Department of Hand and Foot Surgery, Second Affiliated Hospital of Soochow University, Suzhou; Department of Orthopedics, Second Affiliated Hospital of Anhui Medical University, Hefei Anhui, China.
Bosn J Basic Med Sci. 2019 Aug 20;19(3):265-273. doi: 10.17305/bjbms.2019.4177.
Recent studies showed that the activation of prostaglandin (PG) receptor EP1 promotes cell migration and invasion in different cancers. The aim of this study was to investigate the role of EP1 in the proliferation of osteosarcoma (OS) cells in vitro and in vivo. EP1 mRNA and protein levels were analyzed by real-time RT-PCR and Western blot, respectively in human OS cell lines MG63, OS732, U-2OS, and 143B compared to human fetal osteoblastic hFOB 1.19 cells. MG63 cells were treated with PGE2, EP1 specific agonist 17-PT-PGE2, 17-PT-PGE2 + EP1 specific antagonist SC51089, or DMSO (control). EP1R-siRNA or a non-silencing irrelevant RNA duplex (negative control) were used for the transfection of MG63 cells, followed by PGE2 treatment. Nude mice carrying MG63 xenografts were treated with SC51089 (2 mg/kg/day). MG63 cells/xenografts were analyzed by MTT assay, TUNEL assay, PKC enzyme activity assay, and Western blot (EP1 and apoptotic proteins), and tumor growth/volume was evaluated in mice. EP1 levels were significantly higher in OS cells compared to osteoblasts. PGE2 or 17-PT-PGE2 treatment increased the proliferation and decreased the apoptosis of MG63 cells. Inhibition of EP1 by SC51089 or siRNA markedly decreased the viability of MG63 cells. Similarly, SC51089 treatment significantly inhibited MG63 cell proliferation and promoted apoptosis in vivo. The silencing of EP1 receptor by siRNA or blockade of EP1 signaling by SC51089 activated extrinsic and intrinsic apoptotic pathways both in vivo and in vitro, as evidenced by increased levels of Bax, cyt c, cleaved caspase-3, caspase-8 and caspase-9. EP1 appears to be involved in PGE2-induced proliferative activity of MG63 cells. Antagonizing EP1 may provide a novel therapeutic approach to the treatment of OS.
最近的研究表明，前列腺素（PG）受体 EP1 的激活促进了不同癌症中的细胞迁移和侵袭。本研究旨在探讨 EP1 在体外和体内对骨肉瘤（OS）细胞增殖的作用。通过实时 RT-PCR 和 Western blot 分别分析人骨肉瘤细胞系 MG63、OS732、U-2OS 和 143B 与人类胎儿成骨细胞 hFOB 1.19 细胞相比 EP1 mRNA 和蛋白水平。用 PGE2、EP1 特异性激动剂 17-PT-PGE2、17-PT-PGE2+EP1 特异性拮抗剂 SC51089 或 DMSO（对照）处理 MG63 细胞。用 EP1R-siRNA 或非沉默无关 RNA 双链（阴性对照）转染 MG63 细胞，然后用 PGE2 处理。用 SC51089（2mg/kg/天）处理携带 MG63 异种移植物的裸鼠。通过 MTT 测定、TUNEL 测定、PKC 酶活性测定和 Western blot（EP1 和凋亡蛋白）分析 MG63 细胞/异种移植物，评估小鼠肿瘤生长/体积。与成骨细胞相比，OS 细胞中 EP1 水平明显升高。PGE2 或 17-PT-PGE2 处理增加了 MG63 细胞的增殖并减少了其凋亡。SC51089 或 siRNA 抑制 EP1 显著降低了 MG63 细胞的活力。同样，SC51089 处理显著抑制了体内 MG63 细胞的增殖并促进了其凋亡。体内和体外实验均表明，通过 siRNA 沉默 EP1 受体或通过 SC51089 阻断 EP1 信号，通过增加 Bax、细胞色素 c、裂解 caspase-3、caspase-8 和 caspase-9 的水平，激活了外在和内在凋亡途径。EP1 似乎参与了 PGE2 诱导的 MG63 细胞增殖活性。拮抗 EP1 可能为骨肉瘤的治疗提供一种新的治疗方法。
