Understanding the impact of chemotherapy on breast cancer metastasis and immune function in the liver

项目摘要 尽管接受了新辅助化疗，但30%-40%的早期三联症患者被诊断为 阴性乳腺癌(TNBC)发生转移并死于癌症。TNBC标准治疗的一部分 包括蒽环素-环磷酰胺和紫杉烷(AC-T)化疗、放射和手术。 针对T细胞抑制受体的联合化疗和免疫检查点抑制剂(ICI)现在正在 FDA批准用于早期和转移性TNBC。尽管试验结果很有希望，但大多数转移性癌症患者 TNBC没有持久的长期益处，特别是那些肿瘤在既往进展中的患者 化疗。尽管增殖的癌细胞是预期的目标，但全身化疗显然 影响其他器官系统。这包括对免疫系统的有害影响，如消除 细胞毒T细胞。因此，如果化疗损害了抗肿瘤免疫细胞，就会限制ICI的疗效。一位少校 该领域面临的挑战是，我们不知道化疗是如何影响免疫功能或肿瘤细胞的 适应转移的微环境。在我们的TNBC小鼠模型中，AC-T化疗减少了原发肿瘤 肿瘤生长和肺转移。令人惊讶的是，肝转移，这是TNBC的主要转移部位 患者，在AC-T处理的小鼠中显著增强。我们还观察到免疫抑制的标记物 在我们的小鼠模型和临床样本中，化疗后的肝脏中都有。我们假设肝脏是 化疗特别是免疫抑制，从而使肝脏更容易发生TNBC转移 和降低ICI的疗效。我们的目标是了解化疗如何影响肝脏免疫。 微环境和TNBC肝转移，并确定预防肝脏转移的临床前策略 免疫抑制和转移。 我们将使用我们的TNBC肺转移模型和我们的高灵敏分子条形码方法 转移检测。我们将识别生长在转移部位的肿瘤细胞克隆，以及克隆成分 对化疗治疗反应的变化。我们还将确定这些克隆是否固有地 对化疗敏感/耐药或对化疗的反应取决于转移 微环境。我们将对原发肿瘤和肝脏进行高维免疫图谱分析 使用单细胞多组学方法对无肿瘤和带瘤小鼠进行化疗。我们会 在小鼠模型中评估来自转移部位的细胞的免疫功能。我们将验证我们的发现 通过对从转移部位采集的患者活检样本进行多重免疫荧光染色。我们将确定 治疗方案以肿瘤细胞为靶点，同时保护抗肿瘤免疫细胞。我们建议的研究将 加深我们对化疗的全身影响的理解，不仅是对扩散的乳腺癌细胞 对各种器官，也对这些器官中的免疫细胞。在我们的调查中取得成功将会发现新的 对乳腺癌有效但不会减少关键免疫细胞的治疗方法。

Project Summary Despite treatment with neoadjuvant chemotherapy, 30-40% of patients diagnosed with early-stage triple- negative breast cancer (TNBC) develop metastasis and die of their cancer. Part of standard treatment for TNBC includes anthracycline-cyclophosphamide and taxane-based (AC-T) chemotherapy, radiation, and surgery. Combination chemotherapy with immune checkpoint inhibitors (ICI) that target T-cell inhibitory receptors are now FDA-approved for early stage and metastatic TNBC. Despite promising trial results, most patients with metastatic TNBC do not experience durable long-lasting benefits, particularly those whose tumors progressed on prior chemotherapy. Although proliferating cancer cells are the intended targets, systemic chemotherapy clearly impacts other organ systems. This includes detrimental effects on the immune system, such as elimination of cytotoxic T cells. Thus, if chemotherapy impairs anti-tumor immune cells, it would limit ICI efficacy. A major challenge to the field is that we do not understand how chemotherapy impacts immune function or tumor cell fitness in metastatic microenvironments. In our TNBC mouse models, AC-T chemotherapy reduced primary tumor growth and lung metastasis. Surprisingly, liver metastasis, which is a predominant metastatic site in TNBC patients, was significantly enhanced in the AC-T-treated mice. We also observed markers of immunosuppression in the liver after chemotherapy in both our mouse models and clinical samples. We hypothesize that the liver is specifically immunosuppressed by chemotherapy, thus making the liver more hospitable for TNBC metastasis and reducing ICI efficacy. Our objective is to understand how chemotherapy impacts the liver immune microenvironment and TNBC liver metastasis, and to identify pre-clinical strategies that prevent liver immunosuppression and metastasis. We will use our TNBC lung metastasis models and our highly sensitive molecular barcoding method for metastasis detection. We will identify tumor cell clones that grow in metastatic sites and if the clonal composition changes in response to chemotherapy treatment. We will also determine whether those clones are inherently sensitive/resistant to chemotherapy or if their response to chemotherapy relies on the metastatic microenvironment. We will perform high dimensional immune-profiling of primary tumors and liver from chemotherapy-treated tumor-free and tumor-bearing mice using single cell multi-omic approaches. We will assess immune function of cells derived from metastatic sites in the mouse models. We will validate our findings by multiplex immunofluorescence staining on patient biopsy samples taken from metastatic sites. We will identify treatment regimens that target tumor cells while protecting anti-tumor immune cells. Our proposed studies will deepen our understanding of the systemic effects of chemotherapy, not only on breast cancer cells that spread to various organs but also on immune cells in those organs. Success in our line of investigation will identify new treatment approaches that are effective against breast cancer but do not diminish critical immune cells.