The Sensitive Differences Research Of Breast Cancer Cells To Amphibian Antimicrobial Peptide Temporin-1CEa And Its Analogues

Antimicrobial peptides (AMPs) act as an important component of innate immunitysystem. AMPs originally from amphibian is usually hydrophobicity, once they contact withbiological membranes, they will adopt α-helical structure. In this paper, the selectedantimicrobial peptide temporin-1CEa from amphibian skin secretions was composed with17amino acid. In our previous study, the structure of temporin-1CEa was examined, the activityof hemolysis and the anticancer mechanism were also studied. But temporin-1CEa exhibitedhigh cytotoxicity to human blood cell and lower activity anticancer. In order to reduce thehemolytic activity of temporin-1CEa and improve its anticancer potency towards a range ofhuman breast cancer cells, six temporin-1CEa analogues LK1, LK2(5)，LK2(6)，LK3，LK2(6)A(L) and LK2(6)AN(2L) were rationally designed and synthesized, their net chargebetween+4from to+7, they showed decent amphipathic, and adopted α-helical structure inmimic membrane environment.The MTT assay results showed the six analogs can inhibit the proliferation of five breatcancer cells (MCF-7，SK-BR-3，MDA-MB-231，MDA-MB-453and Bcap-37), and MCF-7,SK-BR-3, Bcap-37were sensitive to the peptides. Moreover, LK1, LK2(6), LK2(6)A(L),LK2(6)AN(2L) exhibited high anticancer activities. Compared with the hemolysis and thecytotoxicity to normal human mammary epithelial cell line MCF10A, LK1, LK2(6) andLK2(6)A(L) were selected for further mechanism study.The effects of phospholipid, oligosacharide and net charges existed on the surface ofmembrane of these five breast cancer cells on anticancer activity of peptides were investigated.The results showed that the expression of PS, CS and HS was different in five breast cancercells. By treatment of Chondroitinase ABC, a hydrolytic enzyme of CS, the anticanceractivity of temporin-1CEa, LK1, LK2(6)A(L), LK2(6)AN(2L) showed almost no changes.But HS might exhibit the effects on the activity of peptides. In addition, the sulfuric acidgroup with negative charges and cholesterol existed on the surface of cancer cell membranecan also affect anticancer activity of peptides.