Project 2: Investigating cell intrinsic and extrinsic drivers of prostate cancer bone metastasis

项目总结/摘要 我们的研究目的是阐明肿瘤细胞的内在和外在机制， 骨转移和特定的骨向性。我们研究的基础是NPKYPF小鼠模型， 发展高度渗透的骨转移，其在人前列腺中的骨转移中保存良好 癌对这些小鼠的分析使得能够研究癌症期间骨转移的演变 在雄激素完整和雄激素剥夺的情况下，在天然微环境中的进展。我们发现 MYC和RAS信号传导的共激活对于骨转移是必需的，并且MYC激活是 特别是在雄激素剥夺的情况下。我们的初步研究已经确定ATAD 2是一种 MYC-辅因子在骨转移中表达，特别是在雄激素剥夺的情况下， 骨转移所必需的。在基于人类的互补全基因组体内CRISPR筛选中， 在前列腺癌异种移植物中，我们鉴定了CITED 2，另一种MYC辅因子，作为骨形成的细胞内在驱动因子。 转移，其足以促进体内骨转移。此外，原代细胞的单细胞测序 NPKYPF小鼠的肿瘤和骨转移导致鉴定主调节因子（MR）， 骨转移的候选细胞内在驱动因素，而非肿瘤成分的分析表明， 来自转移性NPKYPF小鼠的原发性肿瘤缺乏大多数免疫细胞群，但高度富集 肿瘤相关的巨噬细胞。 因此，我们将研究骨转移代表细胞内在的 转移骨微环境中的转移细胞驱动因子和肿瘤细胞外源性因子。在 目的1，我们将研究CITED 2与MYC合作促进骨特异性的假设。在 同时，我们将研究与RAS通路激活相关的候选主调节因子（MR）， 阐明它们在骨转移中的潜在作用。在目标2中，我们将研究ATAD 2是一种 雄激素剥夺背景下MYC的辅助因子，并阐明雄激素状态与MYC的关系。 骨转移的演变和潜在机制。在目标3中，我们将研究细胞外在机制 在原发性肿瘤和转移性骨的微环境中，以鉴定相关的细胞群， 与转移，以评估其对骨转移的功能作用，并确定骨的细胞外在驱动因素， 转移 整合：我们的研究与肿瘤微环境的研究高度互补， 神经内分泌分化（项目3）和肿瘤进展（项目1）。候选监管机构的验证 人类骨转移需要核心A。此外，我们的系统分析骨转移在单一的 细胞水平，补充项目1和3的努力，而我们从这些数据中互利的能力将是 由核心B的数据管理组件启用。

Project Summary/Abstract The objective of our research is to elucidate tumor cell intrinsic and extrinsic mechanisms that give rise to bone metastasis and specify bone tropism. The foundation for our studies is the NPKYPF mouse model, which develops highly penetrant bone metastasis that is well-conserved with bone metastasis in human prostate cancer. Analyses of these mice enable investigations of the evolution of bone metastases during cancer progression in the native microenvironment in androgen-intact and androgen-deprived contexts. We have found that co-activation of MYC and RAS signaling is essential for bone metastasis, and that MYC activation is particularly relevant in contexts of androgen deprivation. Our preliminary studies have identified ATAD2 as a MYC-co-factor that is expressed in bone metastasis, particularly in contexts of androgen deprivation, and necessary for bone metastasis. In a complementary genome-wide in vivo CRISPR screening based on human prostate cancer xenografts, we identified CITED2, another MYC co-factor, as a cell-intrinsic driver of bone metastasis that it is sufficient to promote bone metastasis in vivo. Furthermore, single cell sequencing of primary tumors and bone metastases from NPKYPF mice has led to the identification master regulators (MRs) that are candidate cell intrinsic drivers of bone metastasis, while analyses of the non-tumor components have shown that primary tumors from metastatic NPKYPF mice are deficient for most immune cell populations, but highly enriched for tumor associated macrophages. Thus, we will investigate the hypothesis that bone metastasis represents the culmination of cell intrinsic drivers from the metastatic cells and tumor cell extrinsic factors in microenvironment of the metastatic bone. In Aim 1, we will investigate the hypothesis that CITED2 collaborates with MYC to promote bone specificity. In parallel, we will investigate candidate master regulators (MRs) associated with RAS pathway activation to elucidate their potential roles in bone metastasis. In Aim 2, we will investigate the hypothesis that ATAD2 is a co-factor for MYC in contexts of androgen deprivation, and elucidate the relationship of androgen status for the evolution and underlying mechanisms of bone metastasis. In Aim 3, we will investigate cell extrinsic mechanisms in the microenvironment of the primary tumor and metastatic bone, to identify relevant cell populations associated with metastasis, to evaluate their functional role for bone metastasis, and to identify cell extrinsic drivers of bone metastasis. Integration: Our studies are highly complementary to investigations of the tumor microenvironment for neuroendocrine differentiation (Project 3) and tumor progression (Project 1). Validation of candidate regulators for human bone metastasis will require Core A. Further, our systematic analysis of bone metastasis at the single cell level, complement efforts in Projects 1 and 3, while our ability to mutually benefit from these data will be enabled by the data management component of Core B.