5'-NUCLEOTIDASE LEVELS IN NORMAL AND VIRUS-TRANSFORMED CELLS - IMPLICATIONS FOR CELLULAR AGING INVITRO

  • 1 January 1979
    • journal article
    • research article
    • Vol. 41  (1) , 1-4
Abstract
5''-Nucleotidase activity in the postnuclear supernatant of normal and SV-40 virus-transformed human embryonic lung, chick embryo, and mouse embryo fibroblasts, WI-38 [human female embryo lung], IMR-90 [human female fetus lung], VA-13 [human embryo neoplastic lung], CEF [chick embryo fibroblast], 3T3 [Swiss albino mouse fibroblast] and SV 3T3 [mouse neoplastic fibroblast] cells was measured. In IMR-90 and CEF cells, both of which have a limited lifespan in vitro, 5''-nucleotidase activity increased 6- and 20-fold, respectively, with increasing population doublings. VA-13 cells, a permanent cell line, showed no increase in this enzyme activity with progressive population doublings. 5''-Nucleotidase activity was not detectable in 2 other permanent cell lines, 3T3 and SV3T3 cells. Of the 6 cell lines tested, the conspicuous enhancement in 5''-nucleotidase activity with increasing population doublings was observed only in normal cell lines and was absent in transformed cell lines. A molecular mechanism may play a role in aging of normal cells in vitro and may involve catabolism of nucleic acids.