目的:探讨干细胞标志物ABCG2作为肺癌干细胞标志的意义。方法:常规石蜡包埋、切片及HE染色,应用免疫组化SP法检测ABCG2在肺癌组织及肺癌细胞系GLC-82和A549中的定位和表达。显微镜观察ABCG2蛋白表达的部位及分布,用Lei-caQ500MC图像分析系统对其表达强度的阳性单位(positive unit PU)进行定量测试分析。结果:ABCG2蛋白表达在肺癌细胞的胞质和胞膜;肺癌组织中肺鳞癌和肺腺癌呈阳性表达,弥漫分布;肺大细胞癌和肺小细胞癌不表达。ABCG2蛋白表达阳性率和表达强度在肺腺癌中表达最高,其次为肺鳞癌,肺小细胞癌及肺大细胞癌表达最低(P<0.05),且两者之间表达差异无显著性(P>0.05)。ABCG2蛋白在肺癌淋巴结转移灶中的表达特点与原发灶一致,但转移灶中腺癌和鳞癌表达阳性率的差异无显著性(χ2=0.36,P>0.05)。ABCG2蛋白在肺癌细胞系GLC-82和A549中呈弥漫阳性表达。结论:ABCG2单独不适合作为肺癌干细胞的标志物,但可作为肺癌分型的标记物。
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.
OBJECTIVE To investigate the correlations between the expression of thyroid transcription factor-1 （TTF-1） and apoptosis and angiogenesis in lung carcinomas. METHODS A 829 microarray of the paraffin tissue chips was constructed, which contained 196 lung carcinomas, 10 normal lung tissues, and 1 muscular tissue. Terminal deoxynucleotidyl transferase mediated nick end labeling （TUNEL） and immunohistochemical SP method were used to detect apoptosis and expression of TTF-1 and CD34 in different types of lung carcinomas. A Leica Q500 MC image analysis system was used to measure and calculate TTF-1 positive unit （PU）, apoptotic index （AI） and microvessel density （MVD）. RESULTS AI of lung small cell carcinoma and large cell carcinoma were smaller than those of lung adenocarcinoma and squamous cell carcinoma （P = 0.000）. AI of lung carcinomas with lymph node metastases was smaller than that of those without （P = 0.039）. AI of lung carcinomas in TNM stage I-IV was smaller than that in stage I （P = 0.008）. The PU of the TTF-1 was negatively correlated with AI in small cell lung carcinoma （r = -0.752, P = 0.000）. MVD of lung carcinomas without lymph node metastases was smaller than that of those with lymph node metastasis （P = 0.031）. MVD of lung carcinomas in TNM stage I was smaller than that in stage I-IV （P = 0.040）. The PU of TTF-1 was positively correlated with MVD in lung adenocarcinoma （r = 0.708, P = 0.000）. CONCLUSION There is a negative correlation between TTF-1 PU and AI in small cell lung carcinoma. TTF-1 PU and AI may be correlated with each other. There is a positive correlation between TTF-1 PU and MVD in lung adenocarcinoma. TTF-1 may induce the development of lung adenocarcinoma by inducing tumor angiogenesis.
