Determining Gastric Cancer CDK Response to Gallic Acid Exposure

Plant secondary metabolites have shown promise as potential therapeutic agents in recent studies based upon their ability to trigger signal transduction systems within plants and animals alike. Gallic acid is a plant phenolic found in the glandular trichomes of developing prickles in Rubus. This substance is of interest due to its proposed ability to mimic animal ligands, which could potentially affect similar developmental pathways in cancer cells and Rubus. To further examine this, gastric adenocarcinoma (AGS) cells were exposed in a time dependent manner under critical concentrations of gallic acid (0, 25, 40uM).  RNA was extracted and analyzed using quantitative PCR.  This study shows an up regulation of cyclin dependent kinases, specifically those which regulate the G2/M checkpoint, after cancerous cells have been exposed to gallic acid.  Target CDKs were selected based upon their function to facilitate cell cycle progression, specifically at the G2/M checkpoint and G1/S transition for comparison.  Preliminary results show there is an increase in expression of G2/M phase CDKs after exposure for 24 hours to high concentrations (40 mM) of gallic acid. Quantitative analysis showed an increase in CDKs involved in regulation of the G2/M checkpoint by 150% compared to controls. The degree of fold expression suggests an accumulation of exposed cells at the G2/M checkpoint. Since rapid cell cycle proliferation is a popularized aspect for tumorgenesis, if gallic acid is able to halt cell cycle progression at a specific checkpoint in cancers it could have preventative effects on characteristic traits of cancer.  Results bridging the gap between plant science and human health contribute greatly to the growing field of naturally derived therapeutics, specifically those resulting from secondary metabolites.