Tumor Necrosis Factor-A Polymorphisms and Colorectal Cancer Risk: A Meta-Analysis

Background and Objectives

Tumor necrosis factor-alpha (TNF-a) was related to inflammation and involved in the development of colorectal cancer. Polymorphisms located in TNF-a promoter region, such as 308G/A and 238G/A, could affect the risk of various types of cancer by regulating TNF-a production. In this study, a meta-analysis was performed to investigate the association between common polymorphisms of TNF-a promoter region and colorectal cancer susceptibility.

Methods

Searching of several databases was performed for all publications on the association between TNF-a polymorphisms and colorectal cancer. Summary odds ratios (ORs) with their 95% confidence intervals (95% CIs) were calculated using random-effects models. Stratified analyses based on ethnicity and control population source were also conducted.

Results

Overall, TNF-a 308A polymorphism showed a significant association with increased risk of colorectal cancer in worldwide populations under homozygote comparison [AA vs. GG, OR (95% CI) = 1.46 (1.07–1.97)] other than heterozygote comparison [AG vs. GG, OR (95% CI) = 1.05 (0.93–1.19)]. TNF-a 238A was not associated with colorectal cancer risk under homozygote or heterozygote comparisons. In stratified analysis, significant association was observed only in Western populations [AA vs. GG, OR (95% CI) = 1.39 (1.01–1.91)] other than in Eastern populations under homozygote comparison. No significant difference was observed between population-based subgroup and hospital-based subgroup.

Conclusions

TNF-a 308A was moderately associated with an increased risk of colorectal cancer in Western populations, and TNF-a 238A polymorphism was not significantly associated with colorectal cancer risk.     

Tumor Necrosis Factor Alpha Blocking Agents as Treatment for Ulcerative Colitis Intolerant or Refractory to Conventional Medical Therapy: A Meta-Analysis

Background

Efficacy of tumor necrosis factor alpha (TNF-α) blockers for treatment of ulcerative colitis that is unresponsive to conventional therapy is unclear due to recent studies yielding conflicting results.

Aim

To assess the efficacy and safety of anti-TNF-α agents for treatment of ulcerative colitis patients who were intolerant or refractory to conventional medical therapy.

Methods

Pubmed, Embase, and the Cochrane database were searched. Analysis was performed on randomized controlled trials that assessed anti-TNF-α therapy on ulcerative colitis patients that had previously failed therapy with corticosteroids and/or immunosuppressants. The primary outcome focused on was the frequency of patients that achieved clinical remission. Further trial outcomes of interest included rates of remission without patient use of corticosteroids during the trial, extent of mucosal healing, and the number of cases that resulted in colectomy and serious side effects.

Results

Eight trials from seven studies (n = 2122) met the inclusion criteria and were thus included during analysis. TNF-α blockers demonstrated clinical benefit as compared to placebo control as evidenced by an increased frequency of clinical remission (p<0.00001), steroid-free remission (p = 0.01), endoscopic remission (p<0.00001) and a decrease in frequency of colectomy (p = 0.03). No difference was found concerning serious side effects (p = 0.05). Three small trials (n = 57) comparing infliximab to corticosteroid treatment, showed no difference in frequency of clinical remission (p = 0.93), mucosal healing (p = 0.80), and requirement for a colectomy (p = 0.49). One trial compared infliximab to cyclosporine (n = 115), wherein no difference was found in terms of mucosal healing (p = 0.85), colectomy frequency (p = 0.60) and serious side effects (p = 0.23).

Conclusion

TNF-α blockers are effective and safe therapies for the induction and maintenance of long-term remission and prevention of treatment by colectomy for patients with refractory ulcerative colitis where conventional treatment was previously ineffective. Furthermore, infliximab and cyclosporine were found to be comparable for treating acute severe steroid-refractory ulcerative colitis.     

