Follicular dendritic cell-induced microRNA-mediated upregulation of PRDM1 and downregulation of BCL-6 in non-Hodgkin's B-cell lymphomas

J Lin, T Lwin, JJ Zhao, W Tam, YS Choi, LC Moscinski… - Leukemia, 2011 - nature.com
J Lin, T Lwin, JJ Zhao, W Tam, YS Choi, LC Moscinski, WS Dalton, EM Sotomayor, KL Wright…
Leukemia, 2011nature.com
Abstract B-cell lymphoma 6 (BCL6) and PR domain containing 1 (PRDM1) are considered
as master regulators for germinal center (GC) formation and terminal B-cell differentiation.
Dysregulation of BCL6 and PRDM1 has been associated with lymphomagenesis. Here, we
show for the first time that direct cell–cell contact between follicular dendritic cells (FDC) and
B-lymphocytes, by influencing the expression of a set of microRNAs (miRNAs), regulates the
expression of BCL6 and PRDM1. We identify that, on cell adhesion to FDC, FDC induces …
Abstract
B-cell lymphoma 6 (BCL6) and PR domain containing 1 (PRDM1) are considered as master regulators for germinal center (GC) formation and terminal B-cell differentiation. Dysregulation of BCL6 and PRDM1 has been associated with lymphomagenesis. Here, we show for the first time that direct cell–cell contact between follicular dendritic cells (FDC) and B-lymphocytes, by influencing the expression of a set of microRNAs (miRNAs), regulates the expression of BCL6 and PRDM1. We identify that, on cell adhesion to FDC, FDC induces upregulation of PRDM1 expression through downregulation of miR-9 and let-7 families and induces downregulation of BCL-6 through upregulation of miR-30 family in B-lymphocytes and lymphoma cells. We further demonstrate that the miR-30 family directly controls BCL-6 expression and miR-9-1 and let-7a directly control PRDM-1 expression through targeting their 3′ UTR, mediating the FDC effect. Our studies define a novel regulatory mechanism in which the FDC, through induction of miRNAs in B-lymphocytes, orchestrates the regulation of transcription factors, promotes germinal center B-cell survival and differentiation. Dysregulation of miRNAs may interfere with B-cell survival and maturation, thus representing a novel molecular mechanism, as well as a potential therapeutic target in B-cell lymphomas.
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