Endostatin gene therapy for liver cancer by a recombinant adenovirus delivery.
OBJECTIVE
To investigate the expression of adenovirus-mediated human endostatin (Ad/hEndo) gene transfer and its effect on the growth of hepatocellular carcinoma (HCC) BEL-7402 xenografted tumors.


METHODS
Immunohistochemistry analysis with an anti-endostatin antibody was preformed to detect endostatin protein expression in HCC BEL-7402 cells infected with Ad/hEndo. MTT assay was used to investigate the effects of Ad/hEndo on proliferation of human umbilical vein endothelial cells (HUVEC). Intra-tumoral injections of 1X10(9) pfu Ad/hEndo was given to treat BEL-7402 xenografted tumors in nude mice once weekly for 6 wk. Mice received injections of Ad/LacZ and DMEM were regarded as control groups. After intra-tumoral administration with Ad/hEndo, the endostatin mRNA expression in tumor tissue was analyzed by Northern blotting, and plasma endostatin levels were determined using enzyme-linked immunosorbent assay (ELISA).


RESULTS
High level expression of endostatin gene was detected in the infected HCC BEL-7402 cells. Ad/hEndo significantly inhibited HUVEC cell proliferation by 57.2% at a multiplicity of infection (MOI) of 20. After 6-week treatment with Ad/hEndo, the growth of treated tumors was inhibited by 46.50% compared to the Ad/LacZ control group (t=2.729, P<0.05) and by 48.56% compared to the DMEM control group (t=2.485, P<0.05). The ratio of mean tumor volume in treated animals to mean tumor volume in the control animals (T:C ratio) was less than 50% after 24 d of treatment. Endostatin mRNA in tumor tissue was clearly demonstrated as a band of approximately 1.2 kb, which was the expected size of intact and functional endostatin. Plasma endostatin levels peaked at 87.52+/-8.34 ng/mL at d 3 after Ad/hEndo injection, which was significantly higher than the basal level (12.23+/-2.54 ng/mL). By d 7, plasma levels dropped to nearly half the peak level (40.34+/-4.80 ng/mL).


CONCLUSIONS
Adenovirus-mediated human endostatin gene can successfully express endogenous endostatin in vitro and in vivo, and significantly inhibit the growth of BEL-7402 xenografted liver tumors in nude mice.
Li
Li
L
Cancer Center, Sun Yat-sen University, 651 Dongfeng Road East, Guangzhou 510060, Guangdong Province, China.
Huang
Jia-Ling
JL
Liu
Qi-Cai
QC
Wu
Pei-Hong
PH
Liu
Ran-Yi
RY
Zeng
Yi-Xin
YX
Huang
Wen-Lin
WL
D000256:Adenoviridae / Q000235:genetics*; D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000473:pathology / Q000628:therapy*; D002478:Cells, Cultured; D043169:Endostatins / Q000097:blood / Q000235:genetics*; D004730:Endothelium, Vascular / Q000166:cytology; D005260:Female; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D006801:Humans; D008114:Liver Neoplasms, Experimental / Q000473:pathology / Q000628:therapy*; D051379:Mice; D008807:Mice, Inbred BALB C; D011994:Recombinant Proteins / Q000235:genetics; D019076:Transgenes / Q000235:genetics; D014471:Umbilical Veins / Q000166:cytology; D023041:Xenograft Model Antitumor Assays
D043169:Endostatins; D011994:Recombinant Proteins