Thioguanin

Thi abut azide 358 Thialbarbital 1, 275 Thiamphenicol 2 45 Thiamprine 2, 464 Thiamylal I, 274 Thiazinium chloride 3, 240 Thi azolsul Tone 14T Thi ethyl perazi ne 1, 382 Thiobarbital 1, 275 Thiofuradene T, 231 Thioguanine 464... 

Thioguanine is used primarily as part of induction chemotherapy regimens for acute myelogenous leukemia (AML). 

Anti metabolites. Figure 3 Chemical structure of thioguanine. 

Cytarabine is used in the chemotherapy of acute myelogenous leukemia, usually in combination with anthracyclines, thioguanine, or both. It is less useful in acute lymphoblastic leukemia and lymphomas and has marginal activity against other tumors. Myelosuppres-sion is a major toxicity, as is severe bone marrow hypoplasia nausea and mucositis may also occur. 

The current induction therapy for acute myelogenous leukemia (AML) usually consists of a combination of cytara-bine and daunorubicin, with the frequent addition of a steroid and/or an antimetabolite such as 6-thioguanine. The risk of infection is so high during this period that patients receive antibiotic and fungal prophylaxis. 

C, cytarabine ASP, asparaginase CALCB, Cancer and Leukemia Croup B CNS, central nervous system CTX, cyclophosphamide DEX, dexamethasone DNR, daunorubicin DOX, doxorubicin IT, intrathecal captopurine MTX, methotrexate PRED, prednisone TG, thioguanine VCR, vincristine. 

Rappaport HP (1988) The 6-thioguanine/5-methyl-2-pyrimidinone base pair. Nucl Acids Res 16(15) 7253-7267... 

Chen ZS, Lee K, Kruh GD. Transport of cyclic nucleotides and estradiol 17-beta-D-glucuronide by multidrug resistance protein 4 Resistance to 6-mercap-topurine and 6-thioguanine. J Biol Chem 2001 276(36) 33747—33754. 

At cellular level, 6-MP is transformed in a number of active and inactive metabolites, and in the bone marrow, the balance between activation and inactivation of 6-MP is the main determinant of its antiproliferative effect. Similar to other antimetabolites, 6-MP is a prodrug lacking any cytotoxic activity and needs to be activated [3] (Figure 14.1). The first step is 6-MP transformation into 6-thioinosine monophosphate (6-TIMP), which is subsequently converted to 6-thioguanine tri-... 

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