Figure 3.

Correlations of interferon alpha (IFN-α)-induced cell growth inhibition and IFN-α-induced NEDD8 ultimate buster 1 (NUB1) expression in renal cell carcinoma (RCC) cell lines. (A) Cells were treated with or without 3000 U ml^–1 IFN-α for 24 h. Total cell lysates were prepared from each cell line and analysed by western blotting using an anti-NUB1 antibody to detect NUB1 protein (upper panel). To demonstrate equal loading amounts of total cell lysates, western blotting using anti-β-actin antibody was also performed (lower panel). (B) To quantitatively evaluate the data shown in (A), a densitometry analysis was performed. NUB1 expression values are normalised by the β-actin level in each cell line and presented as the relative fold compared with the control. Three individual experiments were performed and means±s.d. are presented. (C) The analysis was performed using the inhibition values of cell proliferation presented in Figure 1B and the induction ratios of NUB1 protein by IFN-α shown in (B). Lines represent RCC cell samples with (solid line: coefficient=0.34, P=0.09) and without (dotted line: coefficient=0.74, ^*P<0.01) the 10RGB cell line (arrow).