The accessibility of reactive metabolites to test cells is critical for a genotoxic response. However, sulfo-conjugates formed outside may not readily enter cells, and some metabolites formed by cytochromes P450 (CYPs) may not endure transport. This topic was addressed in the present study, using V79 cells engineered for human CYPs and/or a sulfotransferase (SULT). First, 1-methylpyrene, 1-hydroxymethylpyrene, benzo[a]pyrene, and aflatoxin B1 significantly induced micronuclei in V79-hCYP1A2-hSULT1A1, V79-hSULT1A1, V79-hCYP1A1, and V79-hCYP1A2 cells, respectively. Subsequently, we used these cell lines as external activating systems in various experimental settings in combination with V79-derived target cells lacking critical enzymes. 1-Methylpyrene (activated by CYPs and SULTs sequentially) showed an activity similar to that in V79-hCYP1A2-hSULT1A1 cells, in each following model: a mixed V79-hCYP1A2:V79-hSULT1A1 (1:1) culture, exposure of V79-hCYP1A2 to 1-methylpyrene followed by transfer of medium to V79-hSULT1A1 target cells, and V79-hSULT1A1 communicating with V79-hCYP1A2 through 0.4-μm pores and over a 1-mm distance in a unique transwell system. These results suggest ready transfer of 1-hydroxymethylpyrene formed in V79-hCYP1A2 to V79-hSULT1A1 for further activation. In the last two models, with V79-hSULT1A1 for activation and V79-Mz as target, 1-hydroxymethylpyrene induced micronuclei mildly, suggesting limited intercellular transfer of the ultimate genotoxicant, 1-sulfooxymethylpyrene. Benzo[a]pyrene induced micronuclei in V79-Mz communicating with V79-hCYP1A1 via porous membranes, whereas aflatoxin B1 was inactive in V79-Mz communicating with V79-hCYP1A2. Our results suggest that the sulfo-conjugate tested may have difficulty entering cells for a genotoxic effect, and the reactive metabolite of aflatoxin B1, unlike that of benzo[a]pyrene, could not travel an adequate distance to enter cells. Environ. Mol. Mutagen. 61:224-234, 2020. © 2019 Wiley Periodicals, Inc.

中文翻译：

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在各种实验设置中，与代谢激活无关的细胞相互作用的无代谢能力的V79细胞中的突变蛋白形成微核。

反应性代谢产物对测试细胞的可及性对于遗传毒性反应至关重要。但是，在外部形成的磺基结合物可能不容易进入细胞，并且由细胞色素P450（CYP）形成的某些代谢物可能无法忍受运输。在本研究中，使用为人类CYP和/或磺基转移酶（SULT）设计的V79细胞解决了该主题。首先，1-甲基py，1-羟甲基py，苯并[a] py和黄曲霉毒素B1分别显着诱导V79-hCYP1A2-hSULT1A1，V79-hSULT1A1，V79-hCYP1A1和V79-hCYP1A2细胞中的微核。随后，我们将这些细胞系与缺乏关键酶的V79衍生靶细胞结合起来，在各种实验设置中用作外部激活系统。1-甲基py（被CYP和SULT依次激活）显示出与V79-hCYP1A2-hSULT1A1细胞相似的活性，在以下每个模型中：混合V79-hCYP1A2：V79-hSULT1A1（1：1）培养，V79-暴露将hCYP1A2转化为1-甲基py，然后将培养基转移至V79-hSULT1A1目标细胞，并且V79-hSULT1A1通过0.4μm的孔并在1mm的距离内与V79-hCYP1A2进行通信，并经过一个独特的transwell系统。这些结果表明在V79-hCYP1A2中形成的1-羟甲基py易于转移到V79-hSULT1A1中以进行进一步激活。在最近的两个模型中，以V79-hSULT1A1激活并以V79-Mz作为靶标，1-羟甲基induced温和地诱导了微核，这表明最终基因毒性物质1-磺氧基甲基oxy的细胞间转移有限。苯并[a] py诱导通过多孔膜与V79-hCYP1A1连通的V79-Mz中的微核，而黄曲霉毒素B1在与V79-hCYP1A2连通的V79-Mz中无活性。我们的结果表明，所测试的磺基结合物可能难以进入细胞以产生遗传毒性作用，并且与苯并[a] reactive不同，黄曲霉毒素B1的反应性代谢物不能经过足够的距离进入细胞。环境。大声笑 诱变剂。61：224-234，2020.©2019 Wiley Periodicals，Inc.