多发性骨髓瘤（MM）细胞染色体异常、微环境中破骨细胞恶性分化是导致MM恶性增殖、复发耐药的重要原因。申请人研究发现：CHK1基因在MM复发、序贯样本中表达明显高于初诊样本，高表达CHK1患者骨破坏剧增，生存率显著降低；CHK1引发MM细胞染色体不稳定，增殖与耐药，促进破骨细胞分化；MM细胞分泌的环状RNA（circCHK1_002）序列包含CHK1蛋白催化中心序列；蛋白组学、免疫共沉淀等提示CHK1可能分别磷酸化激活细胞分裂、破骨细胞分化关键因子CEP170、NFATC1。本项目计划：运用基因编辑、过继性B细胞小鼠模型等技术体内外检验CHK1引发MM细胞染色体不稳定、骨破坏的作用；验证CHK1环状RNA调控微环境MM细胞增殖耐药、骨破坏的功能；应用点突变及质谱等技术阐明其作用机制；运用数字PCR、PDX模型等技术验证其作为MM标志物及药物靶点的可行性。本项目拟为MM诊断与治疗提供新的手段。

Multiple myeloma (MM) is a still incurable plasma cell malignant disease while the MM cellular chromosomal defects and malignant osteoclast differentiation in the bone marrow microenvironment result in MM proliferation, drug-resistance and relapse. Our preliminary study showed that CHK1 expression increases in relapsed or serial MM patients’ samples compared to new-diagnosed samples; CHK1 induces MM cellular chromosomal instability, proliferation, drug-resistance and osteoclast differentiation; MM cells secret CHK1 circle RNA, circCHK1_002, the sequence of which includes the same sequence of CHK1 catalytic active center; proteomics and co-immunoprecipitation assays et al. indicated that CHK1 might activate CEP170, key cellular division factor, and NFATC1, important factor for osteoclast differentiation respectively. In this study, we plan to verify the role of CHK1 on inducing MM chromosomal instability, proliferation, drug-resistance and osteoclast differentiation in vitro and in vivo by using gene edit and adoptive B-cell transplantation mouse model et al.; testify if CHK1 circle RNA, circCHK1_002, could induce MM cellular proliferation, drug-resistance and osteoclast differentiation in the bone marrow microenvironment; explore the mechanism of CHK1 by site mutation and mass spectrum techniques et al.; detect if CHK1 could be utilized as a marker for diagnosis and drug-targeting by digital PCR and PDX (Patient-Derived tumor Xenograft) mouse model et al.. Summarily, our study aims to provide novel theoretical support for MM diagnosis and therapy.