Cheng Dong-Dong, Zhang Hui-Zhen, Yuan Jun-Qing, Li Shi-Jie, Yang Qing-Cheng, Fan Cun-Yi
Department of Orthopedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China.
Department of Pathology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China.
Oncotarget. 2017 Apr 18;8(16):26380-26393. doi: 10.18632/oncotarget.15474.
A label free quantitative proteomic approach (SWATH™ experiment) was performed to identify tumor-associated nuclear proteins that are differentially expressed between osteosarcoma cells and osteoblast cells. By functional screening, minichromosome maintenance protein 2 (MCM2) and minichromosome maintenance protein 3 (MCM3) were found to be related to osteosarcoma cell growth. Here, we show that knockdown of MCM2 or MCM3 inhibits osteosarcoma growth in vitro and in vivo. In co-immunoprecipitation and co-localization experiments, MCM2 and MCM3 were found to interact with DExH-box helicase 9 (DHX9) in osteosarcoma cells. A rescue study showed that the decreased growth of osteosarcoma cells by MCM2 or MCM3 knockdown was reversed by DHX9 overexpression, indicating that MCM2 and MCM3 activity was DHX9-dependent. In addition, the depletion of DHX9 hindered osteosarcoma cell proliferation. Notably, MCM2 and MCM3 expression levels were positively correlated with the DHX9 expression level in tumor samples and were associated with a poor prognosis in patients with osteosarcoma. Taken together, these results suggest that the MCM2/MCM3-DHX9 axis has an important role in osteosarcoma progression.
采用一种无标记定量蛋白质组学方法（SWATH™实验）来鉴定骨肉瘤细胞和成骨细胞之间差异表达的肿瘤相关核蛋白。通过功能筛选，发现微小染色体维持蛋白2（MCM2）和微小染色体维持蛋白3（MCM3）与骨肉瘤细胞生长相关。在此，我们表明敲低MCM2或MCM3可在体外和体内抑制骨肉瘤生长。在免疫共沉淀和共定位实验中，发现MCM2和MCM3在骨肉瘤细胞中与DEAH盒解旋酶9（DHX9）相互作用。一项挽救研究表明，过表达DHX9可逆转因敲低MCM2或MCM3导致的骨肉瘤细胞生长减缓，这表明MCM2和MCM3的活性依赖于DHX9。此外，敲低DHX9会阻碍骨肉瘤细胞增殖。值得注意的是，在肿瘤样本中，MCM2和MCM3的表达水平与DHX9的表达水平呈正相关，并且与骨肉瘤患者的不良预后相关。综上所述，这些结果表明MCM2/MCM3 - DHX9轴在骨肉瘤进展中起重要作用。
