Lipogenesis in Ehrlich ascites tumor cells under anaerobic culture conditions

Abstract

Anaerobic culture conditions (95% argon/5% CO2) caused a slightly greater increase in total lipids of Ehrlich ascites tumor cells than a gas phase of 20% O2, 75% N2, 5% CO2. Whereas the rate of [U-14C]acetate incorporation into total lipids and lipid-subclasses rose markedly in the absence of oxygen, a drastic decrease of [U-14C]pyruvate and [1-14C]octanoate incorporation as well as a 30% reduction of 3H incorporation into lipids from tritiated water were observed under these conditions. Since profound changes in the metabolic state of cells cause alterations in the specific activity of the acetyl-CoA pool but do not alter the specific activity of intracellular water, this precursor is considered to be an adequate monitor for lipogenesis under aerobic and anaerobic culture conditions. Therefore, it is concluded that Ehrlich ascites tumor cells are not able to reoxidize NADH/NADPH in the absence of oxygen by a stimulation of biosynthesis of fatty acids as is discussed to be the case in normal cells. The slight increase in total lipids of anaerobically cultured cells seems to be the result of an imbalance between normal uptake and impaired utilization of lipids from serum-supplemented culture medium.

Tumor uptake of radiolabeled acetate reflects the expression of cytosolic acetyl-CoA synthetase: implications for the mechanism of acetate PET

“…C]acetate incorporated into lipids is increased in Ehrlich ascites tumor cells[31]. Similarly, this study showed that [1-14 C]acetate incorporation into the lipid-soluble fraction tended to be enhanced in tumor cells under hypoxia.…”

Metabolomic Dynamic Analysis of Hypoxia in MDA-MB-231 and the Comparison with Inferred Metabolites from Transcriptomics Data

“…The incorporation of acetate into fatty acids has been investigated by radiolabeling methods. The results indicated that the incorporation of radiolabeled acetate into fatty acid increased under hypoxia in different cancer lines [45,46]. The increase of fatty acid synthesis is correlated with the activated expression of fatty acid synthetase (FAS) in tumor cells under hypoxic conditions [47,48].…”