Understanding the impact that tumor representative oxygen tension has on phosphotyrosine-dependent signaling networks in solid tumors

项目摘要/摘要 磷酸化酪氨酸介导的信号网络的扰动是在 肿瘤发生发展的多步骤过程。因此，这些磷酸酪氨酸的成分 信号网络，特别是酪氨酸激酶，已被证明是可作用分子的关键储存库 癌症治疗的靶点。近年来，研究发现肿瘤微环境在肿瘤的发生发展中起着重要作用。 在调控肿瘤进展和转移的信号通路中发挥关键作用。这些特点 已被证明对肿瘤的微环境产生独特的敏感性和抵抗力 治疗方式。肿瘤微环境的一个主要方面，在临床前常常被忽视 研究的是氧分压。这项建议试图了解氧气压力对 实体肿瘤中依赖磷酸酪氨酸的信号网络，以及由此产生的脆弱性是如何 有针对性地改善患者的预后。在Aim 1.1(先前的研究)中，我们试图确定信号的变化 当肺癌细胞在低氧环境下侵占大脑时，就会形成网络。我们向他们展示了大脑- 转移性肺癌细胞升高并增加对非典型HSF1-E2F的依赖 生存的转录程序。重要的是，我们确定了这个转录程序是有针对性的 通过变构ABL2酪氨酸激酶抑制剂治疗。在AIM 1.2(拟议研究)中，使用了一个小的 分子筛查，我已经确定了以前未知的细胞对低氧反应的调节器，a 肿瘤微环境特征与肿瘤转移增加和总生存期降低相关 实体瘤。排名最靠前的未定名药物是FDA批准的ABL1/2酪氨酸激酶抑制剂达沙替尼和 我的初步研究表明，ABL激酶是HIF-1α蛋白稳定性的关键调节因子。我 将继续在体外和体内对ABL-HIF-1α轴进行机制研究。最后，在目标2(博士后 研究)，我将重点了解代表肿瘤的氧分压对蛋白质的影响 酪氨酸磷酸酶活性。广泛的研究表明，肿瘤缺氧可诱导活化。 但目前的工作几乎完全集中在酪氨酸的作用上 激活剂。我的研究表明，缺氧可以抑制蛋白质酪氨酸磷酸酶(PTPs)的氧化。使用质量- 基于光谱的方法，我将识别肿瘤样本和 在肿瘤中观察到的含氧量的癌细胞。此外，由于PTP抑制细胞信号，我将采用 高通量药物体外筛选技术用于确定PTP丢失引起的紧急敏感性 在许多正常情况下不会被捕捉到的活动(肿瘤-非代表性的氧气水平) 进行了放映。总体而言，我职业生涯的重点是了解肿瘤的不同特征 微环境，如低氧，调节癌细胞选择的信号网络，并翻译 这有助于确定可能适用于治疗性开发的生物学机制。

PROJECT SUMMARY/ ABSTRACT The perturbation of phospho-tyrosine mediated signaling networks is an essential occurrence during the multistep process of tumor development and progression. As a result, the components of these phospho-tyrosine signaling networks, especially tyrosine kinases, have been shown to be a key reservoir of actionable molecular targets for the treatment of cancer. In recent years, it has been revealed that the tumor microenvironment plays a critical role in modulating the signaling pathways that govern tumor progression and metastasis. The features of a tumor's microenvironment have been shown to produce unique sensitivities and resistances to different treatment modalities. One major aspect of the tumor microenvironment which is often overlooked in preclinical studies is oxygen tension. This proposal seeks to understand the impact that oxygen tension has on phosphotyrosine-dependent signaling networks in solid tumors, and how the resultant vulnerabilities can be targeted to improve patient outcome. In Aim 1.1 (prior studies), we sought to identify alterations in signaling networks that occur when lung cancer cells colonize the brain, a hypoxic environment. We showed that brain- metastatic lung cancer cells elevate and have an increased dependence on a non-canonical HSF1-E2F transcriptional program for survival. Importantly, we identified that this transcriptional program is targetable through treatment with allosteric ABL2 tyrosine kinase inhibitors. In Aim 1.2 (proposed studies), using a small molecule screen, I have identified previously unrecognized modulators of the cellular response to hypoxia, a tumor microenvironment feature associated with increased metastasis and lower overall survival in patients with solid tumors. The top uncharacterized hit was the FDA-approved ABL1/2 tyrosine kinase inhibitor Dasatinib and my preliminary investigation has shown that the ABL kinases are critical regulators of HIF-1α protein stability. I will continue mechanistic investigation of the ABL- HIF-1α axis in vitro and in vivo. Finally, in Aim 2 (post-doctoral studies), I will focus on understanding the impact that tumor representative- oxygen tension has on protein tyrosine phosphatase activity. Extensive investigation has demonstrated that tumor hypoxia induces activation of phospho-tyrosine signaling networks, but current work has almost exclusively focused on the role of tyrosine kinases. I show that hypoxia induces inhibitory oxidation of protein tyrosine phosphatases (PTPs). Using mass- spectrometry based approaches, I will identify the oxidized- PTP landscape (ox-PTPome) of tumor samples and cancer cells at oxygen levels observed in tumors. Further, since PTPs restrain cellular signaling, I will employ high-throughput drug screening technologies in vitro to identify emergent sensitivities due to the loss of PTP activity that would not have been captured in the numerous normoxically (tumor-unrepresentative oxygen level) performed screens. Overall, the focus of my career is to understand how the different characteristics of the tumor microenvironment, such as hypoxia, modulates the signaling networks co-opted by cancer cells and translate this to the identification of biological mechanisms that may be amenable to therapeutic exploitation.