| Lung cancer represents the leading cause of malignancy-related mortality at the end of twenty century.The five-year survival rate is not more than 13%. However, the exact mechanism of lung cancer is still not clear.Recent studies showed that the Fas/FasL system, which is related to apoptosis,may contribute to tumor-genesis, growth,and metastasis. Fas/FasL belong to the nerve growth factor/tumor necrosis factor receptor superfamily. Many kinds of tissues express Fas,but FasL is mainly expressed in activated lymphocytes.Under the physiological circumstance,the ligation of Fas(CD95) by the FasL(CD95L) triggers a series of events inside the cell that leads to the rapid induction of apoptosis,which is thought to be the most important mechanisms for the activated T cells to kill target cells(expressing Fas).The immune system can delete tumor cells through the same way.As previously reported,many kinds of malignant cells were found to have reduced or absent expression of Fas,which protect tham from immune attack.At the same time, FasL protein overexpression facilitates tumor cells killing activated immune cells surrounding them.Abnormal expression of Fas working in coordination with overexpressed FasL lead to immune evasion through escaping immunosurvellance.In order to, find effectmethod to diagnose at earlier stage,to understand the molecular mechanisms of Non-small cell lung cancer(NSCLC )carcinogenesis and to expand the knowledge for early detection of NSCLC,think out new treatment, the present study was undertaken to analyze the relationship between the Fas/FasL system and the carcinogenesis and progress of NSCLC, immunohisochemistry(IHC) was used to determine the protein of Fas, FasL and CD45RO in cancer tissues and normal lung tissues, TUNEL technique was also applied to detect the apoptosis in NSCLC.Material and Methods:80 surgical resected primary NSCLC samples and 10 normal lung tissue samples were collected.All the patients were not treated by neither chemotherapy nor radiotherapy before operation. All the resected tissues and biopsy tissues were fixed with formalin, paraffin embedded and serially sectioned for histopathological diagnosis, immuno-staining. SP immunohistochemical method was performed to detect expression of Fas, FasL and CD45RO, the apoptosis tumor cells were determined by TUNEL technique. Software SPSS 10.0, x2-test or exact probability-test were used for the statistics (P<0.05 was considered significant).Results:The expression of Fas: (1)In normal lung tissue,the immunohistochemical staining of Fas protein was located in the cell surface.Fas expression of tumor cells shows in both cytoplasm and/or on the surface,and in pulmonary adenocarcinomas,Fas was stained mainly in the cytoplasm.(2)Fas protein expression was found to be siginificantly (P < 0.05) reduced in the lung cancer(51.25%) compared with normal lung tissue(100%). (3)Fas positive expression in highly , moderately and poorly differentiated carcinomas were 68.97% > 65.28% and 16.00%,the lower the differentiation the lower the positive rate(P < 0.05).There was no close correlation between the expression of Fas and histologic type,TNM stages and lymphnodes metastasis(P > 0.05).The expression of FasL: (1)FasL expression showed in the cytoplasm of neoplastic cells.(2)No staining for FasL was seen in normal tissue.64 of the carcinomas (80.00%)showed positive staining. (3)The rates of expression of FasL was 88.57% in the adenocarcinomas but 73.33% in the squamous cell carcinoma,and there was significant difference between them.(4)The level of FasL expression in the group of lymphanode matastasis was singnificantly higher than the group of non-lymphanode metastasis (P < 0.05).The expression of FasL is not correlation to the degree of tissue differentiation and TNM stages(P > 0.05).The expression of CD45RO: The positive CD45RO located in the cell surface and the cytoplasm.All of the 80 lung cancer samples had different number of TIL,and the number of TIL was lower in the group of lymphanode matastasis than that... |
PDF Full Text Request