Expression of Fas and Fas ligand in uveal melanoma: biological implication and prognostic value

The interaction between Fas and Fas ligand is one possible immune escape mechanism used by tumour cells. In the present study, melanoma tissue from 103 patients who underwent enucleation for malignant uveal melanoma (iris melanomas excluded) was stained by immunohistochemistry with monoclonal antibodies specific for Fas, Fas ligand, CD3, CD8, and CD68. Histological and clinical data for these tumours were assessed. Both Fas and Fas ligand were detected in uveal melanomas. Cells of the monocyte/macrophage lineage rather than T-cells were the predominant group of tumour-infiltrating cells. The metastasis-free 5-year survival rates in the univariate analyses were considerably lower in patients with tumours that lacked Fas ligand expression (< 35% of the tumour cells), in the presence of more than 50 CD8-positive cells in 20 high-power fields and in the presence of more than 100 CD3-positive cells in 20 high-power fields. Fas and Fas ligand expression was associated with scleral infiltration. After adjustment for scleral infiltration, the predictive value of both Fas and Fas ligand expression was markedly decreased. In addition, the CD3- and CD8-positive cell count was positively associated with the histological cell type. Cox proportional hazards models showed that the presence of CD3- and CD8-positive cells was not an independent prognostic factor after adjusting for histological cell type. This preliminary observation deserves further investigation, which may shed more light on the immune escape mechanisms of this tumour and thus enable novel therapeutic strategies. The clinical relevance of this observation is limited, as more predictive parameters have been described for uveal melanoma.     

Fas (APO-1/CD95) ligand and Fas expression in renal cell carcinomas: correlation with the prognostic factors

BACKGROUND AND OBJECTIVE: Fas ligand (FasL, CD95L) is a type II transmembrane protein of the tumor necrosis factor family that induces cells to send an apoptotic signal to cells expressing Fas (CD95, APO-1). It has been shown that cancers have a dysregulated expression of Fas and FasL system, conferring a survival advantage. It is important to understand FasL and Fas expression in tumors, because the growth of cancer might be controlled by Fas-mediated apoptosis. METHODS: The expressions of FasL and Fas were studied by immunohistochemical analyses in 51 cases of renal cell carcinomas and the adjacent normal renal tissues, respectively. In addition, their expressions were compared with prognostic factors, such as tumor size, nuclear grade, TNM stage, and histologic types. RESULTS: In nonneoplastic renal tissues, FasL was expressed in all nephron segments, whereas Fas also expressed in all tubules, except for glomeruli. In renal cell carcinomas, FasL protein was detected in 50 (98.0%) of 51 cases, whereas Fas expressed in 38 (74.5%) of 51 cases. In fact, the immunostaining of Fas was less intense than that in the adjacent normal segments of all cases. The staining pattern showing both high expression of FasL and low expression of Fas was found in 36 (70.6%) (P = .04) of 51 cases, most of which were Fuhrman grade 2 or 3 tumors. However, the expression pattern did not correlate statistically with the tumor size, histologic type, or clinical stage. On the other hand, most grade 4 tumors displayed high expression of both FasL and Fas (P<.001). CONCLUSION: These data indicate that high expression of FasL and low expression of Fas protein in renal cell carcinomas may play a role in evading surveillance of the immune system. In addition, the FasL and Fas expressions appear to have a therapeutic implication for high-grade tumors rather than a prognostic one.     

Expression of Fas and Fas Ligand on Mouse Renal Tubular Epithelial Cells in the Generalized Shwartzman Reaction and Its Relationship to Apoptosis

