Correlation between 18F-FDG uptake and the expression of glucose transporter-1 and hypoxia-inducible factor-1α in transplanted VX2 tumors

Abstract

We investigated the correlation between fluorine-18-fluorodeoxyglucose (F-FDG) uptake and glucose transporter-1 (GLUT-1) and hypoxia-inducible factor-1α (HIF-1α) expression in a rabbit lung VX2 tumor model. Twenty-four VX2 tumor-bearing rabbits underwent F-FDG PET/computed tomography (CT) at 4, 5, 6, and 7 weeks after implantation. PET/CT images were obtained to monitor the tumor/normal tissue (T/N) ratio in each period. Six rabbits were randomly killed after PET/CT, and immunohistochemical staining was used to assess GLUT-1 and HIF-1α expression. We investigated the correlations of F-FDG uptake with GLUT-1 and HIF-1α expression and the pathological tumor (p-tumor) size as well as those of the lymph node metastasis (p-N) stage with the T/N ratio, p-tumor size, and GLUT-1 and HIF-1α expression. The T/N ratio increased gradually over time before subsequently decreasing. The T/N ratio was significantly influenced by time (F=54.63, P<0.05) and was significantly correlated with GLUT-1 (r=0.53, P<0.01) and HIF-1α (r=0.44, P<0.01) expression and p-tumor size (r=0.58, P<0.05). A significant positive correlation between GLUT-1 expression and HIF-1α expression was also identified (r=0.58, P<0.05). The p-N stage showed a significant association with the T/N ratio (P<0.05) but not with GLUT-1/HIF-1α expression (P>0.05). F-FDG uptake is closely correlated with GLUT-1 and HIF-1α expression, tumor size, and lymph node metastasis.