[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.