Extended Data Figure 1: Change in the amino acid metabolism in leukaemic mice.

a–d, Representative chromatograms of (a, c) CP-CML and (b, d) BC-CML plasma samples derivatized with the amine-specific fluorescent labelling agent NBD-F and analysed in mobile phases at (a, b) pH 6.2 or (c, d) pH 4.4. Each NBD–amino acid peak was assigned as indicated. IS, internal standard (NBD–6-aminocaproic acid). e, Plasma amino acid levels in mice with CP- and BC-CML. Blood plasma samples were prepared from mice with CP- and BC-CML, methanol-extracted and dried under a vacuum. The dried extracts were analysed for quantification. Open and closed bars indicate CP-CML (n = 5) and BC-CML (n = 7) specimens, respectively. Two-tailed t-test. †P < 0.06, *P < 0.05, **P < 0.01. f, Leucine transport in primary CP- and BC-CML cells. BCR–ABL1–YFP⁺PI⁻ live leukaemia cells (5 × 10⁵) were sorted from premorbid animals and placed in a pre-warmed uptake media containing 10 μM [(U)-¹⁴C]l-leucine. After incubation at 37 °C for the indicated times, the cells were washed with cold HBSS and lysed with 0.1 M sodium hydroxide, and the radioactivity was measured using a scintillation counter. The grey and blue lines indicate the average leucine uptake in CP- and BC-CML samples (n = 5 and 3, respectively). Error bars, s.e.m. *P < 0.05. NS, not statistically significant (P > 0.05). g, RT–qPCR analysis of Bcat1 and Bcat2 expression in CP- and BC-CML cells (n = 4 each). The expression levels are normalized and displayed relative to the control β-2-microglobulin gene expression. Error bars, s.e.m.; ***P < 0.001, NS, not statistically significant (P > 0.05). h, BCAT1 protein expression in mouse primary CP- and BC-CML cells. This graph shows BCAT1 protein expression levels normalized relative to the HSP90 loading control (CP-CML, n = 7; BC-CML, n = 9). Error bars, s.e.m. *P < 0.05. i, Tissue-specific expression of mouse Bcat1. The expression was detectable in the myeloid cell line M1, primary mouse BC-CML cells, olfactory bulb (Olf bulb), whole brain and testis. B2m, β-2-microglobulin. j, Schematics of the structures of human and mouse BCAT1 proteins. The shaded boxes represent aminotransferase domains. K, a Lys residue for the binding of the pyridoxal phosphate cofactor. CVVC, a conserved redox-sensitive CXXC motif. Regions targeted with shRNAs in this study are shown as thick bars (shBcat1-a and -b, and shBCAT1-c and -d). k, l, Alanine and aspartate transaminase gene expression in CP- and BC-CML. RT–qPCR analysis of (k) Gpt1 and Gpt2, and (l) Got1 and Got2 expression in CP- and BC-CML samples (n = 4 each). The expression levels are normalized and displayed relative to the expression of the B2m control. Error bars, s.e.m.; NS, not statistically significant (P > 0.05).