Expression of NDRG1, a differentiation-related gene, in human tissues.

NDRG1 is a member of the new N-myc downregulated gene (NDRG) family which belongs to the alpha/beta hydrolase superfamily, but without presenting a hydrolytic catalytic site. Diverse physiological and pathological conditions (hypoxia, cellular differentiation, heavy metal, N-myc, neoplasia) modulate NDRG1 transcription, mRNA stability, and translation. In this report we present the immunohistochemical localization of NDRG1 in a large set of normal human tissues at light and electron microscopic levels. The immunoreactivity of NDRG1 is mostly found in epithelial cells with different aspects. We observed NDRG1 primarily in the cytoplasm, but it is also associated with the cellular membrane and adherens junctions. Given the strong upregulation of NDRG1 under hypoxia and its nuclear localization, we propose a role for NDRG1 in protection from ischemic cell damage. The multiple localizations of this protein also suggest pleiotropic functions amongst which a functional involvement in the E-cadherin/catenin complex.