Restoring Physiological Vitamin C Levels to the Normal Range: Influence on Epigenetic Regulation in Normal and Malignant Hematopoiesis

Recently, it was documented that hematological cancer patients with myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) exhibited severe vitamin C deficiency. Vitamin C is an essential co-factor for ten-eleven translocation (TET) enzymes, which initiate DNA demethylation through oxidation of 5-methylcytosine (mC) to 5-hydroxy-methylcytosine (hmC). In-vitro studies show that vitamin C at physiological doses added to DNA methyltransferase inhibitors (DNMTis), induce a synergistic inhibition of cell proliferation and enhanced apoptosis. These effects are mediated via a viral mimicry response recently associated with cancer stem-like cell death and enhanced immune signals including increased expression of bi-directionally transcribed endogenous retrovirus (ERV) transcripts, increased presence of cytosolic double stranded RNAs, and activation of an interferon inducing cellular response to these transcripts. Data suggest that correction of vitamin C deficiency may improve responses to epigenetic therapy with DNMTis. In the EVITA pilot study, the investigators include MDS/AML patients and explore the potential role of restoring vitamin C within the normal physiological range in treatment of hematological cancer with DNMTis.