Granzyme B-truncated VEGF fusion protein represses angiogenesis and tumor growth of OSCC.
OBJECTIVE
To evaluate the antitumor effects of fusion protein hGrB-TV of human granzyme B (hGrB) and truncated vascular endothelial growth factor (tVEGF) on human oral squamous cell carcinoma (OSCC) in vitro and in vivo.


METHODS
The fusion protein hGrB-TV was expressed and purified from E. coli bacteria by affinity chromatography. The cytotoxcity of hGrB-TV on VEGFR-2 (Flk-1)(+) OSCC cells was analyzed in vitro. The antitumor therapeutic study was conducted on OSCC xenografts in vivo.


RESULTS
The purified hGrB-TV fusion protein was selectively internalized into VEGFR-2 (Flk-1)(+) OSCC cells and endothelial cells. It can cleave inactive caspase 3 into its active p20 form. The hGrB-TV showed dose-dependent cytotoxicity on VEGFR-2(+) SCC-9 cells. The morphological changes and cytolysis were appeared within dozen minutes. However, no cytotoxicity was observed on VEGFR-2(-) cells. The hGrB alone or tVEGF alone did not have any toxicity on SCC-9 cells. In addition, hGrB-TV treatment completely destroyed the vasculature of the chick chorioallantoic membrane (CAM) in vivo and consequently led to chick embryo development arrest. Most importantly, the fusion protein hGrB-TV inhibited tumor angiogenesis and growth of human OSCC xenografts in nude mice without any apparent toxicity.


CONCLUSIONS
The fusion protein hGrB-TV specifically inhibits angiogenesis and tumor growth of OSCC; hGrB-TV is a powerful and safe therapeutic molecule for tumor therapy.
Department Oral & Head and Neck Surgery, Nan Fang Hospital, Southern Medical University, Guangzhou, China.
X-Z
XZ
Lv
Department of Cell Biology, School of Basic Medicine, Southern Medical University, Guangzhou, China.
M-Y
MY
Zheng
Department of Cell Biology, School of Basic Medicine, Southern Medical University, Guangzhou, China.
Z-Q
ZQ
Lin
Department Oral & Head and Neck Surgery, Nan Fang Hospital, Southern Medical University, Guangzhou, China.
M
M
Zhao
Department of Cell Biology, School of Basic Medicine, Southern Medical University, Guangzhou, China.
H
H
Wang
Department of Cell Biology, School of Basic Medicine, Southern Medical University, Guangzhou, China. zengws@smu.edu.cn.
W-S
WS
Zeng
D020533:Angiogenesis Inhibitors / Q000494:pharmacology; D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy* / Q000473:pathology*; D002478:Cells, Cultured; D002642:Chick Embryo; D053804:Granzymes / Q000494:pharmacology*; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D009062:Mouth Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D009389:Neovascularization, Pathologic / Q000188:drug therapy*; D014062:Tongue Neoplasms / Q000188:drug therapy; D042461:Vascular Endothelial Growth Factor A / Q000494:pharmacology*
D020533:Angiogenesis Inhibitors; D042461:Vascular Endothelial Growth Factor A; D053804:Granzymes
fusion protein; granzyme B (GrB); oral squamous cell carcinoma (OSCC); tumor therapy; vascular endothelial growth factor (VEGF)