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1.
Lack of surface Fas expression is a main route for apoptotic resistance which is considered an important mechanism of tumorigenesis and tumor progression. Fas and FasL expressions in 110 non-small cell lung carcinomas (NSCLCs) were investigated to evaluate their roles in pulmonary carcinogenesis and to examine the clinicopathologic significance of Fas expression with its relationship with p53 and bcl-2 overexpressions. Immunohistochemical analysis using tissue microarray demonstrated that a large proportion of NSCLC patients (60%) showed lack of membranous Fas expression. The Fas-negative cases revealed the significantly lower survival rate than Fas-positive ones. Also, the loss of Fas receptor expression was found more frequently in advanced stage and higher nodal status. FasL protein was increased in most NSCLCs (89%) compared to normal lungs. p53 and bcl-2 overexpressions showed no association with Fas expression. Conclusively, reduced membranous Fas expression as a mechanism of apoptotic resistance is considered to play an important part of the pulmonary carcinogenesis, which may predict poor survival and have a bad prognostic influence. Increased FasL expression is thought to be a basis for the immune evasion in NSCLCs. The rare bcl-2 overexpression suggests that this anti-apoptotic protein is unlikely to play a role in the apoptotic resistance of NSCLCs.  相似文献   

2.
Objective: Lack of surface Fas expression is a main route for apoptotic resistance which is considered an important mechanism of tumorigenesis and tumor progression. Fas and FasL expression in 110 non-small cell lung carcinomas (NSCLCs) were investigated to evaluate their roles in pulmonary carcinogenesis and to examine the clinicopathologic significance of Fas expression with its relationship with p53 and bcl-2 over- expression. Methods: Immunohistochemical analysis using tissue microarray demonstrated that a large proportion of NSCLC patients (60%) showed lack of membranous Fas expression. The Fas-negative cases revealed the significantly lower survival rate than Fas-positive ones. Also, the loss of Fas receptor expression was found more frequently in advanced stage and higher nodal status. FasL protein was increased in most NSCLCs (89%) compared to normal lungs. Results: p53 and bcl-2 overexpression showed no association with Fas expression. Conclusively, reduced membranous Fas expression as a mechanism of apoptotic resistance is considered to play an important part of the pulmonary carcinogenesis, which may predict poor survival and have a negative prognostic influence. Conclusion: Increased FasL expression is thought to be a basis for the immune evasion in NSCLCs. The rare bcl-2 overexpression suggests that this anti-apoptotic protein is unlikely to play a role in the apoptotic resistance of NSCLCs.  相似文献   

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Breast cancers have been shown to elicit tumor-specific immune responses. As in other types of cancer, the antitumor immune response fails to contain breast tumor growth, and a reduction in both the quantity and cytotoxic effectiveness of tumor-infiltrating lymphocytes (TILs) is associated with a poorer prognosis. Fas ligand (FasL) induces apoptotic death of activated lymphocytes that express its cell surface receptor, FasR (CD95/APO-1). FasL-mediated apoptosis of activated lymphocytes contributes to normal immune downregulation through its roles in tolerance acquisition, immune response termination, and maintenance of immune privilege in the eye, testis, and fetus. In this report, we demonstrate that breast carcinomas express FasL. Using in situ hybridization and immunohistochemistry, we show that breast tumors constitutively express FasL at both the mRNA and protein levels, respectively. FasL expression is prevalent in breast cancer: 100% of breast tumors (17 of 17) were found to express FasL, and expression occurred over more than 50% of the tumor area in all cases. By immunohistochemistry, FasR was found to be coexpressed with FasL throughout large areas of all the breast tumors. This suggests that the tumor cells had acquired intracellular defects in FasL-mediated apoptotic signaling. FasL and FasR expression were independent of tumor type or infiltrative capacity. FasL expressed by tumor cells has previously been shown to kill Fas-sensitive lymphoid cells in vitro and has been associated with apoptosis of TILs in vivo. We conclude that mammary carcinomas express FasL in vivo as a potential inhibitor of the antitumor immune response.  相似文献   

