Fig. 1.

Selected glucose metabolic genes and their potential roles in tumor development. PPP: pentose phosphate pathway. Hexokinases (HK) 2 and GCK/HK4 phosphorylate glucose to produce glucose-6-phosphate (Glucose-6P), the first step in most glucose metabolism pathways including glycolysis ²⁵. GPI (phosphoglucose isomerase) catalyzes the reversible isomerization of Glucose-6P and fructose-6P, and guide the glucose flow to the pentose phosphate pathway (PPP) ²⁸. GPI also functions as an autocrine motility factor (AMF), secreted from the tumor cells to promote progression ²⁹. GFPT1 is the first and rate-limiting enzyme of the hexosamine biosynthesis pathway (HBP) and controls the flux of glucose into the hexosamine pathway. OGT is a glycosyltransferase that catalyzes the addition of a single N-acetylglucosamine in O-glycosidic linkage to serine or threonine residues. O-linked glycosylation plays a role in controlling gene expression, fuel metabolism, cell growth, differentiation, and cytoskeleton organization ³⁰.