Project 2: Functions of ARID1A in muscle invasive bladder cancer

项目摘要/摘要 尽管染色质重塑基因ARID1A在~27%的肌肉侵袭性膀胱中发生突变 癌症(MIBC)的功能后果尚未得到广泛研究。我们建议调查 基于细胞模型的ARID1A在膀胱癌发病机制和治疗反应中的作用 患者衍生的有机化合物，以及我们已经产生和 以与本计划项目的同事合作为特点。我们的研究是基于重要的 初步数据显示ARID1A在人膀胱癌细胞中也具有肿瘤抑制功能 就像老鼠模型一样。特别是，ARID1A在膀胱癌GEMM中的功能丧失加速 肿瘤的发生，部分是通过激活PI-3激酶信号。此外，我们还产生了人类 患者来源的膀胱癌有机类化合物，具有人类膀胱癌中存在的ARID1A突变，以及 已经表明这些有机化合物在细胞培养中降低了对化疗的反应。最后，使用细胞- 在模型的基础上，我们已经表明ARID1A与SWI/SNF染色质复合体的组件相互作用 是形成这些复合体所必需的，为分子生物学研究奠定了基础。 ARID1A在膀胱癌中的研究 我们现在将调查ARID1A缺乏促进膀胱癌发病的假说 通过改变染色质结构和全局基因表达，从而影响治疗反应。在目标1中，我们 我将研究ARID1A在膀胱肿瘤发生中的作用，以及它与其他相关组织的合作 表观遗传调节器和肿瘤抑制因子，通过研究其在GEMM中失去功能的后果， 以及在以人类膀胱癌细胞为基础的模型中。我们将通过对人类的分析来加强这些研究 患者衍生的含有ARID1A突变的有机化合物。在目标2中，我们将执行共同临床分析以 研究ARID1A失活对化疗反应的后果，并测试是否 通过将化疗与靶向药物或免疫治疗相结合，可以改善疗效。在目标3中，我们 将通过以下方式研究ARID1A缺乏促进膀胱癌的分子机制 膀胱癌细胞生化分析及ARID1a缺乏症的研究 基因表达和染色质结构，这将指导基于机制的翻译努力。 整合：我们建议的研究与项目1有很强的互补性，项目1的重点是 表观遗传调节因子KDM6A和项目3，该项目将研究患者来源膀胱对顺铂的耐药性 抗癌有机化合物。此外，该项目的成功将需要核心A的投入，它将提供 人类肿瘤与分子研究结果的相关性，并将确定ARID1A突变出现的时间 在膀胱癌中；核心B，将有助于产生人类有机体和GEMM；以及核心C， 它将提供基本的生物信息和统计支持，以及方案整合。

Project Summary/Abstract Although the chromatin remodeling gene ARID1A is mutated in ~27% of muscle invasive bladder cancer (MIBC), the functional consequences have not been extensively studied. We propose to investigate the role of ARID1A in bladder cancer pathogenesis and treatment response using cell-based models, human patient-derived organoids, and genetically-engineered mouse models (GEMMs) that we have generated and characterized in collaboration with colleagues on this Program Project. Our studies are based on significant preliminary data showing that ARID1A has tumor suppressor functions in human bladder cancer cells as well as in mouse models. In particular, loss-of-function of Arid1a in a GEMM of bladder cancer accelerates tumorigenesis, in part through activation of PI-3 kinase signaling. Additionally, we have generated human patient-derived bladder cancer organoids that have ARID1A mutations as occur in human bladder cancer, and have shown that these organoids have reduced response to chemotherapy in cell culture. Lastly, using cell- based models, we have shown that ARID1A interacts with components of the SWI/SNF chromatin complexes in bladder cells and is necessary for formation of these complexes, providing a foundation for molecular investigations of ARID1A in bladder cancer contexts. We will now investigate the hypothesis that ARID1A deficiency promotes bladder cancer pathogenesis by altering chromatin structure and global gene expression, thereby affecting treatment response. In Aim 1, we will investigate the functions of ARID1A in bladder tumorigenesis, and its collaboration with other relevant epigenetic regulators and tumor suppressors, by studying the consequences of its loss-of-function in GEMMs, as well as in human bladder cancer cell-based models. We will augment these studies with analyses of human patient-derived organoids that harbor ARID1A mutations. In Aim 2, we will perform co-clinical analyses to investigate the consequences of ARID1A inactivation for response to chemotherapy, and to test whether such response can be improved by combining chemotherapy with targeted agents or immunotherapy. In Aim 3, we will study the molecular mechanisms by which ARID1A deficiency promotes bladder cancer, by performing biochemical analyses in bladder cancer cells and investigating the consequences of ARID1A deficiency for gene expression and chromatin structure, which will guide mechanism-based translational efforts. Integration: Our proposed studies are highly complementary with Project 1, which is focused on the epigenetic regulator KDM6A, and Project 3, which will study resistance to cisplatin in patient-derived bladder cancer organoids. Additionally, the success of this project will require input from Core A, which will provide human tumors for correlation of molecular findings and will define the timing at which ARID1A mutations arise in bladder cancer; Core B, which will assist with the generation of human organoid and GEMMs; and Core C, which will provide essential bioinformatic and statistical support, as well as program integration.