RNF2 promotes chondrosarcoma progression by regulating ubiquitination and degradation of CBX7.

Objective: Chondrosarcoma (CHS) is resistant to conventional chemotherapy and radiotherapy and currently lacks effective treatment options when in advanced stages. Accordingly, this research investigated the mechanism of RNF2/CBX7 in CHS to drive the development of molecularly targeted drugs for CHS. Methods: RNF2 and CBX7 levels were detected in CHS cells and tissues. RNF2 and CBX7 expression was modulated through cell transfection to examine their effects on cell proliferation, apoptosis, migration, and angiogenesis. The correlation between RNF2 and CBX7 levels was determined, and the ubiquitination level of CBX7 was tested. Protein synthesis was blocked in RNF2-knockdown/overexpressing cells with CHX to assess the effect of RNF2 on CBX7 stability. JJ012 cells transfected with LV-sh-RNF2 were subcutaneously injected into nu/nu nude mice to ascertain the action of RNF2 in the growth and metastasis of CHS. Results: RNF2 was highly expressed in CHS cells and tissues. RNF2 knockdown curbed CHS cell proliferation, migration, and angiogenesis while promoting apoptosis. RNF2 knockdown in JJ012 cells upregulated CBX7 protein levels and reduced CBX7 ubiquitination, whilst RNF2 had no effect on CBX7 mRNA expression. CBX7 knockdown partially nullified the repressing effects of RNF2 knockdown on CHS cell proliferation, migration, and angiogenesis, and CBX7 overexpression partially abolished the promotional effects of RNF2 overexpression. LV-sh-RNF2 prominently restricted tumor growth and weight and declined lung metastatic nodules and Ki-67-positive cells in mice. Conclusion: RNF2 fosters CHS progression by elevating CBX7 degradation via the ubiquitination pathway. [ABSTRACT FROM AUTHOR]