Phosphoryl group transfer from Ehrlich cells prelabeled in vivo with (32P)-orthophosphate and (14C)-glucose to unlabeled glioma cells.

A transfer of (32P)-labeled phosphoryl groups has been demonstrated to occur between prelabeled Ehrlich cells (donor cells) and glioma cells (acceptor cells). The Ehrlich cells were generally prelabeled in vivo by an intraabdominal injection of (32P)-orthophosphate 24 hours prior to scarifice of the tumor-bearing mice. In some experiments two injections of (14C)-glucose were given to the animals in addition to the injection of (32P)-orthophosphate prior to sacrifice. The prelabeled Ehrlich cells were mixed with the glioma cells, that were still attached to the culture plates, and incubation took place in vitro. Labeled (32P)-phosphoryl (14C)-serine was isolated from the glioma cells as well as from the Ehrlich cells. The 32P/14C-ratio of (32P)-phosphoryl (14C)-serine of the glioma cells (acceptor cells) was significantly higher than found for the Ehrlich cells (donor cells). This was indicative of an interactive mechanism between the cells partly due to binding of membrane fragments from the Ehrlich cells on to the surface of the glioma cells and partly due to a phosphoryl group transfer between the two types of cells. Interaction experiments with a plasma membrane fraction prepared from the prelabeled Ehrlich cells vis à vis the glioma cells clearly showed that the phosphoryl group transfer mechanism between the cells was dominating and only a minor part of the interaction was due to adhesion. This transphosphorylation reaction represents a new type of interaction between cells. It was not influenced by either adenosine 3', 5'-monophosphate or adenosine 5'-diphosphate.