Severe malarial anemia associated with increased soluble Fas ligand (sFasL) concentrations in Gabonese children

To investigate if severe malarial anemia is associated with specific cytokine overproduction, we evaluated serum levels of soluble Fas ligand (sFasL), tumor necrosis factor (TNF-alpha) and interleukin-10 (IL-10) from three groups of young children with Plasmodium falciparum infection (asymptomatic cases, uncomplicated malaria cases and severe malarial anemia cases), in a hyperendemic area of Gabon. In uncomplicated cases, only TNF levels were significantly (p < 0.001) increased in comparison to asymptomatic cases with P. falciparum infection. High levels of sFasL, TNF-alpha and IL-10 were associated with low hemoglobin concentrations, sFasL levels were significantly higher in children with severe malarial anemia (p < 0.001) as compared to both other groups. The parasite density was positively correlated with IL-10, TNF-alpha and sFasL levels. TNF-alpha and sFasL, but not IL-10 or parasitemia, were independent predictors of hemoglobin concentrations. These results suggest that, in malaria, a specific dysregulation of the cytokine balance may lead to complications such as severe anemia.     

Evaluation of p53 and soluble Fas ligand (sFasL) serum level concentration as indicators of apoptosis in serum of patients with benign and malignant primary follicular thyroid tumors

INTRODUCTION: Apoptosis (programmed cell death) is the best described mode of physiological cell death. During embryonal development and morphogenesis, apoptosis may be induced by two pathways. The first is external protein signal originating from other cell--also named as "death signal". Another one is specific cell reaction for external stress factors. Blood concentration of proteins regulating both pathways of apoptosis may be useful in early diagnosis and staging of thyroid tumors. The aim of study was evaluation of p53 and sFasL blood concentration in patients with benign follicular adenoma and follicular thyroid cancer. MATERIALS AND METHODS: The study population was composed of 28 patients: 14 with thyroid carcinoma and 14 patients with follicular neoplasm (NF). All patients underwent surgical treatment. P53 and sFasL levels were evaluated before surgery and related to the histopathological diagnosis obtained post-surgery. RESULTS: The analysis revealed high sFasL blood concentration in patients with follicular thyroid cancer in comparison with the group with follicular adenoma. There was no statistically significant difference between levels of p53 in both groups. CONCLUSIONS: Evaluation of sFasL serum level concentration may be useful in preoperative diagnosis of follicular thyroid tumors.     

Temporal evolution of soluble Fas and Fas ligand in patients with orthotopic liver transplantation

Aim: The aim of this study was to analyze the expression levels of plasma soluble Fas (sFas) and soluble Fas ligand (sFasL) in patients with orthotopic liver transplantation (OLT) procedures routinely performed without venovenous bypass. Methods: The sFas and sFasL were analyzed in the blood of 20 consecutive patients who underwent transplantation. Blood samples were drawn from the radial artery at serial time points before, during, and after surgery. Plasma levels of sFas and sFasL were detected by Enzyme Linked-Immuno-Sorbent Assay. Plasma aspartate transaminase (AST) and alanine transaminase (ALT) were assayed by routine clinical chemistry testing. Results: Marked elevation of plasma AST and ALT were detected at the reperfusion and postoperation time points (P < 0.001), with a peak on the first postoperative day. The mean plasma concentration of sFas and sFasL remained unchanged from preoperative to anhepatic phase (T1 to T3) (P  0.268). The sFas and sFasL concentrations were significantly higher at 15 and 60 min after reperfusion compared to the preoperative value (P  0.048). Postoperatively, sFas and sFasL concentration were decreased to preoperative levels on the first postoperative day (P  0.127). Conclusion: The sFas and sFasL seem to be involved in reperfusion injury during OLT. The understanding of Fas may provide new insights into the mechanisms of ischemia/reperfusion injury during OLT.     

Detection of a putative novel Wolinella species in patients with squamous cell carcinoma of the esophagus

Background. Certain regions of South Africa exhibit an extraordinarily high incidence of esophageal carcinoma that develops via an esophagitis–dysplasia–carcinoma sequence. Bacteria belonging to the family Helicobacteraceae are candidates for involvement in the initiation of the esophagitis. We investigated patients with esophageal carcinoma for the occurrence of Helicobacter‐related species. Methods. Biopsies from tumor and nonlesional tissue of the esophagus from nine patients with squamous cell carcinoma were investigated for Helicobacteraceae using a PCR‐based method targeting the 16S rRNA gene. Results. Four out of nine patients tested negative, while samples from the other five patients revealed an infection by different Helicobacter species. Sequence analysis of the PCR fragments led to the identification of a hitherto unknown bacterium in three of these patients. Phylogenetically, this bacterium was assigned to the genus Wolinella within the family of Helicobacteraceae. Helicobacter pylori was identified in three patients, and one revealed a coinfection with the novel Wolinella species. Conclusions. Helicobacteraceae were detected in approximately 50% of South African patients with esophageal carcinoma. Furthermore, a novel bacterium was identified that might be linked to the enhanced incidence of esophagitis and subsequent malignant disease in South Africa.     

