Inhibition of proliferation, migration and invasion of human non-small cell lung cancer cell line A549 by phlomisoside F from Phlomis  younghusbandii   Mukerjee

Purpose: To determine the effect of phlomisoside F (PMF) on the proliferation, migration and invasion of human non-small cell lung cancer cell line A549 and explore the possible mechanisms.
Methods: The anti-proliferative effect of PMF on A549 cells was determined by CCK-8. Subsequently, migration and invasion were evaluated by Transwell and Transwell with matrigel assays, respectively. Furthermore, cell cycle and apoptosis were assessed by flow cytometry, while the mechanisms of action were determined by Western blotting.
Results: PMF exhibited significant anti-proliferative effect on A549 cells in concentration-dependent and time-dependent manners, with half maximal inhibitory concentration (IC₅₀) of 54.51 μM. Treatment with PMF (10, 20 and 40 μM) for 48 h resulted in significantly decreased migration and invasion in A549 cells. In addition, PMF at concentrations of 25, 50 and 75 μM induced cell cycle arrest in G0/G1phase and enhanced cell apoptosis in A549 cells. Furthermore, caspase-3, caspase-9 and Bax protein expressions were up-regulated while Bacl-2 and COX-2 protein expressions were significantly downregulated at 10, 20 and 40 μM concentrations of PMF.
Conclusion: PMF suppresses A549 cell growth, migration and invasion. The mechanism may be related to the induction of mitochondria-mediated apoptosis pathway via regulation of caspase-3, caspase-9, Bcl-2 and Bax expressions, and inhibition of PGE₂ synthesis by reducing COX-2 expression.

Keywords
Phlomisoside F; Lung cancer; Cell mobility; Apoptosis; PGE₂; COX-2 expression; Caspase; Cell cycle arrest