Metabolism of purine and pyrimidine nucleotides

















                      Many antineoplastic drugs inhibit nucleotide metabolism

•             The development of drugs with selective toxicity for cancer cells is difficult
because cancer cells are too similar to normal cells

•             Therefore, agents that are toxic for cancer cells are toxic also for normal cells

•             Cancer cells do, however,  have a higher mitotic rate than normal cells

•             Therefore they have a higher requirement for DNA synthesis

•             Most antineoplastic drugs act as antagonists of nucleotide synthesis













































                                         Mycophenolic acid

•             Potent, reversible, uncompetitive inhibitor of IMP dehydrogenase

     Used in preventing graft rejection

     It blocks de novo formation of GMP ® supress the proliferation of T and B cells



















                                            Hydroxyurea

     Hydroxyurea inhibits ribonucleotide reductase