Objective: To explore the feasibility of reverse effect of recombinant nm23H(1) adeno-associated virus (rAAV-nm23H(1)) in ovarian carcinoma metastatic orthotopic implantation nude model.
Methods: Using DNA recombination technique to construct AAV main plasmid pUF(1)-nm23H(1). rAAV-nm23H(1) and rAAV-Laz were produced by co-transfection of rAAV system in package cell 293 by phosphate-calcium deposit method, and then the transfection efficiency was measured. The titer was measured by dot hybridization. Ovarian carcinoma cell line SW626 was used in the establishment of the ovarian carcinoma orthotopic implantation nude model. The biologic feature of the model was observed and the expression of nm23H(1) in the tumor was measured by Western blot. Three groups of ovarian carcinoma orthotopic implantation nude model were applied by PBS (as control) (12 mice), rAAV-Laz (13 mice), rAAV-nm23H(1) (13 mice) intraperitoneally on the day 10 after transplantation. Then the effect of rAAV-nm23H(1) on survival and liver metastatic incident rates in models were observed.
Results: rAAV-nm23H(1) and rAAV-Laz were constructed and identified successfully. The titers were both 1 x 10(10) virus particles/ml. The transfection efficiency was 70%. The observation of biological feature showed the orthotopic implantation model was metastatic. The expression of nm23H(1) in AAV-nm23H(1) group was higher significantly than control and rAAV-Laz group (P < 0.05). Survival time of rAAV-nm23H(1) group was 136.67 days, compared with blank control group 106.67 days and rAAV-Laz group 107.06 days. Kaplan-Meier analysis showed rAAV-nm23H(1) group survived longer than control and rAAV-Laz group (P = 0.0051, P = 0.018 P < 0.05). The control and rAAV-Laz groups showed no statistically difference in survival time (P = 0.059 P > 0.05). The metastatic incident rate of control, rAAV-Laz and rAAV-nm23H(1) group was 75%, 61.5%, and 30.8% respectively, the rate of rAAV-nm23H(1) group was lower significantly than that of control and rAAV-Laz group (P = 0.03, P = 0.01). There was no significant difference between control and rAAV-Laz group in liver metastatic rate (P > 0.05).
Conclusion: SW626 line which expressed lower level of nm23H(1) showed high-frequency metastasis properties, rAAV-nm23H(1) could reverse its metastasis in ovarian carcinoma orthotopic transplantation model.