Fig. 3

MEG3 promotes the degradation of P-STAT3 via ubiquitination. The RNA pull-down assay results suggest that MEG3 may bind to P-STAT3 protein (a). The results of RIP assay suggest that P-STAT3 protein may enrich MEG3 (b). CHX-chase assay results suggest that MEG3 may promote P-STAT3 protein degradation (c, d). All groups of cells were treated with 20 μM of an ubiquitination inhibitor MG132 for 4 h or 5 mM of an autophagy inhibitor 3-methyladenine (3-MA, Selleck Chemicals) for 2 h, followed by western blot analysis to determine changes in P-STAT3 expression (e). Ubiquitination assay was used to detect P-STAT3 ubiquitination (f) in all groups of cells. *P < 0.05