Overexpression of GLUT1 correlates with Kras mutations in lung carcinomas

Glucose is the major source of energy for cells, and glucose transporter 1 (GLUT1) is the most common glucose transporter. GLUT1 has been found to be aberrantly expressed in several tumor types. From the results of the microarray and serial analysis of gene expression (SAGE), GLUT1 transcript expression was found to be higher in clones with mutant Kras alleles. We hypothesized that GLUT1 overexpression might be correlated with clinicopathological features of Japanese lung cancers. Immunohistochemistry for GLUT1 was performed in 283 surgically treated non-small cell lung cancer (NSCLC) cases from Nagoya City University Hospital. Thirty-six Kras mutant carcinoma cases were included. GLUT1 overexpression was found in 138 (48.8%) lung cancer patients. The GLUT1 overexpression status was significantly correlated with gender (women 31.9% vs. men 54.5%, P<0.0001), smoking status (never smoker 31.4% vs. smoker 59.4%, P<0.0001) and pathological subtypes (adenocarcinoma 36.4% vs. non‑adenocarcinoma 74.5%, P<0.0001). In addition, the GLUT1 overexpression status was significantly correlated with gene mutation status, including EGFR (mutation-positive 23.4% vs. -negative 58.3%, P<0.0001) and Kras (mutation-positive 66.7% vs. -negative 46.6%, P=0.038). The survival of patients with GLUT1 overexpression (n=137, 50 were deceased) was significantly worse when compared to the patients with normal expression of GLUT1 (n=142, 31 were deceased) (Log-rank test, P=0.0009). Thus, GLUT-1 overexpression correlates with an aggressive phenotype of lung carcinoma.