REVERSION OF UVC-INDUCED TUMORIGENIC HUMAN HYBRID CELLS TO THE NON-TUMORIGENIC PHENOTYPE

摘要: Abstract Non-tumorigenic HeLa x skin fibroblast human hybrid cells were UVC-irradiated (10 J/m2) and induced to neoplastic transformation with accompanying morphological change expression of the tumour-associated antigen, intestinal alkaline phosphatase (IAP). A single-cell-derived cell line was cloned out a neoplastically transformed focus designated as UV-12. In low density culture, this demonstrated ability undergo reversion morphology similar that nontumorigenic parent accompanying, much reduced levels LAP expression. The frequency increased passage cultures reaching 10−2 at 26 passages. revertant colony selected expanded into which UV-12-RM-1. This had 67-fold reduction in compared UV-12 tumorigenic phenotype. reconstituted from tumour derived high level (3-fold less than UV-12) highly tumorigenic. Six lines UV-12-RM-1 all Of these, one an aggressive tumorigenicity, four showed phenotype characteristic UV-12-RM-1, (UV-12-RM-105) non-tumorigenic. However, latter reverted weakly elevated IAP level. It is hypothesised phenotypic shifts by these UV-induced are under epigenetic control, they most likely consequence underlying genetic instability survivors UVC-irradiation.