Cole K E, Jones T W, Lipsky M M, Trump B F, Hsu I C
Department of Pathology, University of Maryland, School of Medicine, Baltimore.
Carcinogenesis. 1989 Jan;10(1):139-43. doi: 10.1093/carcin/10.1.139.
Ultrastructural changes commonly observed in liver cells of rodents exposed to carcinogens in vivo can be induced in hepatocytes exposed to carcinogens in vitro. Human, rat and mouse hepatocytes in primary culture were treated with actinomycin D, aflatoxin B1 (AFB1) and dimethylnitrosamine (DMN). These cultured hepatocytes were examined for ultrastructural alterations following carcinogen exposure for 24 h. Similar to the effects on liver cells in vivo, the most prominent change was a segregation of the nucleolar components. Human, rat and mouse hepatocytes, dosed with 7.9 X 10(-8) M actinomycin D, developed nucleolar segregation in 86%, 98% and 55% of cells, respectively. When incubated with 3.2 X 10(-6) M AFB1, 60% of human and 84% of rat hepatocytes developed nucleolar segregation. However, exposures of mouse hepatocytes less than or equal to 3.2 X 10(-5) M of AFB1 failed to induce segregation of the nucleolus. DMN administered at a dose of 2.0 X 10(-2) M caused segregation in 11% of the rat hepatocytes and in 60% of the mouse hepatocytes. Distinct nucleolar segregation did not occur in human hepatocytes until they were exposed to a concentration of 5.0 X 10(-2) M DMN (31%). Actinomycin D, AFB1, DMN, as well as other compounds that bind to DNA and interfere with template activity cause nucleolar segregation. Morphologic changes observed in cultured rat and mouse hepatocytes correlate well with in vivo experiments with regard to the relative sensitivity of rats and mice to toxicological effects of these carcinogens. Thus, hepatocyte cultures may provide a realistic system to determine the sensitivity of human liver cells to carcinogens.
在体内接触致癌物的啮齿动物肝细胞中常见的超微结构变化，也可在体外接触致癌物的肝细胞中诱导产生。对原代培养的人、大鼠和小鼠肝细胞用放线菌素D、黄曲霉毒素B1（AFB1）和二甲基亚硝胺（DMN）进行处理。在致癌物暴露24小时后，对这些培养的肝细胞进行超微结构改变检查。与对体内肝细胞的影响相似，最显著的变化是核仁成分的分离。用7.9×10⁻⁸M放线菌素D处理的人、大鼠和小鼠肝细胞，分别有86%、98%和55%的细胞出现核仁分离。当与3.2×10⁻⁶M AFB1一起孵育时，60%的人肝细胞和84%的大鼠肝细胞出现核仁分离。然而，小鼠肝细胞暴露于小于或等于3.2×10⁻⁵M的AFB1时，未能诱导核仁分离。以2.0×10⁻²M的剂量给予DMN，导致11%的大鼠肝细胞和60%的小鼠肝细胞出现分离。人肝细胞直到暴露于5.0×10⁻²M DMN（31%）的浓度时才出现明显的核仁分离。放线菌素D、AFB1、DMN以及其他与DNA结合并干扰模板活性的化合物会导致核仁分离。在培养的大鼠和小鼠肝细胞中观察到的形态学变化，在大鼠和小鼠对这些致癌物毒理学效应的相对敏感性方面与体内实验密切相关。因此，肝细胞培养可能提供一个现实的系统来确定人肝细胞对致癌物的敏感性。
