Can SV40 transformation reverse commitment to terminal division in human adult cells in vitro

: Adult Human Eye diploid Fibroblasts (HEF) had an extremely low growth potential in vitro (12 duplication cycles), that was identical in all the isolated clones. HEF cells were transformed with SV40 virus at the 10th duplication cycle, at which stage they were already approaching the crisis phase as demonstrated by the slowing down in the proliferation rate and the inability to produce clones. After SV40-transformation the proliferation rate rapidly increased, reaching a maximal level in a few days, and the transformed cells recovered the ability to produce clones. All the SV40-transformed isolated clones underwent 37 duplication cycles and did not show any slowing down in the proliferation rate or any sign of aging to date. We suggest that SV40 virus was able to "rescue" the cells from an irreversible commitment to cease dividing.