FDG-based quantitative comparison of glucose metabolism in vitro, exemplified by a head-to-head comparison between a triple-negative breast cancer cell line and a non-malignant foetal cell line.
Glucose metabolism can be studied in vitro by a variety of means, also by fluorodeoxyglucose (FDG). As an example of the potential use we have compared the high glucose consumption in cancer cells and in transformed non-malignant foetal cells. The high glucose metabolism in cancer cells is not primarily for the production of energy, a large proportion is transformed to lactate only, producing two instead of potentially 32 ATP equivalents. The secreted lactate reduces the pH in the local microenvironment and gives malignant cells, more apt to thrive in hypoxic and acid environments, a competitive advantage. To demonstrate the use of FDG in head-to-head comparison of glucose uptake and lactate production in a highly malignant and a highly proliferative non-malignant cell line. Cell cultures of a foetal kidney cell line and a triple negative breast cancer cell line were incubated with FDG for one hour, washed, harvested and the radioactivity content in the cells was measured in a well counter. The lactate concentration was measured in conditioned medium. The FDG uptake was consistently higher in the non-malignant foetal cell line. The levels of lactate in the conditioned medium were similar. Quantitative comparison of glucose metabolism by in vitro use of FDG is a practical, cheap and rapid method. Some foetal cells have higher glucose uptake and produce as much lactate as this highly malignant cell line. This is an argument against the high glucose consumption being related solely to malignancy.