Cancer Research Center, School of Medicine, Xiamen University, Xiamen, 361102, China.
Department of Hematology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, 266011, China.
Theranostics. 2022 Nov 14;12(18):7760-7774. doi: 10.7150/thno.76852. eCollection 2022.
Bone destruction is a hallmark of multiple myeloma (MM) and affects more than 80% of patients. Although previous works revealed the roles of N-methyladenosine (m6A) reader hnRNPA2B1 in the development of tumors, whether hnRNPA2B1 regulates bone destruction in MM is still unknown. Alizarin red S staining, TRAP staining, ELISA and quantitative real-time PCR assays were used to evaluate osteogenesis and osteoclastogenesis . X ray and bone histomorphometric analysis were preformed to identify bone resorption and bone formation . Exosome isolation and characterization were demonstrated by transmission electron microscopy, dynamic light scattering, immunofluorescence and flow cytometry assays. The interactions between hnRNPA2B1 and primary microRNAs were examined using RNA pull-down and RIP assays. Coimmunoprecipitation assay was used to test the interaction between hnRNPA2B1 and DGCR8 proteins. Luciferase assay was established to assess miRNAs target genes. Here we show that myeloma cells hnRNPA2B1 mediates microRNAs processing and upregulates miR-92a-2-5p and miR-373-3p expression. These two microRNAs are transported to recipient monocytes or mesenchymal stem cells (MSCs) through exosomes, leading to activation of osteoclastogenesis and suppression of osteoblastogenesis by inhibiting IRF8 or RUNX2. Furthermore, clinical studies revealed a highly positive correlation between the level of myeloma cells hnRNPA2B1 and the number of osteolytic bone lesions in myeloma patients. This study elucidates an important mechanism by which myeloma-induced bone lesions, suggesting that hnRNPA2B1 may be targeted to prevent myeloma-associated bone disease.
骨质破坏是多发性骨髓瘤（MM）的一个标志，影响超过 80%的患者。尽管之前的研究揭示了 N6-甲基腺苷（m6A）阅读器 hnRNPA2B1 在肿瘤发展中的作用，但 hnRNPA2B1 是否调节 MM 中的骨质破坏仍不清楚。茜素红 S 染色、TRAP 染色、ELISA 和实时定量 PCR 检测用于评估成骨和破骨细胞生成。X 射线和骨组织形态计量学分析用于识别骨吸收和骨形成。通过透射电子显微镜、动态光散射、免疫荧光和流式细胞术检测外泌体的分离和特征。使用 RNA 下拉和 RIP 检测来检查 hnRNPA2B1 和初级 microRNAs 之间的相互作用。共免疫沉淀检测用于测试 hnRNPA2B1 和 DGCR8 蛋白之间的相互作用。荧光素酶检测用于评估 microRNAs 靶基因。 在这里，我们表明骨髓瘤细胞 hnRNPA2B1 介导 microRNAs 的加工，并上调 miR-92a-2-5p 和 miR-373-3p 的表达。这两种 microRNAs 通过外泌体被转运到受体单核细胞或间充质干细胞（MSCs）中，通过抑制 IRF8 或 RUNX2 导致破骨细胞生成激活和成骨细胞生成抑制。此外，临床研究表明骨髓瘤细胞 hnRNPA2B1 的水平与骨髓瘤患者溶骨性骨病变的数量之间存在高度正相关。 本研究阐明了骨髓瘤诱导的骨病变的一个重要机制，提示 hnRNPA2B1 可能成为预防骨髓瘤相关骨病的靶点。
