Reliability of a Tissue Microarray in Detecting Thyroid Transcription Factor-1 Protein in Lung Carcinomas

OBJECTIVE To compare the expression of the thyroid transcription factor-1 (TTF-1) in human normal adult type II alveolar epithelial cells, embryonic pneumocytes and cancer cells of lung carcinoma and metastatic lymph nodes using a tissue microarray (TMA) along with paired conventional full sections, and to investigate the reliability of tissue microarrays in detecting protein expression in lung carcinoma. METHODS A lung carcinoma TMA including 765 cores was constructed. TTF-1 protein expression in both TMA and paired conventional full sections were detected by the immunohistochemical SP method using a monoclonal antibody to TTF-1. A PU (Positive Unit) of TTF-1 protein was assessed quantitatively by the Leica Q500MC image analysis system with results from the paired conventional full sections as controls. RESULTS There was no signifi cance between TMA and paired conventional full sections in TTF-1 expression in different nuclei of the lung tissue. CONCLUSION TTF-1 protein expression in lung carcinoma detected by TMA was highly concordant with that of paired full sections. TMA is a reliable method in detecting protein expression.

OBJECTIVE To compare the expression of the thyroid transcription factor-1 （TTF-1） in human normal adult type Ⅱ alveolar epithelial cells, embryonic pneumocytes and cancer cells of lung carcinoma and metastatic lymph nodes using a tissue microarray （TMA） along with paired conventional full sections, and to investigate the reliability of tissue microarrays in detecting protein expression in lung carcinoma. METHODS A lung carcinoma TMA including 765 cores was constructed. TTF-1 protein expression in both TMA and paired conventional full sections were detected by the immunohistochemical SP method using a monoclonal antibody to TTF-1. A PU （Positive Unit） of TTF-1 protein was assessed quantitatively by the Leica Q500MC image analysis system with results from the paired conventional full sections as controls. RESULTS There was no significance between TMA and paired conventional full sections in TTF-1 expression in different nuclei of the lung tissue. CONCLUSION TTF-1 protein expression in lung carcinoma detected by TMA was highly concordant with that of paired full sections. TMA is a reliable method in detecting protein expression.