BRG1 regulation by miR-155 in human leukemia and lymphoma cell lines

• DOI: 10.1007/s12094-017-1633-2
• Publication Date: 2017-03-01T10:46:53Z
• Authors: M. Cuadros; V. Sánchez-Martín; A. Herrera; C. Baliñas; J. Martín-Padrón; L. Boyero; P. Peinado; P. P. Medina
• Keywords: 0301 basic medicine; Leukemia; Lymphoma; DNA Helicases; Nuclear Proteins; 3. Good health; Gene Expression Regulation, Neoplastic; MicroRNAs; 03 medical and health sciences; Tumor Cells, Cultured; Humans; Cell Proliferation; Transcription Factors

BRG1 is a key regulator of leukemia stem cells. Indeed, it has been observed that this type of cells is unable to divide, survive and develop new tumors when BRG1 is down-regulated.We assessed BRG1 and miR-155 expression in 23 leukemia cell lines, and two no pathological lymphocyte samples using qPCR. MiR-155 transfection and western blot were used to analyze the relationship between miR-155 and its validated target, BRG1, by measuring protein expression levels. The effect of miR-155 on cell proliferation and prednisolone sensitivity were studied with resazurin assay.BRG1 expression levels could correlate negatively with miR-155 expression levels, at least in Burkitt's lymphoma and diffuse large B cell lymphoma (DLBCL) cell lines. To clarify the role of miR-155 in the regulation of BRG1 expression, we administrated miR-155 mimics in different leukemia/lymphoma cell lines. Our results suggest that miR-155 regulate negatively and significantly the BRG1 expression at least in the MOLT4 cell line.Our study revealed a previously unknown miR-155 heterogeneity that could result in differences in the treatment with miRNAs in our attempt to inhibit BRG1. However, the expression levels of BRG1 and miR-155, before prednisolone treatment were not statistically significantly associated prednisolone sensitive leukemia cells.