Synthetic lethalities to cell cycle disruption in glioma

摘要 尽管几十年来一直在研究针对胶质瘤的靶向治疗方法，但最成功的治疗方法 残留的DNA损伤剂：辐射和烷化剂替莫唑胺和洛莫司汀。DNA损伤 为快速分裂细胞产生特殊的障碍；因为经历这种损伤的细胞通过 在细胞周期中，它们可能经历遗传毒性或有丝分裂灾难。最近已经开发出多种化合物 干扰细胞周期调节，目的是在癌细胞中产生有丝分裂灾难。这些 包括针对G2/M检查站调节器的化合物，包括CHK1和CHK2；WEE1；以及其他。 其中一些正在临床试验中应用于胶质瘤，包括WEE1抑制剂AZD1775的试验 胶质母细胞瘤患者。然而，要详细了解哪些胶质瘤最有可能需要 功能正常的G2/M检查点以及在什么情况下不可用。因此，尽管这条途径是 与最成功的现有疗法高度相关，我们不知道何时或如何使用调节剂 神经胶质瘤患者的通路。这项提案的目标是确定是否以及在什么情况下 G2/M检查点的抑制剂，特别是CHK1/2，可以改善胶质瘤的预后。我们 综合评价400种生物活性小分子对78种胶质瘤细胞系的作用 基因组特征，包括常规和神经球系。最突出的结果之一 TP53的失活与几乎所有化合物的反应更差有关，但合并损失 TP53和CDKN2A/B使细胞对G2/M检查点抑制剂更敏感，特别是 CHK1/2(CHK1/2I)。我们假设，TP53和其他G1/S细胞周期调控因子的联合丢失导致了 依赖CHK1/2控制的G2/M检查点避免在遗传毒性背景下失控的细胞周期 或者是复制压力。通过了解G2/M抑制剂敏感性的潜在机制，我们将拥有 通过使用这些优化的治疗策略对治疗产生重大近期影响的可能性 已经在开发中的抑制剂，可以立即纳入新的临床试验 战略。我们将通过以下具体目标来实现这一点：目标1：检验综合损失的假设 Tp53和G1/S检查点控制产生对G2/M检查点抑制剂的敏感性。目标2：测试 假设细胞分化状态决定了对G2/M检查点抑制的敏感性。目标3：测试 假设MDM2抑制剂可以增加DNA损伤背景下CHK1/2I的治疗窗口 探员们。总而言之，所描述的建议应该导致对那些受影响的人进行更好的诊断和治疗 通过治疗神经胶质瘤，为临床试验设计和在患者研究中实施提供了新途径。

Summary Despite decades of research into targeted therapeutics against gliomas, the most successful treatments remain DNA damaging agents: radiation and the alkylating agents temozolomide and lomustine. DNA damage generates particular obstacles for rapidly dividing cells; as cells undergoing such damage progress through the cell cycle, they can undergo genotoxic or mitotic catastrophe. Multiple compounds have recently been developed that interfere with cell cycle regulation, with the aim of generating mitotic catastrophe in cancer cells. These include compounds targeting regulators of the G2/M checkpoint, including CHK1 and CHK2; WEE1; and others. Some of these are being applied to gliomas in clinical trials, including a trial of the WEE1 inhibitor AZD1775 in patients with glioblastoma. However, a detailed understanding of which gliomas are most likely to require a functional G2/M checkpoint, and under what conditions, is not available. Therefore, despite this pathway being highly relevant to the most successful existing therapeutics, we do not know when or how to use modulators of the pathway in patients with glioma. The objective of this proposal is to determine whether and in what instances inhibitors of the G2/M checkpoint, and particularly CHK1/2, can lead to improved outcomes in gliomas. We evaluated the effects of 400 biologically active small molecules on 78 glioma cell lines with comprehensive genomic characterization, including conventional and neurosphere lines. One of the most prominent outcomes was that inactivation of TP53 was associated with worse response to almost all compounds, but combined loss of TP53 and CDKN2A/B rendered cells more sensitive to G2/M checkpoint inhibitors, especially inhibitors of CHK1/2 (CHK1/2i). We hypothesize that combined loss of TP53 and other G1/S cell cycle regulators leads to a reliance on the CHK1/2-controlled G2/M checkpoint to avoid uncontrolled cell cycling in the context of genotoxic or replicative stress. By understanding the mechanisms underlying G2/M inhibitor sensitivity, we will have potential for a major near-term impact on treatment through optimized therapeutic strategies using these inhibitors, which are already under development, that can lead to immediate incorporation into new clinical trials strategies. We will achieve this with the following specific aims: Aim 1: Test the hypothesis that combined loss of TP53 and G1/S checkpoint control generates sensitivity to G2/M checkpoint inhibitors. Aim 2: Test the hypothesis that cell differentiation state determines sensitivity to G2/M checkpoint inhibition. Aim 3: Test the hypothesis that MDM2 inhibitors can increase the therapeutic window of CHK1/2i in the context of DNA damaging agents. In summary, the proposal described should lead to better diagnostics and treatments for those afflicted by gliomas and offer new avenues for clinical trial design and implementation in patient studies.