TNF-related apoptosis inducing ligand (TRAIL) gene polymorphism in Japanese patients with multiple sclerosis

Insight into the divergent role of TRAIL in non-neoplastic neurological diseases

Tumour necrosis factor–related apoptosis‐inducing ligand (TRAIL) is a member of the tumour necrosis factor (TNF) superfamily which mainly induces apoptosis of tumour cells and transformed cell lines with no systemic toxicity, whereas they share high sequence homology with TNF and CD95L. These unique effects of TRAIL have made it an important molecule in oncology research. However, the research on TRAIL‐related antineoplastic agents has lagged behind and has been limited by the extensive drug resistance in cancer cells. Given the several findings showing that TRAIL is involved in immune regulation and other pleiotropic biological effects in non‐malignant cells, TRAIL and its receptors have attracted widespread attention from researchers. In the central nervous system (CNS), TRAIL is highly correlated with malignant tumours such as glioma and other non‐neoplastic disorders such as acute brain injury, CNS infection and neurodegenerative disease. Many clinical and animal studies have revealed the dual roles of TRAIL in which it causes damage by inducing cell apoptosis, and confers protection by enhancing both pro‐ and non‐apoptosis effects in different neurological disorders and at different sites or stages. Its pro‐apoptotic effect produces a pro‐survival effect that cannot be underestimated. This review extensively covers in vitro and in vivo experiments and clinical studies investigating TRAIL. It also provides a summary of the current knowledge on the TRAIL signalling pathway and its involvement in pathogenesis, diagnosis and therapeutics of CNS disorders as a basis for future research.

The Impact of TRAIL (C1595T and G1525A) and DR4 (rs20576) Gene Polymorphisms on Systemic Lupus Erythematosus

Apoptosis dysregulation is a distinct hallmark of several disorders like systemic lupus erythematosus (SLE). In fact, SLE has two special features for apoptosis: irregular apoptosis and decline in clearing of apoptotic bodies. Tumor Necrosis Factor (TNF)-Related Apoptosis-Inducing Ligand (TRAIL) is a death ligand that causes to apoptosis via attaching to its receptors such as death receptor-4 (DR4). The present study aimed to evaluate the effects of TRAIL G1525A and C1595T and DR4 A683C (rs20576) gene polymorphisms on SLE development. 160 SLE patients and 160 healthy individuals as the control group participated in the study. Genotype analysis was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). With regard to TRAIL (C1595T) polymorphism, the frequency of CT genotype was significantly higher in the case group than the control with 3-fold increase in SLE development risk (P = 0.0001). Furthermore, the frequency of the TT genotype also was higher in the case group than the control group with 3.2-fold increase in SLE development risk. The allelic distribution analysis defined the T allele as a risk factor for SLE development (P = 0.0001). The frequency of AA genotype and allele A of TRAIL (G1525A) polymorphism also was statistically higher in the case group than the control group (P = 0.0001). There was no significant association between DR4 rs20576 polymorphism and SLE development. TRAIL C1595T and G1525A gene polymorphisms are suggested as the risk factors for SLE development, although the results showed no association between DR4 rs20576 polymorphism and SLE.

Effect of trail C1595T variant and gene expression on the pathogenesis of non-small cell lung cancer

It is known that disorders in apoptosis function play an important role in the pathogenesis of many types of cancer, including lung cancer. Tumor necrosis factor related apoptosis inducing ligand (TRAIL), a type II transmembrane protein, is a death ligand capable of inducing apoptosis by activating distinctive death receptor. Our purpose in this study is to investigate the gene polymorphisms in TRAIL molecular pathway and TRAIL gene expression levels in non-small cell lung cancer (NSCLC) patients in terms of pathogenesis and prognosis of the disease. In this study, TRAIL C1595T polymorphism was genotyped using polymerase chain reaction-restriction fragment length polymorphism analysis in 158 patients with NSCLC and 98 healthy individuals. Surgically resected tissues were examined and classified histopathologically. In addition, TRAIL gene expression levels in tumor tissue and tumor surrounding tissue samples of 48 patients with NSCLC were determined using real-time polymerase chain reaction. TRAIL gene expression levels of NSCLC patients were detected significantly 28.8 fold decrease in the tumor tissue group compared to the control group (p=0.026). When patients were compared to tumor stage, expression of TRAIL gene in advanced tumor stage was found to be significantly 7.86 fold higher than early tumor stage [p=0.028]. No significant relationship was found between NSCLC predisposition and prognostic parameters of NSCLC with TRAIL genotypes, but the frequency of TRAIL gene 1595 CT genotype was observed to be lower in the patients compared to the other genotypes, and the difference was found to be very close to statistical significance (p=0.07). It can be suggested that TRAIL may play an important role in the development of NSCLC and may be an effective prognostic factor in tumor progression.: It is known that disorders in apoptosis function play an important role in the pathogenesis of many types of cancer, including lung cancer. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a type II transmembrane protein, is a death ligand capable of inducing apoptosis by activating distinctive death receptor. Our purpose in this study is to investigate the gene polymorphisms in TRAIL molecular pathway and TRAIL gene expression levels in non-small cell lung cancer (NSCLC) patients in terms of pathogenesis and prognosis of the disease.

