The evaluation of Fas/Fas ligand system in renal cell carcinoma--the effect of preoperative interferon-alpha therapy

OBJECTIVES: In order to investigate the effect of preoperative interferon (IFN)-alpha on Fas/Fas ligand (FasL) system, we examined Fas and FasL expression and the occurrence of apoptotic cell death in a preoperative therapy group, and in a control group using surgically resected renal cell carcinoma (RCC) tissues. METHODS: Ten cases were served as the preoperative therapy group, and sixteen cases as the control group. IFN-alpha was administered at five megaunits daily intramuscularly for two weeks in the preoperative therapy group. Immunohistochemistry for Fas and FasL, and terminal-deoxynucleotidyl-transferase (TdT)-mediated digoxigenin-dUTP nick end-labeling (TUNEL) were employed. We defined the labeling index (LI) as percentage of Fas- or FasL-positive cells in carcinomatous cells, and apoptotic index (AI) as percentage of TUNEL-positive cells in carcinomatous cells. RESULTS: Significant correlations were found between the LIs of Fas and AIs in all 26 cases. LIs of Fas and AIs of the preoperative therapy group were significantly higher than those of the control group. FasL expression was detected in nine out of ten cases in the preoperative therapy group, and in fourteen out of sixteen cases in the control group. There were no significant differences in LIs of FasL between two groups. CONCLUSION: These data suggest that apoptosis via the Fas/FasL system is functional, and that preoperative IFN-alpha treatment may up-regulate the Fas/FasL system in RCC. On the other hand, we need to investigate about an immune-escape mechanism through the FasL expression considering the relatively frequent expression of FasL in our results in RCC from now.     

Fas/Fas-L信号系统在绝经后骨质疏松症中作用的研究进展

Fas/Fas-L信号系统是外源性凋亡通路的重要组成部分。近年来大量研究发现,Fas/Fas-L信号系统通过诱导细胞凋亡,不仅参与了免疫系统稳态的维持,而且在骨内环境稳态的调节中也发挥了重要的作用。Fas/Fas-L信号系统在不同骨细胞上的表达和分布可能随体内雌激素水平波动而发生变化。当绝经后雌激素分泌不足时,Fas/Fas-L信号系统可通过启动骨细胞外源性凋亡通路,介导成骨和破骨平衡向破骨方向偏移,参与绝经后骨质疏松症的发生发展。通过调节骨细胞上Fas/Fas-L信号系统来平衡破骨细胞骨吸收和成骨细胞骨形成,将为绝经后骨质疏松症的治疗提供新的思路。     

Cisplatin-induced oxidative stress stimulates renal Fas ligand shedding

Acute kidney injury (AKI), a significant complication of cisplatin chemotherapy is associated with reactive oxygen species (ROS)-dependent renal cell death, but the cellular targets of ROS in cisplatin nephrotoxicity are not fully resolved. Here, we investigated cisplatin-induced oxidative renal damage and tested the hypothesis that ROS-dependent shedding of death activator Fas ligand (FasL) occurs in cisplatin nephropathy. We show that intraperitoneal injection of sulfobutyl ether-β-cyclodextrin (Captisol?)-solubilized cisplatin elevated the level of lipid peroxidation product malondialdehyde in mouse kidneys and urinary concentration of oxidative DNA damage biomarker 8-hydroxy-2′-deoxyguanosine. Cisplatin increased mouse kidney-to-body weight ratio and the plasma or urinary levels of predictive biomarkers of AKI, including creatinine, blood urea nitrogen, microalbumin, neutrophil gelatinase-associated lipocalin, and cystatin C. Histological analysis and dUTP nick end labeling of kidney sections indicated tubular injury and renal apoptosis, respectively in cisplatin-treated mice. Whereas the plasma concentration of soluble FasL (sFasL) was unaltered, urinary sFasL was increased ～4-fold in cisplatin-treated mice. Real-time quantitative live-cell imaging and lactate dehydrogenase assay showed that cisplatin stimulated caspase 3/7 activation and cytotoxicity in a human proximal tubule epithelial cell line which were attenuated by inhibitors of the FasL/Fas system and poly [ADP-ribose] polymerase-1. Moreover, TEMPOL, an intracellular free radical scavenger mitigated cisplatin-induced renal oxidative stress and injury, AKI biomarker and urinary sFasL elevation, and proximal tubule cell death. Our findings indicate that cisplatin-induced oxidative stress triggers the shedding of membrane-bound FasL to sFasL in the kidney. We demonstrate that cisplatin elicits nephrotoxicity by promoting FasL/Fas-dependent oxidative renal tubular cell death.     

