EFFECT OF SODIUM-BUTYRATE ON HUMAN BREAST-CANCER CELL-LINES

We have investigated the effects exerted by sodium butyrate (NaBu) on the growth and cell cycle perturbations of four human breast cancer ce ll lines (MCF7, T47D, MDA-MB231 and BT20) with different steroid recep tor profiles, Moreover, since one of the supposed mechanisms of action for NaBu activity involves the induction of apoptosis, we have studie d the effects of NaBu on DNA fragmentation by agarose gel electrophore sis and flow cytometry. In all investigated cell lines, NaBu exerted a time- and dose-dependent inhibition of growth and caused a maximum in hibitory effect (85% to 90%) at the concentration of 2.5 mM. The inhib ition was already evident after 3 days of treatment. The antiprolifera tive effect of NaBu was associated with a persistent block of cells in the G(2)M phase. The block was associated with apoptosis only in oest rogen-receptor positive cell lines, The inhibiting effect of NaBu in h ormone-dependent and independent cell lines and its ability to induce apoptosis through a cell cycle perturbation in hormone-dependent cell lines may have important implications in the treatment of human tumour s including breast cancer.