2-Deoxy-D-Glucose Uptake by Chick Embryo Cells: a Biochemical Indicator of Genetic Susceptibility to RNA Tumour Viruses

Abstract

The enhanced glucose uptake by chick embryo cells as early as 72 h after infection with Rous sarcoma virus (RSV) was confirmed in this study to be an early indicator of cellular transformation. The glucose uptake of C/E BrL cells infected by various doses of BS-RSV of subgroup A showed that the relationship between the log-dose of virus and log-uptake was linear (slope, b1 = 1.30 +/- 0.14) when the ratio of the number of infectious virus particles to the number of cells in the culture was above 1:200. But infection of cultures with a relatively high dose of virus, for instance 10(3.5) focus forming units (f.f.u.) was ineffective for the measurement of cellular transformation using the criterion of glucose uptake, whereas a much lower dose such as 10(1.7) f.f.u. was sufficient to induce foci of transformed cells. We concluded therefore that the statistic of glucose uptake assay (GUA) measured at 72 p.i. is less sensitive than that of the focus count assay (FCA) measured after 10 days as a measure of assessing cellular transformation by RSV. Nevertheless, when the cultures were infected with a higher dose of virus (10(4.3) f.f.u. or more), the GUA could discriminate between the transformed (T) and non-transformed (NT) cultures. This was demonstrated in the two genetic crosses, line 7-2 X WC(F1) and line 7-2 C line. Embryo cultures of these two test-crosses were infected with viruses of subgroups A, B, C and D, and the T and NT phenotypes were ascertained. Also, on the basis of focus counts in the cultures the genetically resistant (R) and susceptible (S) phenotypes in response to various infections were determined. The T and NT phenotypes based on the GUA were compared with the S and R phenotypes, respectively, based on the FCA. It was found that in 47 of the 51 cultures, the phenotypic agreement was perfect, suggesting that glucose uptake by cells of embryo cultures exposed to RSV is a biochemical indicator of genetic susceptibility. The discordant results in 4 cultures are discussed in the light of present knowledge of cellular transformation by RSV.