Anti-tumor Effects Of The Hendoglin Single-chain Antibody Targeting The ?-1,3GT Gene In Mice With Lung Cancer

BACKGROUND:Currently,China has one of the highest incidence rates of lung cancer in the world.The lung cancer treatment has been one of the hot spots of cancer treatment research.Nowadays,the traditional methods of treatment of tumors include surgery,radiotherapy and chemotherapy,but these methods could hardly avoid the trauma,some of which might cause other problems and reduce the life quality of patients.As a new type of cancer treatment,tumor biological therapy which can effectively inhibit tumor development and improve the life quality of patients is gradually known by people.Gal-?-1,3GT was produced by the enzyme a-galactosyl transferase.Most non-primates contain this enzyme thus,this epitope is present on the organ epithelium and is perceived as a foreign antigen by primates,which lack the galactosyl transferase enzyme.It has been proved that the primary hyperacute rejection in human and nonhuman primates is caused by naturally occurring Abs that bind to the carbohydrate epitope Gal-?-1,3GT on pig vascular endothelium and subsequently activate the complement system in xenograft.Endoglin(CD105,also known as transforming growth factor ? receptor)is a proliferation-associated and hypoxia-inducible protein that is abundantly expressed in angiogenic endothelial cells.Endoglin mainly distributes in the surface of new blood vessels endothelial cells and tissue around the tumor vascular endothelial cells,and has become a new indicator of early tumor recurrence,metastasis and prognosis.In this present study,the hEndoglin single-chain antibody modified nanoliposome was used as a gene delivery system and loaded with the a-1,3 GT plasmid.The anti-tumor effect of hEndoglin ScFv-?-1,3GT-Lipo(hEndoglin ScFv conjugated ?-1,3GT plasmid Liposome)was investigated in mice with lung cancer.Methods:The hEndoglin ScFv was connected to the surface of theliposome which was loaded with ?-1,3GT plasmid gene by Post-insertion method.The material structure characteristics of hEndoglin ScFv-?-1,3GT-Lipo were examined by dynamic light scattering instrument(DLS)and transmission electron microscope(TEM).And the biophysical and cell transfection properties of hEndoglin ScFv-?-1,3GT-Lipo were determined by a series of in vitro experiments.The lung tumor-bearing NOD/SCID mice were treated by hEndoglin ScFv-?-1,3GT-Lipo via the tail vein injection.In vivo optical imaging was used to track the distribution and metabolism of nanoparticles in tumor-bearing mice.ELISA was used to test the levels of INF-?,CH50,IL-6 and IL-8.Immunohistochemistry was used to detect cell proliferation and apoptosis.In addition,the mice were monitored daily for survival and tumor volume was calculated according to the formula.Results:The diameter of hEndoglin ScFv-?-1,3GT-Lipo was around 100 nm with round surface and negative charge,and the encapsulation efficiency of hEndoglin ScFv-?-1,3GT-Lipo was 54%.This tumor vaccine significantly inhibited the growth of tumor,prolonged the survival of mice in lung tumor-bearing mice,increased in the levels of INF-y,IL-6 and IL-8,and decreased the level of CH50 in the tumor-bearing NOD/SCID mice based on the human immune model.Conclusion:The hEndoglin ScFv-?-1,3GT-Lipo delivery system provide a promising strategy for cancer therapy.