TNF-Alpha rs1800629 Polymorphism Is Not Associated with HPV Infection or Cervical Cancer in the Chinese Population

Background

While HPV infection is the main cause of cervical cancer, genetic susceptibility to HPV infection is not well understood. Tumor necrosis factor alpha (TNF-alpha), involved in the defense against HPV infection, plays an important role in cervical cancer progression and regression. The aim of this study was to investigate the relationship between the TNF-alpha rs1800629 polymorphism and risk of HPV infection or cervical cancer.

Methods

Three groups were involved in this study of Chinese women. Group 1 consisted of 285 high risk HPV positive cervical cancer patients, Group 2, 225 high risk HPV positive patients without cervical cancer, and Group 3, 318 HPV negative women with no cervical cancer. Blood samples were obtained from all patients and genotyped by PCR-RLFP. Fifty randomly selected samples were further sequenced.

Results

The allele and genotype distributions of the TNF-alpha rs1800629 polymorphism were not significantly different between each of the groups (P>0.05). There are no significant relationship between rs1800629 polymorphism and high risk HPV infection (OR  = 0.649, 95% CI: 0.253–1.670, P = 0.371), cervical cancer (OR  = 0.993, 95% CI: 0.376–2.618, P = 0.988), or cervical cancer with HPV infection (OR  = 0.663, 95% CI: 0.250–1.758, P = 0.409).

Conclusions

We demonstrated that there is no association between TNF rs1800629 polymorphism and the HPV infection, or cervical cancer with HPV infection.     

Hsa-miR-499 rs3746444 Polymorphism Contributes to Cancer Risk: A Meta-Analysis of 12 Studies

Background

Single nucleotide polymorphisms (SNPs) occurred in pre-microRNAs or targets of microRNAs (miRs) may contribute to cancer risks. Since 2007, many studies have investigated the association between common SNPs located on hsa-miR-499 (rs3746444) and cancer risks; however, the results were inconclusive.

Methodology/Principal Findings

We conducted a meta-analysis of 12 studies that included 5765 cases and 7076 controls to identify the strength of association. Odds ratio (OR) and 95% confidence intervals (95% CI) were used to assess the strength of association. Overall, individuals with the variant AG (OR = 1.215, 95% CI: 1.027, 1.437; P_{heterogeneity}<0.01) and AG/GG (OR = 1.227, 95% CI: 1.046, 1.439; P_{heterogeneity}<0.01) genotypes were associated with a significantly increased risk of cancer than those with wild AA genotype. Sub-group analysis revealed that the variant AG (OR = 1.411, 95% CI: 1.142, 1.745; P_{heterogeneity} = 0.01) and AG/GG (OR = 1.413, 95% CI: 1.163, 1.717, P_{heterogeneity} = 0.01) genotypes still showed an increased risk of cancer in Asians; however, a trend of reduced risk of cancer was observed in Caucasians (AG vs. AA: OR = 0.948, 955 CI: 0.851, 1.057, P_{heterogeneity} = 0.12; AG/GG vs. AA: OR = 0.959, 95% CI: 0.865, 1.064; P_{heterogeneity} = 0.19). Meta-regression showed that ethnicity (p = 0.048) and sample size (p = 0.02) but not cancer types (p = 0.89) or source of control (p = 0.97) were the sources of heterogeneity.

Conclusions

These meta-analysis results suggest that hsa-miR-499 polymorphism rs3746444 is associated with a significantly increased risk of cancer, especially in Asian populations.     

