In silico and In vitro Investigation of a Likely Pathway for Anti-Cancerous Effect of Thrombocidin-1 as a Novel Anticancer Peptide

Abstract

Background: Antimicrobial and antifungal activities of Thrombocidin-1 (TC-1) is shown previously, however, the anti-cancerous feature of this peptide is still uncovered. Objective: The objective is to evaluate anti-cancerous feature of recombinant TC-1. Methods: In this study, based on the significant similarity of rTC-1 and IL-8 in case of coding sequence, tertiary structure, and also docking and molecular dynamic simulation (MD) results with CXCR1, a receptor which has positive correlation with different cancers, a likely pathway for anticancerous effect of rTC-1 was proposed. In addition, the coding sequence of TC-1+6xhistidine (rTC-1) was inserted into the pET22b(+) vector and cloned and expressed by E. coli BL21 and finally purified through nickel affinity column. Afterward, the retrieved rTC-1 was used in MTT assay against mouse colon adenocarcinoma, hepatocellular carcinoma, chondrosarcoma, mouse melanoma, and breast adenocarcinoma cell lines to investigate its probable anticancer application. Results: Docking and MD simulation results showed that rTC-1 and IL-8 share almost the same residues in the interaction with CXCR1 receptor. Besides, the stability of the rTC-1_CXCR11-38 complex was shown during 100ns MD simulation. In addition, the successful expression and purification of rTC-1 depict an 8kD peptide. The IC50 results of MTT assay revealed that rTC-1 has cytotoxic effect on C26-A and SW1353 cancerous cell lines. Conclusion: Therefore, apart from probable anti-cancerous effect of rTC-1 on C26-A and SW1353 cell lines, this peptide may be able to mimic the anti-cancerous pathway of IL-8.