Construction Of Integrin-targeting Quaternary Ammonium Shell Oligosaccharide ES2 And Its Antitumor Effect

The occurrence and development of solid tumors depends on new blood vessels to provide oxygen and various nutrients.ES2(IVRRADRAAVP)is a polypeptide sequence composed of 11 amino acids in the endostatin structure,which also has the ability to inhibit the proliferation/migration of endothelial cells and induce apoptosis to inhibit angiogenesis and tumor growth.In the early stage of this project,ES2 was modified by quaternized chitooligosaccharide(QCOS),with antibacterial and antitumor activities,and the modified product was found to be improved in terms of stability,half-life and antiangiogenic activity.On this basis,chemical modification of ES2 will be further carried out in this paper,and the antiangiogenesis activity,anti-tumor activity and tumor targeting in vitro of the modified product will be studied.The following results have been achieved in this study:1.Preparation and characterization of CRE and CREMIntegrin αvβ3 is highly expressed on the surface of various tumors and neovascular endothelial cells,which can specifically recognize Arg-Gly-Asp sequence(RGD).Taking advantage of this feature,QCOS was used as a drug carrier in this study,and the ring RGD(cRGD)was chemically connected to obtain the product cRGD-QCOS(CR),so as to improve the ability of drug targeting tumor cells and neosascular endothelial cells.On this basis,QCOS and ES2 were linked to obtain the glycopeptide conjugate cRGD-QCOS-ES2(CRE).Finally,the anti-tumor drug methotrexate(MTX)was further linked to QCOS by chemical method to obtain the modifier cRGD-QCOS-ES2-MTX(CREM),so as to play the therapeutic effect of"one drug and two targets",that is,under the action of cRGD,the drug reaches around the tumor tissue,and ES2 in the drug acts on endothelial cells.MTX kills tumor cells,and the synergistic effect of the two can achieve better tumor inhibition.2.Study on the activity,targeting and mechanism of CRE and CREM in vitro and in vivoIn this study,EAhy926 endothelial cells and B16 melanoma cells were used to study the anti-angiogenesis and anti-tumor activities of CRE and CREM in vitro by CCK-8 assay,scratch assay and lumen assay.The results showed that compared with ES2 peptide,both drugs had significant antiangiogenic and antitumor activities,and CREM was better than CRE.Apoptosis assay showed that CRE and CREM could induce apoptosis of EAhy926 endothelial cells and B16 melanoma cells.The in vitro targeting of CRE and CREM was studied by receptor competitive inhibition experiments.Compared with ES2 peptides,CRE and CREM showed stronger targeting to B16 melanoma cells,and the targeting effect was mediated by cRGD.The anti-tumor activity of CRE and CREM was studied by tumor inhibition experiment in mice.It was found that both CRE and CREM could inhibit the growth of melanoma in mice,with inhibition rates of 56.49%and 77.57%,respectively.In summary,CRE and CREM show good anti-angiogenesis and antitumor activity,providing a new idea for the development of antitumor targeted drugs.