Blocking Fas ligand on leukocytes attenuates kidney ischemia-reperfusion injury

Inflammation contributes to the pathogenesis of ischemic acute kidney injury (AKI), and T cells mediate the early phase of ischemia-reperfusion injury (IRI). The Fas/Fas ligand (FasL) pathway modulates the balance of T cell subsets in the peripheral circulation as well as multiple inflammatory responses, suggesting that FasL may mediate ischemic AKI. Here, we induced bilateral renal IRI in mice bearing a loss-of-function mutation of FasL (the gld mutation) and in wild-type mice. Compared with wild-type mice, serum creatinine was lower in gld mice (1.4 ± 0.9 mg/dl versus 2.6 ± 0.4) at 24 hours after IRI (P<0.05). In addition, gld mice had fewer TNF-α-producing T lymphocytes in the kidneys and renal lymph nodes. Furthermore, pharmacologic blockade of FasL protected the kidneys of wild-type mice from IRI. Analysis of bone marrow chimeric mice suggested that the pathogenic effect of FasL involves leukocytes; reconstitution of wild-type mice with gld splenocytes attenuated IRI. In contrast, reconstitution of gld mice with wild-type splenocytes enhanced IRI. These data demonstrate that FasL, particularly on leukocytes, mediates ischemic AKI.     

HLA-G和Fas配体在肾透明细胞癌中的表达及意义

目的：探讨两种免疫抑制分子人类白细胞表面抗原HLA—G和Fas配体（FasL）与经典型肾透明细胞癌（ccRCC）分级和分期的相关性。方法：采用免疫组织化学方法对60例ccRCC标本石蜡切片进行检测,数据由SPSS软件进行统计分析。结果：肿瘤旁正常肾组织中无HLA—G表达;肾癌组织中,40例（66．7％）表达HLA—G,36例（60．0％）表达FasL。31例（51．7％）两者均表达,15例（25．0％）两者均不表达。在同一标本中,肿瘤侵犯脉管或淋巴结后,其HLA-G或FasL表达较原位肿瘤明显增强。统计分析显示HLA—G表达的阳性率和表达强度与肿瘤的分期、分级均呈正相关（P〈0．01）。FasL表达的阳性率与肿瘤分级呈正相关（P〈0．05）,而表达强度与肿瘤分期呈正相关（P〈0．01）。结论：ccRCC中HLAG和FasL的表达与肿瘤的分期、分级均呈正相关,与淋巴结转移有一定关系;晚期ccRCC高表达免疫抑制分子的机制需进一步研究。     

Glucocorticoid and Fas ligand induced mucosal lymphocyte apoptosis after burn injury

BACKGROUND: The purpose of this study was to examine the effects of a steam burn injury on apoptosis in gut-associated lymphoid tissue and to determine whether endogenous glucocorticoid and Fas ligand signaling were involved in this process. METHODS: Histologic analysis, in situ deoxynucleotidyl transferase dUTP nick-end labeling staining and annexin V and 7-amino-actinomycin-D flow cytometry of lymphocyte populations were evaluated in intraepithelial lymphocytes and Peyer's patch. Additional mice were pretreated with a glucocorticoid receptor antagonist (mifepristone) before the steam burn. Similarly, C3H/HeJ-FasL(gld) mice lacking functional Fas ligand were also studied. RESULTS: Apoptosis was significantly increased in intraepithelial lymphocytes and Peyer's patch after the burn injury. Mifepristone pretreatment significantly reduced apoptosis in both T- and B-cell populations in intraepithelial lymphocytes after the burn injury. In contrast, the increased apoptosis seen in B-cells from Peyer's patch was not seen in C3H/HeJFasL(gld) mice, whereas the increased apoptosis in CD8+ T-cells was unaffected. CONCLUSION: Both corticosteroids and FasL contribute to the apoptosis in gut-associated lymphoid tissues early after burn injury.     

