New factors relevant to polyamine levels in cancer patients.

Results presented show that the polyamines putrescine, spermidine and spermine are degraded in human and bovine serum. Degradation of putrescine in human serum is inhibited by the anti-cancer drugs (±)-1,2 bis (3,5-dioxopiperazin-1-yl) propane (I.C.R.F.-159) (Razoxane I.C.I.), Doxorubicin HCl (Adriamycin, Pharmitalia) and 5-fluorouracil so that polyamine levels are higher than in controls. In calf serum degradation of spermidine is accompanied by formation of putrescine. Irradiated He-La cells give rise to cultures with higher polyamine levels than cultures from non-irradiated cells. Urine polyamine levels of cancer patients receiving drugs and radiation were not well correlated to the clinical progress of their disease. Accordingly, changes in polyamine levels of cancer patients may arise from therapy independently of tumour response and may be unreliable for assessment of tumour state and response to treatment.