Functional Analysis of Histologic Grade in Breast Cancer

描述(申请人提供)：虽然通常旨在控制细胞增殖的抗肿瘤药物在治疗快速生长的肿瘤方面是有效的，但矛盾的是，许多原发乳腺肿瘤生长缓慢，但不一定是惰性的。因此，必须确定基于生物学范式的新的分子靶点，以消除此类肿瘤。在显微镜水平上，生长缓慢、分化良好到中等分化的肿瘤可以很容易地与生长迅速、分化较低的肿瘤区分开来，并被分配不同的组织学级别。然而，这种差异的“组织发生进化”仍然难以捉摸。我们建议使用一种新的方法来检验这一假设，即组织学分级是在肿瘤进展过程中“启动”的乳腺上皮细胞中的全局遗传变化以及随之而来的与周围间质的“串扰”的综合表现。支持这一模型的分子路线图可以帮助靶向所有组织学级别的肿瘤。追求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，这些模型反映了乳腺癌生物异质性的广度。在我们之前的研究中，我们设计和实施了从乳腺癌组织中建立活体上皮和间质培养的全面资源的策略。在这里，我们将利用这一独特的资源：1.利用cDNA微阵列，确定匹配的肿瘤细胞亚群中特定级别的基因表达。2.模拟这些亚群之间的生物相互作用，研究旁分泌对增殖、分化和抗肿瘤药物反应的调节。3.通过外源转导和沉默的方法分析典型细胞培养中特定级别的基因功能。4.评估肿瘤和邻近非恶性组织块中特定级别基因表达的时间性获取。这些研究的完成将导致对细胞亚群内和细胞亚群之间分子信号的更好理解，从而导致具有不同程度的组织学和功能侵袭性的原发性乳腺肿瘤。

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.