ANTITUMOR EFFECT OF TRIMELAMOL AGAINST HUMAN BREAST-CARCINOMA XENOGRAFTS IN NUDE-MICE

The antitumor effect of N-2, N-4, N-6-trihydroxymethyl-N-2, N-4, N-6-t rimethylmelamine (trimelamol), a synthetic analogue of hexamethylmelam ine, was investigated using human breast carcinoma xenografts in nude mice. Four tumor models, T-61, Br-10, R-27 and MCF-7 were estrogen rec eptor (ER)-positive and their growth was estradiol-dependent. The MX-1 model was ER-negative and grew estradiol-independently. Sixty mg of t rimelamol per kg dissolved in 5% dimethylsulphoxide (DMSO) with 5% glu cose was administered intraperitoneally for 5 days weekly for three we eks. Trimelamol showed potent antitumor activity on T-61 and MX-1 in a dose-responsive manner with a marginal effect on Br-10, whilst R-27 a nd MCF-7 were insensitive to this agent. This antitumor spectrum on hu man breast carcinoma xenografts was similar to that of hexamethylmelam ine previously reported using the same xenograft models. Trimelamol is water-soluble and does not require metabolic activation which is need ed for hexamethylmelamine. These advantages allow the paraenteral admi nistration of trimelamol, and warrant the further investigation of thi s drug for breast carcinomas.