The Expression And Significance Of Fas/FasL In Oral Premalignant Lesions And Squamous Cell Carcinoma And Effect Of The Expression On The Apoptosis Of Carcinoma Cells And Tumor Infiltrating Lymphocytes

Objective:To study the expression and significance of apoptosis-related gene Fas/FasL in oral premalignant lesions and squamous cell carcinoma,the expression of Fas/FasL in tumor infiltrating lymphocytes(TIL),and effect of expression of Fas/FasL on the apoptosis of carcinoma cells and tumor infiltrating lymphocytes.Methods:The expression of Fas/FasL,was examined by immunohistochemistry S-P method in 10cases of normal oral mucosa,26 cases of oral epithelial dysplasia and 38 cases of oral squamous cell carcinoma(OSCC).Apoptosis of tumor cells and TIL were detected by terminal deoxynucleotide transferase labeling technique(TUNEL) in 38 cases of OSCC.Results were compared with clinical pathologic parameters,and so on.Results:1.In the normal oral mucosa tissues,Fas showed in epithelium,especially in stratum granulosum and stratum corneum.Normal oral mucosa tissues was all positive for Fas protein.In the tissues from oral epithelial dysplasia,69.2%were positive for Fas protein.Fas protein positive staining was found in 77.7%of light differentiated epithelial dysplasia,70.0%of middle differentiated epithelial dysplasia and 49.2%of high differentiated epithelial dysplasia.In the tissues from OSCC,55.3%were positive for Fas protein.Fas protein positive staining was found in 66.6%of well differentiated tumors,58.3%of moderate differentiated tumors and 25.0%of poor differentiated tumors.Fas protein positive staining was found in 45.5%of lymph node metastasis, but Fas protein positive staining was found in 59.3%of nonlymph node metastasis.Fas protein expression did not show correlation to lymph node metastasis(P＞0.05),but Fas protein expression showed correlation to histological grade(P＜0.05).2.In the tissues from normal oral mucosa tissues,0 were positive for FasL protein. In the tissues from oral epithelial dysplasia,53.8%were positive for FasL protein.FasL protein positive staining was found in 44.4%of light differentiated epithelial dysplasia,50.0%of middle differentiated epithelial dysplasia and 57.1%of high differentiated epithelial dysplasia.In the tissues from OSCC,60.5%were positive for FasL protein.FasL protein positive staining was found in 55.5%of well differentiated tumors,66.6%of moderate differentiated tumors and 62.5%of poor differentiated tumors.FasL protein positive staining was found in 81.8%of lymph node metastasis, but FasL protein positive staining was found in 51.9%of nonlymph node metastasis. FasL protein expression did not show correlation to histological grade(P＞0.05),but FasL protein expression showed correlation to lymph node metastasis(P＜0.05).3.There Was a higher percentage of Fas and FasL immunoreactivity in TIL.Fas protein positive staining was found in 81.6%of TIL,FasL protein positive staining was found in 84.2%of TIL.4.Fas protein positive staining was found in 55.3%of OSCC.Apoptotic index(AI) of tumor cells in Fas positive OSCC was remarkably higher than that in Fas negative OSCC(P＜0.05).There was positive correlation between expression Fas protein and cell differentiation and apoptosis in OSCC(P＜0.05).5.FasL protein positive staining was found in 60.5%of OSCC.AI of tumor cells in FasL positive OSCC was remarkably lower than that in FasL negative OSCC(P＜0.05).There was positive correlation between expression FasL protein and cell differentiation and apoptosis in OSCC(P＜0.05). 6.AI of TIL in FasL positive OSCC was remarkably higher than that in FasL negative OSCC(P＜0.05).There was positive correlation between cell differentiation and apoptosis in OSCC(P＜0.05).Conclusion:The down-regulation of Fas and up-regulation of FasL may play an important role in the development of OSCC.The down-regulation of Fas and up-regulation of FasL in OSCC may be a sign of immune counterattack,and related to the tumorigenesis.Perhaps,Fas/FasL system may be used as a prognostic biomarker in predicting the behavior of OSCC in the near future.