Background: Hypoxia (deprived oxygen in tissues) may induce molecular and genetic
changes in cancer cells.
Objective: To Investigate the genetic changes of glucose metabolism in breast cancer cell line (MCF7)
after exposure to continuous hypoxia (10 and 20 cycles exposure of 72 hours continuously on a weekly
Methods: Gene expression of MCF7 cells was evaluated using real-time polymerase chain reactionarray
method. Furthermore, cell migration and wound healing assays were also applied.
Results: It was found that 10 episodes of continuous hypoxia activated the Warburg effect in MCF7
cells, via the significant up-regulation of genes involved in glycolysis (ANOVA, p value < 0.05). The
molecular changes were associated with the ability of MCF7 cells to divide and migrate. Interestingly,
after 20 episodes of continuous hypoxia, the expression glycolysis mediated genes dropped significantly
(from 30 to 9 folds). This could be attributed to the adaptive ability of cancer cells.
Conclusion: It is concluded that 10 hypoxic episodes increased the survival rate and aggressiveness of
MCF7 cells and induced the Warburg effect by the up-regulation of the glycolysis mediating gene