| Objective: To investigate expression of Fas protein and Fas mRNA and methylation of Fas gene in lung cancer tissues, Paracancerous tissues and normal lung tissues as well as in metastatic lymph nodes and non-metastatic lymph nodes. Analyze the correlation of Fas protein, FasmRNA and methylation of Fas gene. Discuss the effection they may cause in development of lung cancer.Methods: Tumor specimens and corresponding paracancerous tissues were collected from surgical patients who suffered lung cancer. These specimens includ 23 squamous cell carcinomas, 13 adenosquamous carcinomas, 11 bronchioloalveolar carcinomas, 21 adenocarcinomas and 17 small cell lung cancers. 49 metastatic lymph nodes and 36 non-metastatic lymph nodes also were collected. Furthermore, 60 normal lung tissues were collected from surgical patients who were not suffered lung cancer. Fas protein expression of tumor specimen and corresponding paracancerous tissue were detected with immunohistochemical S-P method. Fas mRNA expression of tumor specimen and corresponding paracancerous tissue were detected with RT-PCR method. Methylation of Fas gene of tumor specimen and corresponding paracancerous tissue were detected with methylation-specific polymerase chain reaction (MS-PCR). The correlation and the difference among Fas protein, Fas mRNA, Fas gene methylation and clinical-pathological data were analyzed. Experiment group(according to the experimental purpose): normal lung tissue, cancer tissues, paracancerous tissues; non-small cell lung cancer, small cell lung cancer; squamous cell carcinoma, adenocarcinoma, adenosquamous carcinoma and bronchioloalveolar carcinoma; metastatic lymph nodes and nonmetastatic lymph nodes.Results : 1. In tumor specimen the positive rate of Fas protein is 37.6%(32/85),the rate of Fas mRNA is 43.5%(37/85), both of the rate are lower than 69.4%(59/85) and 72.9%(62/85) in corresponding paracancerous tissue and 71.7%(43/60) and 81.7%(49/60) in normal lung tissue, P<0.01. The positive rate of Fas gene methylation in tumor specimen is 63.5%(54/85), the rate is higher than 21.2%(18/85) in corresponding paracancerous tissue and 13.3%(8/60) in normal lung tissue, P<0.01. To compare the rate of corresponding paracancerous tissue and normal lung tissue , P>0.05. 2. In small cell lun cancer the positive rate of Fas protein is 11.8% (2/17), the rate of Fasm RNA is 17.6% (3/17), both of the rate are lower than 44.1% (30/68) and 50.0% (34/68) in Non-small cell lung cancer, P<0.05. The positive rate of Fas gene methylation in small cell lun cancer is 88.2% (15/17), the rate is higher than 57.4% (39/68) in Non-small cell lung cancer, P<0.05. 3. The positive rate of Fas protein, Fas mRNA and Fas gene methylation in subtypes of non-small cell lung cancer separately are squamous cell carcinoma (43.5%, 52.2% and 60.9%) , adenocarcinoma (42.9%, 47.6% and 57.1%), adenosquamous carcinoma (46.2%, 53.8% and 53.8%), bronchioloalveolar carcinoma (45.5%, 45.5% and 54.5%), To compare the rate of them, P>0.05. 4. The positive rate of Fas protein in metastatic lymph nodes is 32.7% (16/49), the rate of Fas mRNA is 36.7% (18/49), both of the rate are lower than 58.3% (21/36) and 63. 9% (23/36) in non-metastatic lymph nodes, P<0.05. The positive rate of Fas gene methylation in metastatic lymph nodes is 69.4% (34/49), the rate is higher than 47.2% (17/36) in non-metastatic lymph nodes, P<0.05. 5. To compare the positive rate of Fas protein, Fas mRNA and Fas gene methylation in different classes of TNM stage, differentiation, lymph node metastasis, sexuality , ages and smoking index, P>0.05. 6. The correlation index (r) between Fas gene methylation and between Fas gene methylation separately are - 0.471 and - 0.469, P<0.01.Conclusions: 1. Expression of Fas is significantly down-regulation and Fas gene is significantly Hypermethylation in lung cancer. The phenomenon in small cell lung cancer is more obvious than that in non-small cell lung cancer. Fas expression and Fas gene methylation in lung cancer have significantly negative correlation. 2. In metastatic lymph nodes Fas expression is down-regulation and Fas gene is hypermethylation. 3. The difference of Fas expression and of Fas gene methylation in different classes of TNM stage, differentiation, lymph node metastasis, sexuality, ages and smoking index have non statistical significance. |
