NMR study of sugar metabolism in the cultured renal cancer cells*

D-mannose, a monosaccharide C-2 epimer of glucose is a major monosaccharide component of N-glycans and is internalized into mammalian cells via membrane glucose transporters. D-mannose is phosphorylated by hexokinase (HK) and produces mannose-6-phosphate (M6P), can be directed into glycolysis or glycosylation pathway. The metabolism of mannose in mammalian cells depends on the concentration of MPI enzyme. Here we have investigated the metabolism of mannose in presence and in the absence of glucose in RCC renal cell culture and growth. 13C-labelled D-mannose, was used as the 13C NMR metabolic tracer for glycolysis and Warburg effect in RCC Vis-à-vis the glucose metabolism in these cells. Comparative experimental results showed that mannose can be metabolized into mainly lactate indicative of the Warburg effect in cancer, although glucose appears to be the more preferred sugar as energy source.

This study was supported by the Welch Foundation grant AT‐2111‐20220331 and the US Department of Defense CDMRP grants W81XWH-19-1-0741, W81XWH-21-1-0176, W81XWH-22-1-0105, W81XWH-22-1-0003, HT9425-23-1-0062, and HT9425-24-1-0287.