5.
目的 了解Fas和Fas配体(FasL)在发生免疫排斥的角膜植片中的表达情况,探讨其在角膜移植免疫排斥反应中的作用。方法 角膜移植术后排斥反应的患者42例,于再次行穿通性角膜移植术时取其排斥的移植片;正常角膜6例。进行免疫组织化学染色,观察正常角膜和移植片中上皮、基质和内皮层的Fas及:Fas配体的表达。结果 在6例正常角膜中,角膜上皮、内皮Fas和FasL.为阳性表达。42例移植片中,角膜上皮.Fas和FasL均有表达。有新生血管形成及免疫细胞浸润的角膜基质中,血管内皮细胞、基质细胞FasL为阳性表达,Fas在部分浸润的免疫细胞中有表达;移植片内皮细胞层广泛破坏。结论 Fas、FasL在角膜移植片中的表达,可能与角膜移植免疫排斥反应有关。  相似文献   

6.
Breast cancers have been shown to elicit tumor-specific immune responses. As in other types of cancer, the antitumor immune response fails to contain breast tumor growth, and a reduction in both the quantity and cytotoxic effectiveness of tumor-infiltrating lymphocytes (TILs) is associated with a poorer prognosis. Fas ligand (FasL) induces apoptotic death of activated lymphocytes that express its cell surface receptor, FasR (CD95/APO-1). FasL-mediated apoptosis of activated lymphocytes contributes to normal immune downregulation through its roles in tolerance acquisition, immune response termination, and maintenance of immune privilege in the eye, testis, and fetus. In this report, we demonstrate that breast carcinomas express FasL. Using in situ hybridization and immunohistochemistry, we show that breast tumors constitutively express FasL at both the mRNA and protein levels, respectively. FasL expression is prevalent in breast cancer: 100% of breast tumors (17 of 17) were found to express FasL, and expression occurred over more than 50% of the tumor area in all cases. By immunohistochemistry, FasR was found to be coexpressed with FasL throughout large areas of all the breast tumors. This suggests that the tumor cells had acquired intracellular defects in FasL-mediated apoptotic signaling. FasL and FasR expression were independent of tumor type or infiltrative capacity. FasL expressed by tumor cells has previously been shown to kill Fas-sensitive lymphoid cells in vitro and has been associated with apoptosis of TILs in vivo. We conclude that mammary carcinomas express FasL in vivo as a potential inhibitor of the antitumor immune response.  相似文献   

7.
OBJECTIVE: The Fas (CD95) interaction with its receptor Fas ligand (FasL) is one of the main mechanisms of cell apoptosis. High expression of FasL has been consistently observed in a variety of human cancers. In this study, we evaluated FasL and its relationship with apoptosis and proliferation in Lobund-Wistar (L-W) cancers. The L-W rat strain develops spontaneous and induced adenocarcinomas in the anterior prostate and seminal vesicles. Although FasL expression has been observed in a subset of human prostate carcinomas, this multistage model allowed in vivo evaluation of subclones of malignant cells with a single genetic susceptibility. METHODS: Apoptosis was evaluated in spontaneous, induced and transplanted tumors as well as metastasis using the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) technique and transmission electron microscopy. Proliferating cell nuclear antigen (PCNA) and FasL expression were detected using immunohistochemistry and analyzed according to the number of positive cells and intensity of staining using a semiquantitive method. RESULTS: Apoptotic indexes were significantly higher in spontaneous tumors compared to induced (p < 0.008), transplanted tumors (p < 0.0112) and metastases (p < 0.009). TUNEL-positive cells were frequently observed in the leukocytic infiltrate of the stroma in transplanted carcinomas and metastases. These findings were confirmed by electron microscopy. FasL expression was not uniformly localized in L-W carcinomas and its highest expression was observed in transplanted tumors and metastasis (p < 0.005). Moreover, PCNA indices were directly correlated with cancers showing high FasL total scores (Hscores). CONCLUSIONS: In this model, high FasL expression was associated with cells displaying low apoptotic indexes and high PCNA index. Therefore, analysis of FasL may have clinical relevance in detecting the malignant potential of prostate cancers.  相似文献   

