染色体不稳定相关基因AURKA参与多发性骨髓瘤骨病发生的作用机制

Myeloma bone disease (MBD) is a hallmark of multiple myeloma (MM), and negatively impacted the life's quality and survival of MM patients. AURKA is an important gene associated with chromosome instability. In our recent work about AURKA, we noticed that the expression level of AURKA was significantly higher in the CD138+ plasma cells obtained from MM patients carried severe MBD compared with the mild ones. The experiments showed that the supernatant of MM cells with AURKA overexpression could significantly promote the differentiation and maturation of osteoclasts in vitro. It’s suggested that there is a correlation between AURKA and MBD. In addition, several studies in solid tumors showed that AURKA can affect the Wnt/β-catenin pathway which is thought to play the key role in the inhibition of osteoblast’s activity in MBD. Therefore, we speculate that gene AURKA is involved in the occurrence and development of MBD through Wnt/β-catenin signaling and other related pathways. So the purpose of our present project is: (a) to further validate the correlation between the expression level of AURKA and the MBD of MM patients in a larger scale; (b) to elucidate the mechanism of AURKA on MBD from two aspects: inhibition of osteoblast activity and increase of osteoclast activity by constructing AURKA knockout and over-expression cell lines; (c) to further investigate the effect of AURKA on MBD and the corresponding intervention methods in 5TGM1 mice model of MM. The results will help to further understand the pathogenesis of MBD and provide novel clues for the ultimate control of bone disease.

骨髓瘤骨病（MBD）是多发性骨髓瘤（MM）的标志性事件，严重影响患者预后和生活。AURKA是一种染色体不稳定相关基因。我们在前期研究中发现，MBD较重的MM患者其CD138+浆细胞中AURKA的表达水平明显高于MBD较轻者。体外实验显示过表达AURKA的MM细胞培养上清液明显促进破骨细胞分化成熟。此外，多个实体瘤研究显示AURKA影响Wnt/β-catenin通路，而这一通路被认为在MBD成骨抑制中起关键作用。因此，我们推测AURKA通过Wnt/β-catenin等通路参与MBD调控。本项目拟①通过大系列临床队列验证MBD与AURKA的相关性；②通过构建AURKA敲除和过表达细胞系，从成骨抑制和破骨活化两个方面检测AURKA对MBD的作用；③通过5TGM1的MM小鼠模型，进一步研究AURKA对MBD的影响以及治疗干预。研究结果将有助于深入理解MBD的发生机制，为最终控制骨病提供新的思路。

多发性骨髓瘤（MM）是常见于中老年人的一类恶性浆细胞肿瘤，其发病率在血液肿瘤中位居第二/三位。随着我国人口的快速老龄化，MM 发病率近年来呈明显上升趋势，严重影响患者的生存。我们在前期研究染色体不稳定相关基因AURKA的过程中注意到，骨病较重的MM患者其CD138阳性浆细胞中AURKA的表达水平明显高于骨病较轻患者。因此，我们推测AURKA与MBD的发生发展存在相关性。我们经临床资料分析表明，AURKA高表达患者与贫血，骨破坏，较高的Cr和LDH的临床相关性密切相关。同时，我们对部分MM患者进行了治疗前后肿瘤细胞的单细胞测序。其中患者MM6是一例标危MM，治疗后疗效达到VGPR。对其治疗前后的肿瘤细胞进行分析，结果显示：治疗后一个残留较多的亚群与其它的亚群相比，显著差异表达的基因有TUBAIB、STMN1、HBB、TUBB、AURKA、MKI67等。提示AURKA高表达是耐药亚群的特征之一。体外基础研究方面，通过对AURKA基因进行干扰，发现其可以导致p-STAT3通路减少IL-6分泌，从而抑制破骨细胞分化。体外ARP1细胞系研究显示，AURKA敲减组降低IL-6的能力与硼替佐米具有协同作用，这种作用与AURKA抑制剂作用类似。体内动物试验方面，AURKA降低可增加MM细胞对硼替佐米敏感性，降低IL-6分泌，从而抑制破骨活性，抑制肿瘤生长，改善药物疗效。本研究结果有助于深入理解多发性骨髓瘤中预后不良基因AURKA与疾病发生发展的关系，尝试可能的治疗新靶点，为最终控制疾病提供新的思路。