Fig. 6: High matrix stiffness downregulates MHC-I expression through USP8/NBR1 axis.

A The endogenous interaction between MHC-1 and NBR1 was detected in DU145 and PC-3 cells by coimmunoprecipitation and western blot. B Western blot analysis of MHC-1 expression in DU145 and PC-3 cells treated with 3-MA or MG132. C Coimmunoprecipitation and western blot indicating the endogenous non-interaction between USP8 and MHC-1 in DU145 cells. D Western blot showing the effect of USP8 knockdown or overexpression on the expression levels of MHC-1 protein in DU145 and PC-3 cells. E Western blot indicating that the effect of USP8 on MHC-1 expression could be rescued by NBR1. F Western blot and its quantitative results indicating the expression levels of MHC-1 of DU145 and PC-3 cultured in different PAAG stiffness. G IHC staining and its quantitative results indicating the different expression of MHC-1 protein in PCa tissues of Gleason score < 7, or =7, or >7. Data are presented as the mean ± SD of at least three independent experiments and were analyzed with unpaired two-tailed student’s t-test or one-way ANOVA test unless otherwise stated, *P < 0.05, **P < 0.01, ***P < 0.001.