人源性抗TNFα小分子抗体的改构和分析

在获得人源性抗人TNF α单链抗体 (ScFv)基因序列的基础上 ,对ScFv的连接肽部分进行基因改造 ,并构建了Fab抗体基因。改构前后的ScFv分别重组入表达载体pBV2 2 0 ,经 42℃热诱导 ,在E .coliDH5α中表达了ScFv蛋白 ,得到分子量约为 30kD的重组蛋白质 ,改构前后ScFv的表达量分别占菌体总蛋白质的 6 .5 %和13 .8%。同时构建Fab可溶性表达载体并转化非抑制型菌株HB2 15 1,经IPTG诱导 ,在约 5 0kD分子量处呈现一条新生蛋白质条带。从大肠杆菌裂解液中对ScFv进行了复性和层析纯化 ,对Fab基因的表达产物进行了亲和层析纯化 ,并证实 :(1)改构后ScFv在大肠杆菌中的表达量有所提高 ;(2 )改构前后的ScFv与Fab均具有与hTNF α相结合的活性 ,具有GGGGS连接肽的ScFv与hTNF α的亲和常数为 6 .70× 10 4 (mol/L) -1,而改构后具有(GGGGS) 3 连接肽的ScFv的亲和常数提高为 7.2 7× 10 5(mol/L) -1,Fab与hTNF α的亲和常数为 7.6 1× 10 5(mol/L) -1,Fab与改构后ScFv的亲和力无明显差异 ;(3)ScFv与Fab均有中和hTNF α细胞毒的作用 ,具有(GGGGS) 3 连接肽的ScFv与Fab的中和活性基本相同 ,但均明显低于一株鼠源性单抗     

The rs2233678 Polymorphism in PIN1 Promoter Region Reduced Cancer Risk: A Meta-Analysis

Background

Published evidence suggests that the rs2233678 (−842 G>C) polymorphism in the PIN1 (peptidyl-prolyl cis/trans somerase NIMA-interacting 1) promoter region may be associated with cancer risk; however, the conclusion is still inconclusive.

Methods

We conducted a meta-analysis to determine whether −842 G>C polymorphism was associated with cancer risk. Odds ratio (OR) and 95% confidence intervals (95% CI) were used to assess the strength of association. Genotype distribution data and adjusted ORs were collected to calculate the pooled ORs. Meta-regression was conducted to detect the source of heterogeneity. Publication bias was evaluated by Egger’s test and Begg’s test.

Results

A total of 11 eligible studies, including 9280 participants, were identified and analyzed. Overall, we found that carriers of the −842 C allele were associated with significantly decreased cancer risk (C vs. G, OR = 0.750, 95% CI: 0.639–0.880, P_{heterogeneity} = 0.014, estimated by genotype distribution data; CC+GC vs. GG, OR = 0.668, 95% CI: 0.594–0.751, P_{heterogeneity} = 0.638, estimated by adjusted ORs). No evidence of publication bias was observed. Meta-regression revealed that ethnicities (p = 0.021) and sample size (p = 0.02) but not sources of control (p = 0.069) were the source of heterogeneity.

Conclusion

These results suggest that the PIN1 rs2233678 (−842 G>C) polymorphism significantly reduces cancer risk.     

The FTO Gene rs9939609 Polymorphism Predicts Risk of Cardiovascular Disease: A Systematic Review and Meta-Analysis

Objective

Genome-wide association studies have shown that variance in the fat mass- and obesity- associated gene (FTO) is associated with risk of obesity in Europeans and Asians. Since obesity is associated with an increased risk of cardiovascular disease (CVD), several studies have investigated the association between variant in the FTO gene and CVD risk, with inconsistent results. In this study, we performed a meta-analysis to clarify the association of rs9939609 variant (or its proxies [r ²>0.90]) in the FTO gene with CVD risk.

Methods

Published literature from PubMed and Embase was retrieved. Pooled odds ratios with 95% confidence intervals were calculated using the fixed- or random- effects model.

Results

A total of 10 studies (comprising 19,153 CVD cases and 103,720 controls) were included in the meta-analysis. The results indicated that the rs9939609 variant was significantly associated with CVD risk (odds ratio = 1.18, 95% confidence interval = 1.07–1.30, p = 0.001 [Z test], I ² = 80.6%, p<0.001 [heterogeneity]), and there was an insignificant change after adjustment for body mass index (BMI) and other conventional CVD risk factors (odds ratio = 1.16, 95% confidence interval = 1.05–1.27, p = 0.003 [Z test], I ² = 75.4%, p<0.001 [heterogeneity]).

