Functional Analysis of Histologic Grade in Breast Cancer

描述（由申请人提供）：虽然抗肿瘤药物通常旨在控制细胞增殖，对治疗快速生长的肿瘤有效，但矛盾的是，许多原发性乳腺肿瘤生长缓慢，但不一定是惰性的。因此，基于生物学范式的新型分子靶点必须被确定以消除这类肿瘤。在显微镜下，生长缓慢、分化良好至中度的肿瘤可以很容易地与生长迅速、分化较差的肿瘤区分开来，并被划分为不同的组织学分级。然而，这种差异的“组织遗传进化”仍然难以捉摸。我们建议采用一种新的方法来验证以下假设：组织学分级是肿瘤进展过程中“初始”乳腺上皮细胞的整体遗传变化和随后与周围基质的“串扰”的综合表现。支持该模型的分子路线图可以帮助靶向所有组织学级别的肿瘤。实现这一目标的一个主要困难是缺乏用于实验操作的细胞模型，这反映了乳腺癌生物学异质性的广度。在我们之前的研究中，我们设计并实施了从癌性乳腺组织中建立一个完整的活上皮和间质培养资源的策略。在这里，我们将使用这个独特的资源来：利用cDNA微阵列测定匹配肿瘤来源细胞亚群中年级特异性基因表达。2. 模拟这些亚群之间的生物相互作用，以研究旁分泌对增殖、分化和抗肿瘤药物反应的调节。3. 通过外源性转导和沉默方法分析代表性细胞培养中年级特异性基因的功能。4. 评估肿瘤和相邻非恶性组织中等级特异性基因表达的时间获取。这些研究的完成将有助于我们更好地了解导致具有不同程度组织学和功能侵袭性的原发性乳腺肿瘤的细胞亚群内部和之间的分子信号传导。

DESCRIPTION (provided by applicant): While anti-tumor drugs, generally aimed at controlling cell proliferation, are effective in treating fast growing tumors, paradoxically many primary breast tumors are slow growing but not necessarily indolent. Thus, novel molecular targets based on biological paradigms must be identified towards the elimination of such tumors. At the microscopic level, slow growing, well to moderately differentiated tumors can be readily distinguished from fast growing, poorly differentiated tumors and are assigned different histologic grades. However, the 'histogenetic evolution' of such differences remains elusive. We propose to use a novel approach to test the hypothesis that histologic grade is the combined manifestation of global genetic changes in the 'initiated' breast epithelial cells and the ensuing 'cross talk' with the surrounding stroma during tumor progression. A molecular road map supporting this model could assist in targeting tumors of all histologic grades. A major difficulty in the pursuit of this goal is the lack of cellular models for experimental manipulation, which reflect the breadth of biological heterogeneity in breast cancer. In our previous research, we designed and implemented strategies for establishing a comprehensive resource of live epithelial and stromal cultures from cancerous breast tissue. Here, we will use this unique resource to: 1. determine grade-specific gene expression in matched tumor-derived cellular subsets, using cDNA microarrays. 2. simulate biological interactions between these subsets to study paracrine regulation of proliferation, differentiation, and response to anti-tumor agents. 3. analyze grade-specific gene function in representative cell cultures by exogenous transduction and silencing approaches. 4. evaluate temporal acquisition of grade-specific gene expression within the tumor and contiguous blocks of adjacent non-malignant tissue. Completion of these studies will lead to an improved understanding of molecular signaling within and between cellular subsets resulting in primary breast tumors with varying degrees of histological and functional aggressiveness.