Fig. 4: NUB1 reduction promotes PCNA protein expression by increasing NEDD8 in HCCLM3 cells.

A qRT-PCR and western blot were used to analyze the mRNA and protein levels of NEDD8 and PCNA in HCCLM3 cells with the indicated treatments (n = 3). The mRNA levels of NEDD8 and PCNA were normalized to GAPDH. B, C EdU (B) and colon formation assays (C) detected the proliferation capacities of HCCLM3 cells with the indicated treatments (n = 6). D qRT-PCR and western blot were used to analyze the mRNA and protein levels of NUB1 and NEDD8 in HCCLM3 cells with the indicated treatments (n = 3). The mRNA levels of NUB1 and NEDD8 were normalized to GAPDH. E HCCLM3 cells transfected with shNEDD8 or control were transfected with or without shNUB1 and the cell lysates were subjected to immunoblotting. F and G EdU (F) and colon formation assays (G) analyses for the above groups (n = 6). H HCCLM3 cells transfected with His-NEDD8 or control were transfected with or without Flag-NUB1 and the cell lysates were subjected to immunoblotting. I, J EdU (I) and colon formation assays (J) analyses for the above groups (n = 6). Data represent the mean ± SD. *p < 0.05; **p < 0.01; ***p < 0.001.