Functional Characterization of CIGB-300, a Novel Proapoptotic Synthetic Peptide that Impairs the Casein Kinase 2(CK2)-mediated Phosphorylation

YASSER PERERA; JEOVANIS GIL; HERNÁN FARINA; ARIELIS RODRIGUEZ; LILA CASTELLANOS; BORIS ACEVEDO; ROBERTO GÓMEZ; DANIEL F. ALONSO; SILVIO E. PEREA

Varadero, Cuba

Congreso; Proteomics in Cancer and Infectious Diseases,; 2007

CIGB

CIGB-300 is a novel proapoptotic synthetic peptide that impairs the Casein Kinase 2 (CK2)-Mediated Phosphorylation, elicits antitumor activity in different tumor animal models and its evaluation on the clinical onset has also started. In this work, using the potentialities of proteomics, we have described important clues on the functional characterization of the CIGB-300 which contributes to better understand its molecular mechanism of action. To study the CIGB-300 interactome, an appropriated combination of approaches involving pull-down assays in vitro and in vivo followed by ESI-MS analysis were performed. Results permitted to identify a protein array that are bound by the CIGB-300 in both experimental conditions, among them, different CK2 substrates and other proteins related to ribosome biogenesis and cytoskeleton architecture were identified in human lung cancer cells. Furthermore, the proteomic profile regulated by the CIGB-300 on these cells has been also explored and different proteins have been observed to be down-regulated or up-regulated upon the peptide addition. Importantly, data from such analysis confirmed the effect of the CIGB-300 in cell proliferation, apoptosis and also suggest that the intrinsic pathway for this cell death mechanism could be induced by the peptide. To evaluate the ability of CIGB-300 to impair the phosphorylation in vivo of a particular substrate, we performed an approach that combine a first immunoprecipitation step of the substrate followed by an isotopic labeling and ESI-MS analysis in human lung cancer cells. Data indicated that CIGB-300 was able to reduce in some extent the status of the CK2-mediated phosphorylation on the substrate studied. Taking together, the data originated from this experimentation have permitted to robust our working hypothesis concerning the mechanism by which CIGB-300 elicits its antineoplasic effect.