Abstract
Adenosine and ATP have been implicated in the regulation of inflammatory responses. Furthermore, adenosine and ATP affect cell growth, cell differentiation, and apoptosis. The aim of this study was to evaluate differentiation inducing abilities of adenosine and ATP on human monocytic leukemia THP-1 cells. Adenosine at 10-3 M markedly induced the differentiation in leukemia THP-1 cells as assessed by evaluating the expression of CDllb. Similarly, ATP at 10-3 M signifi-cantly induced the differentiation in THP-1 cells. Simultaneously, adenosine at 10-3 M and ATP at 10-3 M significantly inhibited the cell number in THP-1 cells. Next, we have evaluated abilities of adenosine and ATP on THP-1 cells differentiated by differentiation inducers all-trans retinoic acid (ATRA), 1, 25-dihydroxy-vitamin D3 (VD3) and phorbol 12-myristate 13-acetate (PMA) . Interestingly, adenosine at 10-3 M significantly potentiated ATRA-induced CDllb expression. In addition, ATRA significantly increased adenosine-induced CDllb expression. Similarly, ATP at 10-3 M significantly potentiated ATRA-induced CDllb expression. In addition, ATRA potentiated ATP-induced CDllb expression. In contrast, VD3 and PMA further increased the expression of CDllb in the presence of adenosine of ATP, respectively. These results suggest that adenosine and ATP may induce the differentiation in human leukemia THP-1 cells, and may further increase the ATRA-induced differentiation in THP-1 cells.