Clonogenic Characterization of Myeloma Progenitor Cells

描述（由申请人提供）：多发性骨髓瘤（MM）是一种克隆b细胞恶性肿瘤的原型。造血干细胞（HSC）移植和/或新的化疗组合改善了长期无病生存。然而，基础疾病的复发仍然是治疗失败的主要原因，MM本质上是一种无法治愈的疾病。因此，迫切需要旨在提高治疗效果的策略。该项目的中心假设是MM患者的骨髓亚群构成一个具有自我更新能力的祖细胞室，负责疾病的发生、维持和进展。这些细胞可能具有特定的特征，使它们对化疗不敏感，它们可能依赖于造血基质微环境来生存。我们的初步结果表明，MM患者的骨髓中含有一个克隆亚群，不表达syndecan-1 (CD138-)，在克隆测定中分化为成熟细胞（CD138+），并且对硼替佐米治疗相对耐药。拟议的研究将有助于了解MM生物学，分析可能部分负责疾病起始和/或复发的MM祖亚群的表型和独特组成。我们未来的目标是确定这些细胞的临床意义，并开发针对所有MM亚群的药物和/或免疫疗法。在目的1中，我们将确定CD138- MM细胞的分化潜力和自我更新能力。我们提出表征CD138- MM细胞的表型分化并建立其染色体特征。我们计划用患者特异性免疫球蛋白重链重排和体内克隆原性来确定它们的克隆性。在Aim 2中，我们将通过质谱分析相关蛋白，确定自我更新途径作为CD138- MM亚群耐药的内在机制的作用。我们将测试自我更新配体对CD138细胞的蛋白表达、细胞增殖、靶基因激活和克隆生长的影响。在Aim 3中，我们将确定基质细胞在赋予cd138细胞生存优势中的作用。我假设微环境支持CD138- MM细胞的克隆性，这些细胞依赖于它的信号来生存，因为基质提供了一个支持的生态位。我假设基质成分可能对CD138- MM亚群提供细胞保护，部分原因是细胞周期进程的扰动和/或已知的MM-基质存活机制。为了实现这一目标，我们将通过质谱分析评估基质相关细胞因子和纤维连接蛋白对细胞周期的影响，以及对BcL-2凋亡调节蛋白表达的调节，以及与药物反应的相关性。

DESCRIPTION (provided by applicant): Multiple Myeloma (MM) is the prototype of a clonal B-cell malignancy. Hematopoietic stem cell (HSC) transplantation and/or novel chemotherapy combinations have improved long-term disease free survival. However, relapse of the underlying disease remains the primary cause of treatment failure with MM being essentially an incurable disease. Therefore, strategies aiming to improve treatment efficacy are much needed. The central hypothesis of this project is that bone marrow sub-populations in MM patients constitute a progenitor compartment with self renewal capacity that is responsible for disease initiation, maintenance and progression. These cells may have a specific signature to render them insensitive to chemotherapy and they may rely on the hematopoietic stroma microenvironment for their survival. Our preliminary results show that MM patient's bone marrow contain a clonal sub-population that do not express syndecan-1 (CD138-), differentiates in clonogenic assay to a mature cell (CD138+) and is relatively resistant to bortezomib treatment. The proposed study will contribute to the understanding of MM biology analyzing the phenotypic and unique make up of a MM progenitor sub-population that may be in part responsible for disease initiation and/or relapse. Our future goal is to establish the clinical significance of these cells and to develop drugs and/or immune therapies to target all MM sub-populations. In Aim 1, we will determine the differentiation potential and self-renewal capacity of CD138- MM cells. We proposed to characterize phenotypic differentiation of CD138- MM cells and establish their chromosomal signature. We plan to define their clonality with patient-specific immunoglobulin heavy chain rearrangements and clonogenicity in vivo. In Aim 2, we will determine the role of self renewal pathways as an intrinsic mechanism of resistance of CD138- MM sub-populations by analyzing related proteins by mass spectrometry. We will test the effect of self renewal ligands on protein expression, on cell proliferation, on activation of target genes and clonogenic growth of CD138- cells. In Aim 3, we will determine the role of stroma cells in conferring a survival advantage to CD138-cells. I hypothesize that the microenvironment supports CD138- MM cells clonogenicity and these cells depend on it signals for their survival as the stroma provides a supporting niche. I postulate that stroma elements may provide cyto-protection to CD138- MM subpopulations in part due to perturbations in cell cycle progression and/or known MM-stroma survival mechanism. In pursuit of this aim we will assess stroma related cytokines and fibronectin effect on cell cycle and on modulation of protein expression of BcL-2 apoptotic regulators by mass spectrometry and correlation with drug response. PUBLIC HEALTH RELEVANCE: Multiple Myeloma (MM) is an incurable hematological malignancy of plasma cells. Plasma cells grow in the bone marrow (BM) and produce same type of abnormal antibodies (clone). Development of strategies to improve treatment efficacy and to prevent recurrence of disease (relapse) are much needed. An important cause of treatment failure in cancer is drug resistance leading to minimal residual disease (MRD). Developing novel treatment strategies to target mediators of MRD is essential for complete disease eradication. The "cancer stem cell" concept debates that some cells within the tumor are the root of cancer by producing cancer cells and cancer cure depends on the eradication of these cells. To date, the clinical role of these cells is cancer biology is unknown and deep understanding of these cells in MM remains to be determined. Our preliminary results show that MM BM contains a clone of cells that do not express markers used to identify mature MM cells (plasma cells) and are less susceptible to chemotherapy. We hypothesize that these cells maybe responsible for the origin of MM and responsible for MRD. We propose to establish whether these cells play a role in MM generation and to understand growth regulation mechanisms of these cells. We plan to study self renewal pathways and interaction with the BM micro-environment since we believe that this niche provides positive feedback for their survival. Understanding the role of these cell in MM and decipher their survival tools will be essential since eradication of these cells should produce curative results in MM if hypothesis is proven.