Myoepithelial cell differentiation defects in ductal carcinoma in situ (DCIS)

描述（由申请人提供）：DCIS向浸润性癌的进展是乳腺肿瘤进展的一个鲜为人知的关键步骤。我们之前已经证明，在肿瘤进展过程中，所有细胞类型都会发生分子变化，并且在MCF10DCIS异种移植物中，肌上皮细胞的丢失会导致侵袭性肿瘤。我们已经鉴定了来自正常人类乳腺组织的假定的祖样和分化的肌上皮细胞的综合基因表达谱，并鉴定了可用于鉴定的标记物。根据我们的数据，我们假设祖细胞向肌上皮细胞的分化被来自肿瘤上皮细胞和构成微环境的细胞的信号逐渐抑制。因此，肌上皮细胞层逐渐丢失并最终消失，导致过渡到侵袭。我们提出三个具体目标来检验这些假设。目的1：确定DCIS中正常肌上皮细胞分化及其异常的分子决定因素。我们将从健康女性的正常乳腺组织和BRCA1突变携带者以及不同类型的DCIS中分离CD10+细胞亚群。每个细胞群的分子谱将使用全基因组方法进行表征，然后在单细胞水平上在更大的样本集中进行验证。目的2：确定DCIS中肌上皮分化异常是否与进展为侵袭性疾病的风险相关。我们将确定DCIS中肌上皮细胞分化调节因子的表达是否与侵袭性进展有关。目的3：测试调节信号通路是否参与。在肌上皮细胞分化将影响进展到侵袭。使用原代细胞培养模型，我们将确定肌上皮细胞分化调节因子的扰动是否会导致肌上皮细胞的损失和侵袭的进展。确定DCIS中正常肌上皮细胞分化及其异常的决定因素将提高我们对干细胞分化的理解，并为治疗和预防干预提供新的预后标志物和靶点。

DESCRIPTION (provided by applicant): The progression of DCIS to invasive carcinoma is a poorly understood key step in breast tumor progression. We have previously demonstrated that molecular changes occur in all cell types during tumor progression and that the loss of myoepithelial cells leads to invasive tumors in MCF10DCIS xenografts. We have characterized the comprehensive gene expression profiles of putative progenitor-like and differentiated myoepithelial cells from normal human breast tissue and identified markers that can be used for their identification. Based on our data we hypothesize that the differentiation of progenitors to myoepithelial cells is progressively inhibited by signals coming from tumor epithelial cells and cells composing the microenvironment. As a consequence of this, the myoepithelial cell layer is gradually lost and eventually disappears, leading to transition to Invasion. We propose three specific aims to test these hypotheses. Aim 1: To identify molecular determinants of normal myoepithelial cell differentiation and their abnormalities in DCIS. We will isolate CD10+ subpopulations of cells from normal breast tissue of healthy women and BRCA1 mutation carriers, and from different subtypes of DCIS. Molecular profiles of each of the cell populations will be characterized using genome-wide approaches followed by validation in a larger set of samples at the single cell level. Aim 2: To determine if abnormalities of myoepithelial differentiation in DCIS correlate with the risk of progression to invasive disease. We will determine if the expression of regulators of myoepithelial cell differentiation in DCIS is associated with invasive progression. Aim 3: To test if modulating signaling pathways involved.in myoepithelial cell differentiation would effect progression to invasion. Using primary cell culture models, we will determine if perturbations of regulators of myoepithelial cell differentiation lead to loss of myoepithelial cells and progression to invasion. Identification of determinants of normal myoepithelial cell differentiation and their abnormalities in DCIS would improve our understanding of stem cell differentiation and provide novel prognostic markers and targets for therapeutic and preventative interventions.