title: Modulation of POMC expression in human neuroectodermal cells.
abstract: Neuroblastoma cell lines have been reported to contain two proopiomelanocortin (POMC) mRNA transcripts. We have now shown by immunocytochemistry and radioimmunoassay (RIA) that a number of neuroectodermally derived cell lines contain immunoreactive beta-endorphin although cell concentrations were not characteristic of any tumour type. To explore further the functional significance of beta-endorphin expression, we analysed neuroblastoma cell lines having intermediate (I), substrate adherent (S) and neuronal (N) phenotypes. No differences in cell beta-endorphin content were detected. However, the expression of POMC mRNA and of immunoreactive beta-endorphin was reduced within a few hours of treatment of these cell lines with retinoic acid. Culture of the cell lines in the presence of beta-endorphin resulted in small but significant increases in growth. Although the POMC gene is in the same chromosomal segment as N-myc, which is normally amplified in neuroblastoma, no corresponding amplification of POMC could be demonstrated. The data suggest that POMC gene products may contribute to the autocrine/paracrine growth of neuroectodermal tumours.
authors.affiliation: Dept. Experimental Medicine, University of Rome Tor Vergata, Italy.
authors.forename: V
authors.initials: V
authors.lastname: De Laurenzi
authors.forename: G
authors.initials: G
authors.lastname: Melino
authors.forename: R A
authors.initials: RA
authors.lastname: Knight
authors.forename: A R
authors.initials: AR
authors.lastname: Pierotti
authors.forename: P
authors.initials: P
authors.lastname: Cohen
mesh_terms: D002460:Cell Line; D002999:Clone Cells; D004475:Ectoderm; D015870:Gene Expression / Q000187:drug effects; D005909:Glioblastoma; D006801:Humans; D007150:Immunohistochemistry; D008545:Melanoma; D009447:Neuroblastoma; D018241:Neuroectodermal Tumors, Primitive, Peripheral; D011333:Pro-Opiomelanocortin / Q000032:analysis / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000096:biosynthesis; D011863:Radioimmunoassay; D014212:Tretinoin / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D001615:beta-Endorphin / Q000032:analysis / Q000096:biosynthesis
chemical_list: D012333:RNA, Messenger; D014212:Tretinoin; D001615:beta-Endorphin; D011333:Pro-Opiomelanocortin