Astragaloside IV increases MMP-2 mRNA and protein expression in human lung cancer A549 cells

Lung cancer is the leading cause of cancer-related death in Taiwan. In the clinical treatment of lung cancer patients in Asia, an Astragalus-based herbal mixture is commonly used in conjunction with chemotherapy. The principal component of Astragalus (also known as Huang-qi) is Astragaloside IV. The Astragaloside IV marker has been qualified for the phytochemicals of Astragalus. The recurrence and metastasis of lung cancer are positively correlated with matrix metalloproteinase-2 (MMP-2) rnRNA and protein expression. This study examined the effects of Astragaloside IV on the mRNA and protein expression of MMP-2 in lung cancer A549 cells by RT-PCR and Western blotting. The cytotoxicity of Astragaloside IV in these cells was determined using CellTiter 96 (R) AQueous One Solution Reagent and the MTT assay. A549 cells were treated for different durations with Astragaloside IV concentrations of 10, 20, 50 and 100 ng/ml. The respective proliferation rates per amount (relative to the control) were as follows: 24 h, 96.85 +/- 1.12, 95.63 +/- 0.83, 93.92 +/- 0.84, 95.27 +/- 0.57%; 48 h, 98.86 +/- 1.56, 95.7 +/- 0.59, 94.09 +/- 0.68, 93.44 +/- 0.5%; 72 h, 99.48 +/- 0.16, 95.60 +/- 0.48, 95.23 +/- 0.67, 94.72 +/- 1.12%. MMP-2 mRNA expression as well as vascular endothelial growth factor rnRNA expression were upregulated at concentrations of 10, 20 and 50 ng/ml. Additionally, protein expression of MMP-2 was increased at concentrations of 10, 20 and 30 mu g/ml after 24 h of treatment. These results indicate that Astragaloside IV upregulates MMP-2 mRNA and protein expression in A549 cells, and therefore that it may increase recurrence and metastatic rates in lung cancer. This issue should be further examined in the clinical setting.