Assessment of the anti-invasion potential and mechanism of select cinnamic acid derivatives on human lung adenocarcinoma cells

Patients with lung adenocarcinoma are often diagnosed with metastasizing symptoms and die of early and distal metastasis. Metastasis is made up of a cascade of interrelated and sequential steps, including cell adhesion, extracellular matrix degradation, cell movement, and invasion. Hence, substances carrying the ability to stop one of the metastasis-associated steps could be a potential candidate for preventing tumor cells from metastasizing and prolonging the life of cancer patients. Cinnamic acid (CA) was demonstrated to be such a candidate for human lung adenocarcinoma cells. Nevertheless, the effectiveness of CA derivatives on invasion of lung cancer cells is still unclear. The aims of this study were to explore the mechanisms underlying several select CA derivatives against invasion of human lung adenocarcinoma A549 cells. The results revealed that caffeic acid (CAA), chlorogenic acid (CHA), and ferulic acid (FA) can inhibit phorbol-12-myristate-13-acetate (PMA)-stimulated invasion of A549 cells at a concentration of ≥100 μM. The MMP-9 activity was suppressed by these compounds through regulating urokinase-type plasminogen activator (uPA), tissue inhibitor of metalloproteinase (TIMP)-1, plasminogen activator inhibitor (PAI)-1, and PAI-2; the cell-matrix adhesion was decreased by CAA only. The proposed molecular mechanism involved not only decreasing the signaling of MAPK and PI3K/Akt but also inactivating NF-κB, AP-1, and STAT3. In the present study, we selected CAA, CHA, and FA as potential inhibitors for invasive behaviors of human lung adenocarcinoma cells and disclosed the possible mechanisms. The association between structural features and anti-invasive activity of these compounds cannot be determined here and needs to be further verified.