Unexpectedly low incorporation of isotopic acetate into lipids of Ehrlich ascites tumor cells cultured in lipid-poor medium.

The present communication reports data on the lipid biosynthesis of Ehrlich ascites tumor cells grown in culture media supplemented with modified sera. Whereas the metabolisms of [14C]pyruvate and [14C]mevalonate are identical in all media tested, the incorporation of [14C] acetate is higher in medium with dialyzed serum than in medium with delipidized serum; it is suppressed in the absence of all lipids in culture medium. Cellular integrity is not impaired in modified media. The results indicate that acetyl-CoA synthetase of Ehrlich ascites tumor cells is not regulated by exogenous lipids as is known to be the case in nonmalignant cells.