Distribution of vitamin B12 R-binder in lung tumors. Implications for cell differentiation.
Expression of vitamin B12 R-binder, a specific binding protein for vitamin B12, was studied immunohistochemically in normal lung tissues and 107 lung tumors of various types. In normal tissues, vitamin B12 R-binder (R-binder) expression was restricted to the mucous cells of bronchial or bronchiolar epithelium and submucosal glands as well as to nonciliated bronchiolar (Clara) cells. Among lung carcinomas, 38% of squamous cell carcinomas, 42% of adenocarcinomas and 23% of large cell carcinomas showed positive staining for R-binder whereas small cell carcinomas did not. These findings offer the possibility that a majority of the histologic types of lung carcinoma have common histogenetical characteristics with mucous or Clara cells. Of the bronchial gland tumors, R-binder could be detected in a mucoepidermoid carcinoma but not in adenoid cystic carcinomas. Epithelial components in both pulmonary blastomas and hamartomas showed a reactivity for R-binder, suggesting that these tumors contained components composed of cells with bronchiolar cell differentiation. The immunohistochemical examination of lung tumors, using anti-R-binder antibody, may have some implications in the cell differentiation of lung tumors.
Ogawa
K
K
Department of Pathology, Faculty of Medicine, Kyoto University, Japan.
Shima
N
N
Ohshio
G
G
Kudo
H
H
Nakashima
Y
Y
Yamabe
H
H
Takeda
T
T
D001980:Bronchi / Q000032:analysis / Q000166:cytology / Q000378:metabolism; D002471:Cell Transformation, Neoplastic / Q000032:analysis / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008168:Lung / Q000032:analysis / Q000166:cytology / Q000378:metabolism; D008175:Lung Neoplasms / Q000032:analysis / Q000378:metabolism* / Q000473:pathology; D014155:Transcobalamins / Q000032:analysis / Q000378:metabolism*
D014155:Transcobalamins