Browsing by Subject "Bronchiolar metaplasia"

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    A subpopulation of airway epithelial cells that express hepatocyte nuclear factor 4α - its implication in the development of non- terminal respiratory unit-type lung adenocarcinoma.
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2019) Okudela, Koji; Ara, Hiromasa; Kitamura, Hideya; Baba, Tomohisa; Suzuki, Takehisa; Mitsui, Hideaki; Sugiyama, Misaki; Honda, Emi; Matsumura, Mai; Takemura, Tamiko; Kataoka, Toshiaki; Koike, Chihiro; Tateshi, Yoko; Tajiri, Michihiko; Ogura, Takashi; Ohashi, Kenichi
    A normal counterpart and precancerous lesion that non-terminal respiratory unit (TRU) lung adenocarcinomas (LADCs) develop from have not been clarified. Non-TRU LADCs specifically express hepatocyte nuclear factor 4α (HNF4α). Thus, we have been interested in airway epithelial cells that express HNF4α as the potential precursor of non-TRU LADC. The purposes of the present study are to report the frequency and distribution of HNF4α-expressing cells at the different airway levels, and to investigate the potential significance of the expression of HNF4α in the histogenesis of non-TRU LADC with a special reference to the relationship to bronchiolar metaplasia in idiopathic interstitial pneumonia. We herein identified a minor subpopulation of epithelial cells that express HNF4α in a physiological state. This subpopulation was mainly located in the terminal bronchioles and had the appearance of ciliated cells, which were mutually exclusive from Clara cells and others that strongly expressed thyroid transcription factor 1. Furthermore, the expression of HNF4α was similar in bronchiolar metaplastic lesions and the terminal bronchioles, and some of the metaplastic lesions showed an unequivocally higher frequency and expression level of HNF4α, which was comparable to non-TRU LADC. In summary, this is the first study to describe a subpopulation of ciliated cells that express HNF4α as a potential normal counterpart for non-TRU LADCs and suggests that bronchiolar metaplastic lesions that strongly express HNF4α are a precancerous lesion for non-TRU LADCs.
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    Relationship between non-TRU lung adenocarcinomas and bronchiolar metaplasia - potential implication in their histogenesis -
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2018) Okudela, Koji; Kojima, Yoko; Matsumura, Mai; Arai, Hiromasa; Umeda, Shigeaki; Tateishi, Yoko; Mitsui, Hideaki; Suzuki, Takehisa; Tajiri, Michihiko; Ogura, Takashi; Ohashi, Kenichi
    Lung adenocarcinomas (ADCs) have been roughly divided into two groups: the terminal respiratory unit (TRU) type and non-TRU type. These ADCs appear to develop through exclusive carcinogenetic pathways because of differences in their cellular morphologies and the profiles of protein expression and genetic alterations. The TRU type develops from atypical adenomatous hyperplasia as a precursor. On the other hand, the histogenesis of the non-TRU type has not yet been defined in detail. We herein investigated histopathological changes in the non-tumor lung tissues of patients with non-TRU-type ADCs in order to define their potential histogenesis. The non-TRU type preferentially occurs in patients with interstitial pneumonia, in whom tumors are located in honeycomb lesions and are associated with bronchiolar metaplasia (BM). Among patients without interstitial pneumonia, non-tumor lung tissues from non-TRU-type ADCs were often affected by multiple BM. In these cases, tumors often were associated with BM. Metaplastic cells adjacent to non-TRU-type ADCs ectopically expressed HNF-4α, a marker for non-TRU-type ADCs. These results suggest that the non-TRU type develops through distinct histogenesis, in which BM is implicated.