Polymorphisms in TRAIL predict long-term survival and extrahepatic recurrence following initial hepatectomy for hepatocellular carcinoma

BACKGROUND

Liver natural killer (NK) cells are the first cells to respond to infections and malignancies, such as intraoperative tumor spill. Liver NK cells express tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a marker for hepatocellular carcinoma (HCC). However, the influence of TRAIL single-nucleotide polymorphisms (SNPs) on hepatectomy patients with HCC remains unclear.

METHODS

Here, we investigated TRAIL SNPs (rs1131568, rs1131579, and rs1131580) located at positions 1525, 1588, and 1595 of exon 5 of the TNFSF10 gene. A total of 104 HCC patients who underwent initial hepatectomy were analyzed. Kaplan-Meier survival analysis and Cox proportional hazard regression were conducted to evaluate the associations between TRAIL genotypes and clinical HCC outcomes.

RESULTS

Patients harboring the homozygous AA genotype of TRAIL SNPs rs1131568 and rs1131579 and the TT genotype of the TRAIL SNP rs1131580 had lower overall survival and higher rates of extrahepatic recurrence (EHR) than patients harboring the wild type or heterozygous genotypes. Moreover, univariate and multivariate Cox regression analysis revealed that the homozygous genotypes of the target TRAIL SNPs were independent predictive factors for EHR after initial hepatectomy for HCC.

CONCLUSION

Our findings revealed that the homozygous genotypes of TRAIL SNPs are independent predictors of EHR in initial hepatectomy patients with HCC.

Clinical perspectives of TRAIL: insights into central nervous system disorders

The TNF-related apoptosis inducing ligand TRAIL is a member of the TNF superfamily that has been firstly studied and evaluated for its anti-cancer activity, and the insights into its biology have already led to the identification of several TRAIL-based anticancer strategies with strong clinical therapeutic potentials. Nonetheless, the TRAIL system is far more complex and it can lead to a wider range of biological effects other than the ability of inducing apoptosis in cancer cells. By virtue of the different receptors and the different signalling pathways involved, TRAIL plays indeed a role in the regulation of different processes of the innate and adaptive immune system and this feature makes it an intriguing molecule under consideration in the development/progression/treatment of several immunological disorders. In this context, central nervous system represents a peculiar anatomic site where, despite its "status" of immune-privileged site, both innate and adaptive inflammatory responses occur and are involved in several pathological conditions. A number of studies have evaluated the role of TRAIL and of TRAIL-related pathways as pro-inflammatory or protective stimuli, depending on the specific pathological condition, confirming a twofold nature of this molecule. In this light, the aim of this review is to summarize the main preclinical evidences of the potential/involvement of TRAIL molecule and TRAIL pathways for the treatment of central nervous system disorders and the key suggestions coming from their assessment in preclinical models as proof of concept for future clinical studies.

Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand Gene Polymorphisms and Hepatitis B Virus Infection

Background:

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is an apoptotic molecule with a key role in the apoptosis of tumors and virus-infected cells. The association of 1525G/A and 1595C/T polymorphisms in the region of 3’ UTR on the TRAIL gene has been shown in many cancers and diseases. Polymorphism at the positions of 1525G/A and 1595C/T might influence the clearance of hepatitis B virus (HBV).

Objectives:

This study was carried out to determine the role of the TRAIL gene polymorphisms in clinical outcome of HBV infection.

Patients and Methods:

Polymerase chain reaction-based restriction fragment length polymorphism (PCR–RFLP) was applied to genotype TRAIL polymorphisms at positions 1525G/A and 1595C/T. To evaluate the TRAIL gene polymorphism in the 3’ UTR region at position 1525G/A and 1595C/T, 147 patients with HBV infection were divided into three different groups of chronic hepatitis (n = 52), cirrhosis (n = 33), and carrier (n = 62) and there was a group of 101 healthy controls.

Results:

Our data showed that genotypes 1525G/A and 1595C/T were in complete linkage disequilibrium and the genotype frequencies at the two positions were the same. No significant differences in frequencies of genotype and alleles at positions 1525G/A and 1595C/T were observed between all the three groups (P value > 0.05).

Conclusions:

According to our result, 1525G/A and 1595C/T were in strong linkage disequilibrium and the polymorphisms of the TRAIL gene in the 3’ UTR region were not associated with the outcome of HBV infection.

Association of the Polymorphism of TRAIL with the Risk and Severity of Lumbar Disc Degeneration in Chinese Han Population

BACKGROUND

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) induces apoptosis of various normal and tumor cells. Apoptosis plays an important role in the development of lumbar disc degeneration (LDD).

AIMS

The aim of this study was to determine whether the 1595C/T polymorphism of the TRAIL gene is associated with the increased risk and severity of LDD in the Chinese Han population.

METHODS

This study consisted of 312 patients with LDD and 196 healthy controls. The grade of disc degeneration was determined according to Schneiderman's classification for magnetic resonance imaging (MRI).

