title: Inhibition of vascular endothelial growth factor by small interfering RNA upregulates differentiation, maturation and function of dendritic cells.
abstract: This study aimed to investigate the effects of vascular endothelial growth factor (VEGF) secreted by MCF-7 breast cancer cells on the differentiation, maturation and function of dendritic cells (DCs). Small interfering RNAs (siRNAs) directed against the VEGF gene were designed and transfected into MCF-7 breast cancer cells at an optimal concentration (100 nmol/l) using cationic liposome transfection reagent, whereas the control group was transfected with only transfection reagent. Western blot analysis and ELISA were used to determine VEGF protein expression and VEGF concentration, respectively. Mononuclear cells were cultured with the culture supernatants from primary MCF-7 cells (control group) and siRNA-treated MCF-7 cells (siRNA group). The DC phenotypes, including CD1a, CD80, CD83, CD86 and HLA-DR, were evaluated by flow cytometry. The MTT assay was used to assess the cytotoxicity of DC-mediated tumor-specific cytotoxic T lymphocytes (CTLs) against MCF-7 cells in the two different culture supernatants. The VEGF-targeted constructed siRNA inhibited VEGF expression in MCF-7 cells. Cultivation with the culture supernatants from MCF-7 cells treated with siRNA affected DC morphology. DCs in the siRNA group exhibited a significantly higher expression of CD86, CD80, CD83 and HLA-DR compared to the cells in the control group, whereas the expression of CD1a in the siRNA group was significantly lower compared to that in the control group. The cytotoxic activity of CTLs mediated by DCs was significantly altered by siRNA transfection. These results indicated that VEGF may play a significant role in tumor development, progression and immunosuppression.
authors.affiliation: Department of Transfusion, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, Shandong 266033, P.R. China.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Wang
authors.affiliation: Clinical Laboratory, Qingdao Hiser Hospital, Qingdao University, Qingdao, Shandong 266033, P.R. China.
authors.forename: Luping
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Clinical Laboratory, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, Shandong 266033, P.R. China.
authors.forename: Shaoyan
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Transfusion, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, Shandong 266033, P.R. China.
authors.forename: Yannian
authors.initials: Y
authors.lastname: Li
keywords: MCF-7; cytotoxic T lymphocyte; dendritic cells; peripheral blood monouclear cells; small interfering RNA; vascular endothelial growth factor