SLC2A1 and cancer: Moreover, under hypoxic conditions, ascorbate treatment reduced the pro-survival capacity for GLUT-1 up-regulation in nine of the 40 cell lines (from 40 to 31) and doubled the number of cell lines with a decreased expression of GLUT-1 under hypoxia alone (from 10 to 20), suggesting that high-dose ascorbate interferes with pro-survival mechanisms in the cancer cells.