Previously we reported that the consecutive injection of lipopolysaccharide (LPS) into LPS-sensitized mice for the generalized Shwartzman reaction (GSR) appeared to induce the injury of renal tubular epithelial cells via apoptosis. The aim of this study was to characterize the mechanism of renal tubular epithelial cell injury in GSR. The expression of Fas and Fas ligand was immunohistochemically detected on renal tubular epithelial cells from GSR-induced mice, although neither Fas nor Fas ligand was found in cells from untreated control mice or in cells from mice receiving a single injection of LPS. GSR-induced renal tubular epithelial cell injury was produced in neither Fas-negative MRL-lpr/lpr mice nor Fas ligand-negative MRL-gld/gld mice. The administration of anti-gamma interferon antibody together with a preparative injection of LPS prevented the expression of Fas and Fas ligand and the apoptosis of renal tubular epithelial cells. A provocative injection of tumor necrosis factor alpha into LPS-sensitized mice augmented Fas and Fas ligand expression and the apoptosis of renal tubular epithelial cells. The administration of tumor necrosis factor alpha to interleukin-12-sensitized mice resulted in Fas and Fas ligand expression and the apoptosis. Sensitization with interleukin-12 together with anti-gamma interferon antibody did not cause the apoptosis of renal tubular epithelial cells. It was suggested that the Fas/Fas ligand system probably plays a critical role in the development of renal tubular epithelial cell injury through apoptotic cell death.     

幽门螺杆菌致T细胞凋亡：Fas/FasL介导的T细胞无反应性

目的 评价幽门杆菌（Hp）致T细胞死亡的方式和机制,探讨这种作用与Hp感染致宿主产生免疫耐受的关系。方法 应用AnnexinV染色流式细胞术检测Hp致T细胞死亡的方式;应用细胞毒实验（JAM技术）和FasIgG抗体、caspase8抑制剂组断实验评价T细胞凋亡与Fas/FasL作用的关系,并通过流式细胞术直接检测Hp对T细胞FasL表达的上调作用及其与T细胞产生凋亡的时效关系。结果 AnnexinV染色和JAM技术证实H致T慢以凋亡方式进行的。这种细胞凋亡能被抗Fas抗体和caspase8抑制剂阻断,因而是Fas依赖,TH2细胞较TH1样T细胞对这种作用更敏感。由于Hp能直接上调T细胞的FasL且其发生时间与凋亡出现时间吻合,证实Hp是通过凋节T细胞之间Fas/FasL相互作用而致其凋亡的。Hp能通过调节Fas/FasL作用而负调节T细胞的生长,这可能是Hp感染致宿主发生T细胞耐受的机制之一。     

Alteration of Fas and Fas ligand expression during human visceral leishmaniasis

Several studies in murine systems have suggested a role of apoptosis in the pathogenesis of leishmaniasis. However, the role of apoptosis in visceral leishmaniasis in man has not been explored. In this study, we show that patients with visceral leishmaniasis demonstrate significant dysregulation of Fas and Fas ligand. Levels of soluble Fas (sFas) and soluble Fas ligand (sFasL) were elevated in plasma of patients with active visceral leishmaniasis (VL) and individuals co-infected with VL-HIV-1 compared to healthy controls. The levels of sFas and sFasL were normalized 6 months after successful treatment. In VL patients, the expression of membrane bound Fas, and to a lower extent FasL, were up-regulated on Leishmania donovani-infected spleen cells, the site of parasite multiplication. Expression of Fas and FasL on peripheral blood mononuclear cells was within normal range, probably reflecting that the blood is not a normal site of L. donovani infection. Furthermore, this is suggested by the finding that in vitro infection of macrophages with L. donovani up-regulated Fas expression on the surface of infected cells and enhanced the levels of sFasL in supernatants from infected cultures. How this dysregulation may affect the pathogenesis of human visceral leishmaniasis is discussed.     

胃癌组织中Fas基因表达的临床意义

检测胃癌细胞中Ｆａｓ基因表达并探讨其临床意义。运用流式细胞技术,对３９例胃癌细胞和癌旁粘膜中Ｆａｓ抗原的表达进行检测。胃癌细胞和癌旁粘膜组织中均有Ｆａｓ基因表达,而其表达水平无统计学差异（ｔ＝１．５２６,Ｐ〉０．０５）。胃管状腺癌和乳头状腺癌细胞中Ｆａｓ基因表达明显低于粘液癌和低分化癌（Ｐ〈０．０５）。胃癌细胞中Ｆａｓ基因表达低。采用特异性改变凋亡阈限的治疗方案可能有利于改变胃癌的自然进程。     

Significance of Fas and FasL protein expression in cardiac carcinoma and local lymph node tissues

