TTF-1 gene expression in human lung tumours.
Tissue-specific transcription factors control cell determination and differentiation. TTF-1 is a tissue-specific transcription factor expressed in the thyroid and lung. We investigated the expression of TTF-1 in normal human lung, and in various histopathological types of lung cancers by immunohistochemistry. In normal lung, TTF-1 expression was restricted to bronchial and alveolar epithelial cells. TTF-1 expression was found in 7 of the 29 cases of non-small cell lung carcinomas. In these tumours, the expression of TTF-1 did not correlate with the histological degree of differentiation. Results obtained using RNase protection assay confirmed that TTF-1 was expressed only in a subset of non-small cell carcinomas. TTF-1, as expected, was not expressed in neoplasms having a neuroendocrine cell origin, such as carcinoids. Interestingly, TTF-1 was always expressed in small cell lung carcinomas. These findings indicate that: (i) small cell lung carcinomas could originate from the endothermal cell lineage and (ii) dedifferentiation processes that operate in these neoplasms do not affect molecular mechanisms necessary for TTF-1 gene expression.
Fabbro
D
D
Dipartimento di Scienze e Tecnologie Biomediche, Università di Udine, Italy.
Di Loreto
C
C
Stamerra
O
O
Beltrami
C A
CA
Lonigro
R
R
Damante
G
G
D002276:Carcinoid Tumor / Q000235:genetics / Q000378:metabolism; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics / Q000378:metabolism; D018288:Carcinoma, Small Cell / Q000235:genetics / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008168:Lung / Q000378:metabolism; D008175:Lung Neoplasms / Q000235:genetics* / Q000378:metabolism; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
C000614412:NKX2-1 protein, human; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors