Mirnas and Gene Expression Profiles in CD34+ Cells Are Dependent On the Source of Progenitor Cells Employed in Transplantation.

Hematopoietic progenitors cells (HPCs) used in allogenic transplantation (allo-HSCT) may have different biological properties depending on their source of origin: mobilized peripheral blood (PB), bone marrow (BM) or umbilical cord (UC), which may be reflected in miRNAs or gene expression. The identification of different patterns of expression could have clinical implications. The aim of this study was to determine differences in miRNAs and gene expression patterns in the different sources of HPCs used in allo-HSCT.

CD34 + cells were isolated by immunomagnetic separation and sorting from 5 healthy donors per type of source: UC, BM and PB mobilized with G-CSF. A pool of samples from PB not mobilized was used as reference group. We analyzed the expression of 375 miRNAs using TaqMan MicroRNA Arrays Human v2.0 (Applied Biosystems), and gene expression using Whole Human Genome Oligo microarray kit 4×44K (Agilent). The expression levels of genes and miRNAs were obtained by the 2^-ΔΔCTmethod. From expression data hierarchical clustering was performed using the Euclidean distance. To identify genes and miRNAs differentially expressed between the different sources of HPCs statistical Kruskal Wallis test was applied. All analysis were performed using the Multiexperiment Viewer 4.7.1. The function of the miRNAs and genes of interest was determined from the various databases available online (TAM database, Gene Ontology and TargetScan Human).

Forty-two miRNAs differentially expressed between the different sources were identified. As compared to BM or UC, in mobilized PB most miRNAs were overexpressed, including the miRNA family of miR515, which is characteristic of embryonic stem cells. On the other hand, 47 genes differentially expressed between the different sources were identified. Interestingly, a similar pattern of expression was observed between movilized PB and UC as compared to BM. Interestingly, 13 of these genes are targets of the miRNAs also identified in this study, which suggests that their expression might be regulated by these miRNAs.

There are significant differences in miRNAs and gene expression levels between the different sources of HPCs

No relevant conflicts of interest to declare.