Metabolism to methionine and growth stimulation by 5'-methylthioadenosine and 5'-methylthioinosine in mammalian cells.
Viable human and murine lymphoblasts, and normal human tissue extracts, converted the thioether nucleosides 5'-methylthioadenosine (MeSAdo) and 5'-methylthioinosine (MeSIno) to methionine. Both MeSAdo and MeSIno, but not homocysteine, supported the short-term growth of human or murine lymphoblasts in methionine deficient medium. However, MeSAdo at concentrations greater than 25 microM inhibited cell growth. MeSIno was non-toxic at concentrations up to 200 microM, and supported the long-term growth of lymphoblasts in methionine-free medium.
D000241:Adenosine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism*; D002455:Cell Division / Q000187:drug effects*; D002460:Cell Line; D003839:Deoxyadenosines; D006801:Humans; D007288:Inosine / Q000031:analogs & derivatives*; D007939:Leukemia L1210 / Q000378:metabolism*; D008715:Methionine / Q000378:metabolism*; D008778:Methylthioinosine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D051379:Mice; D013872:Thionucleosides / Q000378:metabolism / Q000494:pharmacology*
D003839:Deoxyadenosines; D013872:Thionucleosides; C038025:5'-methylthioinosine; D008778:Methylthioinosine; D007288:Inosine; C008500:5'-methylthioadenosine; D008715:Methionine; D000241:Adenosine