Soluble Fas receptor and soluble Fas ligand in the serum of women with uterine tumors

It is commonly accepted that apoptosis plays an important role in the death of normal and neoplastic cells. Related proteins and their receptors on cell surfaces regulate apoptosis. One of the best-characterized systems is the Fas-Fas ligand system. The aim of the study was to examine the concentrations of soluble Fas receptor (sFas) and the soluble ligand for the Fas receptor (sFasL) in serum of women with uterine tumors.The study included 42 women with uterine tumors. As a normal control, sera were obtained from 20 healthy female volunteers. The concentrations of sFas and sFasL in serum were measured by enzyme-linked immunosorbent assay ELISA.Significant increases of the mean value of sFas and sFasL were found in the serum of women with uterine tumor compared to the control group (p < 0.0001). The mean levels of these parameters increased in consecutive stages of the clinical extent of the uterine cancer (I-III). The lowest concentration was observed in women with stage I and the highest in women with stage III of clinical extent according to FIGO.Apoptosis that appears to occur in the cancerous cells of malignant uterine tumors is associated with high levels of sFas and sFasL in serum.     

Genetic steps in the development of squamous cell carcinoma of the esophagus

Esophageal squamous cell carcinoma (ESCC) is a frequent form of cancer that shows striking variations in geographic distribution, reflecting exposure to specific environmental factors that are still poorly defined. ESCC develops as the result of a sequence of histopathological changes that typically involves esophagitis, atrophy, mild to severe dysplasia, carcinoma in situ and finally, invasive cancer. Genetic changes associated with the development of ESCC include mutation of the p53 gene, disruption of cell-cycle control in G1 by several mechanisms (inactivation of p16MTS1, amplification of Cyclin D1, alterations of RB), activation of oncogenes (e.g., EGFR, c-MYC) and inactivation of several tumor suppressor genes. Loss of heterozygosity on chromosome 17q25 has been linked with tylosis, a rare autosomal dominant syndrome associated with high predisposition to ESCC. Whether this locus is also involved in sporadic ESCC remains to be elucidated. Chronic esophagitis is a frequent occurrence in populations at high risk of ESCC. These lesions often show focal accumulation of p53 protein and in some instances, patches of positive cells in esophagitis area at the margins of tumors were found to contain a mutation in the p53 gene. This observation is consistent with field cancerization in the esophagus and suggests that esophagitis may represent an interesting target for early detection of ESCC as well as for intervention strategies.     

Immunohistochemical analysis for cell proliferation-related protein expression in small cell carcinoma of the esophagus; a comparative study with small cell carcinoma of the lung and squamous cell carcinoma of the esophagus

Small cell carcinoma is a rare neoplasm in the esophagus. To evaluate cell proliferation activity and its underlying mechanisms in this tumor, we examined immunohistochemically 5 cases of small cell carcinoma of the esophagus (SCCE) for expressions of tumor suppressor proteins, oncoproteins and cell proliferation markers including p53, p21WAF1/CIP1, retinoblastoma (Rb) protein, bcl-2, Ki-67 and PCNA, and compared the results with those of 5 cases of small cell carcinoma of the lung (SCCL) and 10 cases of squamous cell carcinoma of the esophagus (SQCE). The prevalence and labeling index of p53-immunoreactivity tended to be higher in SCCE (4/5; 56.6%) and SCCL (4/5; 79.9%) than in SQCE (6/10; 48.8%). Expression of p21WAF1/CIP1 was observed in 2 of 10 cases of SQCE. In contrast, its expression could not be detected in any cases of SCCE and SCCL examined. Expression of Rb protein was observed in 9 out of 10 cases of SQCE, but not in any cases of SCCE and SCCL. SCCE and SCCL showed more frequent and intense immunoreactivity for bcl-2 than SQCE. In expression of cell proliferation markers (Ki-67 and PCNA), no remarkable difference was observed among SCCE, SCCL and SQCE. These results suggest that SCCE and SCCL could share some genetic alternations including mutation of p53, loss of Rb gene and overexpression of bcl-2, and these may be related to the similar biological potentials between the two. Furthermore, SCCE was different from SQCE in expression of Rb protein and bcl-2, and these two types of esophageal carcinoma could arise through different molecular mechanisms.     

