Objective: To explore the effect of all-trans retinoic acid (RA) on the engraftment of unrelated umbilical cord blood stem/progenitor cell transplantation (UCBT) in murine model.
Methods: 1 x 10(6) and 0.5 x 10(6) nucleated cells (NC) from C57BL/6 (H-2(b)) fetal and neonatal peripheral blood (FNPB) were separately transfused into lethally cyclophosphamide (380 mg/kg, ip) treated BALB/C (H-2(d)) recipients, 15 mg.kg(-1).d(-1) and 5 mg.kg(-1).d(-1) RA (15 mg and 5 mg RA) were administrated respectively 2 days before and after UCBT. Hematopoiesis and immune recovery, graft versus host disease (GVHD), engraftment and survival rates were then observed.
Results: Hematopoiesis and immune recovery occurred faster in RA treated than in untreated mice (P < 0.05). Acute GVHD was absent. The levels of engraftment were higher in both 15 mg and 5 mg RA treated mice than those in untreated controls (P < 0.05). In 1 x 10(6) NC transfused mice, 15 mg and 5 mg RA could significantly increased the 30 and 60 days survival rates from 41.67% (without RA) to 72.23% and 70.83%, respectively (P < 0.05). In 0.5 x 10(6) cells transfused mice, 15 mg and 5 mg RA increased the survival rate from 14.29% (without RA) to 42.86% and 43.48%, respectively (P < 0.05), which were comparable to that of being transfused 1 x 10(6) cells without RA treatment (P > 0.05).
Conclusion: RA enhances the engraftment of umbilical cord blood stem/progenitor cells in murine model for UCBT. This might provide an experimental evidence of RA in clinical UCBT.