MicroRNAs (miRNAs) are small non-coding RNAs functioning as regulators of hematopoiesis. Their differential expression patterns have been linked with various pathological processes originating from hematopoietic stem cells (HSCs). However, limited information is available regarding the role of miRNAs in myelodysplastic syndrome (MDS). Using miRNA arrays, we measured expression of 1,145 miRNAs in CD34+ bone marrow cells obtained from 39 MDS and acute myeloid leukemia (AML) evolved from MDS patients, and compared them with those of six healthy donors. Differential miRNA expression was analyzed and a panel of upregulated (n=13) and downregulated (n=9) miRNAs were found (P<0.001) in MDS/AML patients. An increased expression of a large miRNA cluster mapped within the 14q32 locus was detected. Differences in miRNA expression of MDS subtypes showed a distinction between early and advanced MDS; an apparent dissimilarity was observed between RAEB-1 and RAEB-2 subtypes. In early MDS, we monitored upregulation of proapoptotic miR-34a, which may contribute to the increased apoptosis of HSCs. Patients with 5q deletion were characterized by decreased levels of miR-143(*) and miR-378 mapped within the commonly deleted region at 5q32. This is an early report describing differential expression in MDS CD34+ cells, likely reflecting their disease-specific regulation.

• MeSH
• Leukemia, Myeloid, Acute metabolism   MeSH
• Analysis of Variance MeSH
• Antigens, CD34 analysis   immunology   MeSH
• Apoptosis MeSH
• Gene Deletion MeSH
• Adult MeSH
• Down-Regulation MeSH
• Hematopoietic Stem Cells cytology   immunology   MeSH
• Hematopoiesis MeSH
• Middle Aged MeSH
• Humans MeSH
• MicroRNAs genetics   metabolism   MeSH
• Microarray Analysis MeSH
• Young Adult MeSH
• Multigene Family MeSH
• Myelodysplastic Syndromes genetics   pathology   MeSH
• Aged MeSH
• Gene Expression Profiling * MeSH
• Up-Regulation MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Antigens, CD34 MeSH
• MicroRNAs MeSH