A newly developed in vivo Pig-a gene mutation assay displays great potential for integration into genotoxicity tests. To obtain more evidence for application of the Pig-a assay, we integrated this assay, micronucleus test in peripheral blood (MN-pb test) and bone marrow (MN-bm test), as well as a Comet assay into a transgenic RasH2 mice carcinogenicity study. Fourteen male RasH2 mice and five wild-type (WT) mice were treated with a strong mutagen aristolochic acid I at a dose of 5 mg/kg/day for 4 consecutive weeks. Mice recovered in 5 weeks. Peripheral bloods were collected for Pig-a assay, MN-pb test, and Comet assay at several time points, while bone marrow and target organs were harvested for the MN-bm test and pathological diagnosis after mice were euthanized. Finally, 13 of the 14 RasH2 mice developed squamous cell carcinomas in the forestomach, while there were no carcinomas in the WT mice. Pig-a mutant frequencies (MFs) consecutively increased throughout the study to a maximum value of approximately 63-fold more than background. These frequencies were relative to the incidence, size, and malignant degree of tumors. Micronucleated reticulocytes increased from Day 1 to Day 49, before returning to background levels. No positive responses were observed in either the MN-bm test or the Comet assay. Results suggested that, when compared with the other two tests, the Pig-a assay persistently contributed to sustaining MFs, enhanced detection sensitivity due to the accumulation of Pig-a mutations, and demonstrated better predictability for tumorigenicity. Environ. Mol. Mutagen. 61:266-275, 2020. © 2019 Wiley Periodicals, Inc.

中文翻译：

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马兜铃酸Tg.RasH2小鼠致癌性研究中猪a，微核和彗星分析终点的评估

一项新开发的体内Pig-a基因突变测定法具有整合到基因毒性试验中的巨大潜力。为了获得更多应用Pig-a试验的证据，我们将该试验，外周血微核试验（MN-pb试验）和骨髓（MN-bm试验）以及彗星试验整合到了转基因RasH2小鼠中致癌性研究。连续4周，以5 mg / kg /天的剂量用强诱变的马兜铃酸I处理14只雄性RasH2小鼠和5只野生型（WT）小鼠。小鼠在5周内康复。在几个时间点收集外周血进行Pig-a分析，MN-pb试验和Comet试验，同时对小鼠进行安乐死后，收集骨髓和靶器官进行MN-bm试验和病理诊断。最后，在14只RasH2小鼠中，有13只在前胃部发生了鳞状细胞癌，而在WT小鼠中则没有癌变。在整个研究过程中，猪a突变频率（MFs）连续增加，比背景值高出约63倍。这些频率与肿瘤的发生率，大小和恶性程度有关。从第1天到第49天，微核网织红细胞增加，然后又回到背景水平。在MN-bm试验或Comet试验中均未观察到阳性反应。结果表明，与其他两个测试相比，Pig-a测定法持续有助于维持MF，归因于Pig-a突变的积累，提高了检测灵敏度，并显示出更好的致瘤性可预测性。环境。大声笑 诱变剂。2020年61：266-275。