Sub-component for Institution # 16-01848 Novel moleculary targeted therapy of GBM

胶质母细胞瘤(GBM)患者的预后很差。我们发现，超过90%的基底膜患者 白介素13受体α2(IL-13RA2)和EphA2受体过表达 大脑。最近，我们已经证明EphA3受体在GBM中也过表达，并且它的 表达模式与EphA2不同。IL-13RA2、EphA2和EphA3存在于不同的 基底膜肿瘤的间隔区。这三种受体均在肿瘤核心的肿瘤细胞中表达，在 EphA2在肿瘤新生血管中也有高表达。此外，IL-13RA2， EphA2和EphA3与胶质瘤干细胞样细胞的病理生物学相关，并在其中发挥关键作用 (GSC)。IL-13RA2有助于GSC的特性，EphA2和EphA3都推动其自我更新和 致瘤性。最后，在单核细胞来源的GBM浸润性细胞中可以很容易地检测到EphA3受体。 肿瘤相关巨噬细胞()。因此，IL-13RA2、EphA2和EphA3在 主要的基底膜间隔被证明与肿瘤的进展和/或对治疗的抵抗有关。其中之一 Eph2和EphA3与EphA2和EphA3结合，EphB2受体也是唯一的EphB2受体； 后者也在基底膜细胞上特异表达。在目前的项目中，我们将追求一个新颖的想法 用一种药物化合物靶向所有四个受体。这种二价化合物将识别IL- 13RA2、EphA2、EphA3和EphB2，并将药物输送到GBM肿瘤，特异性地杀伤肿瘤细胞和细胞 促进其生长的肿瘤环境。我们还分离出了一种小肽Pep-1L，它 特异性识别IL-13RA2，诱导受体内化，并与颅内肿瘤结合 老鼠。这些和其他性质使多肽成为一种理想的载体，以增加药物/标签的访问 肿瘤。我们将通过两个具体目标继续这一令人兴奋的研究路线。在第一个目标中，我们将 产生一种有效的双价细胞毒素Quad-CTX，同时靶向IL-13RA2、EphA2、EphA3和 EphB2受体。我们将产生一种化学结合物和一种改良的化疗药物，它可以通过 血脑屏障(BBB)本身，称为WP1244。该药物结合物将在体外模型中进行测试。 基底膜和活体的不同隔室。在第二个目标中，我们将利用与IL-13RA2结合的多肽来 有效的靶向全身或局部化疗，用于监测血脑屏障的破坏和 对治疗的反应。我们将利用内化肽Pep-1L，它是颅内肿瘤的家园，用于 与WP1244(Pep-1L-CTX)的结合，并在表达IL-13RA2的GBM模型中进行检测，以验证结合物的 穿透血脑屏障和/或血脑肿瘤屏障的能力。我们还将根据以下条件生成成像探测器 多肽。我们预计，对GBM的这一全面攻击将转化为明确持久的回应 在病人身上。

Patients with glioblastoma (GBM) have a dismal prognosis. We found that over 90% of patients with GBM over-express both interleukin 13 receptor alpha 2 (IL-13RA2) and EphA2 receptor that are absent in normal brain. More recently, we have demonstrated that the EphA3 receptor is also over-expressed in GBM, and its pattern of expression differs from that of EphA2. IL-13RA2, EphA2, and EphA3 are present in various compartments of GBM tumors. All three receptors are expressed in tumor cells of the core of tumor and in locally-infiltrating tumor cells, while EphA2 is also over-expressed in tumor neovasculature. Further, IL-13RA2, EphA2, and EphA3 are associated with, and play crucial roles in, the pathobiology of glioma stem-like cells (GSC). IL-13RA2 contributes to GSC properties and EphA2 and EphA3 both drive their self-renewal and tumorigenicity. Finally, the EphA3 receptor can be readily detected in GBM-infiltrating cells of monocytic origin, tumor-associated macrophages (TAM). Thus, collectively, IL-13RA2, EphA2, and EphA3 are expressed in principal GBM compartments shown to be involved in tumor progression and/or resistance to therapies. One of the Eph receptor ligands, ephrinA5 (eA5), binds EphA2 and EphA3 and also uniquely the EphB2 receptor; the latter also is expressed specifically on GBM cells. In the current project, we will pursue the novel idea of targeting all four receptors with one pharmaceutical compound. This bi-valent compound will recognize IL- 13RA2, EphA2, EphA3, and EphB2 and deliver a drug to GBM tumors, specifically killing tumor cells and cells of the tumor environment promoting its growth. We have also isolated a small peptide, Pep-1L, which specifically recognizes IL-13RA2, induces receptor's internalization and it is bound by intracranial tumors in mice. These and other properties make the peptide a desirable vehicle to augment access of drugs/labels to tumors. We will continue this exciting line of research through two Specific Aims. In the first Aim, we will produce a potent bi-valent cytotoxin, QUAD-CTX, simultaneously targeting the IL-13RA2, EphA2, EphA3, and EphB2 receptors. We will generate a chemical conjugate with a modified chemotherapeutic which can pass the blood-brain barrier (BBB) on its own, termed WP1244. The drug conjugate will be tested in in vitro models of various compartments of GBM and in vivo. In the second Aim, we will exploit a peptide binding to IL-13RA2 for effective targeted systemic or loco-regional chemotherapy, for monitoring of the disruption of the BBB and responses to treatment. We will exploit internalized peptide Pep-1L, which homes to intracranial tumors, for conjugation to WP1244 (Pep-1L-CTX) and test it in GBM models expressing IL-13RA2 to verify the conjugate's ability to penetrate the BBB and/or blood-brain tumor barrier. We will also generate imaging probes based on the peptide. We expect that this comprehensive assault on GBM will translate into clear-cut durable responses in patients.