RESULTS

The genotype frequency of the 1595C/T polymorphism was in agreement with the Hardy-Weinberg equilibrium (p=0.278). Patients with LDD had significantly lower frequencies of CT and TT genotypes compared with normal controls (p<0.001). In addition, a lower frequency of the T allele was found in patients with LDD than normal controls (p<0.001). Unconditional logistic regression analysis revealed that CT and TT genotypes were both significantly associated with a reduced risk of LDD compared with the CC genotype (p<0.001; odds ratio [OR] 0.327; 95% confidence interval [95% CI] 0.217-0.493 and p<0.001; OR 0.393; 95% CI 0.234-0.661, respectively). Furthermore, the T allele was significantly associated with a decreased risk of LDD compared with the C allele (p<0.001; OR 0.483; 95% CI 0.369-0.633). In addition, the CT and TT genotypes, as well as the T allele, were associated with lower degenerative grades of LDD compared with the CC genotype and the C allele, respectively (p=0.008 and p=0.001, respectively).

CONCLUSION

The 1595C/T polymorphism of TRAIL may be adversely associated with the risk and severity of LDD in the Chinese Han population.

Genetic variants in the tumor necrosis factor-related apoptosis-inducing ligand and death receptor genes contribute to susceptibility to bladder cancer

AIM

The aim of this study was to evaluate the role of polymorphisms of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and death receptor (DR4) genes in bladder cancer susceptibility in a Turkish population.

MATERIALS AND METHODS

The study group included 91 bladder cancer patients, while the control group comprised 139 individuals with no evidence of malignancy. Gene polymorphisms of TRAIL C1595T (rs1131580) and DR4 C626G (rs4871857) were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis.

RESULTS

The frequency of the TRAIL 1595 TT genotype was significantly lower in patients with bladder cancer compared to controls (p<0.001; odds ratios [OR]=0.143; 95% confidence interval [CI]=0.045-0.454). A significantly increased risk for developing bladder cancer was found for the group bearing a C allele for TRAIL C1595T polymorphism (p<0.001; OR=1.256; 95% CI=1.138-1.386). The observed genotype and allele frequencies of DR4 626 C/G in all groups were in agreement with the Hardy-Weinberg equilibrium (p=0.540). However, the frequency of DR4 GG genotype was found to be 2.1-fold increased in the bladder cancer patients with high-grade tumor, when compared to those having low-grade tumor (p=0.036). Additionally, combined genotype analysis showed that the frequency of TRAILCT-DR4GG was significantly higher in patients with bladder cancer in comparison with those of controls (p=0.037; OR=2.240; 95% CI=1.138-1.386).

CONCLUSIONS

Our study provides new evidence that TRAIL 1595 C allele may be used as a low-penetrant risk factor for bladder cancer development in a Turkish population. Otherwise, gene-gene interaction analysis revealed that the DR4GG genotype may have a predominant effect on the increased risk of bladder cancer over the TRAIL CT genotype.

Restoring TRAIL mediated signaling in ovarian cancer cells

Ovarian cancer has emerged as a multifaceted and genomically complex disease. Genetic/epigenetic mutations, suppression of tumor suppressors, overexpression of oncogenes, rewiring of intracellular signaling cascades and loss of apoptosis are some of the deeply studied mechanisms. In vitro and in vivo studies have highlighted different molecular mechanisms that regulate tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) mediated apoptosis in ovarian cancer. In this review, we bring to limelight, expansion in understanding systematical characterization of ovarian cancer cells has led to the rapid development of new drugs and treatments to target negative regulators of TRAIL mediated signaling pathway. Wide ranging synthetic and natural agents have been shown to stimulate mRNA and protein expression of death receptors. This review is compartmentalized into programmed cell death protein 4, platelet-derived growth factor signaling and miRNA control of TRAIL mediated signaling to ovarian cancer. Mapatumumab and PRO95780 have been tested for efficacy against ovarian cancer. Use of high-throughput screening assays will aid in dissecting the heterogeneity of this disease and increasing a long-term survival which might be achieved by translating rapidly accumulating information obtained from molecular and cellular studies to clinic researches.

Mining gene expression data of multiple sclerosis

OBJECTIVES

Microarray produces a large amount of gene expression data, containing various biological implications. The challenge is to detect a panel of discriminative genes associated with disease. This study proposed a robust classification model for gene selection using gene expression data, and performed an analysis to identify disease-related genes using multiple sclerosis as an example.

MATERIALS AND METHODS

Gene expression profiles based on the transcriptome of peripheral blood mononuclear cells from a total of 44 samples from 26 multiple sclerosis patients and 18 individuals with other neurological diseases (control) were analyzed. Feature selection algorithms including Support Vector Machine based on Recursive Feature Elimination, Receiver Operating Characteristic Curve, and Boruta algorithms were jointly performed to select candidate genes associating with multiple sclerosis. Multiple classification models categorized samples into two different groups based on the identified genes. Models' performance was evaluated using cross-validation methods, and an optimal classifier for gene selection was determined.

