CLONING OF HUMAN ENC-1 AND EVALUATION OF ITS EXPRESSION AND REGULATION IN NERVOUS-SYSTEM TUMORS

We recently identified and characterized a novel murine gene, ENC-1, t hat is expressed primarily in the nervous system and encodes an actin- binding protein. To gain insight into a potential role for ENC-1 gene in the processes of cell differentiation and malignant transformation in the human nervous system, we first cloned and characterized the hum an homologue of ENC-1. The human ENC-1 gene appeared to be highly expr essed in adult brain and spinal cord, and in a number of cell lines de rived from nervous system tumors we detected low steady-state levels o f ENC-1 mRNA. We used a neuroblastoma differentiation model, the retin oic acid-induced neuronal differentiation of SMS-KCNR cells, to study the regulation of the ENC-1 gene during neural crest cell differentiat ion. We found that the expression of ENC-1 increased dramatically in t he differentiated SMS-KCNR cells as compared to control undifferentiat ed cells. These results suggest that ENC-1 expression plays a role dur ing differentiation of neural crest cells and may be down regulated in neuroblastoma tumors.. (C) 1998 Academic Press.