The Effect of Gallic Acid on Gene Expression in Gastric Adenocarcinoma

Gastric cancer has substantial global impacts. It is the fifth most common cancer with the third highest cause of cancer death; it is relatively resistant to conventional chemotherapeutic agents, necessitating the development of new preventative and therapeutic methods. Plant secondary compounds have the potential to treat cardiovascular diseases, neurodegenerative and other diseases of aging, obesity, and certain human cancers. Gallic acid, a secondary metabolite found in natural products including blackberries and raspberries, has an antiproliferative effect specifically on cancer cells. In this study we investigate the functional and genetic responses of cells from the gastric adenocarcinoma cell-line (AGS) using qPCR to quantify changes in RNA expression. We looked at the effect of gallic acid on the expression of genes associated with cell cycle (cyclin D1, CDK4, CKD6, P21), apoptosis (Bax, Bcl-2, RhoB), and tumor specific angiogenesis (MMP9). First we investigated the time necessary for changes in gene expression to occur by treating AGS with a constant concentration of gallic acid at different time points (0, 6, 12, 24 hours); we also established dosage curves by treating AGS cells with different doses of gallic acid (0, 40, 60, 80, 100 μM) at set time points. Following treatments RNA was extracted and used to make cDNA; changes in expression were evaluated using qPCR and melt curves. We found that genes were generally down regulated except for P21 which was upregulated two fold.These results suggest that gallic acid does have an effect on AGS cell proliferation and therefore may be an enticing therapeutic compound for gastric cancer that can be delivered via the consumption of fruit.