Anti-myeloma strategies by re-establishing bone regeneration and hematopoietic niches

多发性骨髓瘤（MM）通过多种机制抑制骨和血液再生，包括改变干细胞谱系的干细胞生态位调节，血管生成和骨生成的解耦，以及促进溶骨恶性循环。我们已经确定了几个新的靶标机制来调节骨髓瘤和间充质干细胞接触诱导的干细胞生态位和中胚层承诺，例如：(1)骨生成的谱系承诺受损，血管生成和脂肪生成的改变（ROR1， BMPER）；（II）诱导新的预转移龛和竞争性劫持预先形成的干细胞龛（CXCR4/SDF-1, EBF2, JAM2/3）；（III）骨髓瘤骨病的进展（KISS1R，通过GPR的促凋亡信号）。基于这些结果，我们假设这些靶点可以用于敏感的分子成像，血液和骨骼再生的恢复以及特定的骨髓瘤治疗。我们在第二个资助期的具体目标是针对接触诱导/抑制的候选物和信号系统，以便(I)研究抑制剂对谱系承诺和血管生成分解物的生物学相关性，（II）阐明骨髓瘤骨病中依赖局部氧张力的生态位调节和t细胞反应的分子机制。（III）确定KISS1R系统与骨再生的相关性及其在成像和部位特异性靶向方面的潜力。一般策略是通过在2D细胞培养、骨髓中的BioVaSc设备中的3D共培养、临床前模型（例如MOPC315）中逐步表征来评估主要候选物作为诊断和治疗靶点。BM)，并在MM患者的人体材料中验证这些发现。这些研究应该将骨和骨髓生态位整合到抗肿瘤策略中。重建骨和血液再生的生态位和途径可能具有抗骨髓瘤的功效。

Multiple myeloma (MM) inhibits bone and blood regeneration by various mechanisms, including stem cell niche conditioning with altered stem cell lineage commitment, uncoupling of angiogenesis and osteogenesis, and promotion of osteolytic vicious cycles. We have identified several new target mechanisms for modulating the stem cell niche and mesodermal commitment induced by contact between myeloma and MSC, such as (I) impaired lineage commitment for osteogenesis and altered angiogenesis and adipogenesis (ROR1, BMPER); (II) induction of new premetastatic niches and competitive hijacking of preformed stem cell niches (CXCR4/SDF-1, EBF2, JAM2/3); and (III) progression of myeloma bone disease (KISS1R, proapoptotic signaling via GPR). Based on these results we hypothesize that these targets can be addressed for sensitive molecular imaging, restoration of blood and bone regeneration and specific myeloma treatment. Our specific aims for the second funding period are to target contact-induced/repressed candidates and signaling systems in order to (I) investigate the biological relevance of inhibitors for lineage commitment and of disintegrators of angiogenesis, (II) to elucidate molecular mechanisms of niche modulation and T-cell response in myeloma bone disease depending on local oxygen tension, and (III) to define the relevance of the KISS1R system for bone regeneration and its potential for imaging and site-specific targeting. The general strategy is to evaluate lead candidates as diagnostic and therapeutic targets using stepwise characterization in 2D cell culture, 3D co-cultures in the BioVaSc device in bone marrow, preclinical models (e.g. MOPC315.BM) and validate these findings in human material from MM patients. These studies should paradigmatically integrate the bone and bone marrow niche into anti-tumor strategies. Reestablishing niches and pathways for bone and blood regeneration may confer anti-myeloma efficacy.