THE APOPTOTIC EFFECTS OF CISPLATIN AND CARBOPLATIN IN RETINOBLASTOMA Y79 CELLS

This study demonstrated that cisplatin and carboplatin stimulate apopt osis in human retinoblastoma Y79 cells, cisplatin being the most effec tive compound. The apoptotic effect appeared after 8 h and then increa sed in a time-dependent manner. Treatment with cisplatin and carboplat in also provoked an increase in the level of p53 and p21, and a loweri ng in Bcl-2. The prolonged exposure of Y79 cells to cisplatin induced resistance to cisplatin, carboplatin and etoposide. The basal level of p53 was in resistant cells higher than in untreated cells, while Bcl- 2 was not modified. p53 and Bcl-2 levels did not change after treating of resistant cells with cisplatin, carboplatin or etoposide. However, camptothecin which is a powerful inducer of apoptosis in sensitive ce lls, triggered cell death even in resistant cells. Such an effect was not accompanied by any modification in p53 level while Bcl-2 was marke dly reduced.