Up-regulation of miR-182 by β-catenin in breast cancer increases tumorigenicity and invasiveness by targeting the matrix metalloproteinase inhibitor RECK

• Published in: Biochimica et biophysica acta Vol. 1830; no. 4; pp. 3067 - 3076
• Main Authors: Chiang, Chi-Hsiang, Hou, Ming-Feng, Hung, Wen-Chun
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.04.2013
• Subjects: Adult; Aged; beta Catenin - antagonists & inhibitors; beta Catenin - physiology; breast neoplasms; Breast Neoplasms - etiology; Breast Neoplasms - pathology; carcinogenesis; cell invasion; Cell Line, Tumor; Cell Transformation, Neoplastic; chromatin; Female; gene expression regulation; GPI-Linked Proteins - antagonists & inhibitors; GPI-Linked Proteins - physiology; Humans; Matrix metalloproteinase; Matrix Metalloproteinase Inhibitors; messenger RNA; metalloproteinases; MicroRNA; MicroRNAs - physiology; Middle Aged; miR-182; Neoplasm Invasiveness; precipitin tests; reverse transcriptase polymerase chain reaction; Reversion-inducing cysteine-rich protein with Kazal motif (RECK); Signal Transduction; transcription factors; Up-Regulation; Western blotting; β-catenin; miR-182; β-catenin; MicroRNA; Matrix metalloproteinase; Reversion-inducing cysteine-rich protein with Kazal motif (RECK)
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/j.bbagen.2013.01.009

MiR-182 is a member of the miR-183 cluster located at human chromosome 7q32 region and is up-regulated in human cancers. We study the regulation of miR-182 expression and its oncogenic role. MiR-182 level was investigated by real-time reverse transcription-PCR. Chromatin immunoprecipitation assay was used to confirm promoter binding of transcription factors. The correlation between miR-182 and RECK was analyzed by Western blotting, real-time RT-PCR and 3′-untranslated region reporter assay. Zymography, matrix metalloproteinase activity, invasion and colony formation were used to study the tumorigenic activity. MiR-182 is over-expressed in human breast tumor tissues and cell lines. Inhibition or knockdown of β-catenin reduced miR-182 level in MDA-MB-231 cells. ChIP assay confirmed the binding of β-catenin on miR-182 promoter. Anti-miR-182 increased the MMP inhibitor RECK protein in MDA-MB-231 cells while pre-miR-182 reduced RECK protein but not mRNA in normal mammary epithelial H184B5F5/M10 cells. Restoration of RECK protein by anti-miR-182 attenuated MMP-9 activity, cell invasion and colony formation. Ectopic expression of miR-182 inhibited restoration of RECK protein by β-catenin inhibitor indicating miR-182 is important for β-catenin-induced down-regulation of RECK. An inverse association between miR-182 and RECK was demonstrated in breast tumor tissues. We provide evidence that miR-182 is up-regulated by β-catenin signaling pathway in breast cancer and its up-regulation increases tumorigenicity and invasiveness by repressing RECK. Our data demonstrate for the first time that miR-182 expression is controlled by β-catenin. In addition, we identify a new miR-182 target RECK which is important for miR-182-induced tumorigenesis. ► MiR-182 is over-expressed in different stages of breast tumor. ► Wnt/β-catenin pathway is involved in the regulation of miR-182 in breast cancer. ► MiR-182 inhibits a new target RECK to increase MMP activity and invasion ability.