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Immunostaining for epidermal growth factor receptor (EGFR), c-erbB-2, c-erbB-3, c-erbB-4, ER, and PR was performed in 107 cases of primary breast carcinomas from Anyang, China. The expression rates of EGFR, c-erbB-2, c-erbB-3 and c-erbB-4 in this series were 43.9%, 36%, 27%, and 45.8%, respectively, and a stronger c-erbB-4 staining of "normal" glandular structures inside tumors and in the vicinity of tumor clusters was confirmed. Larger tumor size, lymph node metastases, and higher histologic grade in invasive ductal carcinomas were shown to be statistically valuable negative prognostic factors, and c-erbB-2 expression was also weakly associated with a poor prognosis no matter what the nodal status. The expressions of c-erbB-4 and ER in invasive ductal carcinomas were inversely associated with histologic grade of the tumors. Associations between the expression of c-erbB-4 and ER (p = 0.001) and the expression of ER and PR study (p = 0.004) were found in the present study. No significant associations between the expressions of EGFR, c-erbB-3, c-erbB-4, ER, and PR and overall survival were detected. The expression of c-erbB-4 in the node negative group was, however, associated with a better prognosis, indicating a different role of c-erbB-4 protein in breast tumor development than other EGFR family members have. Int J Surg Pathol 9(3):177-187, 2001  相似文献   

10.
To investigate the frequency and pattern of Fas and FasL expression in the gastric mucosa at different stages of gastrocarcinogenesis, the combined examinations of pathology, immunocytochemistry and Western blot hybridisation were performed on the cancer specimens as well as their preneoplastic and non-cancerous counterparts. The frequencies of Fas and FasL expression were found to be 6.3% (1/16) and 62.5% (10/16) in non-cancerous mucosa, 60% (6/10) and 80% (8/10) in atrophic gastritis, 75% (9/12) and 83% (10/12) in intestinal metaplasia, 100% in both dysplasia Grades II (20/20) and Grade III (15/15) and 4 types of gastric carcinomas (74/74). Two forms of FasL protein in 37 kDa and 26 kDa were detected in all FasL+ cases. Soluble Fas (30 kDa) but not the membrane-type (43 kDa) is predominantly expressed in the Fas+ cases. Our data thus suggest a close correlation of soluble Fas with stomach tumour progression P<0.01. The sFas protein, together with the tumor-derived soluble and membrane FasL, may confer on the transforming and transformed gastric epithelial cells an immune advantage enabling escape from endogenous and exogenous suicide signal(s).  相似文献   

11.
Sarcomatoid renal cell carcinomas (SRC) are rare neoplasms associated with a very poor prognosis. The aim of this study was to evaluate biomarker expression and clinical significance in this uncommon renal cancer. Cytokeratin, epithelial membrane antigen, vimentin, desmin, smooth muscle actin, CD34, S-100 protein, MIB 1, p53, Fas and Fas ligand immunohistochemical expression was investigated in seven renal cell carcinomas with sarcomatoid changes. No significant difference between sarcomatoid and nonsarcomatoid areas was observed with the different biomarkers, excepted for Fas ligand. Fas expression was diffuse in sarcomatoid and nonsarcomatoid areas. However, Fas ligand had a higher expression in sarcomatoid in comparison to nonsarcomatoid areas. Our results showed that Fas and Fas ligand are both expressed in renal cancer. We suggest that the aggressive behavior of sarcomatoid carcinoma may be related to a higher expression of Fas ligand by tumor sarcomatoid cells. These findings may indicate that Fas ligand is a possible therapeutic molecular target for treatment of SRC.  相似文献   

