Ascorbate is a physiological tumor suppressor metabolite in leukemia

Accumulation of oncometabolites promotes tumorigenesis, but it is not known if there are naturally occurring tumor suppressor metabolites whose deficiency within cancer-initiating cells causes cancer. Many leukemia patients are ascorbate deficient. Here we show that hematopoietic-specific ascorbate depletion in mice is sufficient to cause or promote leukemogenesis. Hematopoietic-specific ascorbate depletion promoted leukemogenesis by acting within leukemia initiating cells. Ascorbate depletion in myeloid leukemia expanded plasmacytoid dendritic cells, an effect mediated by the ascorbate molecular targets TET2 and TET3. Leukemia cells accumulated ascorbate as part of a tumor suppressor response to neoplastic proliferation that limited progression but depleted circulating ascorbate. Ascorbate restoration in mice with established leukemias extended survival. Hematopoietic-specific ascorbate depletion caused leukemia in collaboration with TET2 loss and was sufficient to cause leukemia with high penetrance even in the absence of other engineered mutations. These results identify ascorbate as a physiological tumor suppressor metabolite in blood cancers.