Fig. 6. The compound S62 interrupted the interaction between PELI1 and EGFR to suppress breast cancer metastasis.

A Chemical structure of S62. B HEK293T/17 cells with overexpression of PELI1 and EGFR were treated with or without S62 (5 or 10 μM) for 24 h. Co-IP assay was subsequently performed to detect the interaction between PELI1 and EGFR. C Western blotting analysis of EGFR and PELI1 in MBA-MB-231 cells with the treatment of S62 for 24 h. D Flow cytometric analysis of the membrane EGFR in MDA-MB-231 cells treated with or without S62 for 24 h (N = 3). E Western blotting analysis of EGFR, PELI1 and phosphorylation of EGFR with or without the treatment of S62 (10 μM) upon EGF stimulation (100 ng/ml). F Western blotting analysis of the tyrosine and threonine phosphorylation of PELI1 immunoprecipitated from MDA-MB-231 cells. The cells were treated as in E. G Western blotting analysis of the K63-mediated polyubiquitination of EGFR immunoprecipitated from HEK293T/17 cells with the treatment of S62 (10 μM). H Quantitative analysis of the migration of MDA-MB-231 cells with the treatment of S62 (N = 3). I Effect of S62 on the invasion of MDA-MB-231 cells. The representative images of invasive cells were shown (scale bar, 100 μm). J Quantitative analysis of the invasion of MDA-MB-231 cells in I (N = 3). K Western blotting analysis of E-cadherin and SNAIL in MDA-MB-231 cells with the treatment of S62. L The representative images of lung metastasis of breast cancer cells in NYG mice with S62 treatment. MDA-MB-231 transfected with lentivirus that stably expressed luciferase (2 × 10⁵/mouse) were injected into NYG mice via the tail vein. The mice were treated with CMC-Na (0.5%) or S62 (10 or 50 mg/kg) every day for 2 weeks, and then were detected using the bioluminescence imaging. *P < 0.05, ***P < 0.001. All P values were determined by unpaired two-tailed Student’s t test.