Effect and mechanism analysis of siRNA in inhibiting VEGF and its anti-angiogenesis effects in human osteosarcoma bearing rats.

OBJECTIVE To explore the effect of siRNA in inhibiting vascular endothelial growth factor (VEGF) expression in tumor cells from human osteosarcoma bearing rats and its anti-angiogenesis effect, to further study the reliability, effectiveness and safety of VEGF as a therapeutic target in treating osteosarcoma. MATERIALS AND METHODS After treatment, the long diameter and short diameter of tumor lesion were detected by Vernier caliper, and the tumor volume and tumor inhibition rate were calculated. The whole-body fluorescence imaging was used to detect the general morphology and volume change of tumor lesion before and after treatment. The rats were killed after treatment, RT-PCR and Western blot were used to detect VEGF expression. MTT was used to detect the proliferative ability of tumor cells in vitro. RESULTS Three chemotherapies could inhibit the growth of tumor lesion, the decrease of tumor volume was significant (p < 0.05), the therapeutic effect in Ad-VEGF-siRNA + neoadjuvant chemotherapy group was better than the other two groups, the differences were statistically significant (p < 0.05). Furthermore, the three chemotherapies could inhibit the invasiveness of tumor cells, which was most significant in Ad-VEGF-siRNA + neoadjuvant chemotherapy group (p < 0.05). CONCLUSIONS The growth of tumor tissue in osteosarcoma bearing rats is inhibited in Ad-VEGF-siRNA group, Ad-VEGF-siRNA + neoadjuvant chemotherapy group and Ad-VEGF-siRNA + anti-angiogenesis chemotherapy group. The effect in Ad-VEGF-siRNA + neoadjuvant chemotherapy is more significant than simple biological therapy or Ad-VEGF-siRNA + anti-angiogenesis chemotherapy.