title: Alternative EWS-FLI1 fusion gene and MIC2 expression in peripheral and central primitive neuroectodermal tumors.
abstract: Primitive neuroectodermal tumors (PNET) occur either in the central nervous system (CNS; central PNET, cPNET) or in the peripheral sites (peripheral PNET, pPNET). Recent molecular approaches have been defining a new concept of PNET, that is, the pPNET including Ewing's sarcoma (ES) which expresses MIC2 glycoprotein and shows the specific chimeric gene of EWS-FLI1. The expression of MIC2 and the genetic rearrangement of EWS-FLI1 are considered to be highly specific to the pPNET/ES. This study examined the expression of MIC2 and EWS-FLI1 gene by means of immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR) on various small round cell tumors originating in the CNS or non-CNS organs. All peripheral PNET tested expressed MIC2 and were positive for EWS-FLI1 (11/11). In contrast, all cPNET and other blastic CNS tumors were negative for MIC2: medulloblastoma (0/3), cerebral PNET (0/2), spinal PNET (0/2), glioblastoma (0/2), retinoblastoma (0/3), and pineoblastoma (0/2). These MIC2-negative tumors were also negative for the chimeric gene product of EWS-FLI1. Interestingly, one PNET originating in the intracranial dura mater was positive for both MIC2 and EWS-FLI1 fusion gene. The results indicate that cPNET lacks any genetic or protein markers, except for a meningeal PNET which falls into the same phenotypic spectrum of pPNET.
authors: Department of Neurosurgery, Hokkaido University School of Medicine, Sapporo, Japan.
authors: N
authors: N
authors: Ishii
authors: H
authors: H
authors: Hiraga
authors: Y
authors: Y
authors: Sawamura
authors: Y
authors: Y
authors: Shinohe
authors: K
authors: K
authors: Nagashima
mesh_terms: D000071443:12E7 Antigen; D015703:Antigens, CD / Q000032:analysis / Q000235:genetics*; D001932:Brain Neoplasms / Q000737:chemistry / Q000473:pathology / Q000503:physiopathology*; D015815:Cell Adhesion Molecules / Q000032:analysis / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008577:Meningeal Neoplasms / Q000737:chemistry / Q000473:pathology / Q000503:physiopathology*; D018241:Neuroectodermal Tumors, Primitive, Peripheral / Q000737:chemistry / Q000473:pathology / Q000503:physiopathology*; D015514:Oncogene Proteins, Fusion / Q000032:analysis / Q000235:genetics*; D010524:Peripheral Nervous System Neoplasms / Q000737:chemistry / Q000473:pathology / Q000503:physiopathology; D010641:Phenotype; D051789:Proto-Oncogene Protein c-fli-1; D012333:RNA, Messenger / Q000032:analysis; D034802:RNA-Binding Protein EWS; D014157:Transcription Factors / Q000032:analysis / Q000235:genetics*
chemical_list: D000071443:12E7 Antigen; D015703:Antigens, CD; C061828:CD99 protein, human; D015815:Cell Adhesion Molecules; C106031:EWS-FLI fusion protein; D015514:Oncogene Proteins, Fusion; D051789:Proto-Oncogene Protein c-fli-1; D012333:RNA, Messenger; D034802:RNA-Binding Protein EWS; D014157:Transcription Factors