ABSTRACT
Amyloid deposits are commonly associated with Pindborg tumors, i.e., calcifying epithelial odontogenic tumors (CEOT). Amyloid fibrils were extracted from sections of formalin-fixed, paraffin-embedded blocks obtained from 3 patients with CEOTs. The proteins were purified by reverse phase-HPLC, the material contained in the peak eluates treated with cyanogen bromide, and the resultant peptides subjected to automated amino acid sequence analyses as described. In immunohistochemical analyses, the intensity of immunostained amyloid was consonant with the amount of FLJ40850- or FLJ20513-related amyloid present in the specimen. The HPLC elution profiles of the 3 CEOT amyloid extracts. Sequence analyses of the cyanogen bromide-derived peptides revealed the presence, in each case, of 37 and 10 to 39 N-terminal residues of FLJ20513 and FLJ40850, respectively.
