A method for simultaneous identification of human active and active-site alkylated O6-methylguanine-DNA methyltransferase and its possible application for monitoring human exposure to alkylating carcinogens.
A method for simultaneous identification of human active and active-site alkylated O6-methylguanine-DNA methyltransferase and its possible application for monitoring human exposure to alkylating carcinogens.
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一种同时鉴定人体活性和活性位点烷基化 O6-甲基鸟嘌呤-DNA 甲基转移酶的方法及其在监测人体接触烷基化致癌物方面的可能应用。
DOI：
10.11501/3054140
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发表时间：
1994
期刊：
影响因子：
11.2
通讯作者：
B. F. Li
中科院分区：
文献类型：
--
作者：
T. Ayi;H. Oh;T. Lee;B. F. Li
细胞通过O 6-甲基鸟嘌呤-DNA甲基转移酶（MGMT）的作用抵抗烷化剂的主要致突变作用，MGMT将这些化学物质在DNA中产生的O 6-烷基鸟嘌呤的烷基（R）转移到其活性位点的半胱氨酸残基（形成R-MGMT）。我们证明，细胞的R-MGMT（这是一个记录或内存内的细胞暴露于这些化学品）可以通过其对蛋白酶V8的蛋白水解的敏感性进行测定。通过使用培养的细胞和使用正常受试者和接受化疗的患者的人血进行的初步研究，研究了该测定法用于监测烷基化致癌物暴露的可能性。培养细胞实验表明，R-MGMT对于监测目的是足够稳定的，并且其水平与所用烷化剂的浓度具有剂量-反应关系。有趣的是，来自接受化疗的患者的血液的实验显示在1-（2-氯乙基）-3-环己基-1-亚硝基脲中逐渐形成R-MGMT，并且在环磷酰胺治疗的患者中诱导MGMT缺乏。使用这种方法，它允许可能的量化活性MGMT（细胞DNA修复能力）和R-MGMT（最近的曝光）同时，在监测人类接触到烷化剂进行了讨论。
Cells resist the major mutagenic effects of alkylating agents by the action of O6-methylguanine-DNA methyltransferase (MGMT), which transfers the alkyl (R) group of O6-alkylguanine, produced in DNA by these chemicals, to a cysteine residue in its active site (formation of R-MGMT). We demonstrate that cellular R-MGMT (which represents a record or memory within the cells exposed to these chemicals) can be assayed by its sensitivity toward proteolysis by protease V8. The possible use of this assay for monitoring exposure to alkylating carcinogens was investigated by using cultured cells and a preliminary study with the use of human blood from normal subjects and patients undergoing chemotherapy. Cultured cell experiments show that R-MGMT is sufficiently stable for the monitoring purpose and its level bears a dose-response relationship to the concentrations of the alkylating agent used. Interestingly, experiments with blood from patients undergoing chemotherapy show a gradual formation of R-MGMT in 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea and an induced MGMT deficiency in cyclophosphamide-treated patients. The use of this methodology, which allows for the possible quantification of active MGMT (cellular DNA repair capacity) and R-MGMT (recent exposure) simultaneously, in monitoring human exposure to alkylating carcinogens is discussed.
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影响因子：
11.2
作者：
Prescilla E. Gonzaga;Philip M. Potter;T. Niu;Dong Yu;D. Ludlum;Joseph A Rafferty;G. P. Margison;T. Brent
通讯作者：
Prescilla E. Gonzaga;Philip M. Potter;T. Niu;Dong Yu;D. Ludlum;Joseph A Rafferty;G. P. Margison;T. Brent
影响因子：
56.9
作者：
DUMENCO, LL;ALLAY, E;GERSON, SL
通讯作者：
GERSON, SL
DOI：
10.1073/pnas.81.20.6271
发表时间：
1984-01-01
期刊：
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES
影响因子：
--
作者：
LOECHLER, EL;GREEN, CL;ESSIGMANN, JM
通讯作者：
ESSIGMANN, JM
影响因子：
7.4
作者：
Rettori MM;de Carvalho AC;Longo AL;de Oliveira CZ;Kowalski LP;Carvalho AL;Vettore AL
通讯作者：
Vettore AL