Expression of glucose transporters 1 and 3 in metastatic and non-metastatic lower lip squamous cell carcinoma.

This study aimed to evaluate the immunoexpression of glucose transporters 1 (GLUT-1) and 3 (GLUT-3) in metastatic and non-metastatic lower lip squamous cell carcinoma (LLSCC). Twenty LLSCCs with regional nodal metastasis and 20 LLSCCs without metastasis were selected. The distribution of staining and the percentage of GLUT-1 and GLUT-3 staining in each tumor core and at the deep invasive front were assessed. Most tumors (70%) exhibited peripheral staining for GLUT-1 in nests, sheets and islands of neoplastic cells, whereas predominantly central staining was observed for GLUT-3 (72.5%). A high percentage of GLUT-1-positive cells was observed at the deep invasive front and in the tumor core of metastatic and non-metastatic tumors (p>0.05). The percentage of GLUT-1-positive cells was much higher than that of GLUT-3-positive cells both in the deep invasive front (p<0.001) and in the tumor core (p<0.001) of LLSCCs. No significant differences in the percentage of GLUT-1- and GLUT-3-positive cells were observed according to nodal metastasis, clinical stage or histological grade of malignancy (p>0.05). In conclusion, the results of the present study suggest an important role of GLUT-1 in glucose uptake in LLSCCs, although this protein does not seem to be involved in the progression of these tumors. On the other hand, GLUT-3 expression may represent a secondary glucose uptake mechanism in LLSCCs.