanism of miR-133b downregulation in CRC has yet to be elucidated. Therefore, the aim of the present study was to determine the existence of an association between DNA methylation and miR-133b expression in CRC cells. It was identified that miR-133b promoter hypermethylation is upregulated in CRC tissues. To investigate the role of miR-133b methylation in CRC cells, the survival, cell cycle and invasion were analyzed in HT-29 and SW620 CRC cells treated with 5-aza-2'-deoxycytidine (5-Aza-CdR), 4-phenylbutyric acid (PBA) and 5-Aza-CdR/PBA. Functional analysis demonstrated that demethylation increased the expression of miR-133b, which restored migration and apoptosis in CRC cells. Thus, these results indicate that the regulation of miR-133b methylation may provide a novel therapeutic strategy for CRC treatment.
authors.affiliation: Department of Emergency Medicine, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, P.R. China.
authors.forename: L V
authors.initials: LV
authors.lastname: Lv
authors.affiliation: Department of General Surgery, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, P.R. China.
authors.forename: Jianyu
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Department of General Surgery, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, P.R. China.
authors.forename: Changwei
authors.initials: C
authors.lastname: Lin
authors.affiliation: Department of General Surgery, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, P.R. China.
authors.forename: Gui
authors.initials: G
authors.lastname: Hu
authors.affiliation: Department of Neurosurgery, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, P.R. China.
authors.forename: L U
authors.initials: LU
authors.lastname: Yi
authors.affiliation: Department of General Surgery, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, P.R. China.
authors.forename: Juan
authors.initials: J
authors.lastname: DU
authors.affiliation: Department of General Surgery, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, P.R. China.
authors.forename: Kai
authors.initials: K
authors.lastname: Gao
authors.affiliation: Department of General Surgery, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, P.R. China.
authors.forename: Xiaorong
authors.initials: X
authors.lastname: Li
keywords: DNA methylation; colorectal carcinoma; microRNA-133b