Fas/Fas Ligand pathways gene polymorphisms in pediatric renal allograft rejection

BackgroundAn essential milestone in pediatric transplantation is to find noninvasive biomarkers to monitor acute rejection (AR). In this retrospective (Case-control) study, we examined the role of Fas − 670A/G and Fas Ligand (FasL) − 843C/T gene polymorphisms in allograft nephropathy in pediatric renal transplant recipients.MethodsIn 47 pediatric kidney transplant recipients and 20 healthy controls, Fas − 670A/G and FasL − 843C/T gene polymorphisms as well as serum soluble Fas Ligand level (sFasL) were measured.ResultsSerum sFasL levels were significantly higher in transplant recipients children than that in controls (548.25 ± 298.64 pg/ml vs 143.17 ± 44.55 pg/ml, p = 0.0001). There was no significant difference between patients with AR and those without AR in regards to serum sFasL levels (567.70 ± 279.87 pg/ml vs 507.85 ± 342.80 pg/ml, p = 0.56). Fas − 670A/G genotypes or alleles were not significantly different between controls and transplant recipients and among transplant recipients with and without AR. (P > 0.05 for all). FasL − 843C/T genotypes were not different between transplant recipients and controls and among transplant recipients with and without AR (P > 0.05 for all). However, Frequency of C allele in transplant patients was significantly higher than that in the control group (44.68% vs 25%, P = 0.03). FasL − 843C/T alleles were significantly different between patients with and without AR (P = 0.03). The percentages of C allele were higher in children with AR (58.82% vs 36.67%). We found that serum FasL and serum creatinine were variables that were independently associated with AR.ConclusionThis study suggests that FasL gene polymorphisms in peripheral blood might be accurate in detecting cellular AR.     

Fas配体在泌尿生殖肿瘤细胞系及肾癌组织中的表达

目的 明确Ｆａｓ配体在泌尿生殖肿瘤细胞系及肾癌组织中的表达情况。方法 采用免疫细胞化学和反转录ＰＣＲ（ＲＴ－ＰＣＲ）法检测膀胱癌（Ｔ２４、ＢＩＵ－８７、ＥＪ）、肾癌（ＧＲＣ－１、ＲＣＣ－９４９）、前列腺癌（ＰＣ－３Ｍ）及１０例肾癌组织上Ｆａｓ配体的表达。结果 免疫细胞化学方法检测细胞系中Ｆａｓ配体表达于ＢＩＵ－８７、ＲＣＣ－９４９和ＧＲＣ－１细胞,而以ＢＩＵ－８７和ＲＣＣ－９４９细胞系表达较强,在     

Fas ligand expression in Hodgkin lymphoma

Because previous investigations suggested involvement of the Fas ligand (FasL) in the selection process in the follicular dendritic cell (FDC)-associated cell cluster of the germinal center, we investigated the expression of FasL in Hodgkin lymphoma (HL) on protein and RNA level, while considering the Epstein-Barr virus status of the Hodgkin and Reed-Sternberg (HRS) cells. Tumor tissue from 47 patients with classic HL (32 nodular sclerosis [NS], 11 mixed cellularity [MC], and 4 lymphocyte-rich [LR]) was analyzed by immunohistochemistry for FasL, Fas, CD21, and CD23 and by Western blotting for FasL. FasL mRNA was detected by an exon 4-specific oligonucleotide and Epstein-Barr virus infection by in situ hybridization for Epstein-Barr virus early RNAs (EBER). Western blotting showed soluble and membrane-bound forms of FasL. Immunohistochemistry showed FasL expression in virtually all HRS of 94% of NS cases and 82% of MC cases. FasL expression did not correlate with the Epstein-Barr virus status of the HRS. Low FasL protein expression was found in some HRS of LR cases. FasL mRNA was detected in 39% of NS, 46% of MC, and 33% of LR cases. Seventy percent to 90% of the HRS cells expressed Fas. CD21 immunohistochemistry showed disrupted FDC networks in the tumor tissue with reduced and virtually absent expression of CD23 and FasL. These observations suggest that FasL expression in HRS cells and the absence of FasL in the FDC cluster represent a disturbed microenvironment that may be involved in the pathogenesis of HL.     

