Prostate-specific antigen in serum during the menstrual cycle

We previously found that prostate-specific antigen (PSA) expression in the female breast is regulated by steroid hormones and their receptors. We have now examined whether the PSA concentration in serum changes during the menstrual cycle of healthy women. Among 14 women studied, 3 had serum PSA > or = 4 ng/L; their changes in PSA content during the menstrual cycle were studied in 7 informative cycles. We found that PSA concentrations in serum are highest during the mid- to late follicular phase, drop continuously with a half-life of 3-5 days between the late follicular phase and mid-cycle, and reach a minimum during the mid- to late luteal phase. PSA changes do not correlate with changes in lutropin (LH), follitropin (FSH), or estradiol concentrations. However, PSA peaks seem to follow the progesterone concentration peaks, with a delay of 10-12 days. Sera of some volunteers were tested for their ability to upregulate PSA protein and PSA mRNA in a tissue culture system based on the T-47D breast carcinoma cell line. Only sera obtained during the mid- to late luteal phase were able to upregulate the PSA mRNA and protein. In stimulation experiments in vitro, progesterone, but not LH, FSH, estradiol, human chorionic gonadotropin, prolactin, or growth hormone, was able to upregulate PSA mRNA and protein in the T-47D cell line. These data suggest that PSA is produced in a cyclical manner during the menstrual cycle.