Fig. 5
KDM4B mediates the ubiquitination of MYC via the E3 ligase complex SCFFBXL3+CRY2. A The qPCR was adopted to assess the mRNA levels of MYC and CCNB1 in KDM4B-knockdown GBM cells. B The shKDM4B plasmid and HA-Ub plasmid were co-transfected into U87-MG and LN229 cells, and the transfected cells were treated with MG132 for the ubiquitination assay. C The degradation rate of MYC was measured. U87-MG and LN229 cells were transfected with the shGFP plasmid or shKDM4B plasmid and then treated with CHX (100 μg/ml) for the indicated times. D Cell lysates were prepared from KDM4B-knockdown cells treated with or without MG132 for 8 h. Equal amounts of cell lysates were immunoblotted with the indicated antibodies. E–F The mRNA and protein levels of FBXL3 and CRY2 were measured after KDM4B knockdown in U87-MG and LN229 cells. G The expression levels of MYC, FBXL3, and CRY2 in response to KDM4B knockdown were evaluated by immunohistochemistry in tumor tissues. *p < 0.05, ** p < 0.01