Elevation of histaminase and its concurrence with Regan isoenzyme in ovarian cancer

Histaminase has been shown to be associated with several types of human cancer. In the present study, we examined the activity of histaminase and its relationship with Regan isoenzyme of alkaline phosphatase in ascitic fluids obtained from patients with ovarian and several other types of cancer. We have found that about 44% of the ovarian cancer patients had elevated levels of histaminase in the ascitic fluid, whereas a less frequent incidence was observed in fluids obtained from other types of cancer. There was concurrence in the elevation of histaminase activity with the appearance of Regan isoenzyme in most of the samples examined. Of the 10 patients who showed elevated histaminase, 9 had high Regan isoenzyme activity; whereas in 9 patients with normal levels of histaminase, all except 1 had low or moderate levels of Regan isoenzyme activity. These results, therefore, confirm the observation of an association of histaminase with human cancer and suggest the possibility for the utilization of histaminase, in conjunction with Regan isoenzyme and cancer-associated proteins, for cancer diagnosis and clinical evaluation of tumor progression and regression during therapy.