DNA-damage inducible 1 is a property of human non-small cell lung cancer

Abstract

Background: DNA damage-inducible 1 (Ddil), one of the ubiquitin-like and ubiquitin-associated family of proteins, may function in the regulation of the ubiquitin-proteasome pathway, which has been validated as a target for antineoplastic therapy. We investigated Ddil expression in human lung cancer tissues and evaluated the relationship of this expression pattern with clinicopathological factors in patients with non-small-cell lung cancer (NSCLC). Methods: Ddil expression was examined by immunohistochemistry in tumor tissues from 97 patients with stage I NSCLC, who had undergone curative surgical resection at two tertiary referral hospitals from 1993 - 2004. None of the patients received preoperative chemotherapy and/or radiation therapy. Results: Thirty-nine (40.2%) of the 97 cases were positive for Ddil. Ddil expression was dominantly seen in cytoplasm rather than in the nuclei of cancer cells in all histological types, whereas adjacent nontumoral lung tissue showed negative Ddil staining in most cases. Ddil expression tended to increase in well-differentiated tumors but without statistical significance. Positive Ddil expression was associated with a tendency for better disease-free survival and disease-specific survival, although the difference was not significant. Conclusion: Ddil expression is a property of NSCLC. Because Ddil could be a potential target for cancer therapy, more research is needed to evaluate its role in NSCLC. Copyright©2012. The Korean Academy of Tuberculosis and Respiratory Diseases. All rights reserved.