Dysregulation of PARP1 is involved in development of Barrett's esophagus

To investigate the potential role of poly(ADP-ribose) polymerase 1 (PARP1) in the development of Barrett's esophagus (BE).

A BE mouse model was established to examine the esophageal morphological changes and molecular changes. Microarray analysis was performed to compare the gene expression profiles between BE patients and healthy controls. qPCR was used to examine the PARP1 expression in cell lines after treatment with H₂O₂ and bile acids (pH 4). Immunofluorescence staining, comet assay, and annexin V staining were used to evaluate the impact of PARP1 activity on cell survival and DNA damage response after oxidative stress.

The gene expression profile in normal and BE esophageal epithelial cells showed that PARP1, the major poly(ADP-ribose) polymerase, was overexpressed in BE. In the mouse model of BE, positive staining for NF-κB, γH2AX, and poly(ADP-ribose) (PAR) was observed. H₂O₂ and bile acids (pH 4) increased the PARP1 mRNA expression level in normal esophageal epithelial cells. Using shRNA-PARP1 to suppress PARP1 activity decreased the cell viability after treatment with H₂O₂ and bile acids (pH 4), and increased the oxidative damage as demonstrated by an increase in the levels of H₂O₂, intracellular reactive oxygen species (ROS), oxidative DNA damage, double-strand breaks, and apoptosis (P < 0.01).

The dysfunction of PARP1 in esophageal epithelial cells increases the levels of ROS and oxidative DNA damage, which could be common risk factors for BE and esophageal adenocarcinoma.