RESULTS

An overlapping feature set was identified consisting of 8 genes that were differentially expressed between the two phenotype groups. The genes were significantly associated with the pathways of apoptosis and cytokine-cytokine receptor interaction. TNFSF10 was significantly associated with multiple sclerosis. A Support Vector Machine model was established based on the featured genes and gave a practical accuracy of ∼86%. This binary classification model also outperformed the other models in terms of Sensitivity, Specificity and F1 score.

CONCLUSIONS

The combined analytical framework integrating feature ranking algorithms and Support Vector Machine model could be used for selecting genes for other diseases.

Sequence polymorphism and expression variability of Crassostrea gigas immune related genes discriminate two oyster lines contrasted in term of resistance to summer mortalities

Summer mortalities of Crassostreagigas are a major concern in oyster aquaculture. They are the result of a complex interaction between the host, pathogens and environmental factors. Oyster genetics have been identified as an essential determinant of oyster susceptibility to summer mortalities. As the capability of oysters to circumvent diseases depends in part on their immune defenses, we aimed to analyze the gene expression and sequence polymorphism of 42 immune related genes in two oyster lines selected for their “High” (H) and “Low” (L) survival to summer mortalities. Results showed that the variability of gene expression and the sequence polymorphism acting on particular genes could enable the discrimination between H and L oyster lines. Besides, a higher sequence polymorphism was observed on the L line affecting 11 of the 42 analyzed genes. By analyzing gene expression, sequence polymorphism and gene copy number of two antimicrobial peptide families (Cg-Defs and Cg-Prp), and an antimicrobial protein (Cg-BPI) on individual oysters, we showed that gene expression and/or sequence polymorphism could also discriminate H and L oyster lines. Finally, we observed a positive correlation between the gene expression and the gene copy number of antimicrobials and that sequence polymorphism could be encoded in the genome. Overall, this study gives new insights in the relationship between oyster immunity and divergent phenotypes, and discusses the potential implication of antimicrobial diversity in oyster survival to summer mortalities.

A Study of the Impact of Death Receptor 4 (DR4) Gene Polymorphisms in Alzheimer's Disease

BACKGROUND

Excessive apoptosis is believed to play a role in many degenerative and non-degenerative neurological diseases including Alzheimer's disease (AD). Much recent data suggest that apoptotic mechanisms may represent the missing link between Aβ deposition and proteolysis of tau protein. However, there is emerging evidence that apoptotic mechanisms may play a role in Alzheimer's Disease pathogenesis in the absence of overt apoptosis. TNF-related apoptosis inducing ligand receptor 1 (Death Receptor 4, DR4) might impair the apoptotic signal transduction and lead to dysregulation of the homeostasis between cell survival and cell death.

AIMS

The aim of our study was to further investigate the relationship between genetic variants of DR4 and Alzheimer's Disease.

STUDY DESIGN

Case control study.

METHODS

Sixty-eight patients with AD were included in the study. The control group comprised 72 subjects without signs of neurodegenerative diseases, as evidenced by the examination.DNA was extracted from whole blood using the salting-out procedure. Genotypes were identified by restriction fragment length polymorphism analysis of polymerase chain reaction (PCR-RFLP) products.

RESULTS

We observed significant differences in the genotypic distribution of the rs6557634 polymorphism in AD patients compared with controls (p<0.05); our data suggest that the GA genotype in rs6557634 could be protective against AD (p<0.05). However, there were no significant differences between AD patients and control groups in terms of the DR4 rs20575 polymorphism (p>0.05) and the DR4 rs20576 polymorphism (p>0.05). According to haplotype analysis of the DR4 gene for rs6557634, rs20575 and rs20576 polymorphisms, GCA and GCC haplotypes might be a risk factor for AD. Also, we have shown that ACA, GGC and GGA haplotypes might be protective factors against AD.

CONCLUSION

The present results indicate for the first time the possible contribution of the DR4 gene rs6557634, rs20575, rs20576 polymorphisms in Alzheimer's Disease, which may influence susceptibility to Alzheimer's Disease.

Candidate gene study of TRAIL and TRAIL receptors: association with response to interferon beta therapy in multiple sclerosis patients

TRAIL and TRAIL Receptor genes have been implicated in Multiple Sclerosis pathology as well as in the response to IFN beta therapy. The objective of our study was to evaluate the association of these genes in relation to the age at disease onset (AAO) and to the clinical response upon IFN beta treatment in Spanish MS patients. We carried out a candidate gene study of TRAIL, TRAILR-1, TRAILR-2, TRAILR-3 and TRAILR-4 genes. A total of 54 SNPs were analysed in 509 MS patients under IFN beta treatment, and an additional cohort of 226 MS patients was used to validate the results. Associations of rs1047275 in TRAILR-2 and rs7011559 in TRAILR-4 genes with AAO under an additive model did not withstand Bonferroni correction. In contrast, patients with the TRAILR-1 rs20576-CC genotype showed a better clinical response to IFN beta therapy compared with patients carrying the A-allele (recessive model: p = 8.88×10⁻⁴, p_c = 0.048, OR = 0.30). This SNP resulted in a non synonymous substitution of Glutamic acid to Alanine in position 228 (E228A), a change previously associated with susceptibility to different cancer types and risk of metastases, suggesting a lack of functionality of TRAILR-1. In order to unravel how this amino acid change in TRAILR-1 would affect to death signal, we performed a molecular modelling with both alleles. Neither TRAIL binding sites in the receptor nor the expression levels of TRAILR-1 in peripheral blood mononuclear cell subsets (monocytes, CD4+ and CD8+ T cells) were modified, suggesting that this SNP may be altering the death signal by some other mechanism. These findings show a role for TRAILR-1 gene variations in the clinical outcome of IFN beta therapy that might have relevance as a biomarker to predict the response to IFN beta in MS.

