Glucose uptake in malignant tumors of the head and neck

Positron emission tomography (PET) studies have shown an elevated glucose u ptake in squamous cell carcinomas of the head and neck (HNSCC). On a cellul ar level glucose uptake is mediated by specific glucose transport proteins. We have used immunohistochemistry to study the expression of different fac ilitative glucose transport proteins (GLUT) in the normal mucosa and in HNS CC. A weak expression of GLUT 1 was observed in epithelial cells of the nor mal mucosa. However, the expression of GLUT 1 was strongly elevated in epit helial cells of HNSCC. GLUT2, 3 and 4 were not detected in any of the epith elial tissues examined. An increased expression of GLUT 3 was found in infl ammatory cells. The storage of glycogen showed a negative correlation to th e GLUT 1 expression. While an increased glycogen storage was accompanied by a decreased GLUT 1 expression in highly differentiated epithelial cells, g lycogen loss was associated with a strong GLUT 1 expression in less differe ntiated cells. The present study with PET indicates that the elevated gluco se uptake of HNSCC is closely related to an increased expression of GLUT 1 in epithelial tumor cells.