Anti-tumor effects of a human VEGFR-2-based DNA vaccine in mouse models.
BACKGROUND
Vascular endothelial growth factor (VEGF) and its receptor, VEGFR-2 (Flk-1/KDR), play a key role in tumor angiogenesis. Blocking the VEGF-VEGFR-2 pathway may inhibit tumor growth. Here, we used human VEGFR-2 as a model antigen to explore the feasibility of immunotherapy with a plasmid DNA vaccine based on a xenogeneic homologue of this receptor.


METHODS
The protective effects and therapeutic anti-tumor immunity mediated by the DNA vaccine were investigated in mouse models. Anti-angiogenesis effects were detected by immunohistochemical staining and the alginate-encapsulate tumor cell assay. The mechanism of action of the DNA vaccine was primarily explored by detection of auto-antibodies and CTL activity.


RESULTS
The DNA vaccine elicited a strong, protective and therapeutic anti-tumor immunity through an anti-angiogenesis mechanism in mouse models, mediated by the stimulation of an antigen-specific response against mFlk-1.


CONCLUSIONS
Our study shows that a DNA vaccine based on a xenogeneic homologue plasmid DNA induced autoimmunity against VEGFR-2, resulting in inhibition of tumor growth. Such vaccines may be clinically relevant for cancer immunotherapy.
Xie
Ke
K
State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Guo Xue Xiang, No 37, Chengdu, Sichuan 610041, PR China.
Bai
Rui-Zhen
RZ
State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Guo Xue Xiang, No 37, Chengdu, Sichuan 610041, PR China.
Wu
Yang
Y
State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Guo Xue Xiang, No 37, Chengdu, Sichuan 610041, PR China.
Liu
Quan
Q
State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Guo Xue Xiang, No 37, Chengdu, Sichuan 610041, PR China.
Liu
Kang
K
State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Guo Xue Xiang, No 37, Chengdu, Sichuan 610041, PR China.
Wei
Yu-Quan
YQ
State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Guo Xue Xiang, No 37, Chengdu, Sichuan 610041, PR China.