In hematologic neoplasms, MiRNA-29 expression levels are inversely correlated with prognosis of Mantle cell lymphoma (MCL) [12]. In addition, MiR-29 reduces cell growth and induces apoptosis in primary acute myeloid leukemia (AML) cells and related cell lines [13]. Moreover, it has been reported that by inhibiting MMP2 activity, MiR-29 plays an important inhibitory role in APOBEC3G induced colon cancer

migration and invasion [14]. Finally, consistent with the data from studies on other types of cancer, MiR-29 family inhibits ovarian cancer development Selleck U0126 by targeting DNA methyltransferases 3A and 3B [15]. Unfortunately, there is relatively lack of information on the role of MiR-29 in breast cancer. Study from JK Richer’s group demonstrated that Mir-29a has an inhibitory role in tumor growth in vivo [16]. However, in another paper, the authors showed that MiR-29a may promote metastasis through facilitating epithelial-to-mesenchymal transition [17]. Thus, the function of Mir-29 in tumorigenesis and metastasis of breast cancer still remains unclear. In the current study, we are endeavored to further elucidate the roles of MiR-29 in breast cancers, which highlights MiR-29 as a potential new biomarker and therapeutic target for breast cancer. Materials and methods Reagents Micro-RNA assays for mir-29a

(002112), mir-29b (000413), mir-29c (000587) and RUN48 (001006) were purchased from Applied Biosystems. Fetal bovine serum (FBS) was from GIBCO. SuperSignal Substrate Western blotting detection system was from Pierce (USA). PVDF membrane was Florfenicol purchased from Bio-Rad Midostaurin Inc. B-Myb antibody (05–175) and cyclin D1 antibody were purchased from Millipore. Cyclin A2 (ab32498) antibody and GAPDH antibody (ab9485) were purchased from Abcam. Luciferase Assay Kit and pMIR-REPORT System were purchased from Applied Biosystems. β-Gal Assay Kit was purchased from Invitrogen (K1455-01). Lipofectamine 2000 reagent was purchased from Invitrogen. Cell culture T-47D, MDA-MB-453, MCF-7 and MCF-10A cells were obtained from American Type Culture Collection. Human Mammary Epithelial Cells (HMEC) were purchased from Invitrogen (A10565). Cells

were maintained in their proper media recommended by the companies and placed in a humidified incubator with 5% CO2 and 95% air at 37°C. Plasmids and transduction A DNA fragment containing the hsa-miR-29a precursor (plus 100 bp upstream and 100 bp downstream) was amplified from genomic DNA of HMEC cells and cloned into pcDNA(+)3.1 vector (Invitrogen). The primers used here are: 5′-gaattcactcattccattgtgcctgg-3′ and 5′-ctcgagttgctttgcatttgttttct-3′. MiRZip-29a construct (MZIP29a-PA-1) and its vector control (SI505A-1) were obtained from System Biosciences. For the luciferase assay, pMIR-REPORT System (Applied Biosystems) was used. The plasmids (pMIR-REPORT-Luciferase-B-Myb-3′-UTR and its mutant) were constructed by following methodology. A 363-bp fragment (nt 2319–2681) of the 3′UTR of B-Myb (NM_002466.