The Effect Of Dendritic Cell Transfected By Soluble Vascular Endothilial Growth Factor Receptor 2 Gene On Experimental Lung Cancer Metastasis In Mice

The incidence rate of lung cancer is the highest one in male malignant tumors all over the world.The incidence of Non-small cell lung cancer(NSCLC)is about 80%in lng cancer,among them 30%of the patients could be operated only when the diagnosis is definite.Those who couldn't be operated usually had bad prognostic,most of them generate the tumor metastasis within 5 years even though the radioactive or chemical therapy were adopted.Despite chemiotherapy drugs from third generation came to the forth, the promotion of 5-year survival rate was still very little. ECOG compared the efficacy of normative paclitaxel/cisplatin regimen to other three regimens,there was no significant difference in median survival duration and 1,2-year survival rate between two groups.Therefore,the new regimens are needed imminently for the NSCLC therapy.The bio-targeted therapy gave new hopes to the therapy of lung cancer Two kinds of important target aim were found at present,one is epithelial growth factors(EGF)and their receptors,another is vascular epithelial growth factors(VEGF) and their receptors.The EGF mediate the growth and proliferation,the VEGF mediate the angiogenesis of tumors. It is testified by researching that tumors growth must rely on its angiogenesis when it was in excess of 2～3mm~3.Inhibiting the angiogenesis could inhibite the growth and metastasis of tumor signally.There are kinds of cell factor relating to tumor angiogenesis,such as vascular epithelial growth factors(VEGF),platelet-derive growth factor(PDGF),basic fibroblast growth factor(bFGF)et al,and VEGF was the most important factor of angiogenesis.At present,many kinds of technics as antisense oligonucleotides,monoclonal antibody,microRNA interference,soluble receptor et al are adopted to block the combination between VEGF and its receptor.By this way,the tumor's angiogenesis was inhibited,then the growth and metastasis were inhibited either.Dendritic cell(DC)has the strongest antigen presentation function in vivo.The reseach of anti-tumor immunity based on DC became the focus. Some scholars used the strong antigen presentation fuction of DC to inhibite the angiogenesis of tumor,the result is very inspiring.Schmitt used the DC transfected with Mrna of bladder cancer cells to incubate T cell,CTL response reaction was promoted observably,therefore the metastasis of tumor was inhibited signally.In this paper, the anti-lung cancer metastasis function and mechanism of DC transfected with the extracellular domain of VEGFR-2 cDNA was researched.MethodsThe cDNA of VEGFR-2 extracellular domain were amplicated specifically from the H5V cell lines that with VEGFR+ by RT-PCR,after identification,the sequence was insert to the site between BamHI and EcoRI of pcDNA3.1;The plasmid with cDNA3.1/ sVEGFR-2 were electroporated to the dendritic cell,the expressed level was determined by ELISA;For immunization,C57BL/6 mice were intravenously injected three time with 1×10~5 cells per mouse of DC,p cDNA3.1 DC(DC-Vector),DC- sVEGFR-2 and 100μl of PBS at one week intervals.At 10 days after the last immunization,the mice were injected with 3LL Lewis lung carcinoma cell in legs,kill all of the mice when the contrast groups begin to die,calculate the number of the metastasis nodules on the pulmonary surface of every mouse with carcinoma,in order to observe the anti-metastasis effect in 3LL Lewis lung carcinoma.ResultsDC- sVEGFR-2 could effectively express sVEGFR-2, whereas DC-Vector and DC could not.The number of tumor nodules on pulmonary surface in mice immunized with DC-sVEGFR-2 was much less than that in mice immunized with DC-Vector(8.5±1.6 vs 28.4±4.5),DC(8.5±1.6 vs 28.7±4.7),PBS(8.5±1.6 vs 29.9±4.2).Conclusion1 DC-sVEGFR-2 can express sVEGFR-2 effectively;2 Immunization with DC-sVEGFR-2 could inhibit the pulmonary metastasis of the experimental mice significantly.