Estradiol-17 beta sulfotransferase activity in canine osteosarcoma D17 cells

Estrogen sulfatase and sulfotransferase (EST) activities are present in bre ast cancer tissues but there are no reports on EST in cancerous bone cells, We incubated [H-3]estradiol-17 beta with cells from a canine osteosarcoma D17 line for periods up to 24 h, Radioactive steroids were recovered from t he media and separated into unconjugated and conjugated fractions using Sep -Pak C18 cartridges. The conjugate fraction was solvolyzed and the resultin g free steroids were obtained from a second C18 cartridge. Little metabolis m was apparent in 4 h of incubation, but by 24 h as much as one half of the radioactivity was seen in the conjugate fraction. Most of the conjugates w ere recovered as sulfates in all three experiments. HPLC profiles showed a limited metabolism of estradiol to other compounds except for estrone, whic h was clearly present in both free and sulfate fractions. These results sug gest that EST may have a role in the local metabolism Of estrogens in bone, (C) 2000 Academic Press.