EXPRESSION OF THE HUMAN ACHAETE-SCUTE-1 GENE IN OLFACTORY NEUROBLASTOMA (ESTHESIONEUROBLASTOMA)

Olfactory neuroblastoma (ONB) is a rare neuronal malignancy of the olf actory mucosal. Markers used in the diagnosis of ONB do not distinguis h ONB from other neuronal tumors or tumors with neuroendocrine feature s thus making the diagnosis of ONB difficult. Using a modified RT-PCR technique, we show that the human homologue of the Drosophila achaete- scute gene HASH1 is expressed in 6 primary and one metastatic ONB spec imens, whereas Olfactory Marker Protein (OMP) is not. Previous studies have shown that HASH1 is expressed in immature olfactory neurons and is required for their development. OMP, whose function is unknown, is expressed exclusively in mature olfactory neurons. Together, these dat a suggest that ONB is derived from immature olfactory neurons of neuro ectodermal origin. Analysis of RNA expression in primary tumor specime ns and in an established cell line make this an ideal system to study olfactory growth and differentiation. Furthermore, these studies repre sent the first molecular genetic analysis of this rare and unusual neu ronal tumor.