Fig. 4

Relationship between tumor ascorbate and expression of the HIF-1 pathway proteins and SVCT2. Levels of HIF-1α, CAIX, VEGF and BNIP3 were stratified according to the mean tumor ascorbate level < 0.2 nmol/μg DNA (n = 31), > 0.2 nmol/μg DNA (n = 16). HIF-1α, CAIX, VEGF and BNIP3 were generally higher in tumor tissue with low ascorbate, culminating in a significant relationship between higher ascorbate levels and a low HIF Pathway score. Means ± S.D. are shown. Statistical significance was determined with an unpaired t-test (HIF-1α, CA-IX) or the Mann Whitney test for non-parametric data (VEGF, BNIP3, HIF Pathway, SVCT-2). SVCT-2 below the mean n = 13, above the mean n = 6