Increased mRNA expression levels of ERCC1, OGG1 and RAIin colorectal adenomas and carcinomas

• Published in: BMC cancer Vol. 6; no. 1
• Main Authors: Sæbø, Mona, Skjelbred, Camilla Furu, Nexø, Bjørn Andersen, Wallin, Håkan, Hansteen, Inger-Lise, Vogel, Ulla, Kure, Elin H
• Format: Journal Article
• Language: English; Japanese
• Published: 16.08.2006
• ISSN: 1471-2407; 1471-2407
• DOI: 10.1186/1471-2407-6-208

Abstract Background The majority of colorectal cancer (CRC) cases develop through the adenoma-carcinoma pathway. If an increase in DNA repair expression is detected in both early adenomas and carcinomas it may indicate that low repair capacity in the normal mucosa is a risk factor for adenoma formation. Methods We have examined mRNA expression of two DNA repair genes, ERCC1 and OGG1 as well as the putative apoptosis controlling gene RAI , in normal tissues and lesions from 36 cases with adenomas (mild/moderat n = 21 and severe n = 15, dysplasia) and 9 with carcinomas. Results Comparing expression levels of ERCC1, OGG1 and RAI between normal tissue and all lesions combined yielded higher expression levels in lesions, 3.3-fold higher (P = 0.005), 5.6-fold higher(P < 3·10 -5 ) and 7.7-fold higher (P = 0.0005), respectively. The levels of ERCC1, OGG1 and RAI expressions when comparing lesions, did not differ between adenomas and CRC cases, P = 0.836, P = 0.341 and P = 0.909, respectively. When comparing expression levels in normal tissue, the levels for OGG1 and RAI from CRC cases were significantly lower compared to the cases with adenomas, P = 0.012 and P = 0.011, respectively. Conclusion Our results suggest that increased expression of defense genes is an early event in the progression of colorectal adenomas to carcinomas.