Fig. 6

The circPTPN22/miR-6788-5p/PAK1 axis regulates autophagy in GC cells by activating AKT and ERK phosphorylation. A–D After knockdown or overexpression of circPTPN22 in mRFP-GFP-LC3-labeled GC cells, PAK1 knockdown or overexpression plasmids were added. Cellular autophagic flux was visualized by confocal microscopy. A and C are representative confocal microscope images, and B and D are quantitative data. Scale bar, 10 μM. E–H After knockdown or overexpression of circPTPN22, inhibitor or mimic of miR-6788-5p was added. The proliferation and metastasis of GC cells were detected by CCK-8 (E), cell colony formation assay (F), migration (G) and invasion (H) assays. Scale bar, 100 μM. I After knocking down or overexpressing circPTPN22, add miR-6788-5p inhibitor or mimic. Western blot was used to detect the protein content of E-cad, vimentin, P62/SQSTM1 and LC3 B in GC cells. J Add miR-6788-5p inhibitor or pc-PAK1 after knocking down circPTPN22 and add miR-6788-5p mimic or shPAK1 after overexpressing circPTPN22. The protein levels of PAK1, p-AKT (s473), AKT, p-Erk (Thr202/Thr204) and Erk in GC cells were detected by Western blot. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.001