PSMA’s enzymatic activity as new target for Prostate Cancer diagnosis and therapy

摘要问题：激素治疗仍然是前列腺癌（PC）的标准治疗方法。而 大多数患者最初对治疗有反应，但最终会发展为致死性去势抵抗性PC（CRPC） 在6到12个月内。在进展过程中，雄激素的典型来源被替代为 即使在没有激素的情况下，也会引发PC生长，这使得在这个阶段的治疗非常困难。提出 解决方案：我们将利用新发现的前列腺特异性膜抗原（PSMA）的生物学功能 为PC开发一种全新的个性化治疗策略， 治疗高水平的PSMA见于大多数侵袭性PC形式，并且是进展的预测因子。 然而，PSMA的生物学作用仍然未知。我们的提议是基于我们最近的范式转变 发现PSMA提供了迄今未知的致癌信号传导功能，其中其酶活性 触发了一个复杂的细胞内信号库，通过激活 Pi 3 K/AKT/mTORC-1以及mTORC-2信号级联。在绘制了PSMA与 在PC中的主要生物信号级联，我们在这里提供了一种新的治疗，破坏这些主要的信号 途径。重要的是，PSMA的抑制导致小鼠的存活益处。我们同时开发了一种伴侣 成像分析，以诊断和监测PC与一个便宜和方便的离体生物发光为基础的测定，从 现成的样品。在该测定中，谷氨酸化的萤光素（GluLuc）被PSMA特异性切割以释放 可通过台式测定系统通过尿/前列腺分泌物中的荧光素酶检测的前列腺素。我们有 已经在小鼠和患者中评估了这种检测方法，并表明它上级PSA的金标准 程度.在这里，目标1将集中在我们的同伴成像分析。我们将测量PSMA在 前列腺分泌物尿（EPS/U）或尿液，并将生物发光信号与局部和 转移性肿瘤负荷和生长。目的2将探索抑制PSMA作为PC的单药治疗或 与雄激素抑制联合使用。由于PSMA活性的抑制将导致减少释放的PSMA蛋白， 我们将把信号的减少与肿瘤反应联系起来。我们将重新使用PSMA抑制剂， 已证实的CNS疾病的安全性特征，由于CNS渗透率低而被放弃。在目标3中，我们将探索 PSMA抑制是否可用于CRPC的治疗和防止转移形成。我们还将测试它是否 可以延缓去势抵抗的发生。与目标2一样，我们将使用台式试验监测治疗。肿瘤 我们的工作意义重大，因为它开辟了一条全新的道路 基于PSMA的特异性生物学功能的PC治疗。PSMA的基础生物学是高度 这是一种创新，因为它从未被探索过，尽管它具有重大的生物学后果。而且我们 还展示了一种创新的，简便的，廉价的体外台式方法来诊断，监测PC和 监测治疗。最终，这将使所有PC患者受益，特别是CRPC患者。

SUMMARY. The problem: Hormone therapy remains the standard treatment for prostate cancer (PC). While most patients initially respond to therapy, they will ultimately progress to lethal castration-resistant PC (CRPC) within 6 to 12 months. During progression, canonical sources of androgens are replaced with mechanisms that trigger PC growth, even in the absence of hormones, making therapy at this stage very difficult. Proposed solution: We will utilize a newly discovered biological function of prostate-specific membrane antigen (PSMA) to develop an entirely new personalized therapeutic strategy for PC that is significantly different from existing therapies. High levels of PSMA are seen in most aggressive forms of PC and are a predictor for progression. However, the biological role of PSMA remains unknown. Our proposal is based on our recent paradigm-shifting discovery that PSMA provides a so far unknown oncogenic signaling function, where its enzymatic activity triggers an intricate intracellular signaling repertoire, promoting cancer growth through activation of the Pi3K/AKT/mTORC-1 as well as the mTORC-2 signaling cascades. Having charted the interface of PSMA with the main biological signaling cascades in PC, we provide here a novel therapy that disrupts these major signaling pathways. Importantly, inhibition of PSMA led to a survival benefit in mice. We developed in parallel a companion imaging assay to diagnose and monitor PC with a cheap and facile ex vivo bioluminescence-based assay from readily available samples. In this assay glutamated luciferein (GluLuc) is cleaved specifically by PSMA to release luciferin that can be detected by luciferase in urine/prostatic secretions with a bench top assay system. We have already evaluated this assay in mice and patients and have shown that it is superior to the gold standard of PSA levels. Here, Aim 1 will focus on our companion imaging assay. We will measure luciferin released by PSMA in expressed prostatic secretions urine (EPS/U) or urine and correlate the bioluminescence signal with local and metastatic tumor burden and growth. Aim 2 will explore inhibition of PSMA as therapy for PC as monotherapy or in combination with androgen inhibition. Since inhibition of PSMA activity will lead to reduced release of luciferin, we will correlate the reduction of signal with the tumor response. We will repurpose PSMA inhibitors, with a proven safety profile for CNS disease that were abandoned due to low CNS penetration. In Aim 3, we will explore if PSMA inhibition can be used as therapy of CRPC and to prevent metastasis formation. We will also test if it can delay onset of castration resistance. As in Aim 2, we will monitor therapy with the benchtop assay. Tumor growth will be interrogated with MR and PET imaging Our work is significant, as it charts an entirely new path for PC therapy based on the specific biological function of PSMA. The underlying biology of PSMA is highly innovative, as it has never been explored in spite of its significant biological consequences. Furthermore, we also demonstrate an innovative, facile, and inexpensive ex vivo benchtop approach to diagnose, monitor PC and monitor therapy. Ultimately, this will benefit all patients with PC, particularly those with CRPC.