ASB7 promotes osteosarcoma lung metastasis through ubiquitin-mediated degradation of ATF2

Osteosarcoma is a highly heterogeneous and aggressive malignancy with a strong propensity for metastasis, highlighting the need to define its molecular drivers. Here, we report that ASB7 promotes tumor cell protrusion formation, invasion, migration, and lung metastasis. High expression of ASB7 is correlated with a poor prognosis. ASB7 forms an E3 ubiquitin ligase complex with CUL5 to ubiquitinate ATF2 at K383 and promote its proteasomal degradation. ATF2 reduction impairs HDAC6 recruitment to the ITGB2 promoter, thereby alleviating the transcriptional repression of ITGB2. Elevated ITGB2 expression subsequently promotes tumor lung metastasis. Our findings reveal that the ASB7-ATF2/HDAC6-ITGB2 axis regulates osteosarcoma metastasis and suggest potential treatment targets.