Osteosarcoma (OS) is the most common malignant bone tumor in children and adolescents. Increasing evidence suggests that aberrant expression of circRNAs is associated with the occurrence and progression of many cancers. Here, we investigated the role of circNRIP1 in osteosarcoma and explored its possible underlying mechanisms. Three pairs of osteosarcoma tissues and adjacent normal tissues were applied to the detection of altered expression of circRNAs through circRNAs microarray. And the level of circNRIP1 expression was elevated in osteosarcoma tissues. Compared with that in adjacent normal tissue, circNRIP1 expression level was obviously elevated in 100 osteosarcoma tissues. Besides, circNRIP1 knockdown inhibited proliferation and migration, promoted apoptosis of osteosarcoma cells. Bioinformatic analysis demonstrated circNRIP1 contributed to FOXC2 expression by sponging miR-199a. Furthermore, METTL3 elevated circNRIP1 expression level via m6A modification. In short, METTL3-induced circNRIP1 exerted an oncogenic role in osteosarcoma by sponging miR-199a, which may provide new ideas for the treatment of osteosarcoma.

骨肉瘤（OS）是儿童和青少年最常见的恶性骨肿瘤。越来越多的证据表明，circRNA 的异常表达与许多癌症的发生和进展有关。在这里，我们研究了 circNRIP1 在骨肉瘤中的作用，并探讨了其可能的潜在机制。将三对骨肉瘤组织和邻近的正常组织通过circRNAs微阵列应用于检测circRNAs表达的改变。并且在骨肉瘤组织中circNRIP1表达水平升高。与邻近正常组织相比，100个骨肉瘤组织中circNRIP1的表达水平明显升高。此外，circNRIP1 敲低抑制了增殖和迁移，促进了骨肉瘤细胞的凋亡。生物信息学分析表明 circNRIP1 通过海绵化 miR-199a 促进 FOXC2 的表达。此外，METTL3 通过 m6A 修饰提高了 circNRIP1 的表达水平。总之，METTL3诱导的circNRIP1通过海绵化miR-199a在骨肉瘤中发挥致癌作用，可能为骨肉瘤的治疗提供新思路。