Monitoring by alpha-hydroxybutyrate dehydrogenase of human ovarian carcinoma grown in nude mice.

In order to establish that the tumor burden in nude mice bearing a xenografted human ovarian tumor can be assessed by measuring plasma levels of alpha-hydroxybutyrate dehydrogenase (HBD) (E.C. 1.1.1.30), the plasma HBD and the tumor volume were measured every week after inoculation of a human ovarian carcinoma cell line designated HR. About 3 weeks after tumor inoculation, all nude mice had a palpable tumor while elevated levels of HBD were observed in a half of the mice at that time. Thereafter the HBD levels rose with increasing tumor volume. There was a quantitative linear relationship between the tumor weight and HBD activity per mouse. When 40 micrograms of cisplatin (about 2 mg/kg) was administered i.p. every week for 5 weeks 2 weeks after inoculation, plasma levels of HBD were significantly decreased on day 27 compared to those in untreated nude mice. Decreases in the HBD levels during treatment with cisplatin occurred 7 days prior to changes in tumor volumes. Further, removal of local tumor mass resulted in a marked decrease in HBD levels on day 1 after surgery and the HBD levels in nude mice which had no recurrent tumor fell into the normal range 8 days after surgery.