title: miR-29b regulates migration of human breast cancer cells.
abstract: microRNAs (miRNAs) are short non-coding RNAs that regulate gene expression by targeting mRNAs, inhibiting the expression of the associated proteins. Although a role for aberrant miRNA expression in cancer has been postulated, the pathophysiologic role and relevance of aberrantly expressed miRNAs in tumor biology has not been established. We evaluated the expression pattern of miRNAs in human breast cancer cells by qPCR, finding out an up-regulated miRNA miR-29b and studying its biological effect by migration assay. We defined a target gene PTEN by bioinformatics approach and western blot. In breast cancer cell line MDA-MB-231 cell, which migrate faster than MCF-7, we observed that miR-29b was highly over-expressed. Inhibition of miR-29b in cultured cells increased the expression of the phosphatase and tensin homolog (PTEN) tumor suppressor, promoting apoptosis, decreasing migration, and decreasing invasion. In contrast, enhanced miR-29b expression by transfection with pre-miR-29b decreased the expression of PTEN and impaired apoptosis, increasing tumor cell migration and invasion. Moreover, PTEN was shown to be a direct target of miR-29b and was also shown to contribute to the miR-29b-mediated effects on cell invasion. Modulation of miR-29b altered the role of PTEN involved in cell migration and invasion. Aberrant expression of miR-29b, which modulates PTEN expression, can contribute to migration, invasion, and anti-apoptosis.
authors.affiliation: School of Life Science, NJU 3 M Laboratory, Jiangsu Diabetes Research Center, Nanjing, Jiangsu, China. wangchen922@sina.com
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
authors.forename: Zhen
authors.initials: Z
authors.lastname: Bian
authors.forename: Da
authors.initials: D
authors.lastname: Wei
authors.forename: Jian-guo
authors.initials: JG
authors.lastname: Zhang
mesh_terms: D001483:Base Sequence; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000473:pathology*; D045744:Cell Line, Tumor; D017931:DNA Primers; D005260:Female; D006801:Humans; D020287:In Situ Nick-End Labeling; D035683:MicroRNAs / Q000502:physiology*; D009362:Neoplasm Metastasis; D009693:Nucleic Acid Hybridization; D016133:Polymerase Chain Reaction
chemical_list: D017931:DNA Primers; C532045:MIRN29a microRNA, human; D035683:MicroRNAs