DIFFERENTIAL-EFFECTS OF P53 MUTANTS ON THE GROWTH OF HUMAN BRONCHIAL EPITHELIAL-CELLS

We investigated the effects of five different p53 mutants on the growt h of primary cultures of normal human bronchial epithelial (NHBE) cell s. The five defective viral pZIP-Neo constructs contained the followin g mutations at mutational hot-spots found in human cancers: codons 143 (ala), 175(his), 248(trp), 249(ser), and 273(his). NHBE cells were inf ected with the p53 muta nts, wild-type p53, or the pZIP-Neo vector con trol. The 143(ala), 248(trp), and 273(his) mutants, as well as wild-ty pe p53, decreased the colony-forming efficiency and inhibited the grow th of NHBE cells. The 175(his) mutant did not significantly change the growth rates. In NHBE cells from three donors, the 249(ser) mutant co nferred a substantial growth advantage to the NHBE cells in a colony-f orming-efficiency assay. In NHBE cells isolated from one donor, the 24 9(ser) mutant also produced a significant life span extension. These c ells grew rapidly through 80 population doublings and entered an appar ent ''crisis'' in passage 14. Karyotypic analyses of one culture at mu ltiple passages revealed aneuploid populations with alterations of chr omosomes 5, 11, and 13, quantitative DNA analysis detected aneuploidy in late passages from that culture and two other primary cultures. The se data demonstrated that the codon 249(ser) mutation could provide a growth advantage to bronchial epithelial cells and suggest that this m utant protein can induce genomic instability. (C) 1997 Wiley-Liss, Inc .(dagger)