Li Hao, Fu Xiaodong, Gao Yingjian, Li Xiaomiao, Shen Yi, Wang Weili
Department of orthopaedics, South Campus, Ren Ji Hospital, School of Medicine, Shanghai Jiaotong University, China.
J Bone Oncol. 2017 Dec 23;11:17-22. doi: 10.1016/j.jbo.2017.12.001. eCollection 2018 Jun.
Osteosarcoma is the most widespread primary carcinoma in bones. Osteosarcoma cells are highly metastatic and frequently develop resistance to chemotherapy making this disease harder to treat. This identifies an urgent need of novel therapeutic strategies for osteosarcoma. G-Protein-coupled receptor 137 (GPR137) is involved in several human cancers and may be a novel therapeutic target.
The expression of GPR137 was assessed in one osteoblast and three human osteosarcoma cell lines via the quantitative real-time polymerase chain reaction and western blot assays. Stable GPR137 knockdown cell lines were established using an RNA interference lentivirus system. Viability, colony formation, and flow cytometry assays were performed to measure the effects of GPR137 depletion on cell growth. The underlying molecular mechanism was determined using signaling array analysis and western blot assays.
GPR137 expression was higher in the three human osteosarcoma cell lines, Saos-2, U2OS, and SW1353, than in osteoblast hFOB 1.19 cells. Lentivirus-mediated small interfering RNA targeting GPR137 successfully knocked down GPR137 mRNA and protein expression in both Saos-2 and U2OS cells. In the absence of GPR137, cell viability and colony formation ability were seriously impaired. The extent of apoptosis was also increased in both cell lines. Moreover, AMP-activated protein kinase α, proline-rich AKT substrate of 40 kDa, AKT, and extracellular signal-regulated kinase phosphorylation levels were down-regulated in GPR137 knockdown cells.
The results of this study highlight the crucial role of GPR137 in promoting osteosarcoma cell growth . GPR137 could serve as a potential therapeutic target against osteosarcoma.
骨肉瘤是骨骼中最常见的原发性癌症。骨肉瘤细胞具有高度转移性，且经常对化疗产生耐药性，使得这种疾病难以治疗。这表明迫切需要针对骨肉瘤的新型治疗策略。G蛋白偶联受体137（GPR137）与多种人类癌症有关，可能是一个新的治疗靶点。
通过定量实时聚合酶链反应和蛋白质印迹分析，评估GPR137在一种成骨细胞系和三种人类骨肉瘤细胞系中的表达。使用RNA干扰慢病毒系统建立稳定的GPR137敲低细胞系。进行细胞活力、集落形成和流式细胞术分析，以测量GPR137缺失对细胞生长的影响。使用信号转导阵列分析和蛋白质印迹分析确定潜在的分子机制。
在三种人类骨肉瘤细胞系Saos-2、U2OS和SW1353中，GPR137的表达高于成骨细胞hFOB 1.19细胞。慢病毒介导的靶向GPR137的小干扰RNA成功敲低了Saos-2和U2OS细胞中GPR137的mRNA和蛋白质表达。在没有GPR137的情况下，细胞活力和集落形成能力严重受损。两种细胞系中的细胞凋亡程度也有所增加。此外，在GPR137敲低的细胞中，AMP激活的蛋白激酶α、40 kDa富含脯氨酸的AKT底物、AKT和细胞外信号调节激酶的磷酸化水平下调。
本研究结果突出了GPR137在促进骨肉瘤细胞生长中的关键作用。GPR137可作为骨肉瘤的潜在治疗靶点。
