N-methyl-N-nitrosourea induces dysplasia and cell surface markers of neoplasia in long-term rat bladder organ cultures.
N-methyl-N-nitrosourea induces dysplasia and cell surface markers of neoplasia in long-term rat bladder organ cultures.
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N-甲基-N-亚硝基脲在长期大鼠膀胱器官培养物中诱导发育不良和肿瘤形成的细胞表面标志物。
DOI：
10.1093/carcin/6.7.1047
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发表时间：
1985
期刊：
影响因子：
4.7
通讯作者：
R. Berry
中科院分区：
文献类型：
--
作者：
M. Knowles;H. Jani;R. M. Hicks;R. Berry
未经处理的正常大鼠膀胱器官培养可在添加Wayoss‘s的MB 752/1培养液中保持较长时间，长达160天。在此期间，尿路上皮保持与体内看到的相似的外观，即具有特殊表面细胞的三细胞厚上皮，其特征表面特征可通过扫描电子显微镜识别。这些表面细胞覆盖了外植体的大部分，但在外植体的切缘和重新上皮化的表面上可以观察到基细胞和中间细胞的表面特征。这些都有描述和插图。用直接作用的致癌物N-甲基-N-亚硝脲(MNU)处理正常培养物时，尿路上皮的体外反应在一定程度上类似于体内直接注入MNU的反应。组织学进展可见于轻度到重度异型增生，类似于原位癌。然而，生长模式没有明显的变化，如乳头状或结节状增生的发展。这可能与外植体的血管和基质成分对MNU处理的反应失败有关。尿路上皮异常增殖症的发展反映在细胞表面分化的显著变化，包括多形性微绒毛的发展，这与体内MNU治疗后看到的非常相似。这些变化在体外出现得更早，而且比体内严重得多。讨论了多形性微绒毛在膀胱培养中的意义。少数在对照培养中可见，但主要是在微孔滤器支架上的上皮突起上，这表明与尿路上皮距离可存活的基质支架的距离有关。在MNU处理的培养物中，它们大量存在于覆盖大部分外植体的细胞表面。在这些培养物中，它们不仅仅与尿路上皮的增殖状态有关。该体外培养系统为研究各种已知和可疑致癌物对尿路上皮细胞的影响提供了有用的模型。
Untreated organ cultures of normal rat bladder can be maintained for long periods, up to 160 days, in a supplemented Waymouth's medium MB 752/1. During that time, the urothelium retains a similar appearance to that seen in vivo, namely a three-cell thick epithelium with specialised superficial cells whose characteristic surface features are identifiable by scanning electron microscopy. These superficial cells cover the major part of the explants, but the surface features of basal and intermediate cells can be observed on the cut edges and re-epithelialising surfaces of the explant. These are described and illustrated. When normal cultures are treated with the direct-acting carcinogen, N-methyl-N-nitrosourea (MNU), the in vitro response of the urothelium resembles to a certain extent the in vivo response to MNU instilled directly into the bladder. A histological progression is seen through mild to severe dysplasia which resembles carcinoma in situ. However, no marked changes in growth pattern, such as the development of papillary or nodular hyperplasia are seen. It is suggested that this is related to the failure of the vascular and stromal elements of the explants to respond to MNU treatment in vitro. The development of urothelial dysplasia is reflected by marked changes in cell surface differentiation, including development of pleomorphic microvilli, which closely resemble those seen following MNU treatment in vivo. These changes appeared earlier and were far more severe in vitro than in vivo. The significance of pleomorphic microvilli in bladder cultures is considered. A few were seen in control cultures but primarily on epithelial outgrowths onto the Millipore filter support, suggesting a relationship to the distance of the urothelium from viable stromal support. In the MNU-treated cultures, they were numerous and found on the surface of cells covering most of the explants. They were not solely related to the proliferative state of the urothelium in these cultures. This in vitro culture system provides a useful model with which to study the effects on the urothelium of various known and suspect carcinogens.