Figure 4.

COMMD1 is involved in the antitumor activity of CIGB-552. (a) H460 cells were transfected with control or COMMD1 siRNA and then the IC₅₀ values were determined using a logarithmic regression of the growth curves obtained from SRB (sulforhodamine B, sodium salt). Mean ± SD of three determinations are shown. Data were obtained from two different experiments. Top, Western blot demonstrating stable shRNA mediated repression of COMMD1 in H460 cells. Actin was used as a control for protein loading. H460 cells were transfected with control or COMMD1 siRNA and then treated with CIGB-552 (25 μM) from 0 to 12 h. (b) Ubiquitination of RelA is greatly impaired in COMMD1 deficiency cells treated with CIGB-552. Anti-RelA immunoblot shows levels of ubiquitinated RelA after 5 h of treatment. (c) Repression of the levels of proteins RelA and Bcl-2 are impaired in COMMD1 deficiency treated with CIGB-552. Bcl-2 and RelA proteins levels were determined by Western blot analysis. Actin was used as a control for protein loading.