Figure 1.

Expression of retinoic acid 4-hydroxylase gene (CYP26A1) in acute myeloid leukemia (AML) cell lines exposed to all-trans-retinoic acid (ATRA) or to 1,25-dihydroxyvitamin D (1,25D). HL60 and KG1 cells were exposed to 1 μM ATRA or to 10 nM 1,25D and after 96 h the expression of CYP26A1 mRNA was measured by Real-time polymerase chain reaction (PCR). The bars represent mean values (±standard error of the mean (SEM)) of the fold changes in mRNA levels relative to glyceraldehyde 3-phosphate dehydrogenase (GAPDH) mRNA levels. Values significantly different from these obtained for respective control cells are marked with asterisks (* p < 0.01, ** p < 0.05).