Remarkable Effect of Increasing Glutamine Metabolism on Caveolin-1 in Breast Cancer: A Brief Report

Background: Caveolin-1(CAV-1) is a key molecule in cancer metabolism and progression and decrease in highly metastatic breast cancer cells. Moreover, glutamine is a crucial amino acid in the tumor microenvironment, and cancer cells are addicted to it. The effect of glutamine metabolism on caveoline-1 was not completely clarified. However, metformin has been demonstrated in separate studies to impair glutamine metabolism, and also affect caveoline-1 expression. Hence, the focus of this study is to evaluate the effect of glutamine metabolism on caveoline-1 expression, and to examine if metformin could affect caveoline-1 in high glutamine media. Methods In this study, 4T1 breast cancer cell line was cultured in different concentrations of glutamine. Caveolin-1 expression was assessed, using immunocytochemistry test. We also conducted MTT assay to evaluate optimum dose for metformin. To understand if metformin could regulate caveoline-1 expression in high glutamine media, 5mM of metformin was administrated and compared with control. Results our results indicated that glutamine metabolism significantly decreased CAV-1. On the other hand, administration of 5mM metformin for 24 hours efficiently re-expressed CAV-1. Conclusion High level of glutamine significantly decreased CAV-1, which may up-regulate the possibility of breast tumor speared, metastasis and metabolic reprogramming. Metformin, however, could be a promising drug, targeting glutamine metabolism to re-express caveoline-1, inhibiting tumor progression and metastasis.