Esophageal adenocarcinoma (EAC) poses a serious clinical problem due to the increasing incidence and limited treatment options. One of the strongest known risk factors for EAC is gastroesophageal reflux disease (GERD), a chronic digestive condition in which acidic contents from the stomach, frequently mixed with duode- nal bile, enter the esophagus resulting in esophageal tissue injury. At the cellular level, gastroesophageal re- flux is characterized by continuous damage to esophageal cell DNA that increases the mutation rate and pro- motes genomic instability. GERD is common among veterans. However, only a percentage of affected individ- uals develop neoplasia, underscoring the importance of defining mechanisms that regulate tumorigenic interac- tions. We have developed an innovative hypothesis to explain how continued reflux induces tumorigenic altera- tions in the esophagus through inhibition of the DNA Damage Response (DDR), a critical tumor suppressor mechanism that is responsible for maintaining the integrity of the genome. This hypothesis is supported by strong preliminary data generated by animal and human studies. We will expand on these novel findings by detailing the impact of GERD on the DDR.
In aim 1, we will define previously unknown molecular mechanisms through which reflux inhibits the DDR.
In aim 2, we will investigate the DDR regulation in the esophageal niche using animal models of esophageal reflux injury. We will also ana- lyze human clinical specimens.
In aim 3, we will test various options to avert inhibition of the DDR induced by GERD in vivo. Combined, our studies will further elucidate the potential risk factors for tumorigenic alterations in the esophagus and lay the groundwork for novel therapeutic approaches that halt the development of malignant esophageal lesions.

Public Health Relevance

Patients with esophageal adenocarcinoma have a poor survival rate and limited treatment options, making this tumor a serious health problem. The proposed research will provide new insights into esophageal tumorigenesis and lay the groundwork for development of novel chemopreventive and chemotherapeutic agents.

Agency
National Institute of Health (NIH)
Institute
Veterans Affairs (VA)
Type
Non-HHS Research Projects (I01)
Project #
2I01BX002115-05A2
Application #
10012259
Study Section
Special Emphasis Panel (ZRD1)
Project Start
2014-07-01
Project End
2024-09-30
Budget Start
2020-10-01
Budget End
2021-09-30
Support Year
5
Fiscal Year
2021
Total Cost
Indirect Cost
Name
Miami VA Health Care System
Department
Type
DUNS #
079275714
City
Miami
State
FL
Country
United States
Zip Code
33125
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Hong, Jun; Chen, Zheng; Peng, Dunfa et al. (2016) APE1-mediated DNA damage repair provides survival advantage for esophageal adenocarcinoma cells in response to acidic bile salts. Oncotarget 7:16688-702
Bhardwaj, Vikas; Horvat, Andela; Korolkova, Olga et al. (2016) Prevention of DNA damage in Barrett's esophageal cells exposed to acidic bile salts. Carcinogenesis 37:1161-1169
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Wei, Jinxiong; Noto, Jennifer M; Zaika, Elena et al. (2015) Bacterial CagA protein induces degradation of p53 protein in a p14ARF-dependent manner. Gut 64:1040-8
Bhardwaj, Vikas; Noto, Jennifer M; Wei, Jinxiong et al. (2015) Helicobacter pylori bacteria alter the p53 stress response via ERK-HDM2 pathway. Oncotarget 6:1531-43
Zaika, Alexander I (2015) Bacterial Pathogen Helicobacter pylori: A Bad AKTor Inhibits p53 Protein Activity [corrected]. Dig Dis Sci 60:822-3

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