Journal: Frontiers in Immunology
Article Title: PSMD12 promotes hepatocellular carcinoma progression by stabilizing CDK1
doi: 10.3389/fimmu.2025.1581398
Figure Lengend Snippet: PSMD12 stabilizes CDK1 protein levels by reducing ubiquitin-mediated degradation of CDK1 in HCC cells. (A, B) Western blot analysis of PSMD12 and CDK1 protein levels in HCC cells following PSMD12 knockdown or overexpression, with GAPDH as a loading control. (C, D) qRT-PCR assessment of PSMD12 and CDK1 mRNA levels in HCC cells after PSMD12 knockdown or overexpression, with GAPDH as a control. (E, F) MHCC97H and HCCLM3 cells were treated with cycloheximide (CHX, 50 μg/mL), and Western blot analysis was performed to detect CDK1 protein levels at different time points. (G, H) MHCC97H and HCCLM3 cells were treated with CHX (50 μg/mL) for specified durations, with or without the addition of the PSMD12 overexpression plasmid, followed by Western blot analysis to assess CDK1 protein levels. (I, J) HCC cells were treated with 15 μmol/L MG132 and collected at 0/3/6/9 hours, followed by Western blot to analyze protein expression levels. (K, L) MG132 (15 μM) treatment of MHCC97H and HCCLM3 cells altered PSMD12 expression, with PSMD12 and CDK1 protein levels assessed by Western blot analysis. (M, N) Co-immunoprecipitation (Co-IP) assays in MHCC97H and HCCLM3 cells confirmed the interaction between ubiquitin (Ub) and CDK1. (O) Colocalization studies in HCC cells using an anti-CDK1 antibody (1:100, red) and anti-ubiquitin antibody (1:100, green), followed by DAPI nuclear counterstaining (blue). Scale bar: 20 mm. (P, Q) MG132 (15 μM) was added to MHCC97H and HCCLM3 cells, which were simultaneously transfected with shPSMD12#1 or HA-PSMD12 plasmids. Co-IP assays were performed to detect ubiquitin binding to CDK1. (R) After 48 hours of transfection of Myc-PSMD12, Flag-CDK1, and HA-Ub WT/K48/K63, cells were lysed, and then immunoprecipitation was performed with Flag antibody, and immunoblot analysis was performed with HA antibody. (S) The docking conformation and three-dimensional structure of PSMD12 and CDK1.PSMD12 and CDK1 are shown in orange and cyan respectively. Statistical significance was determined using Student's t-tests and one-way ANOVA followed by Tukey's multiple comparisons test. *p < 0.05, **p < 0.01, ***p < 0.001; ns, not significant.
Article Snippet: Additional human HCC cell lines HCCLM3 (CL-0042) and SMCC7721 (CL-0216) were obtained from Procell (Wuhan, China), and the MHCC97H (ZB001) cell line was acquired from Bei Zhi Creatures (Shanghai, China).
Techniques: Ubiquitin Proteomics, Western Blot, Knockdown, Over Expression, Control, Quantitative RT-PCR, Plasmid Preparation, Expressing, Immunoprecipitation, Co-Immunoprecipitation Assay, Transfection, Binding Assay