Glucose transporter 2‑transported glucosamine inhibits glycolysis in cancer cell lines through competition with glucose for hexokinase II.

Antiproliferative effects of glucosamine, a glucose derivative with a similar structure to glucose, have been discovered, but the molecular mechanisms are not yet fully understood. Since glucosamine and glucose not only have similar structures but also are catalyzed by the same enzyme, hexokinase (HK), the present study delved into determining whether the antiproliferative effect of glucosamine involved the inhibition of glycolysis by competition with glucose. Whole‑genome screening analysis showed that a number of the gene pathways controlled by glucosamine were directly and indirectly involved in glycolysis. experiments revealed that as more glucose was added, the antiproliferative effect of glucosamine decreased. Also, it was found that glucosamine was transported into cells mainly through glucose transporter (GLUT) 2 which was responsible for the antiproliferative effects of glucosamine. In addition, the present study found that cancer cell lines with low expression level of HKII show high sensitivity to glucosamine and a HK inhibitor, 3‑bromopyruvate, enhanced the antiproliferative effect of glucosamine. Under hypoxic conditions, activated hypoxia‑inducible factor 1α (HIF‑1α) inducing glucose uptake and glycolysis hampered glucosamine‑induced cell death and knockdown or HK inhibitors restored the antiproliferative effects of glucosamine. These findings demonstrated that glucosamine is an efficient glycolysis inhibitor and that GLUT2 and HKII play important roles as biomarkers for determining sensitivity to glucosamine. Moreover, the results suggested that the antiproliferative effect of glucosamine may be more efficient when administered in combination with other glycolytic agents or inhibitors targeting HIF‑1α.