6-Thioguanine (isG) has been used for the past thirty years as an anti-cancer agent in maintenance chemotherapy for childhood acute lymphoblastic leukemia as well as acute myeloid leukemia. Despite its long-standing clinical use, little is understood of the molecular basis of the cytotoxicity associated with 6SG. Research has shown that 6SG is incorporated into DNA during replication after whic...

6-Thioguanine, an immunosuppressant and anticancer prodrug, has been shown to induce DNA damage and cell death following exposure to UVA radiation. Its metabolite, 6-thioguanosine, plays a major role in the prodrug's overall photoreactivity. However, 6-thioguanine itself has proven to be cytotoxic following UVA irradiation, warranting further investigation into its excited-state dynamics. In th...

Azathioprine and 6-mercaptopurine are antimetabolite thiopurine drugs that play important roles in the treatment of leukemia and in the management of conditions requiring immunosuppression, such as inflammatory bowel disease. The biochemical pharmacology of these drugs suggests that inhibition of purine nucleotide formation through the 6-thioguanine nucleotide metabolites is their key molecular...

Of 142 purines, purine nucleosides, and analogues tested for inhibition of growth of Escherichia coli B Hill, 45 were active. Of these, 27 were evaluated for inhibition of other E. coli lines, including those resistant to 6-thioguanine, 2-fluoroadenosine, 2,6-diaminopurine, or 6-mercaptopurine. Most toxic to the parent lines were 2-fluoroadenosine, 2-fluoroadenine, 2-fluoro-5'-deoxyadenosine, a...

Azathioprine is a widely used anti-inflammatory, immunosuppressive, and anticancer agent. However, chronic treatment with this drug is associated with a profoundly increased risk (in certain cases by more than 100-fold) of developing squamous cell carcinoma of the skin. Incorporation of its ultimate metabolite, thio-dGTP, in DNA results in partial substitution of guanine with 6-thioguanine whic...

The standard therapy for some autoimmune diseases consists of a combination of corticosteroids and thiopurines. In non-responders to thiopurine drugs, the measurement of the metabolites of azathioprine, 6-thioguanine, and 6-methylmercaptopurine, can be a useful tool. The measurement has been used during the treatment of inflammatory bowel diseases and, less commonly, in autoimmune hepatitis. Ma...

The tumor-inhibitory jxitency of combinations of the cupric chelate of kethoxal bis(thiosemicarbazone) [Cu(II)KTS] with several compounds that cause inhibition of the synthesis of DNA by different biochemical mechanisms was assessed in Sarcoma 180 ascites cells. Cu(II)KTS prolonged the survival time of tumor-bearing mice, whereas neither cupric chloride, copper stéarate,nor kethoxal bis(thiose...