A synthetic, nitrogenated antimetastatic and anti-angiogenic compound with low toxicity in vivo.

The design of more effective therapies for metastatic disease involves development of new compounds able to specifically block the malignant process. We demonstrated previously that a new synthetic nitrogenated compound 3'-1-chloroethyl-2,3-dihydro-1H-imidazo-(2, 1-i)-purine-4-ium-7-yl-3'-deoxy-1',5', 6'-tri-O-(methylsulfonyl)-muco-inositol chloride (DIC) had an anti-proliferative activity on tumor cells in vitro. In the present work we demonstrate that DIC induces apoptosis on the LM3 murine mammary adenocarcinoma cell line in vitro and has anti-angiogenic activity in vivo. We also evaluated toxicity, biodistribution and anti-neoplastic properties of DIC in vivo. Toxicity studies allowed us to establish the LD50 (750 mg/kg body weight). Administration of 250 mg/kg/day (LD10) for 6 days did not cause overt toxic effects. Biodistribution assays revealed that DIC was rapidly eliminated (60% at t=10 min), although it accumulated in tumor tissue at higher concentrations than in other tissues. Daily s.c. treatment with DIC (LD10) for 24 days significantly reduced the number of spontaneous lung metastases. These results suggest that DIC has the ability of impairing the metastatic development by inhibiting angiogenesis and inducing apoptosis on tumor cells.

Nucleosteroids: reaction of activated purine bases with steroidal reactive centers.

The reaction of 16 alpha,17 alpha-epoxy-3 beta-hydroxy-5-pregnen-20-one with 6-methyl thiopurine activated with sodium hydride leads to the coupling of the purine base with the carbonyl group at C-20 to give a steroidal nucleoside analog, which is termed "nucleosteroid." In the presence of an excess of purine, a parallel reaction occurs in which the oxirane ring is opened, presumably by nucleophilic attack of an intermediate C-20 oxyanion, and yields as the main product of reaction an oligomeric mixture of nucleosteroid units linked together by ether linkages. Analogous reactions conducted with 3 beta-hydroxy-5-pregnen-20-one and with 3 beta,17 alpha-dihydroxy-5-pregnen-20-one gave minor amounts or only traces of the corresponding coupling adduct, and oligomerization did not occur. This behavior is interpreted in terms of the conformational differences showed by the different steroids to the attack by the purine.