Objective: To investigate the relation of Fas and Fas ligand (FasL) protein expression with carcinogenesis and metastasis of cardiac carcinoma. Methods: Immunohistochemistry was used to detect Fas and FasL protein expression in 64 cardiac carcinoma tissue samples and 20 normal gastric tissue samples. Relation between FasL and Fas expression, age and gender of gastric cancer patients, and pathological subtype and lymph node metastasis of gastric cancer was analyzed. Results: The Fas expression level was significantly higher in normal gastric tissue samples than in cardiac carcinoma tissue samples (85.0% vs. 25.0%, P<0.001), while the FasL expression level was significantly lower in normal gastric tissue samples than in cardiac carcinoma tissue samples (30.0% vs. 81.3%, P<0.001). The Fas expression level was significantly higher in invasive lymph nodes than in non-invasive lymph nodes (82.9% vs. 56.5%, P<0.003) and in well-differentiated gastric carcinoma tissue samples than in poorly-differentiated cardiac carcinoma tissue samples (50.0% vs. 18.0%, P=0.015). The FasL expression level was significantly lower in well-differentiated cardiac carcinoma tissue samples than in poorly- differentiated cardiac carcinoma tissue samples (42.9% vs. 84.0%, P=0.021). The Fas and FasL expression levels (25.0% and 81.3%) were significantly different in cardiac carcinoma tissue samples (P<0.001), but had a non-linear correlation (P=0.575). Conclusion: Abnormal Fas and FasL expressions in cardiac carcinoma and lymph node tissues are involved in carcinogenesis and metastasis of gastric cancer.     

Immunolocalization of Fas and Fas ligand in the ovaries of women with polycystic ovary syndrome: relationship to apoptosis

Both Fas (APO-1, CD95), an apoptosis-inducing receptor, and its ligand, Fas ligand (FasL, CD95L), have been localized to the ovary. Granulosa cell apoptosis occurs in antral follicular atresia. In polycystic ovary syndrome (PCOS), antral follicles accumulate with some atretic features. The ovarian expression of Fas and FasL was examined in PCOS by immunohistochemistry and correlated with immunodetection of apoptotic cells. Fas immunostaining was present in pre-antral follicle oocytes, some primary and secondary pre-antral follicle granulosa cells, and both granulosa and theca of antral follicles. Thecal staining persisted with advancing atresia, while granulosa staining declined. In antral follicles, abundant Fas-positive cells co-localized with scattered nuclei immunopositive for apoptosis. Ovarian vascular myocytes were strongly Fas-immunopositive. FasL immunostaining was present in pre-antral follicles in oocytes and variably in granulosa. In antral follicles, granulosa and thecal FasL staining increased with advancing atresia. Normal control ovaries showed follicular Fas and FasL staining patterns similar to those in PCOS, but vascular staining was less prominent. In one healthy follicle, Fas immunostaining was seen in the oocyte and weakly in mural granulosa and theca interna. The results suggest that in PCOS, an alteration in Fas-mediated apoptosis, does not cause abnormal folliculogenesis, but may promote ovarian vascular remodelling.     

Fas和Fas配体在角膜移植免疫排斥反应中的表达

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。     

MCT1 promotes the cisplatin-resistance by antagonizing Fas in epithelial ovarian cancer

This study was designed to investigate the role of MCT1 in the development of cisplatin-resistant ovarian cancer and its possible relationship with Fas. We found the expression of MCT1 was obviously increased both in cisplatin-resistant ovarian cancer tissue and A2780/CP cells compared with sensitive ovarian cancer tissue and cell lines A2780. And in A2780 cells treated with Cisplatin, the expression of MCT1 increased in a concentration-dependent manner, MCT1 knockdown attenuates cisplatin-induced cell viability. In A2780 and A2780/CP cells transfected with MCT1 siRNA, the activation of several downstream targets of Fas, including FasL and FAP-1 were largely prevented, whereas the expression of Caspase-3 was increased, accompanying with increased abundance of Fas. Coimmunoprecipitation and immunofluorescence showed that there is interaction between endogenous MCT1 with Fas in vivo and in vitro. In vivo, depletion of MCT1 by shRNA reverses cisplatin-resistance and the expression of Fas. This study showed that down regulation of MCT1 promote the sensibility to Cisplatin in ovarian cancer cell line. And this effect appeared to be mediated via antagonizing the effect of Fas.     

Mechanisms of neutrophil apoptosis in uremia and relevance of the Fas (APO-1, CD95)/Fas ligand system

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.     

