Journal of Cell Science, Vol 13, 421-427, Copyright © 1973 by Company of Biologists

Submitted on December 12, 1972

Clonal Variability of Adenovirus-Transformed Cells

¹ Département de Microbiologie, Centre Hospitalier Universitaire Sherbrooke, Québec, Canada

Cells transformed by DNA oncogenic viruses acquire characteristic properties which have been considered criteria for transformation. SV40- and polyoma virus-transformed cells are capable of selective reversion for several of these properties. Until now, reversion of transformed cell properties has not been reported in the adenovirus system. The stability of several transformed cell properties was examined in a line (HTC) of Ad. 12-transformed (in vivo) cells after several hundred generations of in vitro passage. From a large number of clones isolated by the soft-agar suspension technique, 7 were selected for detailed examination. The clones, as the parental cells, were free of infectious virus and type-specific antigen, but contained intranuclear Ad. 12 T antigen. Cell growth profiles with 0, 1 and 10% serum in the culture medium revealed that while 4 clones retained the parental characteristic of growth in the absence of serum, 3 lost this ability and grew only in serum concentrations greater than 1%. Agglutination profiles with 4-fold dilutions of concanavalin A (Con. A) and wheat germ agglutinin (WGA) directly or after trypsin treatment revealed 2 clones which failed to agglutinate with Con. A; trypsin treatment reversed this effect. Each clone agglutinated with WGA directly, though one clone showed reduced agglutination. On the basis of superinfection with Ad. 2 the clones could be grouped into low, intermediate and high yielders with 10-fold intervals. All clones were transplantable into random-bred adult Syrian hamsters. There was no marked correlation between the reversion or modification of individual transformed cell properties among the clones. The phenotypic stability of these transformed cell properties was confirmed by re-cloning the tumours induced by one of the revertant clones. It was concluded that some of these properties are not essential for the maintenance of oncogenic potential.

Note:
Scholar of the Medical Research Council of Canada.