Enhanced programmed death 1 (PD-1) and PD-1 ligand (PD-L1) expression in patients with actinic cheilitis and oral squamous cell carcinoma

PD-1 and PD-L1 can be involved in tumor escape, and little is known about the role of these molecules in oral tumors or pre-malignant lesions. In the present study, we investigated the expression of PD-1 and PD-L1 in the blood and lesion samples of patients with actinic cheilitis (AC) and oral squamous cell carcinoma (OSCC). Our results showed that lymphocytes from peripheral blood and tissue samples exhibited high expression of PD-1 in both groups analyzed. Patients with AC presented higher percentage as well as the absolute numbers of CD4⁺PD-1⁺ and CD8⁺PD-1⁺ lymphocytes in peripheral blood mononuclear cells (PBMC) than healthy individuals, while patients with OSCC presented an increased frequency of CD8⁺PD1⁺ in PBMC when compared with controls. On the other hand, increased frequency of CD4⁺ and CD8⁺ T cells expressing PD-1⁺ accumulate in samples from OSCC, and the expression of PD-L1 was intense in OSCC and moderate in AC lesion sites. Lower levels of IFN-γ and higher levels of TGF-β were detected in OSCC samples. Our data demonstrate that PD-1 and PD-L1 molecules are present in blood and samples of AC and OSCC patients. Further studies are required to understand the significance of PD-1 and PD-L1 in oral tumors microenvironment.     

Serum SCC-Ag in head and neck squamous cell carcinoma

We estimated the serum levels of SCC-Ag, CEA and TPA in 69 patients with head or neck neoplasia and 31 healthy patients using a radioimmunometric method (double antibody). SCC-Ag concentrations were significantly increased in 43.4% cancer patients with respect to the cut-off point value (1.7 ng/ml) of the control group, and the specificity was 96.7%. The data varied according to the evolutive phase of disease. Since the combined evaluation of SCC-Ag, TPA and CEA serum levels increased the sensitivity, that was 71.0%, we thought it opportune to use all these markers in the tumoral pathology taken into consideration.     

Salivary analytes in patients with oral squamous cell carcinoma

Literature data indicates that measurement of certain salivary constituents might serve as a useful diagnostic/prognostic tool in the patients with oral squamous cell carcinoma (OSCC). In 24 patients with OSCC (60 +/- 2.5 yrs) and in 24 controls (24 +/- 3.7 yrs) we have determined levels of salivary magnesium, calcium, copper, chloride, phosphate, potassium, sodium, total proteins and amylase. Sodium, potassium and chloride were determined by indirect potentiometry whereas copper, magnesium and phosphate were determined by atomic absorption spectrophotometry. Total proteins were determined by pyrogalol colorimetric method. Amylase levels were determined by continued colorimetric method. Statistical analysis was performed by use of chi2 test and Spearman's correlation test. The results of this study indicate that the concentrations of sodium and chloride were significantly elevated in patients with OSCC when compared to the controls. However, level of total protein was significantly decreased when compared to the healthy controls. Furthermore, there was a negative correlation between alcohol consumption and total protein concentration in patients with oral carcinoma. We might conclude that in patients with OSCC increased salivary sodium and chloride might reflect their overall dehydration status due to alcohol consumption rather than consequence of OSCC itself.     

Fas ligand (CD95 ligand) controls angiogenesis beneath the retina

A principal cause of blindness is subretinal neovascularization associated with age-related macular degeneration. Excised neovascular membranes from patients with age-related macular degeneration demonstrated a pattern of Fas+ new vessels in the center of the vascular complex, surrounded by FasL+ retinal pigment epithelial cells. In a murine model, Fas (CD95)-deficient (Ipr) and FasL-defective (gld) mice had a significantly increased incidence of neovascularization compared with normal mice. Furthermore, in gld mice there is massive subretinal neovascularization with uncontrolled growth of vessels. We found that cultured choroidal endothelial cells were induced to undergo apoptosis by retinal pigment epithelial cells through a Fas-FasL interaction. In addition, antibody against Fas prevented vascular tube formation of choroidal endothelial cells derived from the eye in a three-dimensional in vitro assay. Thus, FasL expressed on retinal pigment epithelial cells may control the growth and development of new subretinal vessels that can damage vision.     

Opposing roles for membrane bound and soluble Fas ligand in glaucoma-associated retinal ganglion cell death

Glaucoma, the most frequent optic neuropathy, is a leading cause of blindness worldwide. Death of retinal ganglion cells (RGCs) occurs in all forms of glaucoma and accounts for the loss of vision, however the molecular mechanisms that cause RGC loss remain unclear. The pro-apoptotic molecule, Fas ligand, is a transmembrane protein that can be cleaved from the cell surface by metalloproteinases to release a soluble protein with antagonistic activity. Previous studies documented that constitutive ocular expression of FasL maintained immune privilege and prevented neoangeogenesis. We now show that FasL also plays a major role in retinal neurotoxicity. Importantly, in both TNFα triggered RGC death and a spontaneous model of glaucoma, gene-targeted mice that express only full-length FasL exhibit accelerated RGC death. By contrast, FasL-deficiency, or administration of soluble FasL, protected RGCs from cell death. These data identify membrane-bound FasL as a critical effector molecule and potential therapeutic target in glaucoma.     

