Fig. 2
TMEM160 stabilizes PD-L1 protein expression by inhibition of ubiquitination-dependent degradation of PD-L1. A, B Western blotting assays and C RT-qPCR were performed to test the expression of TMEM160 and PD-L1 at the protein and mRNA levels, respectively. The expression analysis was performed following interference with TMEM160 expression using two different siRNAs (#1 and #2) in HCT116 and DLD1 cells, as well as TMEM160 overexpression in SW480 and RKO cells. D IF experiments of HCT116 cells transfected with siScr or siTMEM160#1 plasmid were assessed with PD-L1 expression by the fluorescence intensity of PD-L1. E Flow cytometric analysis of DLD1 cells transfected with siScr or siTMEM160#1 plasmid were assessed with surface PD-L1 expression. F, G To assess the effect of TMEM160 expression on PD-L1 stability, the CHX assay was performed in DLD1 cells transfected with siTMEM160#1 and SW480 cells with Myc-TMEM160. H Western blotting assay detected that MG132 can reverse the reduced expression of PD-L1 due to TMEM160 downregulation. I The ubiquitination assay was conducted in HCT116 cells to analyze the impact of TMEM160 overexpression on PD-L1 ubiquitination