Validating the eCyPA/CD147 signaling complex for myeloma therapy

 描述(申请人提供)：背景：多发性骨髓瘤(MM)是一种积聚在骨髓(BM)中的浆细胞癌。尽管最近在治疗方面取得了进展，但它仍然无法治愈，迫切需要新的、更有效的治疗方法。然而，最近出现了一种新的治疗模式，它通过破坏骨髓微环境(土壤)对MM细胞(种子)起作用的取向，显示出改善患者预后的巨大希望。由于骨髓血管生成是MM进展与疾病分期相关的标志，因此在MM细胞与骨髓微环境的相互作用中，与骨髓内皮细胞(BMECs)的相互作用必然在MM进展中发挥重要作用。初步数据：在MM细胞与骨髓微环境相互作用的研究中，我们发现了规范的Wnt信号的关键作用，它是细胞间沟通和趋向性的通道，最终导致亲迁移、增殖和生存基因的转录激活。Wnt信号的末端效应器是一个转录复合体，其中包括另外两个信号蛋白：？-catenin和bcl9。此外，在使用骨髓组织微阵列的免疫组织化学研究中，我们观察到BMECs中BCL9的限制性和高水平表达，而其他BM细胞则没有。此外，利用蛋白质组学分析，我们证明细胞外亲环素A(ECyPA)是Wnt/？-catenin/bcl9复合体的下游转录靶点，该复合体由BMEC分泌，而不是由其他BM基质细胞分泌，并促进MM的多效性信号变化，包括增强eCyPA的已知受体CD14的表达。此外，BMECs中的eCyPA或MM细胞中的CD147的敲除显著降低了MM细胞的迁移和增殖。工作假说：(I)骨髓间充质干细胞的信号对多发性骨髓瘤的进展至关重要；(Ii)eCyPA在骨髓间充质干细胞的信号输出中发挥关键作用，该信号输出调节多发性骨髓瘤细胞的迁移、侵袭、定植、生长、存活和耐药性。因此，靶向eCyPA与其在MM细胞上的同源受体CD147之间的相互作用对MM是治疗的，特别是对标准化疗获得性耐药的病例。目的：(I)进一步研究BMECs在MM进展中的作用，(Ii)验证eCyPA/CD147信号复合体作为MM治疗靶点的作用，(Iii)鉴定和功能鉴定由BMECs分泌的促进MM进展的其他信号分子，以及(Iii)建立高通量筛选方法，以确定eCyPA/CD147相互作用的小分子抑制剂，为未来MM的靶向治疗提供依据。预期结果：i)验证eCyPA/CD147信号复合体作为MM治疗的有效无毒靶点的作用；ii)确定MM进展的新的潜在生物标志物和治疗靶点。对医学的更广泛的影响：针对多发性骨髓瘤和其他表达CD147的血液系统恶性肿瘤开发更有效的靶向治疗方法。

 DESCRIPTION (provided by applicant): Background: Multiple Myeloma (MM) is a cancer of plasma cells that accumulate in the bone marrow (BM). Despite recent advances in treatments, it remains incurable and there is urgent need of novel and more effective therapies. However, there has recently surfaced a new treatment paradigm that shows great promise to improve patient outcome by disrupting the tropism that the BM microenvironment, the `soil', plays on MM cells, the `seeds'. Since BM angiogenesis is a hallmark of MM progression that correlates with disease stage, it became evident that among the interactions between MM cells and the BM microenvironment, those with BM endothelial cells (BMECs) must play an important role in MM progression. Preliminary data: During studies of the interaction of MM cells with the BM microenvironment, we uncovered a critical role of canonical Wnt signaling, a conduit for cell-cell communication and tropism culminating in transcriptional activation of pro- migration, proliferation, and survival genes. The terminal effector of Wnt signaling is a transcriptional complex that includes two other signaling proteins, ß-catenin and BCL9. Moreover, during immunohistochemical studies using BM tissue microarrays, we observed restricted and high-level BCL9 expression in BMECs but not other BM cells. In addition, using proteomic analysis we have documented that extracellular Cyclophilin A (eCyPA) is a downstream transcriptional target of the Wnt/ß-catenin/BCL9 complex, which is secreted by BMECs but not other BM stromal cells and promote pleiotropic signaling changes in MM including enhanced expression of CD14, the know receptor of eCyPA. Furthermore, knockdown of either eCyPA in BMECs or CD147 in MM cells markedly decreased migration and proliferation of MM cells. Working hypothesis: (i) signaling from BMECs is essential for MM progression; (ii) eCyPA plays critical roles in the signaling output from BMECs that modulate migration, invasion, colonization, growth, survival, and drug resistance of MM cells. Thus, targeting the interaction between eCyPA and its cognate receptor CD147 on MM cells is therapeutic for MM, particularly for cases with acquired resistance to standard chemotherapy. Goals: (i) to further characterize the role of BMECs in MM progression, (ii) to validate the role of the eCyPA/CD147 signaling complex as therapeutic target for MM, (iii) to identify and functionally characterize additional signaling molecules secreted by BMECs that promote MM progression, and (iii) to develop a high throughput screening assay to identify small molecule inhibitors of eCyPA/CD147 interaction for future development of targeted therapies for MM. Expected results: i) validate role of eCyPA/CD147 signaling complex as effective nontoxic target for MM therapy; ii) identification of novel potential biomarkers of MM progression and therapeutic targets. Broader implications for medicine: Development of more effective targeted therapies for MM and other hematologic malignancies that express CD147 and 'home in' the BM.