Quantitative study of thyroid transcription factor-1 protein expression in lung carcinoma cell nucleus by tissue microarray / 南方医科大学学报

ABSTRACT

<p><b>OBJECTIVE</b>To investigate thyroid transcription factor-1 (TTF-1) expression in normal human adult type II alveolar epithelial cells, embryonic pneumocytes, lung carcinoma cells and lymph node metastases of lung cancer.</p><p><b>METHODS</b>Lung carcinoma tissue microarray was constructed containing 765 cores of 20 normal adult lung tissues, 15 embryonic lung tissues, 100 lung carcinomas and 55 corresponding lymph node metastases. TTF-1 protein expression on the microarray was detected by immunohistochemical SP method using TTF-1 monoclonal antibody and assessed quantitatively with Leica Q500MC image analysis system.</p><p><b>RESULTS</b>The number TTF-1 positive units (PU) was smaller in the nuclei of embryonic pneumocytes than in those of normal adult type II alveolar epithelial cells (P<0.001). The nuclei of lung carcinoma cells had smaller TTF-1 PU than normal adult type II alveolar epithelial cells and embryonic pneumocyte nuclei (P<0.001). The lung adenocarcinoma and small cell lung carcinoma cell nuclei had greater TTF-1 PU than squamous cell carcinoma and large cell lung carcinoma cell nuclei (P<0.001). TTF-1 PU was greater in squamous cell carcinoma cell nuclei than in large cell lung carcinoma cell nuclei (P<0.001). In lung adenocarcinoma, squamous cell lung carcinoma and large cell lung carcinoma, TTF-1 PU was greater in the cancerous cell nuclei of lymph node metastases than in the corresponding primary carcinoma cell nuclei (P<0.001, P<0.001, and P<0.05, respectively). In small cell lung carcinoma, TTF-1 PU of the cancerous cell nuclei of lymph node metastases was similar to that of primary carcinomas (P>0.05). TTF-1 PU was greater in lung carcinoma with lymph node metastases than in those without metastalsis (P<0.001). TTF-1 PU of the cell nuclei was not associated with the tumor growth pattern, differentiation and patients' gender (P>0.05), but was greater in TNM stage II-IV than in stage I (P<0.001).</p><p><b>CONCLUSIONS</b>The amount of TTF-1 in the cell nuclei decreases in the order of normal adult type II alveolar epithelial cells, embryonic pneumocytes and lung carcinoma cells. TTF-1 expression is higher in adenocarcinoma and small cell carcinoma and lower in squamous carcinoma and large cell carcinoma. Stronger TTF-1 expression is associated with greater likeliness of lung carcinoma metastatie, and can be an important hallmark for metastasis potential of lung adenocarcinoma, squamous cell carcinoma and large cell carcinoma.</p>