RESUMEN
Tamoxifen (TAM) is an antiestrogenic drug widely used in breast cancer treatment. By using the Differential Display technique in normal and malignant breast tissues, before and during TAM therapy, we were able to demonstrate that expression of the CD36 gene is down-regulated by this drug. CD36 is a cell-surface glycoprotein that acts as a receptor for thrombospondin-1, oxidized-LDL and collagens type I and IV. Thrombospondin-1 is involved in invasion, metastasis and angiogenesis and therefore the down-regulation of CD36 induced by TAM, might correspond to an alternative mechanism of action of this drug. CD36 is also one of the receptors for the oxidized-LDL which in turn is involved in pathogenesis of arteriosclerosis; thus the down-regulation of CD36 during TAM might explain the at least in part the lower levels of myocardial infarction during its use.