Conversion of 5'-deoxy-5'-methylthioadenosine and 5'-deoxy-5'-methylthioinosine to methionine in cultured human leukemic cells.
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.
D000241:Adenosine / Q000031:analogs & derivatives* / Q000378:metabolism; D002478:Cells, Cultured; D003839:Deoxyadenosines; D006801:Humans; D007288:Inosine / Q000031:analogs & derivatives*; D007938:Leukemia / Q000378:metabolism; D015470:Leukemia, Myeloid, Acute / Q000378:metabolism*; D008715:Methionine / Q000378:metabolism*; D008778:Methylthioinosine / Q000378:metabolism* / Q000031:analogs & derivatives; D011683:Purine-Nucleoside Phosphorylase / Q000037:antagonists & inhibitors; D013601:T-Lymphocytes; D013872:Thionucleosides / Q000378:metabolism*
D003839:Deoxyadenosines; D013872:Thionucleosides; C038025:5'-methylthioinosine; D008778:Methylthioinosine; D007288:Inosine; C008500:5'-methylthioadenosine; D008715:Methionine; D011683:Purine-Nucleoside Phosphorylase; D000241:Adenosine