Vitamin B6 Addiction in Acute Myeloid Leukemia

• DOI: 10.1016/j.ccell.2019.12.002
• Publication Date: 2020-01-13T18:57:45Z
• Authors: Chi-Chao Chen; Bo Li; Scott E. Millman; Cynthia Chen; Xiang Li; John P. Morris; Allison Mayle; Yu-Jui Ho; Evangelia Loizou; Hui Liu; Weige Qin; Hardik Shah; Sara Violante; Justin R. Cross; Scott W. Lowe; Lingbo Zhang
• Keywords: Gene Expression Regulation, Leukemic; Phosphotransferases; Membrane Proteins; Vitamin B 6; GTP Phosphohydrolases; 3. Good health; Leukemia, Myeloid, Acute; Mice; Phosphotransferases (Alcohol Group Acceptor); Cell Line, Tumor; Pyridoxal Phosphate; Polyamines; Animals; Humans; CRISPR-Cas Systems; RNA, Small Interfering; Cell Proliferation; Monomeric GTP-Binding Proteins

Cancer cells rely on altered metabolism to support abnormal proliferation. We performed a CRISPR/Cas9 functional genomic screen targeting metabolic enzymes and identified PDXK-an enzyme that produces pyridoxal phosphate (PLP) from vitamin B6-as an acute myeloid leukemia (AML)-selective dependency. PDXK kinase activity is required for PLP production and AML cell proliferation, and pharmacological blockade of the vitamin B6 pathway at both PDXK and PLP levels recapitulated PDXK disruption effects. PDXK disruption reduced intracellular concentrations of key metabolites needed for cell division. Furthermore, disruption of PLP-dependent enzymes ODC1 or GOT2 selectively inhibited AML cell proliferation and their downstream products partially rescued PDXK disruption induced proliferation blockage. Our work identifies the vitamin B6 pathway as a pharmacologically actionable dependency in AML.