Microvesicle Dynamics in B-Cell Chronic Lymphocytic Leukemia Tumor Microenvironme

B 细胞慢性淋巴细胞白血病肿瘤微环境中的微泡动力学

• 批准号: 8574032
• 负责人: Asish Kumar Ghosh
• 金额: $ 32.4万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-01 至 2018-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8574032
• 关键词: 11q23; 17p13; AKT Signaling Pathway; Address; B-Lymphocytes; Biochemical Genetics; Blood Circulation; Blood Platelets; Bone Marrow; CD19 gene; Cancer Patient; Cell Communication; Cell Proliferation; Cell Survival; Cell physiology; Cells; Chromosome Deletion; Chronic Lymphocytic Leukemia; Clinic; Clinical; Clinical Trials; Coculture Techniques; Code; Communication; Country; Cyclin D1; Data; Disease; Disease Progression; Environment; Evaluation; Functional RNA; Generations; Grant; Health; Human; In Vitro; Knowledge; Malignant Neoplasms; Mediating; Mediator of activation protein; Megakaryocytes; Messenger RNA; MicroRNAs; Monitor; Mutation; Nature; North America; Outcome; Pathogenesis; Patients; Phenotype; Phosphoric Monoester Hydrolases; Plasma; Play; Population; Prevention; Process; Production; Prognostic Factor; Proto-Oncogene Proteins c-akt; Reporting; Risk; Role; SRC gene; Sampling; Signal Pathway; Signal Transduction; Staging; Stimulus; Stromal Cells; System; Testing; Therapeutic; Time; Tissues; Transcript; Vascular Endothelial Growth Factors; Vesicle; autocrine; axl receptor tyrosine kinase; base; c-myc Genes; cancer cell; cell type; extracellular; follow-up; high risk; human ITGB3 protein; improved; in vivo; insight; leukemia; neoplastic cell; novel; paracrine; prevent; prognostic; public health relevance; response; therapy duration; tumor

DESCRIPTION (provided by applicant): Tumor cells influence their neighboring stroma to create a favorable niche for survival and advancement of the clinical course. To date, how the malignant cells alter the function of other cell types in surrounding tissues is largely unknown. Emerging evidence suggests that microvesicles (MV) produced by malignant cells are biologically active as a result of their ability to have both intimate and remote influences on hos stromal cells. Recently, we discovered circulating MV from B-Cell Chronic Lymphocytic Leukemia plasma are unique mediators of communication within the CLL microenvironment. We detected: (a) majority of CLL plasma contained elevated levels of MV; and (b) a phenotypic shift from predominantly "platelet-derived" (PD) MV (CD61+) in early stages of CLL toward a more "leukemic B-cell derived" (LD) MV (CD19+) during advanced stages. Most recently, we have detected that CLL B-cells can spontaneously or with stimulation produce LD MV in vitro irrespective of disease stages (Rai stage). In addition, we have shown that CLL MV and CLL stromal cell interaction results in robust activation of the AKT signaling pathway in CLL-bone marrow stromal cells (BMSC), leading to enhanced production of vascular endothelial growth factor (VEGF), a facilitator of leukemic B-cell survival, and sustained increases in cyclin D1 and c-myc, at least in part, by delivering Axl receptor tyrosine kinase (RTK). In contrast, increase in VEGF upon MV exposure also occurs with normal BMSC but at very subtle or diminished levels. Interestingly, we have detected intrinsic functional differences between normal and CLL BMSC that include: (i) CLL BMSC are hyper responsive to MV-mediated modulation of intracellular signaling; and (ii) express aberrantly activated signaling components, e.g., Axl and its downstream c-Src, involved in cell proliferation and survival. In addition, CLL BMSC express higher levels of the Src homology phosphatase-2 (SHP-2), reported to positively regulate the Src-signaling pathway. Based on our findings, the central hypothesis of this proposal is that MV generation in CLL is a dynamic process and that the circulating MV play a critical role in CLL pathogenesis as a result of MVs' unique ability to reprogram BMSC function with facilitation of CLL progression. Thus, neutralization of MV from circulation or inhibition of MV generation by the leukemic B-cells and/or prevention of MV interaction with the CLL stroma may halt disease progression and ultimately may apply to other human malignancies. Our hypothesis will be tested by addressing three specific aims: (1) Study the dynamics of MV generation in vitro by CLL B-cells; (2) Study the in vivo dynamics of MV generation and establish the relationship of CLL MV parameters to CLL progression and therapeutic outcome; (3) Interrogate the mechanism of aberrant function in CLL BMSC. We will study dynamics of in vitro generation of MV by purified CLL B-cells and whether CLL prognostic parameters or other in vitro stimulations are critical for the generation of LD-MV. We will study sequentially the dynamics of MV generation in CLL plasma and their relationship with prognostics and time to therapy. We will also study whether plasma MV levels and phenotype parameters predict therapeutic outcome in CLL patients being treated on two chemoimmunotherapy (CIT) clinical trials. Finally, using biochemical and genetic approach we will dissect mechanism of aberrant signaling in CLL BMSC and role of the Axl RTK in modulation of BMSC functions. Using these approaches we will be able to address our central hypothesis by acquiring more definitive knowledge of the dynamics of MV generation in CLL both in vitro and in vivo, ability of the circulating plasma MV to predict therapeutic outcome in CLL patients, nature of aberrant signaling in CLL BMSC and how the MV parameters associate with disease progression.

