INVOLVEMENT OF RB-1, P53, P16(INK4) AND TELOMERASE IN IMMORTALIZATIONOF HUMAN-CELLS

Involvement of the retinoblastoma susceptibility (RB-1), p16(INK4), p5 3 and telomerase genes in immortalisation was examined by determining their status in 15 human cell lines representing four immortalisation complementation groups, No abnormalities of RB-1, p53 and p16(INK4) we re detected in cell lines containing DNA tumour virus proteins known t o bind to the protein products of the RB-1 and p53 genes, In contrast, in all other cell lines from each of the four groups either RB-1 was mutant or p16(INK4) protein was undetectable and there were cell lines containing p53 mutations in three of Telomerase activity was detected in 12/15 lines, including some of the virally immortalised lines and in some lines from each group, Since none of these changes correlated with complementation group, other genetic changes must be required for immortalisation.