The Antitumor Peptide CIGB-552 Increases COMMD1 and Inhibits Growth of Human Lung Cancer Cells
Figure 2
CIGB-552 promotes accumulation of endogenous COMMD1. (a) The cell lines H460, HT-29, and MCF-7 were treated with CIGB-552 (25, 60, and 20 μM, resp.) or MG132 (25 μmol/L) during 5 h. The levels of COMMD1 were determined by Western blot analysis of whole-cell lysates. NT untreated cells. Actin was used as a control for protein loading. (b) Cellular distribution of COMMD1 in HT-29 and MCF-7 cells following CIGB-552 treatment. Representative confocal micrographs of the duplicate samples are shown (scale bar = 5 μm). Color bar (bottom left of the figure) indicate the signal strength. (c) In H460 cells, the localization of endogenous COMMD1 in the presence of CIGB-552 (25 μM) at the indicated times was determined by cell fractionation followed by immunoblotting using antibodies directed against endogenous COMMD1. The protein expression of human ribonucleoprotein (hRNP) and tubulin were used as loading controls and markers for nuclear and cytosolic fractions. Nuc indicates nuclear fraction and cyt indicates cytosolic fractions. (d) COMMD1 mRNA expression determined after CIGB-552 treatment in H460 cells. mRNA expression was normalized to an expression on time point zero and shown as the mean fold induction ± SEM of three biological replicates. No differences were found at any time in the levels of COMMD1 mRNA.
