title: The inhibitory role of Mir-29 in growth of breast cancer cells.
abstract: Mir-29 microRNA families are involved in regulation of various types of cancers. Although Mir-29 was shown to play an inhibitory role in tumorigenesis, the role of Mir-29 in breast cancer still remains obscure. In this study, we showed that Mir-29a is the dominant isoform in its family in mammary cells and expression of Mir-29a was down-regulated in different types of breast cancers. Furthermore, over-expression of Mir-29a resulted in significant slower growth of breast cancer cells and caused higher percentage of cells at G0/G1 phase. Consistent with this over-expression data, knockdown of Mir-29a in normal mammary cells lead to higher cell growth rate, and higher percentage of cells entering S phase. We further found that Mir-29a negatively regulated expression of B-Myb, which is a transcription factor associated with tumorigenesis. The protein levels of Cyclin A2 and D1 are consistent with the protein level of B-Myb. Taken together, our data suggests Mir-29a plays an important role in inhibiting growth of breast cancer cells and arresting cells at G0/G1 phase. Our data also suggests that Mir-29a may suppress tumor growth through down-regulating B-Myb.
authors.affiliation: Department of Surgery, Division of Thyroid and Mammary Surgery, Nanjing Medical University Affiliated Wuxi People's Hospital, 299 Qingyang Road, Wuxi 214000, China. zqhsyy@sohu.com.
authors.forename: Zhenglong
authors.initials: Z
authors.lastname: Wu
authors.forename: Xiaona
authors.initials: X
authors.lastname: Huang
authors.forename: Xing
authors.initials: X
authors.lastname: Huang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zou
authors.forename: Yujiang
authors.initials: Y
authors.lastname: Guo
mesh_terms: D001483:Base Sequence; D014408:Biomarkers, Tumor / Q000096:biosynthesis / Q000235:genetics; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology* / Q000628:therapy; D018797:Cell Cycle Proteins / Q000096:biosynthesis / Q000235:genetics; D048708:Cell Growth Processes / Q000502:physiology; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D015536:Down-Regulation; D005260:Female; D055785:Gene Knockdown Techniques; D015316:Genetic Therapy; D006801:Humans; D061986:MCF-7 Cells; D035683:MicroRNAs / Q000096:biosynthesis / Q000235:genetics*; D015534:Trans-Activators / Q000096:biosynthesis / Q000235:genetics; D014162:Transfection
chemical_list: D014408:Biomarkers, Tumor; D018797:Cell Cycle Proteins; C532045:MIRN29a microRNA, human; C064352:MYBL2 protein, human; D035683:MicroRNAs; D015534:Trans-Activators