Variation in the loss of O6-methylguanine-DNA methyltransferase during immortalization of human fibroblasts.


Journal Article

We have examined O6-methylguanine-DNA methyltransferase (MT) activity in four human fibroblast cell lines during immortalization. Transfection of primary fibroblasts with the plasmid pSV3gpt or pSV3neo, which encode the SV40 large T antigen, confers a transformed phenotype but not immediate immortality. After a period of growth (pre-crisis) the cells enter a quiescent phase (crisis) from which an immortal clone of cells eventually grows out. From measurements of MT activity in extracts of cells taken at different defined stages of the immortalization process, we conclude that the establishment of a Mex- (MT-deficient) cell population is not specifically associated with cellular transformation or with any particular stage of immortalization. It appears that in different cell populations the change from Mex+ to Mex- may occur at different times during the immortalization process and that the change may be very abrupt.

Full Text

Cited Authors

  • Green, MH; Karran, P; Lowe, JE; Priestley, A; Arlett, CF; Mayne, L

Published Date

  • January 1990

Published In

Volume / Issue

  • 11 / 1

Start / End Page

  • 185 - 187

PubMed ID

  • 2153058

Pubmed Central ID

  • 2153058

Electronic International Standard Serial Number (EISSN)

  • 1460-2180

International Standard Serial Number (ISSN)

  • 0143-3334

Digital Object Identifier (DOI)

  • 10.1093/carcin/11.1.185


  • eng