Regulation of the human TRAIL gene

TRAIL is a member of the TNF superfamily that induces tumor-selective cell death by engaging the pro-apoptotic death receptors DR4 and DR5. The antitumor potential of the TRAIL pathway has been targeted by several therapeutic approaches including recombinant TRAIL and TRAIL-receptor agonist antibodies among others. Interest in sensitizing tumor cells to TRAIL-mediated apoptosis has driven investigations of TRAIL-receptor gene regulation, though regulation of the TRAIL gene has been less studied. Physiologically, TRAIL serves as a pro-apoptotic effector molecule in the immune surveillance of cancer that is conditionally expressed by immune cells upon stimulation via an interferon-response element that was identified in early studies of the TRAIL gene promoter. Here, we map the TRAIL gene promoter and review studies of TRAIL gene regulation that involve several modalities of gene regulation including transcription factors, epigenetics, single-nucleotide polymorphisms and functionally distinct isoforms.

Association between endometriosis and polymorphisms in tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), TRAIL receptor and osteoprotegerin genes and their serum levels

PURPOSE

To evaluate the relationship between endometriosis and polymorphisms in the genes encoding tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), TRAIL receptor (DR) and osteoprotegerin (OPG) and their serum levels in Korean women.

METHODS

A case-control study was conducted with 138 women with endometriosis and 214 women without endometriosis in academic medical center. TRAIL c.49G>A, c.592A>G, c.615A>G, and c.662T>C; DR4 c.626G>C and c.1322A>G; DR5 c.95C>T, c.200C>T, and c.72T>G; OPG -245T>G, c.9C>G, c.788A>C, and c.9938G>T polymorphisms were investigated and circulating levels of TRAIL and OPG were measured.

RESULTS

The TRAIL c.49G>A, c.615A>G, and c.662T>C; the DR4 c.626G>C; the DR5 c.72T>G; the OPG c.788A>C and c.9938G>T polymorphisms were not observed. The genotype distributions and allele frequencies of single or combined polymorphisms of TRAIL, DR4, DR5, and OPG measured in women with endometriosis were not different from those in women without endometriosis, regardless of endometriosis stage. Serum TRAIL and OPG levels were significantly lower in women with endometriosis than in women without endometriosis, but these levels did not show differences between early and advanced endometriosis.

CONCLUSIONS

Endometriosis is associated with circulating TRAIL and OPG levels in Korean women but not with the TRAIL, DR, and OPG polymorphisms.

Death receptor signalling in central nervous system inflammation and demyelination

Death receptors (DRs) are members of the tumor necrosis factor receptor (TNF-R) superfamily that are characterised by the presence of a conserved intracellular death domain and are able to trigger a signalling pathway leading to apoptosis. Strong evidence suggests that DRs contribute to the pathology of tissue destructive diseases, including multiple sclerosis (MS), the most common inflammatory demyelinating disease of the central nervous system (CNS). Here, we review the evidence supporting a role for DRs in MS pathology and its implications for the development of therapeutic strategies for MS and other demyelinating pathologies of the CNS.

Evaluation of apoptosis-related genes: Fas (CD94), FasL (CD178) and TRAIL polymorphisms in Iranian multiple sclerosis patients

Multiple sclerosis (MS) is a central nervous system (CNS) demyelinating disease characterized by a relapsing-remitting course leading to progressive disability. Given the critical role of apoptosis-related genes in the maintenance of homeostasis in the immune privilege sites, mutations in these genes have a profound effect on occurring autoimmune diseases such as multiple sclerosis. In the current study, polymorphisms in the apoptosis-related genes: Fas _-670 A>G, FasL _-844C>T, FasLIVS2nt _124 A>G and TRAIL_1595C>T were analyzed in 107 Iranian patients suffering from MS and 112 unrelated healthy controls using PCR-RFLP method. Our results demonstrated that among Iranian patients with MS and controls being homozygous in Fas_670A/A, G/G and FasL_-844C/C, TT in the promoter region and homozygocity in the minor allele for FasLIVS2nt_124G/G and TRAIL_1595C/C, polymorphisms were not associated with the MS risk in Iranian patients when compared with normal controls. However, the Fas _-670G/G genotype had a borderline significantly increased frequency with secondary progressive MS type (X(2)=5.8, P=0.05). In conclusion, no statistical association was found between the Fas, FasL and TRAIL polymorphisms and the risk of MS in Iranian patients.

