Thioguanine in Deoxyribonucleic Acid from Tumors of 6-Mercaptopurine-Treated Mice

Abstract

Summary Deoxyribonucleic acid was isolated from a mercaptopurine-resistant adeno-carcinoma 755 after treatment of the mice with 8-C¹⁴-labeled 6-MP. The DNA was degraded to the deoxyribonucleoside level with pancreatic deoxyribonuclease and the digest was subjected to 2-dimensional chroma tography. Deoxyadenosine and deoxyguanosine contained 20% and 10%, respectively, of the total radioactivity. The material of the major spot (60% of total radioactivity) migrated with authentic thioguanosme deoxyriboside, and after acid hydrolysis, with thioguanine. No 6-MP derivative could be detected.