Background & objective: Bio-chemotherapy is a new trend in cancer therapy. Antiangiogenic therapy represents a new strategy of tumor biotherapy. This study was designed to explore antitumor effect of recombinant quail vascular endothelial growth factor receptor 2 (qVEGFR) combined with cisplatin.
Methods: Lewis lung carcinoma model (LL/2) was established in C57BL/6 mice. Seven days after inoculation of tumor cells, mice were randomized into combination group, qVEGFR group, chemotherapy group, and normal saline (NS) group (10 mice/group), and received relevant treatments. Tumor growth, survival rate of mice, and side effects were observed. Anti-VEGFR-2 antibody-producing B cells (APBCs) was detected by enzyme-linked immunospot (ELISPOT), microvessel density (MVD) of tumor was detected by immunohistochemistry, and tumor cell apoptosis was also detected.
Results: Tumor volume of mice was obviously smaller in combination group than in NS group. Complete regression of tumor growth was observed in 3 of the 10 mice in combination group. Seventy days after inoculation of tumor cells, survival rate of mice was significantly higher in combination group than in qVEGFR, cisplatin, and NS groups (90% vs. 60%, 0%, and 0%, P < 0.05). APBCs counts were (156.8+/-19.3)/10(6) spleen cells in combination group, and (143.6+/-18.6)/10(6) spleen cells in qVEGFR group. MVD was significantly lower in combination group than in cisplatin, and NS groups (11.4+/-1.3 vs. 33.4+/-4.5, and 45.5 +/- 4.5, P < 0.01), MVD in qVEGFR group was 16.4+/-1.6. Tumor cell apoptosis was significantly higher in combination group than in qVEGFR, cisplatin, and NS groups [(36.2+/-3.5)% vs. (15.4+/-2.4)%, (17.6+/-2.6)%, and (4.1+/-1.4)%, P < 0.05].
Conclusion: The combination therapy of qVEGFR and cisplatin has synergistic antitumor effect.