Sugar effects on murine sarcoma virus transformation.

Transformation of NIH Swiss mouse fibroblasts by a murine sarcoma virus was influenced by the type of carbohydrate in the culture medium. Exposure to D-mannose and 2-deoxy-D-glucose caused a reduction in the number of transformed colonies in vitro and tumor formation in vivo. This is a new type of interference in the transformation process, manifested also by the absence of the pronounced enhancement of hexose entry into transformed cells, characteristic of a sarcoma virus infection. The uptake of D-glucose, D-mannose, and D-galactose, was repressed by normal mouse cells grown in the presence of D-mannose and D-glucose in the medium, while uptake of the same sugars was derepressed in cells grown in media containing D-xylose, L-xylose, or L-arabinose. D-Galactose had an intermediate effect on hexose uptake and permitted derepression. In every case, enhancement of the primary transport by sarcoma virus transformation was consistently beyond that observed at any time in the derepressed control cells, demonstrating the occurrence of another mechanism of enhancement of hexose uptake after sarcoma virus infection.