Regulation of acute graft-versus-host disease by microRNA-155.

Acute graft-versus-host disease (aGVHD) remains a major complication of allogeneic hematopoietic stem cell transplant (alloHSCT), underscoring the need to further elucidate its mechanisms and develop novel treatments. Based on recent observations that microRNA-155 (miR-155) is up-regulated during T-cell activation, we hypothesized that miR-155 is involved in the modulation of aGVHD. Here we show that miR-155 expression was up-regulated in T cells from mice developing aGVHD after alloHSCT.

MicroRNA 29b functions in acute myeloid leukemia.

MicroRNAs (miRNAs) are associated with cytogenetics and molecular subtypes of acute myelogeneous leukemia (AML), but their impact on AML pathogenesis is poorly understood. We have previously shown that miR-29b expression is deregulated in primary AML blasts. In this work, we investigated the functional role of miR-29b in leukemogenesis.

MicroRNA-29b induces global DNA hypomethylation and tumor suppressor gene reexpression in acute myeloid leukemia by targeting directly DNMT3A and 3B and indirectly DNMT1.

Aberrant DNA hypermethylation contributes to myeloid leukemogenesis by silencing structurally normal genes involved in hematopoiesis. MicroRNAs (miRNAs) are noncoding RNAs that regulate gene expression by targeting protein-coding mRNAs. Recently, miRNAs have been shown to play a role as both targets and effectors in gene hypermethylation and silencing in malignant cells.