Fathy L M, el-Hossary N M
Oral Pathology Department, Faculty of Oral and Dental Medicine, Cairo University.
Egypt Dent J. 1994 Jul;40(3):795-804.
The quantitative and qualitative changes of transcriptionally active nucleolar organizer regions (NORs) identified by silver staining (AgNORs) were observed in rat tongue lesions induced by 9-10 dimethyl 1-2 benzanthracene (DMBA). Epithelial hyperplasia, mild, moderate dysplasia and severe dysplasia (with or without invasive squamous cell carcinoma) were induced 4,6,8 & 10 weeks respectively after implantation of 5 mg DMBA in the submucosa of rat's tongues. A general trend towards an increase in the mean AgNOR counts with longer time and resultant histopathological findings was observed, where the lowest value (2.44 +/- 1.00) was found in specimens showing epithelial hyperplasia (4 weeks after DMBA implantation) and the highest value in those showing severe dysplasia with invasive squamous cell carcinoma (10 weeks after DMBA implantation). Clumping and irregularity of AgNOR dots were demonstrated in DMBA treated specimens and were found to increase with higher degrees of epithelia dysplasia. The dispersal of the AgNOR dots in the nucleoplasm indicating high cellular activity was characteristically evident in specimens showing severe dysplasia with invasive squamous cell carcinoma. Our results suggest that although AgNORs can be useful as a qualitative marker of cellular activity at the early stages of DMBA tongue carcinogenesis, counting the AgNOR dots cannot be relied upon in discriminating the different degrees of induced cellular changes.
在由9,10 - 二甲基 - 1,2 - 苯并蒽（DMBA）诱导的大鼠舌部病变中，观察了通过银染色鉴定的转录活性核仁组织区（AgNORs）的定量和定性变化。在大鼠舌黏膜下植入5mg DMBA后，分别在4、6、8和10周诱导出上皮增生、轻度、中度发育异常和重度发育异常（伴或不伴浸润性鳞状细胞癌）。观察到随着时间延长和组织病理学结果的出现，平均AgNOR计数有增加的总体趋势，其中在显示上皮增生的标本（DMBA植入后4周）中发现最低值（2.44±1.00），在显示重度发育异常伴浸润性鳞状细胞癌的标本（DMBA植入后10周）中发现最高值。在DMBA处理的标本中显示出AgNOR点的聚集和不规则性，并且发现随着上皮发育异常程度的增加而增加。在显示重度发育异常伴浸润性鳞状细胞癌的标本中，AgNOR点在核质中的分散表明细胞活性高，这一特征很明显。我们的结果表明，虽然AgNORs可作为DMBA舌癌发生早期细胞活性的定性标志物，但在区分不同程度的诱导细胞变化时，不能依赖于对AgNOR点的计数。
