title: Calcifying epithelial odontogenic (Pindborg) tumor-associated amyloid consists of a novel human protein.
abstract: Calcifying epithelial odontogenic tumors (CEOTs), also known as Pindborg tumors, are characterized by the presence of squamous-cell proliferation, calcification, and, notably, amyloid deposits. On the basis of immunohistochemical analyses, the amyloidogenic component had heretofore been deemed to consist of cytokeratin-related or other molecules; however, its chemical composition had never been elucidated. We have used our microanalytic techniques to characterize the protein nature of CEOT-associated amyloid isolated from specimens obtained from 3 patients. As evidenced by the results of amino-acid sequencing and mass spectrometry, the fibrils were found to be composed of a polypeptide of approximately 46 mer. This component was identical in sequence to the N-terminal portion of a hypothetical 153-residue protein encoded by the FLJ20513 gene cloned from the human KATO III cell line. That the amyloid protein was derived from this larger molecule was demonstrated by reverse transcription-polymerase chain reaction amplification of tumor-cell RNA where a full-length FLJ20513 transcript was found. Furthermore, immunohistochemical analyses revealed that the amyloid within the CEOTs immunostained with antibodies prepared against a synthetic FLJ20513-related dodecapeptide. Our studies provide unequivocal evidence that CEOT-associated amyloid consists of a unique and previously undescribed protein that we provisionally designate APin.
authors.affiliation: Human Immunology and Cancer Program, Department of Medicine, University of Tennessee Graduate School of Medicine, Knoxville 37920, USA. asolomon@mc.utmck.edu
authors.forename: Alan
authors.initials: A
authors.lastname: Solomon
authors.forename: Charles L
authors.initials: CL
authors.lastname: Murphy
authors.forename: Kristal
authors.initials: K
authors.lastname: Weaver
authors.forename: Deborah T
authors.initials: DT
authors.lastname: Weiss
authors.forename: Rudi
authors.initials: R
authors.lastname: Hrncic
authors.forename: Manfred
authors.initials: M
authors.lastname: Eulitz
authors.forename: Robert L
authors.initials: RL
authors.lastname: Donnell
authors.forename: Knut
authors.initials: K
authors.lastname: Sletten
authors.forename: Gunilla
authors.initials: G
authors.lastname: Westermark
authors.forename: Per
authors.initials: P
authors.lastname: Westermark
mesh_terms: D000293:Adolescent; D000595:Amino Acid Sequence; D000682:Amyloid / Q000032:analysis / Q000235:genetics* / Q000276:immunology; D000686:Amyloidosis / Q000378:metabolism / Q000473:pathology*; D000906:Antibodies; D003001:Cloning, Molecular; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007573:Jaw Neoplasms / Q000737:chemistry* / Q000473:pathology*; D008875:Middle Aged; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000032:analysis / Q000235:genetics* / Q000276:immunology; D018333:Odontogenic Cyst, Calcifying / Q000737:chemistry* / Q000473:pathology*
chemical_list: D000682:Amyloid; D000906:Antibodies; D009363:Neoplasm Proteins; C480049:ODAM protein, human