Fig. 6From: Extracellular vesicle-packaged circBIRC6 from cancer-associated fibroblasts induce platinum resistance via SUMOylation modulation in pancreatic cancercircBIRC6 augments SUMOylation of XRCC4 at K115 residue. (A) Western blot analysis illustrating cytoplasmic and nuclear distribution of XRCC4 in Panc-1 cells treated with EVs isolated from CAFs and the SUMOylation inhibitor (2-D08). (B) Co-immunoprecipitation (Co-IP) study presenting the SUMO1 binding on XRCC4 in Panc-1 cells treated with EVs from CAFs transfected with lenti-circBIRC6-shRNA or lenti-NC-shRNA. (C) Co-IP assays elucidating the interaction between XRCC4 and SAE1 in Panc-1 cells treated with EVs from CAFs transduced with lenti-circBIRC6-shRNA or lenti-NC-shRNA. (D) Co-IP analysis of SUMO1 binding on XRCC4 in Panc-1 cells transfected with SAE1 siRNA and treated with EVs from CAFs. (E) Western blot analysis of cytoplasmic and nuclear distribution of XRCC4 in Panc-1 cells transfected with SAE1 siRNA and treated with EVs from CAFs. (F) Schematic depiction of the predicted SUMO1 binding sites on XRCC4 obtained via GST-SUMO. (G) Sequence alignment of XRCC4 homologs across various species. (H) Sequencing evaluation of the XRCC4K115R and XRCC4K210R mutations. (I) Co-IP assays assessing the SUMO1 binding sites on XRCC4. (J) Western blot analysis of cytoplasmic and nuclear distribution of XRCC4 in Panc-1 cells transfected with XRCC4 K115R or XRCC4K210R mutations and treated with EVs from CAFs. (K) Representative image and quantification of apoptosis in Panc-1 cells transfected with XRCC4K115R mutations and treated with EVs from CAFs using flow cytometry. n.s., not significant. Data are expressed as mean ± SD. **p < 0.01Back to article page