The antitumor effect of N-2, N-4, N-6-trihydroxymethyl-N-2, N-4, N-6-trimethylmelamine (
trimelamol), a synthetic analogue of
hexamethylmelamine, was investigated using human
breast carcinoma xenografts in nude mice. Four
tumor models,
T-61, Br-10, R-27 and MCF-7 were
estrogen receptor (ER)-positive and their growth was
estradiol-dependent. The MX-1 model was ER-negative and grew
estradiol-independently. Sixty mg of
trimelamol per kg dissolved in 5%
dimethylsulphoxide (
DMSO) with 5%
glucose was administered intraperitoneally for 5 days weekly for three weeks.
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 and MCF-7 were insensitive to this agent. This antitumor spectrum on human
breast carcinoma xenografts was similar to that of
hexamethylmelamine previously reported using the same xenograft models.
Trimelamol is water-soluble and does not require metabolic activation which is needed for
hexamethylmelamine. These advantages allow the paraenteral administration of
trimelamol, and warrant the further investigation of this
drug for
breast carcinomas.