OBSERVATIONS WITH AN S-ADENOSYLMETHIONINE DECARBOXYLASE INHIBITOR IN RATS WITH PROSTATIC ADENOCARCINOMA

CGP 48664A (2-(4-aminoiminomethyl)-2,3-dihydro-1H-1-ylidene, dihydroch loride, CAS 149400-88-4) is a new potent inhibitor of S-adenosylmethio nine decarboxylase with antitumor properties. In view of the eminent c linical problems in the treatment of non hormone dependent prostatic c ancer, the antiproliferative potency of this compound was tested in Du nning MAT-LyLu rat prostatic adenocarcinoma. The compound proved ineff icient in preventing the growth of this tumor, even at a near toxic do se. A reason for the lacking effect is presumably the inadequate accum ulation of the drug in the tumor cells due to the excessive growth rat e of the MAT-LyLu xenografts. Tumor growth seems not to be accompanied by a proportionally rapid vascularization of the tumor mass. CGP 4866 4A was found to be a potent inhibitor of polyamine oxidase. This prope rty of the drug may have contributed to the activation of the phagocyt ic capacity of peritoneal macrophages from tumor-bearing rats.