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中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，所有类型的细胞都会发生分子变化，肌上皮细胞的丢失会导致MCF10DCIS异种移植瘤的侵袭性肿瘤。我们已经确定了正常人类乳腺组织中可能的祖细胞样细胞和分化的肌上皮细胞的全面基因表达谱，并确定了可以用于鉴定它们的标记。根据我们的数据，我们假设祖细胞向肌上皮细胞的分化受到来自肿瘤上皮细胞和构成微环境的细胞的信号的逐渐抑制。其结果是，肌上皮细胞层逐渐丢失并最终消失，导致向侵袭过渡。我们提出了三个具体目标来检验这些假说。目的1：鉴定DCIS肌上皮细胞正常分化及其异常的分子决定因素。我们将从健康女性和BRCA1突变携带者的正常乳腺组织以及不同亚型的DCIS中分离CD10+细胞亚群。每个细胞群体的分子图谱将使用基因组范围的方法进行表征，然后在单细胞水平上对更大的样本集进行验证。目的2：确定DCIS中肌上皮细胞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：检测调控肌上皮细胞分化的信号通路是否会影响侵袭性进展。利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丧失和进展为侵袭。识别DCIS中正常肌上皮细胞分化的决定因素及其异常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.