描述（由申请人提供）：肿瘤细胞会影响其邻近的基质，以创造出良好的生存和临床过程中的利基市场。迄今为止，恶性细胞如何改变其他细胞类型在周围组织中的功能是未知的。新兴的证据表明，由于对HOS基质细胞的亲密和远程影响，由恶性细胞产生的微泡（MV）在生物学上具有活性。最近，我们发现B细胞慢性淋巴细胞性白血病血浆中的MV循环MV是CLL微环境中通信的独特介体。我们检测到：（a）大多数CLL等离子体含有MV的水平升高； （b）在高级阶段，在CLL的早期阶段从主要的“血小板衍生”（PD）MV（CD61+）转移到更“白血病B细胞衍生”（LD）MV（CD19+）的表型转移。最近，我们检测到CLL B细胞可以自发或刺激会在体外产生LD MV，而与疾病阶段无关（RAI阶段）。 In addition, we have shown that CLL MV and CLL stromal cell interaction results in robust activation of the AKT signaling pathway in CLL-bone marrow stromal cells (BMSC), leading to enhanced production of vascular endothelial growth factor (VEGF), a facilitator of leukemic B-cell survival, and sustained increases in cyclin D1 and c-myc, at least in part, by delivering Axl receptor酪氨酸激酶（RTK）。相反，增加 MV暴露后的VEGF也会在正常的BMSC中发生，但水平非常微妙或降低。有趣的是，我们已经检测到正常和CLL BMSC之间的固有功能差异，包括：（i）CLL BMSC对MV介导的细胞内信号传导的调节反应超过反应； （ii）表达异常激活的信号传导成分，例如AXL及其下游C-SRC，涉及细胞增殖和存活。此外，CLL BMSC表达较高水平的SRC同源性磷酸酶-2（SHP-2），据报道积极调节SRC信号途径。根据我们的发现，该提案的中心假设是，CLL中的MV生成是一个动态过程，并且由于MVS独特的CLL进展能力重新编程BMSC功能，循环MV在CLL发病机理中起关键作用。因此，通过白血病B细胞和/或预防MV与CLL基质的相互作用，通过循环或抑制MV产生MV中和MV可能会停止疾病进展，最终可能适用于其他人类恶性肿瘤。 我们的假设将通过解决三个特定目的来检验：（1）CLL B细胞在体外研究MV生成动力学； （2）研究MV生成的体内动力学，并建立CLL MV参数与CLL进展和治疗结果的关系； （3）询问CLL BMSC中异常功能的机制。我们将通过纯化的CLL B细胞研究体外生成MV的动力学，以及CLL预后参数还是其他体外刺激对于LD-MV的产生至关重要。我们将依次研究CLL血浆中MV产生的动力学及其与预后和治疗时间的关系。我们还将研究血浆MV水平和表型参数是否可以预测在两项化学免疫疗法（CIT）临床试验中接受治疗的CLL患者的治疗结果。最后，使用生化和遗传方法，我们将剖析CLL BMSC中异常信号的机制，以及AXL RTK在BMSC功能调制中的作用。使用这些方法，我们将能够通过对CLL的MV生成动力学的更确定的了解来解决我们的中心假设，即在体外和体内，循环血浆MV预测CLL患者治疗结果的能力，CLL BMSC中异常信号的性质以及MV参数与疾病的进展相关。