In a recent report published in Gastroenterology, researchers examined tissue samples from African Americans and European Americans, including both those with esophageal adenocarcinoma and those without. Esophageal cancer primarily affects Caucasians and very rarely affects African Amercians, therefore researchers were interested in understanding why some people have low risk, and whether this information can be used to prevent cancer in people at high risk. The research team found that Caucasians have a duplication on a portion of the genome that appears to reduce the expression of a gene called Glutathione S-Transferase Theta 2 (GSTT2), which is an enzyme that protects cells against oxidative damage, such as the type caused by reflux, a key risk factor for esophageal adenocarcinoma. These findings were confirmed using sequence data from the 1000 Genomes project. Risk factors for esophageal cancer such as obesity and reflux happen at the same rate for Caucasians and African Americans; however, African Americans are less likely to develop cancer. The highest risk of cancer appears to be among individuals with the genomic duplication plus obesity. These results are being used to identify potential treatments for prevention of esophageal adenocarcinoma.
For more information, a short summary can be found on ScienceDaily. The complete research article, "Constitutively higher level of GSTT2 in in esophageal tissues from african americans protects cells against DNA damage" by Ferrer-Torres et al. was published in Gastroenterology.
