Effect of bevacizumab on proliferation and invasion of human lung cancer A549 cells

Objective To study the effect and mechanism of bevacizumab on proliferation and invasion of human lung cancer A549 cells. Methods A549 cells were treated with bevacizumab. Proliferation and invasion of the bevacizumab-treated A549 cells were detected using cell counting kit CCK-8 and Transwell assay, respectively. The expression of the mRNA and protein of MMP-2, MMP-9 and c-Met were detected by real-time PCR and Western blotting, respectively. Results Proliferation activity was inhibited at the concentration of 10 μg/ml and promoted at the concentration of 100 μg/ml bevacizumab. Bevacizumab in the concentration of 50 μg/ml had a stronger inhibitory effect on the invasion of A549 cells(16 406.19±5 674.23 penetrated cells ) than that of control group (36 108.68±6 263.83, P<0.05). The real-time PCR showed that bevacizumab had a stronger inhibitory effect on the expression of MMP-2 and MMP-9 mRNA at the concentration of 50 μg/ml and on the expression c-Met mRNA at the concentration of 10 μg/ml bevacizumabin the A549 cells. However bevacizumab at the concentration of 100 μg/ml showed a promoting effect on the expression of MMP-2, MMP-9 and c-Met mRNA (1.82±0.31, 1.60±0.25, 2.63±0.48), significantly higher than that of the control group (1.00±0.19, 1.00±0.23, 1.00±0.22, P<0.05). The expression of MMP-2, MMP-9 and c-Met mRNA and protein was inhibited by 10 μg/ml bevacizumab in a time-dependent manner. The Western blot assay showed that bevacizumab had a bi-directional effect on the expression of MMP-2 and c-Met proteins in the A549 cells: a promoting effect at 100 μg/ml and inhibitory effect on the expression of MMP-2 at 50 μg/ml bevacizumab, and inhibitory effect on the expression of c-Met protein at 10 μg/ml bevacizumab. Conclusions Our findings indicate that in a certain range of concentrations, bevacizumab has prominent inhibitory effect on the proliferation and invasion of A549 cells. However, over the concentration of 100 μg/ml, bevacizumab shows a weakening anti-invasion effect, even has a promoting effect on cell proliferation. This phenomenon may be related to the inhibiting effect on the expression of MMP-2 and c-Met proteins in a non-concentration-dependent manner by bevacizumab. Key words: Lung neoplasms; Cells; Bevacizumab; Cell proliferation; Matrix metalloproteinase-2; Matrix metalloproteinase-9; Hepatocyte growth factor receptor