The neuronal EGF-related genes NELL1 and NELL2 are expressed in hemopoietic cells and developmentally regulated in the B lineage

NELL1 and NELL2 (neural epidermal growth factor-like 1 and 2) are recently described members of the epidermal growth factor gene family that have prev iously been shown to be expressed almost exclusively in brain tissue. Here we demonstrate regulated expression of NELL1 and NELL2 in human hematopoiet ic cells. Mature NELL1 mRNA is not detected in any normal hemopoietic cell type, although the gene is transcribed during a narrow window of pre-B cell development, and cell lines at the same developmental stage express the NE LL1 mRNA. The related NELL2 gene is expressed by all nucleated peripheral b lood cells examined (B, T, monocyte, and natural killer cells), but not in any of the bone marrow B lineage cells at earlier stages of development. Ho wever, leukemic cell lines corresponding to the same early differentiation stages express abundant NELL2 mRNA. These results suggest normal and possib le oncogenic roles for the NELL proteins in hemopoietic cells. (C) 1999 Els evier Science B.V. All rights reserved.