Fig. 5

CircNF1 blocks USP7 binding to ANXA1, leading to increased binding between USP7 and PD-L1. A Co-IP assays were performed using antibodies against USP7 and ANXA1 in KYSE150 cells. B Co-IP analysis of the interaction between USP7 and ANXA1 in circNF1-overexpressed KYSE150 cells and control cells. C Detection of ANXA1 polyubiquitination level in KYSE150 (left panel) and TE1 (right panel) cells transfected with si-USP7 or si-circNF1 using immunoprecipitation. D Detection of PD-L1 polyubiquitination level in KYSE150 (left panel) and TE1 (right panel) cells transfected with si-USP7 or overexpressed circNF1 using immunoprecipitation. E, F Co-IP analysis of the interaction between USP7 and PD-L1 in control and ANXA1-deficient KYSE150 (left panel) and TE1 (right panel) cells