This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Lowe, J. K. Articles by Henderson, J. F. Search for Related Content PubMed PubMed Citation Articles by Lowe, J. K. Articles by Henderson, J. F.

Consequences of Inhibition of Guanine Nucleotide Synthesis by Mycophenolic Acid and Virazole¹

University of Alberta Cancer Research Unit (McEachern Laboratory) and Department of Biochemistry, Edmonton, Alberta, Canada T6G 2H7

Mycophenolic acid and virazole are inhibitors of inosinate dehydrogenase and produce growth inhibition and loss of viability in cultured murine lymphoma L5178Y cells. Treatment with 1 µM mycophenolic acid produced the following changes in concentrations of acid-soluble nucleotides: (a) guanosine triphosphate decreased to less than 10% of control within 2 hr; (b) uridine triphosphate and cytidine triphosphate concentrations increased markedly; (c) adenosine triphosphate did not change; (d) deoxyguanosine triphosphate decreased; and (e) thymidine triphosphate increased. DNA synthesis was inhibited by 90% within 2 hr, whereas the incorporation of adenosine into RNA and of leucine into protein were much less affected. Virazole (100 µM) produces similar effects. These biochemical effects of mycophenolic acid, as well as its effects on cell growth, can be prevented by addition of guanylate to the medium. Mycophenolic acid treatment also appears to cause breakdown of high-molecular-weight DNA.

¹ This work was supported by the National Cancer Institute and Medical Research Council of Canada.

² To whom requests for reprints should be addressed.

Received 8/17/76. Accepted 12/ 2/76.