Parrish A R, Fisher R, Bral C M, Burghardt R C, Gandolfi A J, Brendel K, Ramos K S
Faculty of Toxicology, College of Veterinary Medicine, Texas A&M University, College Station, USA.
Toxicol Appl Pharmacol. 1998 Oct;152(2):302-8. doi: 10.1006/taap.1998.8525.
Benzo(a)pyrene (BaP) and related aromatic hydrocarbons are suspected carcinogens; however, the molecular basis underlying tumorigenesis remains unclear. To identify acute molecular targets of BaP within the liver and kidney, precision-cut slices harvested from naive, adult female Sprague-Dawley rats were challenged with BaP (0.3-30 microM) for 0.5 to 24 h. BaP did not elicit cytotoxicity, as assessed by intracellular K+ and ATP content and histological evaluation over the 24-h period. To determine if molecular signaling pathways were maintained in precision-cut slices, induction of the aryl hydrocarbon receptor (AhR) pathway was assessed following BaP challenge. Induction of cytochrome P450IA1 (P450IA1) mRNA and protein expression was observed in both liver and kidney slices. c-fos and c-Ha-ras gene expression was enhanced in liver, but not kidney, slices by BaP. c-jun mRNA levels were decreased in liver and kidney slices, although the effect was earlier (0.5 h) in liver slices compared to kidney slices. BaP increased the DNA binding of nuclear proteins to the AP-1 consensus recognition element in liver, but decreased DNA binding in kidney slices. In contrast, DNA binding of NF-kappa B was not affected by BaP in either liver or kidney slices. These results suggest that acute BaP challenge is associated with altered expression of several growth-related genes and AP-1 signaling and establish precision-cut slices as a useful in vitro system to investigate the molecular basis of BaP-induced tumorigenesis, including organ-specific differences.
苯并(a)芘（BaP）及相关芳烃被怀疑具有致癌性；然而，肿瘤发生的分子基础仍不清楚。为了确定BaP在肝脏和肾脏中的急性分子靶点，从未接触过BaP的成年雌性Sprague-Dawley大鼠获取的精密切片用BaP（0.3 - 30 microM）处理0.5至24小时。通过细胞内K+和ATP含量以及24小时内的组织学评估发现，BaP未引发细胞毒性。为了确定精密切片中分子信号通路是否保持完整，在BaP处理后评估芳烃受体（AhR）通路的诱导情况。在肝脏和肾脏切片中均观察到细胞色素P450IA1（P450IA1）mRNA和蛋白表达的诱导。BaP增强了肝脏切片中c-fos和c-Ha-ras基因的表达，但在肾脏切片中未增强。c-jun mRNA水平在肝脏和肾脏切片中均降低，尽管肝脏切片中的效应比肾脏切片更早（0.5小时）出现。BaP增加了肝脏中核蛋白与AP-1共有识别元件的DNA结合，但降低了肾脏切片中的DNA结合。相比之下，BaP对肝脏或肾脏切片中NF-κB的DNA结合均无影响。这些结果表明，急性BaP处理与几个生长相关基因的表达改变和AP-1信号传导有关，并确立了精密切片作为一种有用的体外系统，用于研究BaP诱导肿瘤发生的分子基础，包括器官特异性差异。
