2-Methoxy-1,4-Naphthoquinone (MNQ) Inhibits Glucose Uptake and Lactate Production in Triple-Negative Breast Cancer Cells

OBJECTIVE: The persistent activation of aerobic glycolysis in cancer cells results in accumulation of lactate and other metabolic intermediates that contribute to tumorigenesis. Increased glycolysis is frequently dysregulated in triple-negative breast cancer (TNBC), which promotes tumor growth and immune escape. This study was conducted to investigate the effect of 2-methoxy-1, 4-naphthoquinone (MNQ), compound extracted from Impatiens balsamina on glycolytic activities in human breast adenocarcinoma, MDA-MB-231 cells.

METHODS: Initially, MTT proliferation assay was used to test the cell viability with various doses of MNQ (5-100 µM). As the half maximal inhibitory concentration (IC50) was obtained, glucose uptake and lactate assays of the cells were tested with IC50 dose of MNQ. The treated cells were also subjected to gene and protein analysis of glycolysis-related molecules (GLUT1 and Akt).

RESULTS: The results showed that MNQ decreased the percentage of MDA-MB-231 cell viability in a dose-dependent manner with the IC50 value of 29 µM. The percentage of glucose uptake into the cells and lactate production decreased significantly after treatment with MNQ as compared to untreated cells. Remarkably, the expressions of GLUT1 and Akt molecules decreased in MNQ-treated cells, suggesting that the inhibition of glycolysis by MNQ is GLUT1-dependent and possibly mediated by the Akt signaling pathway.

CONCLUSION: Our findings indicate the ability of MNQ to inhibit the glycolytic activities as well as glycolysis-related molecules in MDA-MB-231 cells, suggesting the potential of MNQ to be further developed as an effective anticancer agent against TNBC cells.