Human endostatin gene transfer, either naked or with liposome, has the same inhibitory effect on growth of mouse liver tumor cells in vivo.
OBJECTIVE
To explore a safe and efficient strategy of tumor therapy using anti-angiogenetic agents.


METHODS
Endostatin gene with a signal sequence of human IgGgamma chain was amplified by PCR and cloned into pVAX1 plasmid which was the only vector authorized by FDA in clinical trial to construct a recombinant plasmid named as pVAX-sEN. The recombinant plasmid was detected with EcoRI/KpnI and DNA sequencing. BALB/c mice bearing hepatocarcinoma cell line H22 were treated with naked pVAX-sEN or liposome-DNA complex in which the dose of DNA and the ratio of DNA and liposome were different from each other. To compare the efficiency of gene transfection, expression of endostatin at the treated tumor site was assayed with ELISA. To investigate the effect of pVAX1-sEN on hepatocellular carcinoma, pVAX-sEN either naked or in liposome-DNA complex was injected into BALB/c mice bearing H22, then the diameter of tumors was measured, microvessel density was detected by immunohistochemistry, endostatin expression in vivo was assayed at different time points.


RESULTS
DNA sequencing showed the endostatin gene with the signal peptide was correctly cloned. In situ gene expression assay indicated that both the ratio of DNA and liposome and the dose of DNA could affect the gene transfection efficiency. Interestingly, naked pVAX-sEN had a similar in situ endostatin expression to pVAX-sEN with liposome. Animal experiments showed that pVAX-sEN together with pVAX-sEN-liposome complex could efficiently suppress the growth of mouse hepatoma cells.


CONCLUSIONS
Naked endostatin plasmid intratumoral injection can get a similar gene transfection efficiency to liposome-DNA complex when used in situ.
Ma
Chun-Hong
CH
Institute of Immunology, Medical College of Shandong University, Jinan 250012, Shandong Province, China. machunhong@sdu.edu.cn
Zhang
Yan
Y
Wang
Xiao-Yan
XY
Gao
Li-Fen
LF
Liu
Hua
H
Guo
Chun
C
Liu
Su-Xia
SX
Cao
Ying-Lin
YL
Zhang
Li-Ning
LN
Sun
Wen-Sheng
WS
D000818:Animals; D001483:Base Sequence; D006528:Carcinoma, Hepatocellular; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D017931:DNA Primers; D043169:Endostatins / Q000097:blood / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D005786:Gene Expression Regulation; D018014:Gene Transfer Techniques; D006801:Humans; D008081:Liposomes / Q000494:pharmacology; D008113:Liver Neoplasms; D051379:Mice; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000097:blood / Q000378:metabolism / Q000494:pharmacology
D017931:DNA Primers; D043169:Endostatins; D008081:Liposomes; D011994:Recombinant Proteins