The metabolism of galactose in hypoxic cancer cells

The Le Loir pathway is a cellular metabolic pathway for the processing of galactose into glucose-1-phosphate which is then converted into glucose-6-phosphate for use in glycolysis. Traditionally, galactose is processed in the liver, kidney, and gut. However, significant metabolism of galactose has been found in breast and glioblastoma cancers. In preliminary trials, we examined the metabolism of galactose in Colo-205 and LoVo colorectal cancer cells, SFXL and U87 Glioblastoma cells, Miapaca2 pancreatic cancer cells, and HUH-7 liver cancer cells. When adding 5mM of [1-13C] Galactose to complete media, we saw only a negligible boost in the C3 lactate peak for all but HUH-7 cells. Additionally, we tested the response of the cells to a 2% O2 hypoxic environment using a 5% CO2 hypoxia incubator. Under hypoxia, the HUH-7 cells seemed to stop metabolizing galactose to lactate. These NMR results will be discussed together with other supporting data.