Combination Of Membrane Active Peptide HPRP-A1 And Apoptosis-induced Peptide Kla And Its Anticancer Mechanism

The high incidence,high death rate and low survival rate of cancer are becoming more and more serious,which has become the main killer of human health in the 21 st century.Among them,the incidence of lung cancer and breast cancer respectively in China's male and female cancer incidence first(national cancer center).At present,the main methods of clinical treatment for cancer include surgical treatment,chemotherapy and radiotherapy.These traditional treatment methods generally have defects such as low targeting selectivity,large toxic and side effects of drugs,and easy to recover and relapse after surgery,which greatly limit their anti-cancer efficacy.In recent years,anticancer peptides have attracted much attention due to their broad spectrum of biological activities and unique mechanism of action.Many anticancer peptides have good tumor targeting and penetration,and are not easy to develop drug resistance.Some anticancer peptides can also activate the immune system.In the preliminary work,we studied two anticancer peptides with different physical and chemical characteristics and active mechanisms,cationic membrane active peptide HPRP-A1 and apoptosis-induced peptide kla.HPRP-A1 is a helix structure with good membrane permeability and targeting of cancer cells.High concentration of HPRP-A1 can lead to the necrosis of cancer cells by breaking the membrane.kla has a folded structure and is composed of all d-type amino acids.It can induce cell apoptosis by inducing mitochondrial apoptosis,but its cell uptake rate is not high and it is difficult to enter the cell to play an active role.This topic with cation membrane active polypeptide HPRP-A1 and apoptosis induction of peptide kla as the research object,with lung cancer cell line A549 and breast cancer cell line MCF-7 as the research model,to whether can through combination play two polypeptide complementary cooperation effect,to further improve the antitumor activity and lower the drug toxicity of anticancer peptide problem is studied.Firstly,the polypeptide HPRP-A1 and kla were synthesized by FMOC solid phase synthesis method,and the pure peptides were prepared by HPLC.Secondly,MTT assay and flow cytometry were used to detect the effect of co-administration of HPRP-A1 and kla on the activity and proliferation of lung cancer cells A549 and breast cancer cells MCF-7.The results showed that low dose HPRP-A1 could significantly improve the anti-cancer activity of kla.Compared with A549,the effect of co-administration group on the activity and proliferation of MCF-7 was more obvious.Thirdly,the cell uptake and co-localization of the polypeptide were detected by confocal laser microscopy.The results showed that the co-administration group could significantly improve the cell uptake rate of the polypeptide kla.Further,using fluorescence microscope with mitochondrial apoptosis detection kit to affect cell mitochondria,results show that the total dose groups cause the obvious changes of the mitochondrial membrane potential,Western Blot experiments confirmed that the kla caused by the change of mitochondrial membrane potential,leading to the mitochondrial membrane damage and mitochondria cytochrome C released into the cytoplasm.Finally,a mouse model of breast cancer was constructed,and the anti-cancer peptides were injected daily to observe the changes in cancer volume,and immunohistochemical analysis was performed on the tissues and organs after the drug was administered.The results showed that the co-drug group effectively inhibited the growth of cancer and did not cause toxic damage to normal tissues.