Feedback Inhibition by 6-Methylthioinosine 3',5'-Cyclic Monophosphate in Tumor Cells Resistant to the Nucleoside

Abstract

The 3′, 5′-cyclic phosphate derivative (cMTIMP) of methylthioinosine (MTI) was shown to produce feedback inhibition of the de novo purine pathway in an Ehrlich ascites tumor subline resistant to MTI because of lack of adenosine kinase activity for the nucleoside analog.