Targeting CDK7 in CCNE1-amplified Ovarian Cancer

项目摘要。 高级别浆液性卵巢癌（HGS-OvCa）是卵巢癌中最恶性的形式。中 大多数侵袭性HGS-OvCa肿瘤是那些具有CCNE 1基因组扩增和过表达的肿瘤， 编码细胞周期蛋白E1的基因，细胞周期蛋白E1是一种关键的细胞周期调节因子。这种具有挑战性的HGS-OvCa子集携带不良的 标准细胞毒性化疗后的结果，并与高增殖率，快速 铂耐药性的发展，以及对聚ADP（核糖）聚合酶抑制剂的从头耐药性。尽管 尽管进行了大量的努力，但用于治疗CCNE 1扩增的HGS-OvCa的靶向治疗仍然难以捉摸，部分原因是， 药物分子靶点的缺乏。因此，仍然有一个迫切的未满足的医疗需求， 开发CCNE 1扩增的HGS-OvCa和其他CCNE 1标记的癌症的新疗法 过度表达有希望的临床前证据表明，敲低或抑制细胞周期蛋白依赖性 细胞周期蛋白E1的催化激酶配偶体CDK 2选择性杀伤CCNE 1扩增的卵巢癌细胞 线，突出显示与CCNE 1扩增相关的潜在依赖性。然而，努力直接 用药理学试剂靶向CDK 2一直受到难以实现对CDK 2特异性的困扰。 我们最近采用了一种选择性抑制CDK 7的替代策略，CDK 7是CDK 2的关键上游激活剂， 以实现选择性杀死CCNE 1扩增的卵巢癌细胞。在原理验证研究中，YKL-5-124，a 一种新的CDK 7抑制剂，其选择性上级现有的同类抑制剂，导致明显的肿瘤缩小 在CCNE 1扩增的HGS-OvCa的人异种移植小鼠模型中。拟议研究的主要目标 是通过阐明CCNE 1扩增的基本原理来扩展我们的初步发现， HGS-OvCa对CDK 7抑制的敏感性。这些知识将用于指导进一步的临床前研究。 在CCNE 1扩增的HGS-OvCa中靶向CDK 7的研究。在此，我们提出鉴定（1）HGS-OvCa 对YKL-5-124敏感的癌细胞和遗传背景;（2）与药物相关的生物标志物 （3）增强或扩大药物反应的联合策略（目标1）。而YKL-5-124 在小鼠中显示出有效的体内活性，我们将继续优化这些CDK 7抑制剂，以改善 药代动力学，以促进该化学系列的临床前开发（目的2）。最后，我们将评估 YKL-5-124（或进一步的体内优化的类似物）在CCNE 1扩增的和未扩增的HGS-1的小鼠模型中的表达。 OvCa（目标3）。为了实现这些目标，我们组建了一个多学科团队， 药物化学（NathanaelGray，斯坦福大学）;细胞和系统生物学（Caitlin米尔斯和PeterSorger， 哈佛医学院）;卵巢癌小鼠模型（Panagiotis Konstantinopoulos，DFCI）;和 转化和临床卵巢研究（Ursula Matulonis，DFCI）。这项研究描述了一种新的方法， 选择性靶向CCNE 1过表达的肿瘤，并确定新的小分子， 用于治疗CCNE 1扩增的HGS-OvCa的该策略的临床前评价。

Project Abstract. High-grade serous ovarian carcinoma (HGS-OvCa) is the most malignant form of ovarian cancer. Among the most aggressive HGS-OvCa tumors are those that harbor genomic amplification and overexpression of CCNE1, the gene that encodes for cyclin E1, a key cell cycle regulator. This challenging HGS-OvCa subset carries poor outcomes after standard cytotoxic chemotherapy, and is associated with high proliferative rate, rapid development of platinum resistance, and de novo resistance to poly ADP (ribose) polymerase inhibitors. Despite intense efforts, targeted therapies for the treatment of CCNE1-amplified HGS-OvCa remain elusive, in part, due to the paucity of druggable molecular targets. As such there remains an urgent unmet medical need for the development of new therapies for CCNE1-amplified HGS-OvCa and other cancers marked by CCNE1 overexpression. Promising preclinical evidence demonstrates that knockdown or inhibition of cyclin-dependent kinase (CDK2), the catalytic kinase partner of cyclin E1, selectively kills CCNE1-amplified ovarian cancer cell lines, highlighting a potential dependency associated with CCNE1 amplification. However, efforts to directly target CDK2 with pharmacological agents have been plagued by difficulties in achieving specificity for CDK2. We recently employed an alternative strategy of selectively inhibiting CDK7, a key upstream activator of CDK2, to achieve selective killing of CCNE1-amplified ovarian cancer cells. In proof-of-principle studies, YKL-5-124, a new CDK7 inhibitor with superior selectivity over existing inhibitors of its kind, led to pronounced tumor shrinkage in a human xenograft mouse models of CCNE1-amplified HGS-OvCa. The primary goal of the proposed research is to expand on our preliminary findings by elucidating the underlying principles governing CCNE1-amplified HGS-OvCa sensitivity to CDK7 inhibition. This knowledge will then be leveraged to guide further preclinical inquiry into targeting CDK7 in CCNE1-amplified HGS-OvCa. Herein we propose to identify (1) HGS-OvCa cancer cells and genetic backgrounds that are sensitive to YKL-5-124; (2) biomarkers that correlate with drug response; and (3) combination strategies that augment or expand drug response (Aim 1). While YKL-5-124 displays potent in vivo activity in mice, we will continue to optimize these CDK7 inhibitors for improved pharmacokinetics to further the preclinical development of this chemical series (Aim 2). Lastly, we will evaluate YKL-5-124 (or a further in vivo optimized analog) in mouse models of CCNE1-amplified and non-amplified HGS- OvCa (Aim 3). To accomplish these goals we have assembled a multi-disciplinary team with expertise in medicinal chemistry (Nathanael Gray, Stanford); cell and systems biology (Caitlin Mills and Peter Sorger, Harvard Medical School); mouse models in ovarian cancer (Panagiotis Konstantinopoulos, DFCI); and translational and clinical ovarian research (Ursula Matulonis, DFCI). This research describes a new approach to selectively target CCNE1-overexpressing tumors and identifies novel small-molecules that will enable the preclinical evaluation of this strategy for the treatment of CCNE1-amplified HGS-OvCa.