Immunohistochemical and immunoblotting detection of cytokeratin in smooth muscle tumors.
Forty-six smooth muscle tumors, including 35 of gastrointestinal origin, were studied immunohistochemically for the localization of cytokeratin using a variety of monoclonal antibodies. In formalin-fixed, paraffin-embedded material, six of 40 leiomyomas, two of five leiomyosarcomas and one leiomyoblastoma were immunoreactive for cytokeratin in a few tumor cells. A proportion of non-neoplastic smooth muscle cells also exhibited a positive reaction. In fresh frozen sections of one gastric leiomyosarcoma, a high percentage of tumor cells were reactive with nine of the eleven anti-cytokeratin monoclonal antibodies examined. Cytokeratin-positive cytoplasmic filaments were further demonstrated by immunoelectron microscopy. By immunoblot analysis, an extract of this immunohistochemically cytokeratin-positive leiomyosarcoma showed a distinct band at the same position as an extract of pancreas, whereas no bands were seen in an extract of a cytokeratin-negative esophageal leiomyosarcoma. These immunohistochemical and immunoblotting findings indicate that a certain subset of smooth muscle neoplasms express genuine cytokeratin filaments.
Department of Pathology, Tokai University School of Medicine, Kanagawa, Japan.
K
K
Tauchi
Y
Y
Tsutsumi
S
S
Yoshimura
K
K
Watanabe
D006801:Humans; D015151:Immunoblotting / Q000379:methods; D007150:Immunohistochemistry / Q000379:methods; D007633:Keratins / Q000378:metabolism*; D007889:Leiomyoma / Q000378:metabolism* / Q000473:pathology; D007890:Leiomyosarcoma / Q000378:metabolism* / Q000473:pathology; D008854:Microscopy, Electron / Q000379:methods; D009379:Neoplasms, Muscle Tissue / Q000378:metabolism* / Q000473:pathology
D007633:Keratins