[Effects of bevacizumab and cisplatin on human lung adenocarcinoma A549/DDP xenografts in nude mice]

Abstract

Objective: To explore the effects of bevacizumab with or without cisplatin (DDP) on the growth of lung adenocarcinoma A549/DDP cell xenografts in mice.

Methods: Human lung cancer A549/DDP cells was subcutaneously transplanted in to 25 nude mice, which were randomly divided into control group (group A), bevacizumab group (group B), DDP group (group C), combined treatment group (group D) and half-dose combined treatment group (group E). After corresponding treatments for 4 consecutive weeks, the tumor inhibition rate was evaluated, tumor microvessel density (MVD) measured with immunohistochemistry, and the mRNA expression of apoptosis-associated gene (bcl-2) and multidrug resistance genes (LRP and GST-pi) assessed by RT-PCR.

Results: The tumor growth inhibition rates in groups B, D, and E with bevacizumab treatment were 20.96%, 51.67% and 50.95%, respectively, and the two combined treatment groups showed better effects. MVD in these 3 groups were 18.6-/+1.14, 13.6-/+1.14, and 14.4-/+0.55, respectively, and no significant difference was found in MVD between DDP group and the control group. Compared with the control group, the 3 bevacizumab-treated groups showed decreased expression of bcl-2 genes in A549/DDP tumors at a comparable amplitude, and LRP and GST-pi mRNA expression showed no significant differences between the 5 groups.

Conclusion: Bevacizumab has synergetic inhibitory effect with conventional chemotherapy against lung adenocarcinoma A549/DDP cell xenografts in mice by inhibiting angiogenesis of the tumor, and may enhance the sensitivity of A549/DDP cells to DDP by inducing cell apoptosis.