Abstract: Purpose : In order to study the effects of trans - BPDE on the development in human lung cancer , human fetal tracheal epithelium cells (HFTEs) cultured in vit ro were exposed to t rans - BPDE , a metabolite of benzo (a) pyreneB (a) P . Methods : For 8～12 weeks , the point mutations in exon 6～8 of p53 tumor suppressor gene in these HFTEs were detected by PCR - SSCP assay. Results : The results showed that the HFTEst reated with t rans - BPDE had point mutations in exons 7 and 8 of p53 tumor suppressor gene , even though no malignantly t ransformed characteristics were observed in cellular morphology. Conclusion : these result ssuggest that t rans - BPDE can induce point mutation in p53 tumor suppressor gene in these HFTEs and the point mutation and activation of p53 may occur in the cells before morphological t ransformation.

Key words: Benzo (a) pyrene, tracheal epithelium, p53 tumor suppressor gene, point mutation