TRAIL/TRAIL receptor system and susceptibility to multiple sclerosis

The TNF-related apoptosis inducing ligand (TRAIL)/TRAIL receptor system participates in crucial steps in immune cell activation or differentiation. It is able to inhibit proliferation and activation of T cells and to induce apoptosis of neurons and oligodendrocytes, and seems to be implicated in autoimmune diseases. Thus, TRAIL and TRAIL receptor genes are potential candidates for involvement in susceptibility to multiple sclerosis (MS). To test whether single-nucleotide polymorphisms (SNPs) in the human genes encoding TRAIL, TRAILR-1, TRAILR-2, TRAILR-3 and TRAILR-4 are associated with MS susceptibility, we performed a candidate gene case-control study in the Spanish population. 59 SNPs in the TRAIL and TRAIL receptor genes were analysed in 628 MS patients and 660 controls, and validated in an additional cohort of 295 MS patients and 233 controls. Despite none of the SNPs withstood the highly conservative Bonferroni correction, three SNPs showing uncorrected p values<0.05 were successfully replicated: rs4894559 in TRAIL gene, p = 9.8×10⁻⁴, OR = 1.34; rs4872077, in TRAILR-1 gene, p = 0.005, OR = 1.72; and rs1001793 in TRAILR-2 gene, p = 0.012, OR = 0.84. The combination of the alleles G/T/A in these SNPs appears to be associated with a reduced risk of developing MS (p = 2.12×10⁻⁵, OR = 0.59). These results suggest that genes of the TRAIL/TRAIL receptor system exerts a genetic influence on MS.

How do immune cells overcome the blood-brain barrier in multiple sclerosis?

The presence of the blood-brain barrier (BBB) restricts the movement of soluble mediators and leukocytes from the periphery to the central nervous system (CNS). Leukocyte entry into the CNS is nonetheless an early event in multiple sclerosis (MS), an inflammatory disorder of the CNS. Whether BBB dysfunction precedes immune cell infiltration or is the consequence of perivascular leukocyte accumulation remains enigmatic, but leukocyte migration modifies BBB permeability. Immune cells of MS subjects express inflammatory cytokines, reactive oxygen species (ROS) and enzymes that can facilitate their migration to the CNS by influencing BBB function, either directly or indirectly. In this review, we describe how immune cells from the peripheral blood overcome the BBB and promote CNS inflammation in MS through BBB disruption.

Haplotypes covering the TNFSF10 gene are associated with bronchial asthma

Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) is elevated in the airways of subjects with asthma and has been linked to the development of allergic airway disease by promoting STAT6-dependent T helper 2 cell (T(H) 2) effector functions. To determine whether single nucleotide polymorphisms (SNPs) in the TNFSF10 gene are associated with bronchial asthma we genotyped 498 Caucasian subjects living in Southern Germany for eight SNPs in the TNFSF10 by restriction fragment length polymorphism analysis. In contrast to single SNPs, haplotypes constructed from eight SNPs were robustly associated with asthma (p=0.00012). A small haplotype approach returned four alleles consisting of two (rs3136586/ rs3136598), three (rs12488654/rs3136586/rs3136598 and rs3136586/rs3136598/rs3136604), and four SNPs (rs12488654/ rs3136586/ rs3136598/ rs3136604) that were highly associated with asthma (p=0.00005, p=0.00008, p=0.00017 and p=0.00038). Combinations of SNPs in the TNFSF10 allele were strongly associated with asthma supporting the concept that TRAIL is important in the development of hallmark features of this disease.

Is there any correlation between TNF-related apoptosis-inducing ligand (TRAIL) genetic variants and breast cancer?

INTRODUCTION

TNF-related apoptosis-inducing ligand (TRAIL) is a death ligand and also a member of the TNF superfamily. We aimed to investigate the possible relationship between TRAIL and breast cancer. Here, we report the results of the first association study on genetic variation in the TRAIL gene and its effect on breast cancer susceptibility and prognosis.

MATERIAL AND METHODS

A C/T polymorphism at 1595 position in exon 5 of the TRAIL gene was genotyped in a Turkish breast cancer case-control population including 53 cases (mean age: 55.09 ±11.63 years) and 57 controls (mean age: 57.17 ±17.48 years) using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis.

RESULTS

There were no differences in the distribution of TRAIL genotypes and frequencies of the alleles in the breast cancer patients and controls. A heterozygous TRAIL CT polymorphism in exon 5 was present in 8.3% of tumour stage III-IV and 48.8% of stage I-II patients, and in 42.1% of controls. The reduced frequency of this genotype in patients who had advanced tumour stage was statistically significant (p = 0.017).

CONCLUSIONS

Our findings indicate that genetic variants of TRAIL at position 1595 in exon 5 might be associated with progression of breast cancer.

Polymorphism in tumor necrosis factor-related apoptosis-inducing ligand receptor 1 is associated with poor viral response to interferon-based hepatitis C virus therapy in HIV/hepatitis C virus-coinfected individuals

OBJECTIVE(S)

HIV/hepatitis C virus (HCV) coinfection causes accelerated liver disease compared to HCV monoinfection, and only 30-60% of HIV/HCV-coinfected individuals respond to HCV therapy with pegylated interferon and ribavirin. There are currently no biomarkers that predict treatment response in these coinfected patients.