12.
Grading of invasive ductal carcinoma of no special type using the Nottingham combined histologic grading system provides independent prognostic information. The prognostic utility of grading invasive lobular carcinomas, however, has not been fully elucidated. In addition, the relationship between grade in invasive lobular carcinomas and expression of predictive biomarkers is less certain. The purpose of this study was to correlate histologic grade in invasive lobular carcinoma with known prognostic and predictive markers. All primary resections for invasive mammary carcinomas diagnosed in Mount Sinai Hospital, Toronto, between the years 1996 and 2002 were reviewed (n=1053). Of these cases, 50 were pure invasive lobular carcinoma (incidence 4.7%). The median age at diagnosis was 64 years. These tumors were graded using the Nottingham combined histologic grading system and analyzed for estrogen receptor, progesterone receptor, HER2/neu and E-cadherin expression. Tumor grade was correlated with tumor size (P=0.03), and the American Joint Committee on Cancer nodal status (P=0.05). Assessment of the individual components of grade showed that the mitotic score was highly correlated with tumor size (P=0.02), lymph node positivity (P=0.02) and overall American Joint Committee on Cancer stage (P=0.01). Estrogen receptor and progesterone receptor were highly expressed irrespective of the grade of tumor. HER2/neu protein overexpression and E-cadherin protein expression was absent in all invasive lobular carcinomas studied. We conclude that pure invasive lobular carcinoma is uncommon and occurs predominantly in postmenopausal women. Increasing tumor grade is correlated with median tumor size and the American Joint Committee on Cancer nodal stage, but not correlated with the expression of estrogen receptor, progesterone receptor, E-cadherin or HER2/neu protein overexpression.  相似文献   

13.
Pax-2 expression in adult renal tumors   总被引:6,自引:0,他引:6  
To assess the expression of the homeogene Pax-2 in adult renal cell carcinomas, we did a retrospective immunohistochemical analysis of 56 frozen tumor samples representing all major histologic subtypes of renal tumors. There were 33 conventional renal cell carcinomas (58.9%), 12 papillary renal cell carcinomas (21.4%), 4 chromophobe cell renal carcinomas, 4 urothelial cell renal carcinomas, and 3 oncocytomas. Forty-five tumors (62.5%) were localized, and 21 tumors had extrarenal involvement. Eight patients (14%) had metastatic disease at the end of the follow-up. We searched for relationships between Pax-2 expression and nuclear grading, TNM staging, Ki-67 proliferation index, expression of transforming growth factor-beta1 (TGF-beta 1), an in vitro down-regulator of Pax-2 expression, and finally cytogenetic abnormalities. All histologic subtypes expressed Pax-2 protein, except urothelial renal carcinomas. The highest expression was in papillary renal cell carcinomas. In this subtype, all tumors and 83.3% +/- 12.3% of tumor cells were immunoreactive for Pax-2. All but 2 conventional renal cell carcinomas expressed Pax-2, but with 26.3% +/- 29.6% of immunoreactive cells (P <.001). Pax-2 expression was not correlated with nuclear grading (P =.6), tumor size (P =.3), and TGF-beta 1 expression (P =.1). Nevertheless, Pax-2 expression correlated with the Ki-67 proliferation index only for the conventional histologic subtype (P =.03). In this histologic subtype, Pax-2 expression was higher in patients with metastatic disease than in those without (P =.02). Pax-2 expression was not associated with specific cytogenetic abnormalities like trisomy 7 (P =.1), 3p deletion (P =.5), and hyperdiploidy (P =.2). TGF-beta 1 expression, positive in 33 tumors (59%), was not correlated with either Pax-2 expression (P =.1) or current prognostic factors such as nuclear grading (P =.2). Interestingly, we also observed an expression of TGF-beta RI and TGF-beta RII in the tumors with high nuclear grading (P =.005). We conclude that Pax-2 protein is expressed in all major histologic subtypes of renal cell carcinomas. The pattern of expression differs between these subtypes. Pax-2 expression in conventional renal cell carcinomas is correlated with the proliferation index and is significantly higher in patients with metastatic disease. HUM PATHOL 32:282-287.  相似文献   

