Reprogramming the Tumor Microenvironment in Ovarian Cancer

项目总结 高级别浆液性卵巢癌(HGSOC)是妇科恶性肿瘤死亡的主要原因。 大多数患者手术后最初对化疗有反应，但约80%的患者会因病情恶化而复发 对治疗有抗药性。免疫疗法显示出巨大的前景，但对HGSOC的疗效有限。这个 HGSOC肿瘤微环境(TME)是高度免疫抑制的，这被认为是为了促进 肿瘤免疫逃避。我们已经开发出两种新的可移植的同基因小鼠卵巢肿瘤模型 将允许对驱动免疫逃避的肿瘤和宿主特异性信号进行分子分析。通过选择 为了在小鼠中积极生长，我们广泛地表征了KMF细胞(KRAS，Myc， 和FAK)，表现出许多与HGSOC相似的表型；固有的化学耐药和强大的免疫力 压制。我们将关注FAK(粘着斑激酶)，它是一种典型的支持酪氨酸激酶的细胞 运动性信号。FAK是HGSOC中扩增第五高的基因，超过65%的患者表现出 FAK信使核糖核酸水平升高，预后不良。使用药理上的FAK抑制剂，FAK基因敲除， 我们发现，在荷瘤小鼠中，KMF细胞的FAK重新表达、互补和生物信息学分析 FAK驱动一组选定的细胞因子和肿瘤相关表面蛋白的表达 在调节肿瘤生长和免疫逃避方面的作用。抑制FAK导致髓系来源减少 抑制细胞(MDSC)募集，增加了CD4和CD8T细胞的肿瘤侵袭，并降低了 PD-L1、CD112和CD155蛋白在KMF细胞中的体内表达这些变化 与肿瘤固有的FAK抑制对卵巢TME的正常化或重新编程是一致的 举止。在KMF模型中，抑制FAK还可以防止血性腹水的形成。第二个新开发的T 抗原驱动的FAK粘附性小鼠卵巢癌模型(MOVCAR)显示FAK缺失可预防肿瘤 同基因Low-T小鼠的生长。FAK缺失的MOVCAR肿瘤被CD45+白细胞渗透，以及何时 在免疫缺陷小鼠中进行评估，原位FAK缺失的MOVCAR肿瘤生长得到促进。这项建议 将检验这样的假设，即肿瘤固有的FAK激活促进免疫抑制相关的改变 TME。AIM-1将使用一种新的可诱导FAK表达系统来评估FAK核定位-以及 驱动恶性肿瘤、趋化因子表达和MDSC募集的依赖于激酶的信号。AIM-2将进行测试 CD112/CD155免疫检查点蛋白表达的作用及FAK抑制是否与 抗TIGIT(具有Ig和ITIM结构域的T细胞免疫受体)抗体通过对T细胞的作用来抑制肿瘤生长 细胞。AIM-3将使用可诱导的FAK、相关的Pyk2激酶(新模型)或可诱导的基因敲除 用Kmf移植瘤模型检测小鼠内皮细胞中激酶失活的FAK的表达 TME上的基质FAK和PYK2信号。这些小鼠研究，结合对患者肿瘤的分析，将 为FAK抑制在提高HGSOC免疫治疗疗效中的作用提供重要的见解。

PROJECT SUMMARY High-grade serous ovarian cancer (HGSOC) is the leading cause of death from gynecologic malignancies. Most patients initially respond to chemotherapy after surgery, yet ~80% will recur with disease that becomes resistant to treatment. Immune therapies have shown great promise, but with limited efficacy in HGSOC. The HGSOC tumor microenvironment (TME) is highly immuno-suppressive and this is hypothesized to promote tumor immune evasion. We have developed two new implantable syngeneic mouse ovarian tumor models that will allow for the molecular analysis of tumor- and host-specific signals driving immune evasion. By selecting for aggressive growth in mice, we have extensively characterized KMF cells (gains in genes for KRas, Myc, and FAK) that exhibit many phenotypic similarities to HGSOC; intrinsic chemo-resistance and potent immune suppression. We will focus on FAK (focal adhesion kinase), a tyrosine kinase canonically supporting cell motility signaling. FAK is the fifth highest amplified gene in HGSOC and greater than 65% of patients exhibit elevated FAK mRNA with poor prognostic significance. Using pharmacological FAK inhibitors, FAK knockout, FAK re-expression, complementation, and bioinformatic analyses of KMF cells in tumor-bearing mice, we find that FAK drives the expression of a select group of cytokines and tumor-associated surface proteins involved in regulating tumor growth and immune evasion. Inhibiting FAK results in decreased myeloid-derived suppressor cell (MDSC) recruitment, increased CD4 and CD8 T cell tumor infiltration, and decreased expression of PD-L1, CD112, and CD155 checkpoint regulatory proteins on KMF cells in vivo. These changes are consistent with a normalization or reprogramming of the ovarian TME by FAK inhibition in a tumor-intrinsic manner. FAK inhibition also prevents bloody ascites formation in the KMF model. A second newly-developed T antigen-driven FAK floxed mouse ovarian carcinoma model (MOVCAR) revealed that FAK loss prevents tumor growth in syngeneic low-T mice. FAK-null MOVCAR tumors were infiltrated by CD45+ leukocytes, and when evaluated in immune-deficient mice, orthotopic FAK-null MOVCAR tumor growth was enhanced. This proposal will test the hypothesis that tumor-intrinsic FAK activation facilitates immune-suppressive related changes to the TME. Aim-1 will use a new inducible FAK expression system to evaluate FAK nuclear localization- and kinase-dependent signals driving malignancy, chemokine expression, and MDSC recruitment. Aim-2 will test the role CD112/CD155 immune checkpoint protein expression and whether FAK inhibition may combine with antibodies to TIGIT (T cell immunoreceptor with Ig and ITIM domains) to limit tumor growth via effects on T cells. Aim-3 will use an inducible knockout of FAK, of the related Pyk2 kinase (new model), or inducible expression of kinase-inactive FAK in mouse endothelial cells, with the KMF implantable tumor model, to test stromal FAK and Pyk2 signaling on the TME. These mouse studies, with analyses of patient tumors, will provide important insights on the role of FAK inhibition to enhance immunotherapy efficacy for HGSOC.