Ponente
Descripción
Introduction: CIGB-552, a novel cell-penetrating synthetic peptide, was effective in reducing tumor size and increasing lifespan in tumor-bearing mice. Studies of protein–peptide interactions have shown that COMMD1 protein is a major mediator of CIGB-552 antitumor activity. Knowledge of the physical-chemical and biological properties of the metabolites is crucial from the regulatory point of view.
Objectives: A comparative analysis between CIGB-552 and its main metabolites regarding physicochemical properties, cellular internalization, and their capability to elicit apoptosis.
Materials and Methods: MCF-7, HT-29 and H460 cells were cultured in DMEM supplemented with 10% (v/v) FBS. Sulforhodamine B Assay, Annexin V and Caspase 7 activation were used as indicator of apoptosis. For the internalization assays Flow Cytometry and Confocal Microscopy was used.
Results: CIGB-552 induces apoptosis but its derived metabolites do not. derived metabolites showed reduced binding capacity to COMMD1 in vitro. CIGB-552 has the highest cell penetrating capacity. In addition, cell penetrating capacity varies among the three cell lines studied. H460 displayed the highest internalization levels, while MCF-7 presented the lowest internalization capacity. Moreover, CIGB-552 used both endocytosis and transduction as internalization mechanisms, although the contributions of each mechanism varied among the studied cell lines.
Conclusions: Overall, our results suggest that features conferred by the amino acid sequence are decisive for CIGB-552 biological activity, turning it into the minimal functional unit. H460 sensitivity could be explained by its high internalization capacity of CIGB-552, by using the endocytosis as a preferred mechanism, which in turn favors the interaction between the peptide and its target protein COMMD1.
Palabras clave. anti-cancer peptides; cell penetrating peptides; COMMD1, CIGB-552
