Savarese T M, Ghoda L Y, Dexter D L, Parks R E
Cancer Res. 1983 Oct;43(10):4699-702.
5'-Deoxy-5'-methylthioadenosine and 5'-deoxy-5'-methylthioinosine, which are metabolized to the methionine precursor, 5-methylthioribose-1-phosphate, by 5'-deoxy-5'-methylthioadenosine phosphorylase and purine nucleoside phosphorylase, respectively, can serve as sources of methionine for cultured HL-60 promyelocytic leukemia cells. CCRF-CEM T-cell leukemia cells, which lack 5'-deoxy-5'-methylthioadenosine phosphorylase, convert 5'-deoxy-5'-methylthioinosine (but not 5'-deoxy-5'-methylthioadenosine) to methionine; this conversion is blocked by purine nucleoside phosphorylase inhibitors. Therefore, the pathway for the conversion of 5-methylthioribose-1-phosphate to methionine is present in both human leukemic lines.
5'-脱氧-5'-甲硫基腺苷和5'-脱氧-5'-甲硫基肌苷分别通过5'-脱氧-5'-甲硫基腺苷磷酸化酶和嘌呤核苷磷酸化酶代谢为甲硫氨酸前体5-甲硫基核糖-1-磷酸，它们可以作为培养的HL-60早幼粒细胞白血病细胞的甲硫氨酸来源。缺乏5'-脱氧-5'-甲硫基腺苷磷酸化酶的CCRF-CEM T细胞白血病细胞将5'-脱氧-5'-甲硫基肌苷（而非5'-脱氧-5'-甲硫基腺苷）转化为甲硫氨酸；这种转化被嘌呤核苷磷酸化酶抑制剂阻断。因此，5-甲硫基核糖-1-磷酸转化为甲硫氨酸的途径在这两种人类白血病细胞系中均存在。
