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) mRNA 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® 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, 95.71±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 mRNA 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 µg/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.