Abstract: ObjectiveTo study the possibility of endothelial progenitor cells（EPCs） induced from human bone marrow and being the vectors of immune factor gene for cancer immunotherapy. MethodsMononuclear cells were separated from healthy bone marrow by gradient centrifugation and cultured in vascular endothelial growth factor（VEGF165） containing medium for 2 weeks. EPCs specific surface markers CD133, KDR and CD34 were tested by flow cytometry. Adenovirus vectors encoding enhanced green fluorescent protein gene （Ad-EGFP） were used to test the adenovirus vectors infecting efficiency to EPCs. hγIFN secreted by EPCs-hγIFN was tested by ELISA method. EPCs-hγIFN cells were cocultured with human lung cancer cell line H460， human gastric cancer cell line SGC7901 and human colon cancer cell line LoVo to study the inhibition efficacy. ResultsCultured in VEGF165 containing medium 2 weeks later， the cells expressed EPCs specific surface markers CD133，KDR and CD34. When AdEGFP transduced EPCs at multiplicity of infection（MOI） at 150fu／EPCs， EGFP was positive in more than 90％ of EPCs two days later. AdhγIFN transduced EPCs（EPCs-hγIFN） could secret hγIFN well（hγIFN secreted in the culturing medium： 1305.28pg／ml at 1st day， 1419.10pg／ml at 14th day），and when cocultured with three cancer cell lines for four days， cancer cells were inhibited（cancer cells growing percentage to control：SGC7901：79.36 ± 4.35％，H460：77.87 ± 6.50％，LoVo：69.52 ± 3.78％， P＜0.05）. ConclusionThe genes delivered by adenovirus express well after transduction， and EPCs.hγIFN can inhibit the growth of cancer cells. EPCs can be good gene vectors to cancer immunotherapy for further study.