The effects of caffeic, coumaric and ferulic acids on proliferation, superoxide production, adhesion and migration of human tumor cells in vitro

Abstract

Reactive oxygen species are well-known mediators of various biological responses. In this study, we examined the effect of three phenolic acids, caffeic, coumaric and ferulic acids, on superoxide anion production, adhesion and migration of human lung (A549) and colon adenocarcinoma (HT29-D4) cancer cell lines. Proliferation of both tumor cells was inhibited by phenolic acids. Caffeic, coumaric and ferulic acids also significantly inhibited superoxide production in A549 and HT29-D4 cells. Superoxide anion production decreased by 92% and 77% at the highest tested concentration (200 µM) of caffeic acid in A549 and HT29-D4 cell lines respectively. Furthermore, A549 and HT29-D4 cell adhesion was reduced by 77.9% and 79.8% respectively at the higher tested concentration of ferulic acid (200 µM). Migration assay performed towards A549 cell line, revealed that tested compounds reduced significantly cell migration. At the highest concentration tested (200 µM), the covered surface was 7.7%, 9.5% and 35% for caffeic, coumaric or ferulic acids, respectively. These results demonstrate that caffeic, coumaric and ferulic acids may participate as active ingredients in anticancer agents against lung and colon cancer development, at adhesion and migration steps of tumor progression.

Introduction

Reactive oxygen species (ROS) are usually known as cytotoxic, mutagenic and linked to tumor progression. Reactive oxygen species are well-known mediators of various biological responses. Recently, new homologs of the catalytic subunit of NADPH oxidase have been discovered in non-phagocytic cells. These new homologs (Nox1–Nox5) produce low levels of superoxides compared to the phagocytic homolog Nox2/gp91phox (Sadok et al., 2008). Most anticancer drugs kill their target cells, at least in part, through the generation of elevated amounts of intracellular reactive oxygen species (Benhar et al., 2001, Jackson and Loeb, 2001, Tobiume et al., 2001). Redox homeostasis of the cell is greatly dependent on prooxidant and antioxidant enzymes. Reactive oxygen species, such as superoxide anions (${\mathrm{O}}_2^{-}$) and hydrogen peroxide (H₂O₂) are produced by mitochondria, peroxisome, cytochrome P-450 and NADPH oxidase (D'Autreaux and Toledano, 2007) and have been shown to play a role in proliferation, apoptosis, differentiation and migration (Abid et al., 2000, Finkel, 1999). The acquisition of cell motility and the capacity to invade basement membranes and adjacent tissues plays a central role in the complex multistep process of metastasis. Cell migration results in dynamic interactions between the cell, the extracellular matrix (ECM) and the cytoskeleton. These interactions are partly mediated by integrins, a family of cell surface adhesion receptors composed by the non covalent association of α and β subunits (Humphries, 2000). Integrins connect the ECM proteins outside to the actin cytoskeleton within the cell, allowing the traction required for cell migration (Geiger et al., 2001, Small et al., 1999). In addition to regulating cell adhesion, integrins relay molecular cues regarding the cellular environment that influence cell shape, survival, proliferation and gene transcription. Integrins therefore play a pivotal role during tumor progression (Hood and Cheresh, 2002, Parise et al., 2000). Currently, the search for biological antitumor agents from plants has revealed many molecules that block the growth, progression, and spread of cancer. As cancer treatments generally being preventive rather than curative (Lemjabbar-Alaoui et al., 2015), we looked for molecules that could intervene to prevent the spread of a tumorigenisation process already started by inhibiting or reducing the adhesion and migration of cancer cells as they are two early stages participating in the spread of a tumor. The present study shows, for the first time to our knowledge, that caffeic, coumaric and ferulic acids are potent inhibitors of superoxide anion and act by influencing the adhesion and migration of human lung (A549) and colon (HT29-D4) cancer cell lines, two preliminary steps to the tumor spread, as colorectal and lung cancers were the most common causes of cancer death in Europe for more than 50% of all cancer incidence and mortality (Znaor et al., 2013).