Glöckner S, Lehmann U, Wilke N, Kleeberger W, Länger F, Kreipe H
Institute of Pathology, Medizinische Hochschule Hannover, Germany.
Pathobiology. 2000;68(4-5):173-9. doi: 10.1159/000055920.
Gene amplification is one essential mechanism leading to oncogene activation which is supposed to play a major role in the pathogenesis of invasive breast cancer. However, using standard methodologies the detection of gene amplifications has been limited especially in small-sized lesions, like pre-invasive precursor lesions. The combination of two novel technologies, laser-based microdissection and quantitative real-time PCR, facilitates the detection of low-level amplifications in morphologically defined lesions. As a model system we investigated in situ breast cancer (ductal carcinoma in situ, DCIS) classified according to the morphology-based Van Nuys grading system for amplification of growth-regulatory genes. In this study 83 formalin-fixed, paraffin-embedded archival DCIS specimens were examined after laser-based microdissection by quantitative real-time PCR using the TaqMan detection system for amplification of the c-erbB2, topoisomerase IIalpha, c-myc and cyclinD1 gene. In a subset of 17 DCIS with adjacent infiltrating tumour components we compared intraductal and invasive tumour components in parallel for differences in amplification status. The combination of these new techniques represents an excellent tool to gain new insights into carcinogenesis by analyzing genetic alterations in morphologically identified heterogeneous lesions in breast cancer progression within the very same specimen or even tissue slide.
基因扩增是导致癌基因激活的一种重要机制，被认为在浸润性乳腺癌的发病机制中起主要作用。然而，使用标准方法检测基因扩增一直受到限制，尤其是在小尺寸病变中，如浸润前的前驱病变。激光显微切割和定量实时PCR这两种新技术的结合，有助于在形态学明确的病变中检测低水平扩增。作为一个模型系统，我们研究了根据基于形态学的Van Nuys分级系统分类的原位乳腺癌（导管原位癌，DCIS）中生长调节基因的扩增情况。在本研究中，使用TaqMan检测系统对83个福尔马林固定、石蜡包埋的存档DCIS标本进行激光显微切割后，通过定量实时PCR检测c-erbB2、拓扑异构酶IIα、c-myc和细胞周期蛋白D1基因的扩增。在17个伴有相邻浸润性肿瘤成分的DCIS子集中，我们平行比较了导管内和浸润性肿瘤成分的扩增状态差异。这些新技术的结合是一种极好的工具，通过分析同一标本甚至组织切片中乳腺癌进展过程中形态学确定的异质性病变中的基因改变，来深入了解致癌作用。
