Effect of Avastin combined with NP chemotherapy regime on tumor growth and blood vessels in mice bearing PC-9

Abstract

Objective To explore the effects of Avastin combined with NP chemotherapy regime on tumor growth and blood vessels of mice bearing PC-9. Methods Sixty nude mice bearing human lung adenocarcinoma PC-9 xenografted tumor were randomly divided into control group, avastin group, chemotherapy group and combination group. Mice in Avastin group were treated with Avastin (4 mg/kg) by intraperitoneal injection. Mice in control group were treated with phosphate buffer (PBS) by intraperitoneal injection. Mice in chemotherapy group were treated with Gemcitabine and cisplatin (4 mg/kg) by intraperitoneal injection. Mice in combination group were treated with Avastin (4 mg/kg), Gemcitabine and cisplatin (4 mg/kg) by intraperitoneal injection. After 30 days of treatment, tumor growth and survival rate among four groups were analyzed. Vascular endothelial growth factor (VEGF) mRNA and protein levels in four groups were analyzed real-time quantitative polymerase chain reaction (Real-time PCR) and enzyme linked immunosorbent assay (ELISA). Tumor vessels density was analyzed by immunohistochemistry. Results As compared with control group, tumor growth in avastin group, chemotherapy group and combination group was significantly inhibited and survival rate was significantly increased (t=2.091, P=0.021; t=2.103, P=0.025; P=0.011; P=0.007). Tumor growth in combination group was significantly inhibited and survival rate was significantly increased as compared with that in avastin group and chemotherapy group (t=2.913, P=0.010; t=3.016, P=0.009; P=0.005; P=0.002). VEGF mRNA and protein levels in avastin group and combination group were significantly decreased as compared with those in control group and chemotherapy group (t=6.193, P=0.000; t=6.693, P=0.000; t=10.198, P=0.000; t=11.183, P=0.000). As compared with Avastin group and combination group, tumor vessel density in chemotherapy group and control group was significantly reduced (t=3.187, P=0.000; t=3.481, P=0.000). Conclusion Avastin can significantly reduce levels of VEGF in tumor tissue, inhibit tumor blood vessels, inhibit tumor growth and prolong survival time in mice bearing PC-9 tumor. Key words: Avastin; Gemcitabine; Cisplatin; Tumor vessel; Transplanted tumor