Background/aims: Cancer cells require increased nutrient uptake to support a high rate of proliferation, and the overexpression of glucose transporters, in particular GLUT1, is a common characteristic of human malignancies. Here, we investigated the relationship between the expression of GLUT1 and cell viability, colony forming ability and apoptosis of head and neck squamous cell carcinoma (HNSCC) in vitro and in a xenograft mouse model in vivo.
Methods: Lentiviral mediated overexpression and knock-down of GLUT1 was performed in two oral cancer cell lines (CAL27 and SCC25). QRT-PCR and Western blot analysis were used to detect the mRNA and protein expression of GLUT1 and nuclear factor-kappa B (NFκB) p65 subunit. Cell viability and apoptosis were assessed by MTT and flow cytometry analyses, respectively. Colony formation assays were performed by staining with 0.5% crystal violet. The role of GLUT1 in HNSCC was examined in vivo through the generation of a CAL27 (or CAL27 with different transfections) nude mice xenograft model of HNSCC.
Results: GLUT1 overexpression promoted cell viability and colony formation whereas GLUT1 silencing had the opposite effect. GLUT1 knock-down significantly increased the number of Annexin V positive cells in both cell lines and GLUT1 overexpression had the opposite effect, indicating that GLUT1 modulates apoptosis. Xenograft mouse models of GLUT1 knockdown and overexpression showed that GLUT1 expression was associated with poor survival and increased tumor growth. GLUT1 overexpression significantly upregulated the expression of NFκB-p65, and this effect was reversed by inhibition of GLUT1 expression.
Conclusions: GLUT1 expression plays an important role in the survival of HNSCC, and its effects may be associated with the activation of the NFκB pathway.
© 2013 S. Karger AG, Basel.