DESIGN

We investigated whether there is an association between HCV treatment response and SNPs of apoptosis-related genes during HIV/HCV coinfection.

METHOD

Genomic DNA from 53 HIV/HCV-coinfected individuals was analyzed for 82 SNPs of 10 apoptosis-related genes.

RESULTS

We found that the presence of the rs4242392 SNP in tumor necrosis factor receptor superfamily, member 10a (TNFRSF10A), which encodes for tumor necrosis factor-related apoptosis-inducing ligand receptor 1, predicts poor outcome to HCV therapy, in HIV/HCV-co-infected patients [odds ratio 5.91 (95% confidence interval 1.63-21.38, P = 0.007)].

CONCLUSION

The rs4242392 SNP of the tumor necrosis factor-related apoptosis-inducing ligand receptor 1 gene predicted poor interferon-based HCV treatment response in HIV/HCV-coinfected patients.

Functional implication of TRAIL -716 C/T promoter polymorphism on its in vitro and in vivo expression and the susceptibility to sporadic breast tumor

Recently, TRAIL function has been elucidated beyond its known classical role of mediating cellular homeostasis and immune surveillance against transformed cells. Here, we show how CC genotype of -716 TRAIL promoter SNP rendered risk for sporadic breast cancer as compared to the CT and TT genotypes (P (recessive model) = 0.018, OR = 1.4, 95% CI = 1.1-1.9; P (allele model) = 0.010, OR = 1.3, 95% CI = 1.1-1.7). The in silico prediction of the introduction of core Sp1/Sp3-binding motif suggested the functional significance of the SNP variation. This functional implication was validated by luciferase assay in HeLa (P = 0.026), MCF-7 (P = 0.022), HepG2 (P = 0.024), and HT1080 (P = 0.030) cells and also by real-time expression studies on tumor tissues (P = 0.01), revealing the transcriptionally repressed status of -716 T when compared to -716 C allele. The SNP-SNP interactions reflected an enhanced protective effect of CT and TT genotypes with the protective genetic backgrounds of TP53-BRCA2 (P = 0.002, OR = 0.2, 95% CI = 0.1-0.6), IFNG (P = 0.0000002, OR = 0.3, 95% CI = 0.2-0.4), and common variant Casp8 (P = 0.0003, OR = 0.5, 95% CI = 0.3-0.7). Interestingly, a comparison with clinical parameters showed overrepresented CT and TT genotypes in progressing (P = 0.041) and ER/PR negative tumors (P = 0.024/0.006). This was explained by increased apoptotic index, calculated as a ratio of selected pro-apoptotic and anti-apoptotic gene expression profiles, in CC genotyped tumors, favoring either intrinsic (P = 0.008,0.018) or extrinsic (P = 0.025,0.217) pathway depending upon the ER/PR status. Our study reveals for the first time that a promoter SNP of TRAIL functionally modulates the gene and consequently its role in breast cancer pathogenesis, cautioning to consider the -716 TRAIL SNP status in patients undergoing TRAIL therapy.

TNF superfamily gene polymorphism as prognostic factor in early breast cancer

PURPOSE

Since apoptosis may play a role in the prognosis of breast cancer, the present study analyzed the polymorphisms of apoptosis-related genes and their impact on the survival of 240 patients with early invasive ductal breast cancer.

METHODS

The genomic DNA was extracted from paraffin-embedded tumor-free tissue or blood, and 12 single nucleotide polymorphisms (SNPs) of 11 apoptosis-related genes in the apoptosis pathway determined using a Sequenom MassARRAY system.

RESULTS

During the median follow-up of 53.4 (range 2.9-205.9) months, 37 relapses and 22 deaths occurred. Among the target polymorphisms, the tumor necrosis factor superfamily member 10 gene polymorphism (TNFSF10 rs1131532) in a recessive model of the T allele and prostaglandin-endoperoxide synthase 2 gene polymorphism (PTGS2 rs5275) in a dominant model of the C allele were associated with survival in a log-rank test. The TT genotype of TNFSF10 (rs1131532) was also significantly correlated with a lower disease-free, distant disease-free, and overall survival in a multivariate analysis (HR = 3.304, 4.757, and 6.459; P = 0.002, 0.001, and 0.009, respectively), while PTGS2 rs5275 was only associated with a higher distant disease-free survival (HR = 0.302; P = 0.041). No clinicopathologic difference was observed according to the genotypes of these two polymorphisms.

CONCLUSION

The TNFSF10 (rs1131532) polymorphism was identified as a possible prognostic factor of survival in patients with operated invasive breast cancer.

sTRAIL levels and TRAIL gene polymorphisms in Chinese patients with fatty liver disease

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a member of the TNF superfamily, and has been identified as a novel mediator of fatty liver disease (FLD). The aim of our study was to further investigate the relationship between TRAIL and FLD. We found that soluble TRAIL (sTRAIL) concentrations in non-alcoholic FLD (NAFLD) patients were significantly higher than those of controls, and that sTRAIL levels positively correlated with triglyceride concentrations in NAFLD patients. Our results also indicated that the AA/TT genotypes of TRAIL at 1525/1595 engendered a lower risk of FLD attack and a less severe form of steatosis for NAFLD patients in Chinese population. This study provides a means to test for susceptibility to FLD and may assist in the diagnosis of FLD. In addition, we found that 1525G/A and 1595C/T sites were in complete linkage disequilibrium in Chinese population. This might indicate a haplotype with high genetic frequency of TRAIL.

