BREAST CANCER MOLECULAR CYTOGENETICS

这个项目的目的是描述目前存在的细胞遗传学变化 间期乳腺肿瘤细胞。细胞遗传学分析带来了更好的 了解肿瘤DNA中的分子缺陷，是一种独立的 肿瘤行为的预后标志，并将有助于精确定位染色体 需要进一步分子分析的特别感兴趣的区域。该实用程序 通过分析中期染色体对经典细胞遗传学的影响 由于难以准备足够的肿瘤，因此仅限于实体肿瘤 活检组织中的中期细胞。肿瘤细胞短期后的分析 培养是有选择性的二倍体细胞，能够在 限制培养条件。 间期肿瘤的细胞遗传学分析技术现已成熟 逐个单元格的单元格。染色体拷贝数和主要结构 将使用荧光原位杂交检测到像差 染色体特异的DNA探针。每条染色体的拷贝数为 使用染色体特异的着丝粒周围重复探针进行检测 1、7、11、133、16和17。这些染色体是根据 他们可能与DNA异常有关。探测库特定于 排列在整个染色体上的低拷贝数序列将被用于 “涂抹”这些染色体以检测易位或复制 主要染色体区域。作为进一步的针对染色体的探针 感兴趣的子区域由我们的合作者开发，它们将是 用于检测小分子的扩增、缺失和移位 地区。类似的技术将被用来描述在多大程度上 细胞遗传学定义的肿瘤细胞亚群具有增殖性 比其他亚群更有优势。细胞增殖状态将是 溴脱氧尿苷的免疫荧光特性测定 在进行细胞遗传学鉴定的同时掺入 荧光原位杂交。两色和三色分析将 允许比较由染色体定义的群体之间的增殖 拷贝数或易位的存在。 肿瘤中染色体异常的异质性程度可以是 用具有染色体特异性的荧光原位杂交进行定义 探测器。细胞遗传异质性与遗传不稳定性和 从而促进肿瘤的发生发展。染色体的分布 将使用组织中的原位杂交来确定异常 切片，并将其与肿瘤的结构和 DNA含量和抗原标志物的分布。在计划内 该项目中，细胞遗传学信息将与肿瘤病理相关联， 临床随访及相关分子研究。

The aim of this project is to characterize cytogenetic changes present in interphase breast tumor cells. Cytogenetic analysis leads to a better understanding of molecular defects in tumor DNA, is an independent prognostic marker for tumor behavior, and will help to pinpoint chromosome regions of particular interest for further molecular analysis. The utility of classical cytogenetics by analysis of metaphase chromosomes has been limited in solid tumors due to the difficulty in preparing adequate tumor metaphases from biopsy tissue. Analysis of tumor cells after short term culture is selective for diploid cells capable of proliferating in restricted culture conditions. Techniques are now available for cytogenetic analysis of interphase tumor cells on a cell by cell basis. Chromosome copy number and major structural aberrations will be detected using fluorescence in situ hybridization with chromosome-specific DNA probes. Copy number of each chromosome will be detected using peri-centromeric repetitive probes specific for chromosomes 1, 7, 11, 133, 16, and 17. These chromosomes have been chosen based on their likely involvement in DNA aberrations. Probe libraries specific for low copy number sequences lining the entire chromosome will be used to "paint" these chromosomes in order to detect translocations or duplications of major chromosome regions. As further probes specific for chromosomal subregions of interest are developed by our collaborators, they will be used to detect amplifications, deletions, and translocations of smaller regions. Similar techniques will be used to characterize to what extent cytogenetically defined subpopulations of tumor cells have proliferative advantage over other subpopulations. Cell proliferative status will be determined by immunofluorescent characterization of bromodeoxyuridine incorporation simultaneously with cytogenetic characterization by fluorescence in situ hybridization. Two and three color analysis will allow comparison of proliferation between populations defined by chromosome copy number or the presence of translocations. The degree of heterogeneity of chromosome abnormalities in tumors can be defined using fluorescence in situ hybridization with chromosome specific probes. Cytogenetic heterogeneity is related to genetic instability and thus to tumor development and progression. The distribution of chromosome abnormalities will be determined using in situ hybridization in tissue sections, and will be compared to tumor architecture and to the distribution of DNA content and antigenic markers. Within the Program Project, cytogenetic information will be correlated with tumor pathology, clinical followup, and related molecular studies.