Glucose Promotes a Pro-Oxidant and Pro-Inflammatory Stromal Microenvironment Which Favors Motile Properties in Breast Tumor Cells

Abstract

Chronic inflammation and metabolic reprogramming have been proposed as hallmarks of cancer development. Currently, many of the functional clues between these two phenomena are studied under the integrative view of functional stroma-epithelia interaction. It has been proposed that stromal cells, due to their abundance and avidity for glucose, are able to modify the metabolic behavior of an entire solid tumor. In the present study, using a mammary stromal cell line derived from healthy tissue subjected to long-term culture in low (5 mM) or high (25 mM) glucose, we found that the hyperglycemic condition favors the establishment of a pro-inflammatory and pro-oxidant environment characterized by the induction of the COX-2/PGE2 axis. In this condition, epithelial migration was stimulated. Moreover, we also found that stromal-derived PGE2, acting as a stimulator of IL-1 epithelial expression was one of the factors that promote the acquisition of motile properties by epithelial cells and the maintenance of a COX-2/PGE2-dependent inflammatory condition. Overall, our work provides experimental evidence that glucose stimulates a tumor inflammatory environment that, as a result of a functional cross-talk between stroma and epithelia, may be responsible for tumor progression.