Differential role of Fas/Fas ligand interactions in cytolysis of primary and metastatic colon carcinoma cell lines by human antigen-specific CD8+ CTL

We have previously identified mutated ras peptides reflecting the glycine to valine substitution at position 12 as HLA-A2-restricted, CD8+ CTL neo-epitopes. CTL lines produced against these peptide epitopes lysed the HLA-A2+ Ag-bearing SW480 primary colon adenocarcinoma cell line, although IFN-gamma treatment of the targets was necessary to achieve efficient cytotoxicity. Here, we compared the lytic phenotype of the SW480 cell line to its metastatic derivative, SW620, as an in vitro paradigm to further characterize the nature of a HLA class I-restricted, Ag-specific CTL response against neoplastic cell lines of primary and metastatic origin. Although both colon carcinoma cell lines were lysed by these Ag-specific CTL following IFN-gamma pretreatment, the mechanisms of lysis were distinct, which reflected differential levels of sensitivity to the Fas pathway. Whereas IFN-gamma pretreatment rendered SW480 cells sensitive to both Fas-dependent and -independent (perforin) pathways, SW620 cells displayed lytic susceptibility to Fas-independent mechanisms only. Moreover, pretreatment of SW480 cells with the anti-colon cancer agent, 5-fluorouracil (5-FU), led to enhanced Fas and ICAM-1 expression and triggered Ag-specific CTL-mediated lysis via Fas- and perforin-based pathways. In contrast, these phenotypic and functional responses were not observed with SW620 cells. Overall, these data suggested that 1) IFN-gamma and 5-FU may enhance the lytic sensitivity of responsive colon carcinoma cells to immune effector mechanisms, including Fas-induced lysis; 2) the malignant phenotype may associate with resistance to Fas-mediated lysis in response to Ag-specific T cell attack; and 3) if Ag-specific CTL possess diverse lytic capabilities, this may overcome, to some extent, the potential "escape" of Fas-resistant carcinoma cells.     

Age related changes of soluble Fas, Fas ligand and Bcl-2 in autoimmune thyroid diseases

INTRODUCTION: Apoptosis plays a pivotal role in the regulation of immune mechanisms in the pathogenesis of autoimmune thyroid diseases (AITD). The prevalence of AITD increases with age. Purpose to compare soluble Fas, FasL and Bcl-2 in Graves disease (GD) and Hashimoto thyroiditis (HT) in relation to the age of the studied patients. MATERIAL AND METHODS: 3 groups of subjects: 1/25 patients with GD in euthyreosis on methimazol 2/27 patients with ChH in euthyreosis on levothyroxine. 3/12 healthy volunteers age and sex-matched to group 1-2. The serum levels of Fas, FasL and Bcl-2 were determined by the ELISA kit. RESULTS: We found positive correlations between sFas and age in GD patients (r = 0.35; p < 0.05). In GD patients we found a negative correlation between sFasL and age in all studied patients with AITD (r = -0.34; p < 0.01). We also found a negative correlation between sBcl-2 and age in HT patients (r = -0.42; p < 0.05). CONCLUSIONS: Fas/FasL and Bcl-2 signaling pathways seem to be age-related and may explain, at least in part, milder course of Graves disease in elderly patients and increased prevalence of Hashimoto disease in this group of subjects.     

Proteomic analysis of global alteration of protein expression in squamous cell carcinoma of the esophagus

Squamous cell carcinoma of the esophagus (ESCC), a major subtype of esophageal carcinoma, is one of the aggressive cancers with worst prognosis in the world. The dismal outcome of ESCC is attributed to multiple reasons including its aggressive nature, largely unknown molecular mechanism of its progression, and the lack of biomarkers for early detection and effective prediction of its clinical behavior. To identify proteins with prognostic and/or predictive value, we applied a proteomics strategy to quantify proteins differentially expressed in ESCC using matched samples of carcinoma and adjacent normal epithelial cells. The analysis led to identification of 28 proteins aberrantly expressed in cancer cells with changes of at least three-fold in ESCC relative to normal squamous epithelial cells. These changes represent functional alterations of essential proteins for normal cellular physiology, accounting for many cellular changes involved in development of ESCC, including cell transformation, loss of differentiation, tumor growth, apoptosis, tumor invasion, and cell metabolism. The differentially expressed proteins shed new insights on the mechanism of tumorigenesis and provide candidate biomarkers for early detection of ESCC.     

Serum exosome-derived biomarkers for the early detection of oral squamous cell carcinoma

Molecular and Cellular Biochemistry - Blood exosomes help regulate communication between tumour cells, moderating their behaviour. We sought to determine the protein content in serum exosomes...