miRNA-15a, miRNA-16, miRNA-126, miRNA-146a, and miRNA-223 expressions in autologous hematopoietic stem cell transplantation and their impact on engraftment.

Objective: MicroRNAs engaged in angiogenesis and hematopoiesis can influence hematopoietic stem cells (HSCs) homing after transplantation by targeting bone marrow niche microenvironment. This study aimed to examine the kinetics of miRNA-15a, miRNA-16, miRNA-126, miRNA-146a, and miRNA-223 in autologous HSC transplantation settings.

Methods: The study comprised of 51 patients with hematological malignancies (42 multiple myeloma, 9 lymphoma). Samples were taken at four time points: before conditioning, after chemotherapy but prior to autologous HSC transplantation (day 0), on day +7, and +14 days after HSCT. The miRNA levels were evaluated by the real-time PCR method.

Results: A significant, steady decline of all tested microRNAs in the course of transplantation, as compared to the baseline, was found. The study revealed that higher levels of miRNA-15a, miRNA-16, miRNA-126, and miRNA-146a on day 0 correlated with longer time to engraftment. Additionally, a positive correlation between the levels of miRNA-15a, miRNA-146a, and miRNA-223 assessed on day +7 and the time to engraftment was observed.

Conclusions: In conclusion, all investigated microRNAs changed significantly in the course of transplantation. Our results suggest that the miRNAs may participate in hematopoietic recovery in the early post-transplant period and influence engraftment efficiency after HSCT.