[Hypoxia augments the killing effect of herpes simplex virus thymidine kinase gene expression actuated by the promoter of the vascular endothelial growth factor gene on human hepatocellular tumor cells].
OBJECTIVE
To investigate the killing effect of herpes simplex virus thymidine kinase gene expression actuated by the promoter of the vascular endothelial growth factor gene on human hepatocellular tumor cells under hypoxic condition.


METHODS
Recombinant adenoviral vectors, AdVEGF-tk and AdVEGF-GFP, were constructed with HSV-tk or GFP under the control of VEGF promoter through AdEasy system. Then GFP expression in hepatoma cell line HepG2 and normal liver cell line L02 transfected with AdVEGF-GFP were observed under fluorescence microscope, and the sensitivity to GCV of the AdVEGF-tk-transfected cells under normoxia or hypoxia condition were monitored by MTT method.


RESULTS
GFP expression actuated by VEGF promoter was detected in sporadic L02 cells, but in almost all HepG2 cells after transfected with AdVEGF-GFP. With GCV at 10 micro g/ml and MOI at 100, L02 cells were insensitive to GCV under oxic condition, but more than 70% L02 cells were killed under hypoxic condition. Moreover, HepG2 cells infected with AdVEGF-tk showed the increased GCV sensitivity under hypoxia (over 80% killed) as compared with normoxia (over 60% killed) conditions.


CONCLUSIONS
Hypoxia enhances the GCV sensitivity of human hepatocellular tumor cells infected with recombinant AdVEGF-tk under the control of VEGF promoter.
Wang
Menglong
M
Molecular Oncology Laboratory, Eastern Hepatobilliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China.
Yin
Zhengfeng
Z
Wu
Zongdi
Z
Wang
Shuai
S
Qian
Haihua
H
Kang
Xiaoyan
X
Wu
Mengchao
M
D000256:Adenoviridae / Q000235:genetics; D006528:Carcinoma, Hepatocellular / Q000473:pathology; D016228:Endothelial Growth Factors / Q000235:genetics*; D015870:Gene Expression / Q000187:drug effects*; D018014:Gene Transfer Techniques; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D000860:Hypoxia; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics*; D008113:Liver Neoplasms / Q000473:pathology; D008222:Lymphokines / Q000235:genetics*; D010100:Oxygen / Q000494:pharmacology*; D011401:Promoter Regions, Genetic / Q000502:physiology*; D018139:Simplexvirus / Q000201:enzymology; D013937:Thymidine Kinase / Q000235:genetics / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D016228:Endothelial Growth Factors; D036341:Intercellular Signaling Peptides and Proteins; D008222:Lymphokines; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D013937:Thymidine Kinase; D010100:Oxygen