A premalignant chronology of cell-state variability in basal-like breast cancer

项目概要/摘要 基底细胞样癌是一种进展迅速且高度变异的乳腺癌亚型， 自发（通常在非洲裔美国人中）或遗传易感的女性中。这种肿瘤被认为是 由于未定向基底管腔中BRCA 1和TP 53肿瘤抑制因子的功能丧失， 乳房的祖细胞然而，由于缺乏足够的证据， 适当的工具，使得很难想象癌前突变体的细胞状态变异性如何使 上升为基底样乳腺癌。这项工作的长期目标是确定关键的细胞和分子 基底细胞样乳腺癌遗传学基础的转变。目前的应用程序部署了一种新的基因 工程小鼠模型称为双标记镶嵌分析（MADM），随机删除小鼠 Brca 1-Trp 53在乳腺的过渡扩增祖细胞。在MADM中，随机删除是 通过GFP的共表达进行遗传学定义，允许局部扩大的癌前病变被可视化 在基底细胞样疾病发作之前，我们发现癌前扩张伴随着 通过广泛募集特异性免疫亚群，表明它们在肿瘤发生中起着至关重要的作用。我们 目的是将联合收割机与无解离转录组学的创新方法相结合， 突变上皮细胞内的细胞状态变异性和癌前病变的浸润性免疫谱系。 假设上皮细胞可塑性和基质微环境协调地使突变体多样化 病变，揭示癌前转录状态，最终进展为乳腺基底样癌 和乳腺。该提案的目的是：1）定义共同的癌前轨迹， BRCA 1-TP 53缺陷在小鼠和人类中引发的基底管腔多样化。2)去卷积 与基底样乳腺癌的特定癌前生态系统局部配对的免疫异质性 癌3)通过使用遗传学、药理学和生物学方法， 使离体癌前细胞的内在或外在变异性均质化的旁分泌扰动。Co-PI Janes和Zong是各自肿瘤内细胞状态异质性领域的思想领袖， 基因工程小鼠建模与多年的合作记录。连同一对 高级临床医生，该团队准备对我们对基底细胞样的理解产生重大的整体影响。 乳腺肿瘤发生

PROJECT SUMMARY/ABSTRACT Basal-like carcinoma is a rapidly-progressing and highly variable subtype of breast cancer that arises spontaneously (often in African Americans) or in genetically predisposed women. Such tumors are believed to arise from the functional loss of the BRCA1 and TP53 tumor suppressors in uncommitted basoluminal progenitors of the breast. However, it has been challenging to dissect the origins of the disease for lack of appropriate tools, making it difficult to conceive of how the cell-state variability of premalignant mutants gives rise to basal-like breast cancer. The long-term goal of this work is to identify the critical cellular and molecular transitions underlying basal-like breast cancer genetics. The current application deploys a novel genetically engineered mouse model called mosaic analysis of double markers (MADM), which randomly deletes murine Brca1–Trp53 in transit-amplifying progenitors of the mammary gland. In MADM, stochastic deletion is genetically defined by coexpression of GFP, allowing locally expanded premalignant lesions to be visualized within the gland before the onset of basal-like disease. We found that premalignant expansion is accompanied by extensive recruitment of specific immune subsets, suggesting they play crucial roles in tumorigenesis. Our objective is to combine MADM with innovative methods for dissociation-free transcriptomics that will identify cell-state variabilities within mutant epithelial cells and the infiltrating immune lineages of a premalignancy. The hypothesis is that epithelial-cell plasticity and the stromal microenvironment coordinately diversify mutant lesions, revealing premalignant transcriptional states that ultimately progress to basal-like cancer in the breast and mammary gland. The aims of the proposal are: 1) To define shared premalignant trajectories of basoluminal diversification triggered by BRCA1–TP53 deficiency in mice and humans. 2) To deconvolve the immune heterogeneities that are locally paired with specific premalignant ecosystems for basal-like breast cancer. 3) To functionally validate cell states important for progression by using genetic, pharmacologic, and paracrine perturbations that homogenize intrinsic or extrinsic variability of premalignant cells ex vivo. Co-PIs Janes and Zong are thought leaders in their respective fields of intratumor cell-state heterogeneity and genetically engineered mouse modeling with a multi-year track record of collaboration. Together with a pair of senior clinicians, the team is poised to have a significant overall impact on our understanding of basal-like breast tumorigenesis.