The Anticancer Effect Of The Antibacterial Peptide Pc-pis In Yellow Croaker And Fusing Protein Expression

Pc-pis,cloning from Marine fish large yellow croaker(Pseudosciaena crocea),is one of the antibacterial peptides(AMP)with cationic amphiphilic structures.It has broad-spectrum antibacterial,anti-fungi and anti-parasites activity,and lower hemolysis activity.In order to investigate the anti-tumor effect of Pc-pis,we did a lot of work.Here,we found that Pc-pis had the antitumor activity against a variety of cancer cells(Hela,HCT116,DU145,MCF7).Interestingly,the appropriate size osmotic pressure protectant PEG4000 can prevent HeLa cells from being induced to die by Pc-pis.Therefore,we hypothesized that Pc-pis interacted with the cell membrane of HeLa cells,destroying the integrity of the cell membrane and leading to the cell death.We also found that the fusion protein of GFP-Pc-pis mainly accumulated on the nuclear membrane of HeLa cells,and the modified Pc-pis with positive charge enhances this effect,but negative charge has the opposite influence.In our study,three of Piscidins or related family members showed nuclear membrane localization and anti－tumor activity.So,we speculate that the positive charge of AMPs is important to it’s biological function.In addition,GFP-Pc-pis would not locate in nuclear membrane when shortening or shielding the C-terminal of Pc-pis.Hence we believe that free C-terminal and the complete structure of AMPs is very important for their membrane binding capacity.Then,we studied the expression of Pc-pis fusion protein in prokaryotes.Although the cytotoxicity of Pc-pis inhibited the expression of fiusion proteins,the C-terminal of Pc-pis fused with calmodulin(CaM)can improve this effect.In addition,GST labeling on the Pc-pis N terminal can also promote expression of the fusion protein in prokaryotes.In order to promote development of the clinical use of Pc-pis,we will use Msln/MUC16 interaction system to deliver Pc-pis fusion protein to cancer cells in the future.