14.
AIMS: Disruption of apoptotic cell death has been implicated in tumour aggressiveness in colonic carcinogenesis. The Fas-Fas ligand (FasL) system is involved in the execution of apoptosis induced by the immune system. c-FLIP protein constitutes an inhibitor of Fas and other (TRAIL) death receptor-mediated apoptosis. The aim of this study was to investigate the simultaneous expression of Fas, FasL and c-FLIP in relation to standard clinicopathological parameters and patients' outcome in colorectal cancer. METHODS AND RESULTS: Levels of Fas, FasL and c-FLIP protein expression were quantified immunohistochemically in paraffin-embedded tissues from 90 patients. Immunopositivity was detected for Fas, FasL and c-FLIP in 71%, 35.5% and 68.8% of cases, respectively. Concurrent expression of Fas/FasL was seen in 28 samples (31%), of which 24 (85.7%) also displayed c-FLIP positivity (P = 0.04). c-FLIP overexpression (> 10%) tended to prevail marginally in higher stage tumours (P = 0.09). Additionally, FasL and c-FLIP adversely affected survival on both univariate (P = 0.001 and P = 0.0024, respectively) and multivariate analysis [hazard ratio (HR) 3.491, P = 0.005 and HR 2.960, P = 0.036, respectively]. CONCLUSIONS: The frequent expression and coexpression of Fas, FasL and c-FLIP in colorectal carcinoma implicates c-FLIP as an inhibitor of the Fas-FasL-induced death pathway in these tumours. Moreover, c-FLIP conveys independent prognostic information in the presence of classical prognosticators.  相似文献   

15.
The regulation of neutrophil apoptosis in chronic renal failure (CRF) has not been clearly defined. The Fas/FasL system is an important apoptotic regulatory pathway in a wide variety of cells. Fas is a widely expressed cell surface protein that transduces an apoptotic signal after interaction with its natural ligand FasL. In contrast to the extensive tissue distribution of Fas, constitutive expression of FasL is relatively limited. We examined Fas and FasL expression by neutrophils in healthy subjects, patients with CRF, and patients on hemodialysis (HD) and peritoneal dialysis (PD). Fas expression was significantly higher among patients with CRF compared with control subjects, HD patients, and PD patients. FasL expression was significantly higher among patients with CRF compared with control subjects. At 24 h, neutrophil apoptosis was higher among patients with CRF compared with control subjects. Furthermore, high-neutrophil Fas expression was paralleled by a higher sensitivity to Fas-mediated apoptosis. There was a strong correlation between Fas-stimulated apoptosis and creatinine clearance as well as Fas expression. Finally, we found that uremic serum increased the expression of neutrophil-associated Fas and FasL proteins, when compared with normal serum. Further studies are under way to examine the regulation of this pathway in the uremic environment.  相似文献   

16.
The interaction between FasL on tumor cells and Fas on lymphocytes may represent a tumor immune escape mechanism. We explored FasL expression and function in human urinary bladder transitional cell carcinomas (TCCs). FasL expression was observed in situ in 45% of TCCs (n = 45) and was absent in normal urothelium (n = 20). A correlation existed between FasL expression and high tumor grade (0% in G1, 14% in G2, and 75% in G3; P < 0.0001) and stage (13% in superficial Ta-T1 versus 81% in invasive T2-T4; P < 0.0001). FasL function was shown by the ability of two FasL-positive primary culture TCC cell lines (established from two FasL-positive invasive TCCs) to induce Fas-mediated killing not only of conventional Fas-sensitive targets (such as Jurkat cells or phytohemagglutinin-lymphoblasts), but also of autologous T lymphocytes generated in a mixed lymphocyte tumor-cell culture. In addition, an association between FasL expression by TCC cells and activated caspase-8, -9, and -3 expression by interferon-gamma-producing CD8-positive tumor-infiltrating lymphocytes was observed in situ. Our results show a functional expression of TCC-expressed FasL that correlates with tumor progression. These results suggest that TCC-expressed FasL may induce apoptosis of anti-tumor T lymphocytes in vivo, providing new insights on the mechanisms involved in bladder TCC progression.  相似文献   

