Dietary clofibrate stimulates the formation and size of estradiol-induced breast tumors in female August-Copenhagen Irish (ACI) rats.

Administration of 0.4% clofibrate in the diet stimulated estradiol (E(2))-induced mammary carcinogenesis in the August-Copenhagen Irish (ACI) rat without having an effect on serum levels of E(2). This treatment stimulated by several-fold the NAD(P)H-dependent oxidative metabolism of E(2) and oleyl-CoA-dependent esterification of E(2) to 17beta-oleyl-estradiol by liver microsomes.

Melanoma mouse model implicates metabotropic glutamate signaling in melanocytic neoplasia.

To gain insight into melanoma pathogenesis, we characterized an insertional mouse mutant, TG3, that is predisposed to develop multiple melanomas. Physical mapping identified multiple tandem insertions of the transgene into intron 3 of Grm1 (encoding metabotropic glutamate receptor 1) with concomitant deletion of 70 kb of intronic sequence. To assess whether this insertional mutagenesis event results in alteration of transcriptional regulation, we analyzed Grm1 and two flanking genes for aberrant expression in melanomas from TG3 mice.

Progressive appearance of pigmentation in amelanotic melanoma lesions.

We previously described a transgenic mouse line (TG-3) that spontaneously develops pigmented cutaneous melanoma. The generation of several albino mice that developed amelanotic melanoma has also been reported. In this report, we describe an unanticipated result with crosses between C57BL/6-c2j and TG-3 mice.