title: Cytoplasmic expression of c-erbB2 in non-small cell lung cancers.
abstract: The aim of this study was to investigate the expression of c-erbB2 in non-small cell lung cancers (NSCLCs) with attention both to membranous and cytoplasmic reaction, and to try to elucidate the meaning of cytoplasmic expression of c-erbB2 in NSCLCs. Immunohistochemical c-erbB2 expression and related clinico-pathological features were examined in 312 surgically resected patient tissues of NSCLCs, including 175 cases of adenocarcinoma and 137 cases of squamous cell carcinoma. Immunostaining of inner- and ecto-domain of c-erbB2, mRNA expression and the quantitation of soluble c-erbB2 in cultured media were performed in five NSCLC cell lines. Cytoplasmic expression of c-erbB2 was observed more frequently than membranous, both in patient tissues and cell lines. Neither membranous nor cytoplasmic expression of c-erbB2 was significantly correlated with short outcome in NSCLCs. Membranous c-erbB2 was expressed by both inner and ecto-domain, while cytoplasmic c-erbB2 was expressed by either or both inner and ecto-domain. c-erbB2 mRNA was produced in most cell lines; however, the soluble form was only detectable in a cell line that only presented a membranous c-erbB2. In conclusion, cytoplasmic c-erbB2 of NSCLCs was not a full-length protein only expressed in cellular membrane, but reflected degenerated c-erbB2 fragments with less functional ability.
authors.affiliation: Department of Pathology, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Chun-Mei
authors.initials: CM
authors.lastname: Cheng
authors.forename: Koichi
authors.initials: K
authors.lastname: Tsuneyama
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Matsui
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takahashi
authors.forename: Shin
authors.initials: S
authors.lastname: Ishizawa
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Takano
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism* / Q000401:mortality; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism*; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000378:metabolism* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis*; D016019:Survival Analysis
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases