Effect And Mechanism Of Deubiquitination Protease 22 On Invasion And Migration Of Osteosarcoma

Background and Objective:Osteosarcoma(OS),as the most common clinical malignant bone tumor,can occur in all ages,and most of them are adolescents.Due to its rapid growth,early metastasis and high degree of malignancy,the cure rate of simple surgical treatment is low and the prognosis is poor,which also brings endless pain to patients and their families.How to improve the cure rate and prognosis of osteosarcoma is an urgent problem to be solved.Therefore,it is of great significance to study the molecular mechanism of the occurrence and development of osteosarcoma and find new molecular biological therapeutic targets.Ubiquitin-specific protease 22(USP22)is involved in a variety of malignant biological behaviors of tumors,such as stemness maintenance,invasion,migration,apoptosis,and drug resistance.However,little is known about the role and mechanism of USP22 in OS.Based on the above background,the aim of this study is to analyze the effect of USP22 on the invasion and migration of osteosarcoma and explore its mechanism.It provides new ideas for the treatment of osteosarcoma.Method:1.The expression of USP22 in osteosarcoma tissues and cells was analyzed by Western blot and q RT-PCR.2.sh USP22 lentivirus was constructed to infect the cell line with the highest expression level of USP22.Western blot and q RT-PCR were used to screen the cell line with the best down-regulation effect of sh USP22 lentivirus stable transfection,and then Western blot was used to detect the effect of down-regulation of USP22 on EMT mechanism of osteosarcoma.In addition,the effect of down-regulation of USP22 expression on the invasion and migration of osteosarcoma cells was detected by Transwell assay and wound healing assay.Finally,the constructed stable cell line sh USP22/143B-OS was transplanted into nude mice and injected into the tail vein to observe the metastasis of osteosarcoma cells in the lungs of nude mice.3.The expression level of β-Catenin in osteosarcoma tissues and corresponding adjacent tissues was detected by Western blot and q RT-PCR.After changing the expression of USP22,the expression of β-Catenin in osteosarcoma cells was detected.To further analyze the correlation between β-Catenin and USP22 expression in osteosarcoma tissues,the expression of β-Catenin was upregulated in cells with stable low expression of USP22,and the expression of β-Catenin was downregulated in cells with stable high expression of USP22.Western blot was used to detect the expression levels of the two proteins.Transwell assay and scratch test were used to observe the invasion and migration ability of osteosarcoma cells.Finally,Co-IP was used to detect whether USP22 could directly bind to β-Catenin and regulate its expression.Result:1.Western blot and q RT-PCR results showed that the expression level of USP22 in osteosarcoma tissues and cells was significantly higher than that in normal osteoblasts in adjacent tissues(p<0.01).2.After down-regulation of USP22 expression in 143 B cells,the scratch test and Transwell test showed that the invasion and migration ability of 143 B cells was also significantly reduced(p<0.01).In vivo experiments also showed that the number of lung metastasis in nude mice with USP22 knockdown was less than that in the corresponding control group(p<0.05).3.Knockdown of USP22 in osteosarcoma cells reduced the expression level ofβ-Catenin.On the contrary,overexpression of USP22 increased the level of β-Catenin,and the reversion experiment further verified that USP22 affected the invasion and migration of osteosarcoma by mediating the expression level of β-Catenin.Co-IP results confirmed that USP22 directly binds to β-Catenin.Conclusion:USP22 affects the invasion and migration of osteosarcoma by mediating the expression level of β-Catenin.The results of this study suggest that USP22 andβ-Catenin are promising potential targets for the treatment of osteosarcoma.