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一种。在这些人中 最具侵袭性的HGS-OvCa肿瘤是那些含有基因组扩增和CCNE1过表达的肿瘤， 该基因编码细胞周期蛋白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亚群携带的是穷人 标准细胞毒化疗后的结果，并与高增殖率、快速 对聚腺苷二磷酸(核糖)聚合酶抑制剂的铂耐药和从头抗药性的发展。尽管 紧张的努力，针对CCNE1扩增的HGS-OvCa的治疗仍然难以捉摸，部分原因是 缺乏可用药的分子靶点。因此，仍有迫切的医疗需求未得到满足 CCNE1扩增的HGS-OvCa及以CCNE1为标志的其他癌症的新疗法的开发 过度表达。有希望的临床前证据表明，抑制或抑制细胞周期蛋白依赖 细胞周期蛋白E1的催化蛋白激酶(CDK2)选择性杀伤CCNE1扩增的卵巢癌细胞 Lines，强调了与CCNE1扩增相关的潜在依赖性。然而，努力直接 以药物为靶点的CDK2在实现CDK2的特异性方面一直存在困难。 我们最近采用了另一种策略，选择性地抑制CDK2的关键上游激活因子CDK7， 实现对CCNE1扩增的卵巢癌细胞的选择性杀伤。在原则证明研究中，YKL-5-124，a 新的CDK7抑制剂比现有的同类抑制剂具有更好的选择性，导致显著的肿瘤缩小 在人类异种移植模型中，CCNE1扩增HGS-OvCa。拟议研究的主要目标是 是通过阐明CCNE1扩增的潜在原理来扩展我们的初步发现 HGS-OvCa对CDK7抑制的敏感性。然后将利用这些知识来指导进一步的临床前工作 CCNE1扩增的HGS-OvCa靶向CDK7的探讨在此，我们建议鉴定(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组合策略(目标1)。而YKL-5-124 在小鼠体内显示出强大的活性，我们将继续优化这些CDK7抑制剂以改进 药代动力学，以促进该化学系列的临床前开发(目标2)。最后，我们将评估 YKL-5-124(或体内进一步优化的类似物)在CCNE1扩增和非扩增HGS-小鼠模型中的应用 OvCa(目标3)。为了实现这些目标，我们组建了一支多学科团队，具备以下方面的专业知识 药物化学(Nathanael Gray，斯坦福)；细胞和系统生物学(Caitlin Mills和Peter Sorger， ；卵巢癌小鼠模型(Panagiotis Konstantinopoulos，DFCI)；以及 翻译和临床卵巢研究(Ursula Matulonis，DFCI)。这项研究描述了一种新的方法来 选择性靶向CCNE1过度表达的肿瘤并识别新的小分子，使其能够 该策略治疗CCNE1扩增的HGS-OvCA的临床前评估。

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.