Glucose transporter-1 expression in renal cell carcinoma and its correlation with hypoxia inducible factor-1 alpha

To evaluate transcription factor hypoxia inducible factor-1 alpha (HIF-1 alpha) activity, by analysing a target gene for HIF-1 alpha, glucose transporter-1 (GLUT-1), using a tissue microarray (TMA) in different types of renal cell carcinoma (RCC, a tumour with a variable clinical course, partly due to angiogenic activity), as angiogenesis is important for tumour progression and metastatic spread, and is activated by hypoxia.

GLUT-1 and HIF-1 alpha expressions were semiquantitatively analysed using immunohistological staining of a prepared TMA, using samples from 187 patients, including 148 with conventional, 26 with papillary and 13 with chromophobe RCC.

GLUT-1 staining was found mainly in the cytoplasm. The tumours were subdivided into GLUT -1(LOW) and GLUT-1(HIGH), based on staining intensity. There was a significant difference in GLUT-1 expression between RCC types (P < 0.05). In conventional RCC, GLUT-1 had no correlation with clinicopathological variables. By contrast there was a correlation with tumour stage in papillary RCC. There was an insignificant trend to better survival of patients with GLUT-1(LOW) expression in both conventional and papillary RCC. GLUT-1 correlated significantly (P = 0.008) with HIF-1 alpha.

Most patients with conventional RCC had GLUT-1(HIGH) staining and there was a significant correlation with HIF-1 alpha. In papillary RCC, GLUT-1 expression was associated with stage; GLUT-1 expression was significantly higher in conventional RCC than in papillary and chromophobe RCC. GLUT-1(LOW) in both papillary and conventional RCC appeared to correspond with a better prognosis.