OBJECTIVETo screen and analyze CD34(+) cell specific microRNAs (miRNAs) from the patients with acute myelogenous leukemia (AML) and their expression.

METHODSCD34(+) cells were sorted from AML patients or the mobilized peripheral blood of the donors of hematopoietic stem cell transplantation (normal control subjects) and followed by the extraction of the cell total RNAs. The differentially expressed microRNAs (miRNAs, miR) were selected after hybridizing with miRNA microarray, real time polymerase chain reaction (real-time PCR) was subsequently applied to confirm the expression of the selected miRs, and PCR products were further cloned and sequenced to check their specificity.

RESULTSOf the differentially expressed miRNAs, 191 were found to be at least one-fold change in the CD34(+) cells between the AML patients and the normal control subjects. Of the 191 miRNAs, the expression difference of 94 was significant (P < 0.05). Among these 94 miRNAs, the expression of 44 miRNAs was increased and the other 50 miRNAs was decreased in the CD34(+) cells from the bone marrow of AML patients compared with the CD34(+) cells from the mobilized peripheral blood of the normal control subjects. Real time PCR verified that the expression level of miR-10a and miR-220c in the CD34(+) cells from the bone marrow of AML patients was 19.6% and 19.0% of that of CD34(+) cells from mobilized peripheral blood of the normal control subjects. DNA sequencing and BLAST DNA database searching results indicated that the PCR products were really miR-10a and miR-220c.

CONCLUSIONA variety of differentially expressed-miRNAs are existed between AML and normal control subjects CD34(+) cells, the expression of miR-10a and miR-220c was significantly down-regulated in the CD34(+) cells from the bone marrow of AML patients.