Aromatase expression in human peripheral blood leucocytes (PBLs) and in various tissues in primates: studies in elderly humans and cynomolgus monkeys

Background Previous analysis of aromatase gene and protein expression in peripheral blood leucocytes (PBLs), studied in children and adults, was extended to elderly subjects. In addition, we assessed whether aromatase expression in PBLs could be used as a parameter of aromatase expression in other tissues, using the cynomolgus monkey as model. Methods Real-time PCR analysis of aromatase gene expression and protein evaluation by Western blot was performed in PBLs of human elderly subjects and in various tissues from cynomolgus monkeys. Results No gender-related difference in CYP19A1 mRNA and protein expression in PBLs from human elderly women and men was found. In elderly male cynomolgus monkeys, CYP19A1 mRNA and protein were expressed in all cells and tissues analysed, with the lowest levels in PBLs but no clear-cut correlation with other tissues. Conclusions Aromatase expression in PBLs in elderly human subjects is not gender-related and cannot be a surrogate of aromatase expression for other tissues.