title: miR-206 is down-regulated in breast cancer and inhibits cell proliferation through the up-regulation of cyclinD2.
abstract: MicroRNAs act as important gene regulators in human genomes, and their aberrant expression is linked to many malignancies. Aberrant expression of miR-206 has been frequently reported in cancer studies; however, the role and mechanism of its function in breast cancer remains unclear. Quantitative real-time PCR was performed to detect the relative expression levels of miR-206 in breast cancer and normal breast tissues. Lower expression of miR-206 in breast cancer tissues was associated with larger tumour size and a more advanced clinical stage. Further in vitro observations showed that the enforced expression of miR-206 in MCF-7 breast cancer cells inhibited cell growth by blocking the G1/S transition and suppressed cell proliferation and colony formation, implying that miR-206 functions as a tumour suppressor in the progression of breast cancer. Interestingly, Luciferase assays first revealed that miR-206 inhibited cyclinD2 expression by targeting two binding sites in the 3'-untranslated region of cyclinD2 mRNA. qRT-PCR and Western blot assays verified that miR-206 reduced cyclinD2 expression at both the mRNA and protein levels. A reverse correlation between miR-206 and cyclinD2 expression was noted in breast cancer tissues. Altogether, our results identify a crucial tumour suppressive role of miR-206 in the progression of breast cancer, at least partly via up-regulation of the expression of cyclinD2, and suggest that miR-206 might be a candidate prognostic predictor or an anticancer therapeutic target for breast cancer patients.
authors: Department of Oncology, Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, PR China. zhougjing9888@163.com
authors: Jing
authors: J
authors: Zhou
authors: Ye
authors: Y
authors: Tian
authors: Juan
authors: J
authors: Li
authors: Binbin
authors: B
authors: Lu
authors: Ming
authors: M
authors: Sun
authors: Yanfen
authors: Y
authors: Zou
authors: Rong
authors: R
authors: Kong
authors: Yanhong
authors: Y
authors: Luo
authors: Yongguo
authors: Y
authors: Shi
authors: Keming
authors: K
authors: Wang
authors: Guozhong
authors: G
authors: Ji
mesh_terms: D020413:3' Untranslated Regions; D001665:Binding Sites; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D056742:Cyclin D2 / Q000235:genetics / Q000378:metabolism*; D015536:Down-Regulation; D005260:Female; D016193:G1 Phase / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*; D012016:Reference Values; D016196:S Phase / Q000235:genetics; D015854:Up-Regulation
chemical_list: D020413:3' Untranslated Regions; C080336:CCND2 protein, human; D056742:Cyclin D2; C546087:MIRN206 microRNA, human; D035683:MicroRNAs