[Gene therapy for ovarian cancers by adenovirus-mediated complete antibody gene].
OBJECTIVE
To study the feasibility of adenoviral transduction of Herceptin complete antibody gene and its effect on Her2 over-expressing cancer.


METHODS
The genes of VH and VL from the monoclonal antibody Herceptin were cloned into the genome of replication-defective adenovirus by viral recombination technology to produce the recombinant adenovirus Ad-SG-Her. Normal human liver cells of the line L-02 were transfected with Ad-SG-Her and ELISA was used to detect the expression of Herceptin antibody 3 and 7 days after. Forty BALB/c nude mice were inoculated with Her2 high-expressing oophoroma cells of SK-OV-3 line and were randomized into 4 equal groups: group A injected with Ad-SG-Her at the dosage of: 2 x 10(9) plaque forming unit (pfu) through the caudal vein, group B injected with Ad-SG-Her at the dosage of 1 x 10(9) pfu, group C injected with Ad-SG-Her at the dosage of 5 x 10(8) pfu, and control group. On the days 3, 7, 10, 14, 21, 28, and 35 after the injection of virus, the antibody expression in the serum was measured by ELISA and the size of tumor was measured vernier caliper. Western blot and IFA was used to detect the specificity for Her2-overexpressing ovarian cancer cell lines SK-OV-3 and the integrity of complete antibody. Anti-tumor effects were also observed in nude mice bearing SK-OV-3 tumors.


RESULTS
The constructed recombinant adenovirus Ad-SG-Her could express Herceptin efficiently both in vitro and in vivo. The biological activity of the expressed antibody was similar to that of the commercial Herceptin as shown by Western blotting, IFA, and ELISA. Herceptin expression of Ad-SG-Her was detected since day 3 after treatment in the groups A, B, and C and reached the peak on days 7 - 10. The expression lasted for four weeks or so. The expression level was significantly different between group A and the groups B and C (all P < 0.05), however, without a significant difference between the group B and group C. The antibody expression of group A might increase to 103.5 micro g/ml, high enough to inhibit tumor growth and induce tumor cell apoptosis. The antibody expression of the group B was below 40 micro g/ml, and that of the group C was below 30 micro g/ml. Furthermore the expressed antibody doses were statistically significantly different at different time points. Almost no tumor growth was seen in the group A during the observation period in comparison with the groups B and C and the control group (all P < 0.05). The tumor growth was almost not influenced in the group B and C and the control group.


CONCLUSIONS
Ad-SG-Her efficiently expresses humanized complete Herceptin with effective bioactivity and induces long-term stable expression both in vitro and in vivo. The system may serve as a new antitumoral gene therapy strategy in antibody field.
Guo
Ming-gao
MG
Laboratory of Virus and Gene Therapy, Eastern Hepatobiliary Surgical Hospital, the Second Military Medical University, Shanghai 200438, China.
Jiang
Ming-hong
MH
Yang
Qin
Q
Li
Yue-min
YM
Cui
Zhen-fu
ZF
Li
Lin-fang
LF
Wu
Meng-chao
MC
Qian
Qi-jun
QJ
D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000951:Antigens, Neoplasm / Q000276:immunology; D000970:Antineoplastic Agents / Q000627:therapeutic use; D045744:Cell Line, Tumor; D005260:Female; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D010051:Ovarian Neoplasms / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D010446:Peptide Fragments / Q000096:biosynthesis / Q000276:immunology; D011897:Random Allocation; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000276:immunology; D011994:Recombinant Proteins / Q000276:immunology / Q000627:therapeutic use; D014161:Transduction, Genetic; D000068878:Trastuzumab
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000951:Antigens, Neoplasm; D000970:Antineoplastic Agents; D010446:Peptide Fragments; D018719:Erb-b2 Receptor Tyrosine Kinases; D011994:Recombinant Proteins; D000068878:Trastuzumab; C091577:HER2-neu-derived peptide (654-662)