Fas and Fas ligand expression in cystic fibrosis airway epithelium

BACKGROUND: Cystic fibrosis (CF) is a genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene and defective expression of CFTR protein in epithelial cells. The main cause of mortality in CF is linked to chronic inflammatory and infectious airway processes. Recent studies have suggested perturbations in the apoptotic process in CF cell lines and enterocytes. A study was undertaken to investigate the expression of Fas and Fas ligand (FasL) in CF bronchial epithelium and CF tracheal cell lines. METHODS: Immunohistochemical staining for Fas (alkaline phosphatase anti-alkaline phosphatase) and FasL (immunoperoxidase) was performed in eight CF bronchial epithelial samples and four controls and immunohistochemical DNA fragmentation (TUNEL) was carried out in four CF patients and four controls. Immunofluorescence staining and flow cytometric analysis of Fas and FasL expression was performed in two human tracheal epithelial cell lines (HTEC) with normal and CF genotype. The dosage of serum soluble FasL was examined in 21 patients with CF and 14 healthy volunteers. RESULTS: FasL expression was markedly increased in patients with CF in both the ciliated and submucosal glandular bronchial epithelium compared with controls; Fas was similarly expressed in bronchial samples from controls and CF patients in both the ciliated epithelium and submucosal glands. High levels of DNA fragmentation were observed in CF but with some epithelial cell alterations. Serum concentrations of soluble FasL were frequently undetectable in patients with CF. In vitro, HTEC expressed Fas and FasL in both genotypes. A higher mean fluorescence intensity for FasL expression was noted in CF genotype HTEC with median (range) for six experiments of 74 (25-101) for CF cells and 42 (21-70) for non-CF cells. CONCLUSION: Fas/FasL interaction is probably implicated in the human CF airway apoptotic pathway. The mechanisms of induction of FasL expression and its role in inducing tissue damage or remodelling or in controlling local inflammatory cell apoptosis remain to be determined.     

食管癌的Fas配体表达及意义

目的 检验Fas配体在食管癌细胞的表达,及其与食管癌浸润淋巴细胞、与食管癌浸润与转移的关系和对病人术后生存的影响。方法 采用免疫组化方法检测30例原发食管癌标本中Fas配体的表达,用CD45标记肿瘤浸润巴细胞。结果 76.6％的标本有Fas配体的表达,且不同TNM分期的病人表达水平差异显著,Fas配体的表达与食管癌中肿瘤浸润淋巴细胞数呈负相关,但Fas配体的表达与病人术后生存无显著关系。结论 Fas配体的表达有利于食管癌逃避免疫攻周,有利于其浸润与转移。     

Fas/Fas ligand interactions play an essential role in the initiation of murine autoimmune diabetes

Apoptosis via Fas/Fas ligand (FasL) interactions has been proposed to be a major T-cell-mediated effector mechanism in autoimmune diabetes. To elucidate the role of Fas/FasL interactions in NOD diabetes, the effects of neutralizing anti-FasL antibody on autoimmune responses were evaluated. Islet-specific CD8(+) and CD4(+) T-cells expressed FasL upon activation and mediated FasL-dependent cytotoxicity against Fas-expressing target cells in vitro, although their cytotoxicity against islet cells was not blocked by anti-FasL antibody. Moreover, administration of anti-FasL antibody failed to inhibit diabetes in vivo in the CD8(+) T-cell adoptive transfer model. On the other hand, blockade of Fas/FasL interactions significantly inhibited CD4(+) T-cell-dependent diabetes in adoptive transfer models. These results suggest a substantial contribution of Fas/FasL interactions to CD4(+), but not CD8(+), T-cell-mediated destruction of pancreatic beta-cells. When anti-FasL antibody was administered to NOD mice between 5 and 15 weeks of age, the onset of diabetes was slightly delayed but the incidence was not decreased. However, administration of anti-FasL antibody at 2-4 weeks of age completely prevented insulitis and diabetes. These results suggest that Fas/FasL interactions contribute to CD4(+) T-cell-mediated beta-cell destruction and play an essential role in the initiation of autoimmune NOD diabetes.     