An investigation of susceptibility loci in benign, aggressive and primary progressive multiple sclerosis in Northern Irish population

OBJECTIVE

To investigate the possibility that susceptibility loci in multiple sclerosis (MS) have a role in determining the disease outcome in Northern Ireland population.

BACKGROUND

The Genetic Analysis of Multiple Sclerosis in Europeans (GAMES) initiative and follow-up refined analysis identified 15 candidate susceptibility loci within the Northern Irish population for MS. We aimed to investigate the 12 most significant markers for their role in disease outcome.

METHODS

Cases with probable or definite MS (Poser criteria) were classified as benign onset (Kurtzke Expanded Disability Status Scale [EDSS]<or=3.0 at 10 years), aggressive (Kurtzke EDSS>or=6.0 by 10 years), or primary progressive MS. All cases were Caucasian of Northern Irish origin. DNA was extracted from venous blood, microsatellite markers were amplified using polymerase chain reaction and typed using fluorescent fragment analysis. Allele frequencies were compared statistically using a chi-squared test with allowance for multiple comparisons (critical P<0.0042); significant markers were further analyzed by CLUMP (critical P<0.0014).

RESULTS

Two microsatellite markers were significant: D3S1278 (Chr 3q13, P<0.001) and tumor necrosis factor (TNF)-alpha (Chr 6p21, P<0.001). A further three markers were significant in our preliminary analysis suggesting a trend toward impact on disease outcome; D4S432 (Chr 4p16, P=0.001), D2S347 (Chr 2q14, P=0.003), and D19S903 (Chr 19p13, P=0.003).

CONCLUSIONS

This is the first study to suggest a role for TNF-alpha in the disease outcome in MS. Larger replication studies need to be performed to assess the role of markers D4S432, D2S347, and D19S903.

CASP-9: A susceptibility locus for multiple sclerosis in Italy

Caspase-9 is a primary effector CASP that executes programmed cell death, which plays an important role in the development of multiple sclerosis (MS). Polymorphisms in the CASP-9 gene may influence its activity, thereby modulating the susceptibility to MS. To test this hypothesis, we evaluated a SNP in the CASP-9 gene in a set of Italian patients from Southern Italy and healthy control subjects. Our results suggest that the presence of the G/G genotype represents a higher risk factor in our MS population and a differential production of CASP-9 might be a contributory factor in determining the severity of MS.

Recent advances in genetic analysis of multiple sclerosis: genetic associations and therapeutic implications

Epidemiological studies have confirmed that genetic factors are a key component in the pathogenesis of multiple sclerosis (MS) and that those determining MS susceptibility have been extensively studied. Many papers have been published regarding the heritable differences useful in genetic studies; these include variations in DNA, such as single-nucleotide polymorphisms, microsatellites and insertion/deletion polymorphisms. However, to date, among other regions, HLA is the only region confirmed to possess genes that determine MS susceptibility. In this article, we review the progress during the last 5 years in the studies on the susceptibility genes and the pharmacogenetics of MS. Newer techniques and methods of analysis will hopefully result in better screening of individuals who are at highest risk and novel treatments.

Familial aggregation and linkage analysis of autoantibody traits in pedigrees multiplex for systemic lupus erythematosus

Autoantibodies are clinically relevant biomarkers for numerous autoimmune disorders. The genetic basis of autoantibody production in systemic lupus erythematosus (SLE) and other autoimmune diseases is poorly understood. In this study, we characterized autoantibody profiles in 1,506 individuals from 229 multiplex SLE pedigrees. There was strong familial aggregation of antinuclear antibodies (ANAs), anti-double-stranded DNA (dsDNA), anti-La/SSB, anti-Ro/SSA, anti-Sm, anti-nRNP (nuclear ribonucleoprotein), IgM antiphospholipid (aPL) antibodies (Abs) and rheumatoid factor (RF) across these families enriched for lupus. We performed genome-wide linkage analyses in an effort to map genes that contribute to the production of the following autoantibodies: Ro/SSA, La/SSB, nRNP, Sm, dsDNA, RF, nuclear and phospholipids. Using an approach to minimize false positives and adjust for multiple comparisons, evidence for linkage was found to anti-La/SSB Abs on chromosome 3q21 (adjusted P=1.9 x 10(-6)), to anti-nRNP and/or anti-Sm Abs on chromosome 3q27 (adjusted P=3.5 x 10(-6)), to anti-Ro/SSA and/or anti-La/SSB Abs on chromosome 4q34-q35 (adjusted P=3.4 x 10(-4)) and to anti-IgM aPL Abs on chromosome 13q14 (adjusted P=2.3 x 10(-4)). These results support the hypothesis that autoantibody production is a genetically complex trait. Identification of the causative alleles will advance our understanding of critical molecular mechanisms that underlie SLE and perhaps other autoimmune diseases.