The characteristic expression pattern of BMI-1 and SALL4 genes in placenta tissue and cord blood

Introduction: SALL4 and BMI-1 are important factors in hematopoiesis. Placental tissue (PT) and umbilical cord blood (CB) are rich in hematopoietic stem/progenitor cells (HSCs/HPCs), but their SALL4 and BMI-1 expression levels remain unknown. Methods: Real-time PCR was used to determine the expression level of these genes in PT and CB from ten cases, and ten healthy donors were used as controls. Results: A significantly higher BMI-1 and SALL4 gene expression level was found in PT (median: 17.548 and 34.362, respectively) than in cord blood mononuclear cells (CBMCs) (median: 2.071 and 11.300, respectively) (P = 0.0001 and P = 0.007) and healthy peripheral blood mononuclear cells (PBMCs) (median: 0.259 and 0.384, respectively) (P = 0.001 and P < 0.0001), and their expression level was lower in PBMCs than in CBMCs (P = 0.029 and P = 0.002). A positive correlation between the BMI-1 and SALL4 genes was found in the PT and CB groups, while there was no significant correlation between these genes in the healthy group. There was also no significant correlation between the expression level of each gene in PT and CB. Conclusions: These results describe the characteristic features of the BMI-1 and SALL4 gene expression pattern in placental tissue and cord blood. Placental tissue with higher expression level of both genes may be considered as a potential resource for SALL4-related HPC expansion.