Expression patterns of Neil3 during embryonic brain development and neoplasia.

Background: The base excision repair pathway is responsible for repairing small DNA base lesions caused by endogenous and exogenous damaging agents. Repair is initiated by DNA glycosylases that recognize and remove the lesions. NEIL3 is one of 11 mammalian DNA glycosylases identified to date and it was discovered on the basis of sequence homology to the E. coli Fpg and Nei glycosylases. Difficulties in purifying the protein have limited its biochemical characterization and in contrast to the other glycosylases, its function remains unclear.

Results: In this study we describe the expression pattern of Neil3 during mouse embryonic development with special focus on brain development. We have also looked at the expression of NEIL3 in several normal and tumor tissues. Quantitative real-time PCR and in situ hybridization revealed that Neil3 was highly expressed at embryonic days 12-13, when neurogenesis starts. The expression decreased during development and in the adult brain,Neil3 could not be detected in any of the brain areas examined by quantitative real-time PCR. During embryogenesis and in newborn mice specific expression was observed in areas known to harbour neural stem and progenitor cells such as the subventricular zone and the dentate gyrus. Finally, NEIL3 expression was higher in tumors compared to normal tissues, except for testis and pancreas.

Conclusion: Our findings indicate that mammalian NEIL3 is specifically expressed in brain areas where neurogenesis takes place during development and that its expression is tightly regulated both temporally and spatially. In addition, NEIL3 seems to be upregulated in tumor tissues compared to normal tissues. Altogether, mammalian NEIL3 seems to be highly expressed in cells with high proliferative potential.