Bone cancer pain (BCP) is a common chronic pain that is caused by a primary or metastatic bone tumor.More detailed molecular mechanisms of BCP are warranted.In this study,we established a BCP rat model.The von Frey hair test,body weight,and hematoxylin and eosin staining were employed.We screened differentially expressed circRNAs (DECs) between the BCP group and sham group.The results revealed that 850 DECs were significantly up-regulated and 644 DECs were significantly down-regulated in the BCP group.Furthermore,we identified 1177 differentially expressed genes (DEGs) significantly up-regulated and 565 DEGs significantly down-regulated in the BCP group.Gene Ontology annotation of all 1742 DEGs revealed that biological regulation of metabolic processes,cellular processes,and binding were the top enriched terms.For Kyoto Encyclopedia of Genes and Genomes analysis,phagosome,HTLV-I infection,proteoglycans in cancer,and herpes simplex infection were significantly enriched in this study.In addition,we identified four selected circRNAs,chr6:72418120|72430205,chr20:7561057|7573740,chr18:69943105|69944476,and chr5:167516581|167558250,by quantitative real time PCR.chr6:72418120|72430205 (circSt3) was selected for further study based on expression level and the circRNA-miRNA-mRNA network table.Weste blot analysis suggested that knockdown of circSt3 could effectively induce Walker 256 cell apoptosis.In summary,our study provided a more in-depth understanding of the molecular mechanisms of BCP.