17.
Expression of Fas and FasL in human serous ovarian epithelial tumors   总被引:5,自引:0,他引:5  
The expression of Fas and FasL was studied in 86 patients with benign, borderline, and malignant serous ovarian lesions. Four normal ovaries, and monolayer epithelial cultures from a human fetal ovary, a borderline, and a serous adenocarcinoma were used for comparison. Expression of Fas and FasL was studied immunohistochemically and flowcytometrically. Fas was expressed in all 90 lesions; FasL in 57 lesions, including 2 normal ovaries. Fas expression was significantly increased in borderline tumors compared with benign (P = 0.005, t = -2.94) or malignant serous tumors (P = 0.0001, t = 4.15). FasL expression was significantly increased in malignant tumors compared with benign (P = 0.039, t = -2.10) and borderline tumors (P = 0.0016, t = -3.33). Flow cytometry showed a range of Fas expression in short-term cultures isolated from normal, borderline, and malignant ovarian serous tissue; in the few samples studied, FasL was not expressed. Expression in three serous ovarian cell lines was similar. Fas and FasL expression differed throughout the spectrum of ovarian lesions. FasL expression was increased in malignant tumors, and Fas expression was increased in borderline tumors. Changes in Fas/FasL expression in ovarian surface epithelium might play a functional role in the biology of ovarian tumors.  相似文献   

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19.
转染反义Fas阻断T细胞凋亡及对肿瘤的治疗意义   总被引:1,自引:0,他引:1  
目的 通过阻断T细胞的Fas信号传递途径,探讨消除肿瘤对T细胞的攻击及其对肿瘤的治疗意义。方法 流式细胞术、RT-PCR方法检测卵巢癌细胞表达Fas和FasL。构建pcDNA3-反义Fas真核表达载体,经脂质体转染Jurkat细胞,流式细胞仪检测Fas表达变化。以Annexin-V和MTT法检测转染反义Fas基因对Jurkat细胞凋亡的影响。采用MTT体外杀伤实验观察3AO对Jurkat细胞杀伤变化。结果 6种卵巢癌细胞均表达Fas和FasL。pcDNA3-反义Fas基因可以使Jurkat细胞表达Fas量下降并部分阻断Fas单抗诱导的Jurkat细胞凋亡,3AO对其杀伤减弱。结论 卵巢癌细胞表达FasL可能是其逃逸免疫监视并产生对淋巴细胞攻击的原因之一;应用反义技术阻断Fas表达,可部分阻断Fas单抗诱导Jur  相似文献   

20.
乙型肝炎肝组织Fas,FasL和HBV抗原的表达   总被引:6,自引:0,他引:6  
目的 评价Fas和FasL介导细胞凋亡在乙型肝炎肝损伤中的作用及其与HBV抗原的关系。方法 应用免疫组化方法检测了62例乙型肝炎患者肝组织内的Fas、FasL和HBsAg、HBcAg,并以6例下正常肝组织为对照。结果 Fas/FasL在正常肝组织内无表达;Fas主要在乙型肝炎患者肝细胞质内表达,58例阳性(93.5%);FasL在肝内浸润的单个核细胞和肝细胞质内均见到,37例阳性(59.7%)。结论 Fas/FasL的表达程度与肝组织活动性炎症程度密切相关;Fas/FasL介导的细胞凋亡可能在乙型肝炎时肝损伤中起重要作用;Fas/FasL表达程度与肝内HBV抗原HBsAg、HBcAg无明显相关性。  相似文献   

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