Yp. Tsao et al., Apoptosis is induced in aging SV40 T antigen-transformed human fibroblaststhrough p53- and p21(CIP1/WAF1)-independent pathways, CANCER LETT, 133(1), 1998, pp. 77-82
When comparing SV40 T antigen-transformed human fibroblasts of a younger ge
neration (24 population doubling) and aging stage (58 population doubling),
we found that detachment of cells from the culture surface occurred more f
requently in aging cells. DNA fragmentation and chromatin condensation whic
h are typical findings of apoptosis occurred more frequently in aging cells
as compared to cells of a younger generation. There is no increase in the
p53 level or decrease in the SV40 T antigen level in aging cells as compare
d to cells of a younger generation. Retinoic acid treatment which can effec
tively suppress p21 gene expression did not prevent apoptosis. These findin
gs indicate that apoptosis that occurs due to aging-transformed human fibro
blasts is mediated through p53- and p21-independent pathways. (C) 1998 Else
vier Science Ireland Ltd. All rights reserved.