The thiopurines azathioprine, mercaptopurine, and thioguanine are prodrugs that are converted to active thioguanine nucleotide metabolites or methylated by thiopurine methyltransferase (TPMT) to compounds with less pharmacologic activity. In the absence of TPMT activity, patients are likely to have higher concentrations of thioguanine nucleotides, which can pose an increased risk of severe life...

-When thioguanine-resistant V79 cells are introduced into spinner flasks containing V79 multicell spheroids, the mutant cells attach to the surface of the spheroids. The composite spheroids thus formed consist of external, thioguanineresistant (TGr) and internal, thioguanine-sensitive cells. Cell sorting with a Becton Dickinson FACS II was used to determine the relative position of TGr cells an...

The actions of 6-thioguanine (TG) and 6-mercaptopurine (MP) were compared in Chinese hamster ovary (CHO) cells. Several differences were noted between these two agents. TG caused a greater maximal loss of clonogenicity, leaving about one log fewer survivors than did MP, although the cells killed by MP appeared to succumb much more rapidly than those killed by TG. MP-treated populations experien...

The antitumour activities of four triorganophosphinegold(I) thiolates, R(2)PAu(S'R) [R = Ph, Cy, Et; SR'H = 6-mercaptopurine and R Et; SR'H = 6-thioguanine] against the National Cancer Institute (NCI) panel of 60 cell lines are reported The [Cy(3)PAu(6-MP)] complex proved to be the more cytotoxic of the four complexes tested. For the 6-MP series, an order of cytotoxicity was established such th...