Fas配体在膀胱癌中的表达及意义

探讨肿瘤免疫逃避与膀胱发生、侵袭及复发的关系。方法采用ＳＡＢＣ免疫组化法检测１４例膀胱腺癌,３４例移行细胞癌及１０例慢性单纯性膀胱炎石蜡切片中Ｆａｓ配体的表达情况。结果ＳＣＣ中ＦａｓＬ无表达;ＡＣ８例表达、ＴＣＣ２０例明显表达且与组织类型无关;ＦａｓＬ的表达与临床分期及复发密切相关,而与ＴＣＣ的病理分级关系不密切。     

Enhanced cell death in NR-S1 tumor by photodynamic therapy: possible involvement of Fas and Fas ligand system

BACKGROUND AND OBJECTIVES: To investigate the effect of photodynamic therapy (PDT) on cell death in malignant tumor tissue, the frequency of terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL)-positive cells and the possible involvement of Fas and Fas ligand system were evaluated. STUDY DESIGN/MATERIALS AND METHODS: NR-S1 tumor-bearing C3H/HeNCrj mice were treated by PDT with Photofrin(R) (12 mg/kg body weight) and Nd:YAG dye laser (630 nm, 10 Hz, 150 J/cm(2)). Paraffin-embedded tissue sections from the excised tumor tissues at 6, 12, 24, 48 hours after PDT were analyzed by TUNEL for the occurrence of apoptosis and by immunohistochemistry for Fas and Fas ligand (FasL) expression. TUNEL-positive cells as well as Fas- or FasL-positive cells were counted and expressed as a percentage of positive cells per total cells. RESULTS: Based on the percent area of tumor necrotic foci, the most effective conditions for PDT were first determined. Under these conditions, PDT increased the number of TUNEL-positive tumor cells at 12 hours after irradiation. In parallel with the increase in TUNEL-positive cells, Fas-positive tumor cells were also found in the same area where many TUNEL-positive tumor cells were found. The expression of Fas ligand was found in the tumor cells surrounding TUNEL-positive cells on serial sections. A significant increase in FasL-positive lymphocytes was observed at 12 hours, whereas the infiltration of such lymphocytes into the area where TUNEL-positive tumor cells were observed was rare. CONCLUSION: The possible role of Fas/FasL system in the cell death induced by PDT with Photofrin(R) and Nd:YAG dye laser was suggested. Moreover, the role of infiltrated lymphocytes seemed not to be so much in this model.     

Differential involvement of the Fas receptor/ligand system in p53-dependent apoptosis in human prostate cancer cells

BACKGROUND: The objective of this study was to characterize the involvement of the Fas receptor/ligand system in p53-dependent apoptosis in human prostate cancer cells. METHODS: The effects of adenovirus-mediated p53 gene transfer (Ad5CMV-p53) into human prostate cancer LNCaP, DU145, and PC3 cells on their growth, apoptosis and Fas receptor/ligand expression were examined by the MTT assay, DNA fragmentation assay, and Northern blot analysis, respectively. The sensitivity of these cells to an agonistic anti-Fas receptor antibody (CH11) and the effects of an antagonistic anti-Fas ligand antibody (4H9) on Ad5CMV-p53-induced apoptosis were analyzed by the MTT assay and DNA fragmentation assay. RESULTS: Ad5CMV-p53 treatment resulted in substantial growth inhibition, induction of apoptosis and up-regulation of Fas receptor as well as Fas ligand mRNA expression in LNCaP, DU145 and PC3 cells. Despite the abundant expression of Fas receptor in all of these cells, CH11 induced apoptosis only in PC3 cells. Furthermore, 4H9 partially blocked the apoptosis induced by Ad5CMV-p53 in PC3 cells, but not in LNCaP and DU145 cells. CONCLUSIONS: The Fas receptor/ligand system is differentially involved in p53-dependent apoptosis in prostate cancer cells; therefore, reintroduction of wild-type p53 into prostate cancer cells may induce apoptosis through Fas receptor/ligand interaction as well as through an alternative pathway.     

The significance of Fas/FasL molecular system in breast cancer

Fas (CD95/APO-1) and its natural ligand, FasL, are molecules expressed on cellular membranes, being involved in the induction of programmed cells death or apoptosis. Recently, it has been shown that malignant cells originating from solid tumors tend to inhibit the expression of Fas, as an escape mechanism from the immune cells' attack and to express FasL, as a counterstrike mechanism against the immune effector cells. The purpose of this study was to investigate, by immunohistochemistry, the presence of Fas and FasL in 15 breast carcinomas and to establish possible associations between the expression of these molecules and the histological type and grading of the tumors. Our results showed that 7 breast tumors have lost the expression of Fas and 11 tumors were positive for the Fas-ligand expression, important arguments for the mechanisms of immune escape and tolerance induction. Furthermore, 7 of the 11 FasL+ tumors were poorly differentiated invasive ductal carcinomas, suggesting a possible association between FasL expression and tumor aggressivity.