Expression of Regenerating Gene I in Gastric Adenocarcinomas: Correlation with Tumor Differentiation Status and Patient Survival

BACKGROUND. Regenerating gene I (REG) was identified as a growth factor for pancreatic islet beta cells. Enhanced REG expression was observed during the healing of gastric mucosa. REG expression was observed in various tumors including gastric carcinoma, but to the authors' knowledge, the correlation between REG expression and clinicopathologic characteristics and patient prognosis have not been evaluated. METHODS. The REG messenger RNA level was analyzed by Northern blot analysis and localization was performed by in situ hybridization and immunohistochemistry in gastric adenocarcinoma specimens. The correlations between REG expression and clinicopathologic features and survival of the patients were analyzed. RESULTS. Of the 68 patients studied, 24 (35%) were positive for REG. There was a significant consistency in the intensity and localization of REG transcript and protein expressions. REG expression was enhanced in advanced T classification tumors and in tumors that were not well differentiated. A significant number of metastatic lymph nodes were present in REG-positive tumors. Overall and disease-free survival were found to be poor for patients with REG-positive tumors. REG expression was reported to be an independent predictor of overall patient survival. CONCLUSIONS. Determination of REG expression may help to identify aggressive gastric tumors and to tailor appropriate therapy for patients with REG-positive tumors.