INTERCELLULAR INDUCTION OF APOPTOSIS OF TRANSFORMED-CELLS IS MODULATED BY THEIR INTRACELLULAR GLUTATHIONE CONCENTRATION

Reduction of the intracellular glutathione concentration increased the sensitivity of transformed fibroblasts for intercellular induction of apoptosis by TGF-beta-treated nontransformed cells. This finding demo nstrates a modulating role of glutathione for the induction of apoptos is in transformed cells and strengthens the involvement of reactive ox ygen species in this process. Reduction of the intracellular glutathio ne concentration however, did not render nontransformed cells sensitiv e for intercellular induction of apoptosis or abrogate the resistance of BPV-transformed cells. Therefore, the intracellular glutathione con centration is not the key that determines sensitivity of transformed c ells, insensitivity of nontransformed cells or resistance of BPV-trans formed cells.