Fas ligand and tumour counter-attack in colorectal cancer stratified according to microsatellite instability status

Expression of membrane-bound Fas ligand (FasL) by colorectal cancer cells may allow the development of an immune-privileged site by eliminating incoming tumour-infiltrating lymphocytes (TILs) in a Fas-mediated counter-attack. Sporadic colorectal cancer can be subdivided into three groups based on the level of DNA microsatellite instability (MSI). High-level MSI (MSI-High) is characterized by the presence of TILs and a favourable prognosis, while microsatellite-stable (MSS) cancers are TIL-deficient and low-level MSI (MSI-Low) is associated with an intermediate TIL density. The purpose of this study was to establish the relationship between MSI status and FasL expression in primary colorectal adenocarcinoma. Using immunohistochemistry and a selected series of 101 cancers previously classified as 31 MSI-High, 30 MSI-Low, and 40 MSS, the present study sought to confirm the hypothesis that increased TIL density in MSI-High cancers is associated with low or absent membrane-bound FasL expression, while increased FasL in MSS cancers allows the killing of host TILs. TUNEL/CD3 double staining was also used to determine whether MSS cancers contain higher numbers of apoptotic TILs in vivo than MSI-High or MSI-Low cancers. Contrary to the initial hypothesis, it was found that MSI-High cancers were associated with higher FasL expression (p = 0.04) and a stronger intensity of FasL staining (p = 0.007). In addition, mucinous carcinomas were independently characterized by increased FasL expression (p = 0.03) and staining intensity (p = 0.0005). Higher FasL expression and staining intensity did not correlate with reduced TIL density or increased numbers of apoptotic TILs. However, consistent with the hypothesis that curtailment of the host anti-tumour immune response contributes to the poor prognosis in MSS cancers, it was found that apoptotic TILs were most abundant in MSS carcinomas and metastatic Dukes' stage C or D tumours (p = 0.004; p = 0.046 respectively). This study therefore suggests that MSS colorectal cancers are killing incoming TILs in an effective tumour counter-attack, but apparently not via membrane-bound FasL.     

不稳定型心绞痛病人血清sFas、sFasL及sIL-2R水平的临床价值

目的　探讨血清sFas、sFasL和sIL 2R水平与不稳定型心绞痛 (Unstableanginapectoris,UAP)之间的关系。方法　应用酶联免疫吸附双抗体夹心 (ELISA)法 ,测定了 32例UAP病人 (UAP组 )和 2 0例对照组受试者血清sFas、sFasL和sIL 2R水平。结果　UAP组病人血清sFas和sIL 2R水平均明显高于对照组 (P <0 .0 1) ,而 2组sFasL水平无显著性差别 (P >0 .0 5 )。UAP组病人sFas水平与sIL 2R水平存在显著正相关 (r=0 .4 4 7,P <0 .0 5 )。结论　高水平的血清sFas、sIL 2R与UAP有关。高水平的血清sFas可能通过维持自身免疫炎性反应而导致UAP的发生发展     

丹红注射液对脑梗死患者血浆可溶性Fas及Fas配体浓度的影响

目的：观察丹红注射液对脑梗死患者血浆可溶性Fas及Fas配体浓度的影响,探讨丹红注射液用于脑梗死治疗的抗凋亡作用。方法：80例脑梗死患者分为对照组和治疗组,每组40例。对照组接受常规治疗,治疗组接受常规治疗加用丹红注射液治疗。脑梗死患者静脉血在人院时,人院后第1、2、3、7和14d获得,ELISA测定血浆可溶性Fas及Fas配体浓度。结果：治疗前,治疗组美国国立卫生院神经功能缺损评分与对照组比较差异无统计学意义（P〉0．05）;治疗后,治疗组美国国立卫生院神经功能缺损评分较对照组显著下降（P〈0．05）。人院时,治疗组血浆可溶性Fas及Fas配体浓度与对照组比较差异无统计学意义（P〉0．05）,人院后第1、2、3、7和14d,治疗组血浆可溶性Fas及Fas配体浓度显著低于对照组（P〈0．05）。结论：丹红注射液可能通过抑制脑梗死后神经细胞凋亡,从而达到改善神经功能的目的。