Conclusions

The present meta-analysis confirmed the significant association of the rs9939609 variant in the FTO gene with CVD risk, which was independent of BMI and other conventional CVD risk factors.     

MDM2 SNP309 rs2279744 Polymorphism and Gastric Cancer Risk: A Meta-Analysis

Background

MDM2 is a major negative regulator of p53, and a single nucleotide polymorphism (SNP) in the MDM2 promoter region SNP309 has been demonstrated to be associated with an increased MDM2 expression and a significantly earlier age of onset of several tumors, including gastric cancer. Several studies were published to evaluate the association between SNP309 and gastric cancer risk. However, the results remain conflicting rather than conclusive.

Objective

The aim of this study was to assess the association between the MDM2 SNP309 polymorphism and gastric risk.

Methods

We performed a meta-analysis to investigate this relationship. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the association. The pooled ORs were performed for codominant model, dominant model, and recessive model, respectively.

Results

Five published case-control studies, including 1,621 gastric cancer cases and 2,639 controls were identified. We found that the MDM2 SNP309 polymorphism was associated with a significantly increased risk of gastric cancer risk when all studies were pooled into the meta-analysis (GG versus TT, OR = 1.54; 95%CI = 1.04–2.29, and GG versus GT/TT, OR = 1.49, 95%CI = 1.30–1.72). Furthermore, Egger''s test did not show any evidence of publication bias (P = 0.799 for GG versus TT).

Conclusion

Our results suggest that the MDM2 SNP309 polymorphism may be a low-penetrant risk factor for the development of gastric cancer.     

KCNE1 rs1805127 Polymorphism Increases the Risk of Atrial Fibrillation: A Meta-Analysis of 10 Studies

Background

Atrial fibrillation (AF) is one of the most common types of arrhythmia in humans. Recently, many studies have investigated the relationship between human atrial fibrillation and the single nucleotide polymorphism (SNP) of rs1805127 (A>G) in KCNE1 gene, but the results were still inconsistent and inconclusive.

Method

Electronic databases and bibliographies of retrieved studies were searched. We performed a meta-analysis of ten case-control studies, including 2099 cases and 2252 controls, to evaluate the association of rs1805127 polymorphism (A>G) with the risk of AF. Random-effects model was used when the heterogeneity was obvious; otherwise, fixed-effects model was applied. Meta-regression was performed to examine potential source of heterogeneity. Egger''s test and Begg''s test were used to detect publication biases.

Results

The results showed a significantly increased risk of AF in homozygote comparison (GG vs. AA:OR = 1.899, 95%CI: 1.568, 2.300; P_{heterogeneity} = 0.217), heterozygote comparison (GA vs. AA:OR = 1.436, 95% CI:1.190, 1.732; P_{heterogeneity} = 0.739), dominant model(GA /GG vs. AA: OR = 1.624, 95%CI: 1.361, 1.938; P_{heterogeneity} = 0.778) and recessive model (GG vs. GA/AA: OR = 1.394, 95%CI:1.152, 1.686; P_{heterogeneity} = 0.03). Meta-regression revealed that the sample size and the types of AF were the source of the heterogeneity.

Conclusion

The rs1805127 polymorphism (A>G) of KCNE1 is associated with an increased risk of AF, which suggests the rs1805217 polymorphism of KCNE1 gene may play an important role in the pathogenesis of AF.     

Distinct Pathways for Tumor Necrosis Factor Alpha and Ceramides in Human Cytomegalovirus Infection

Human cytomegalovirus (HCMV) infection can be fatal to immunocompromised individuals. We have previously reported that gamma interferon and tumor necrosis factor alpha (TNF-α) synergistically inhibit HCMV replication in vitro. Ceramides have been described as second messengers induced by TNF-α. To investigate the mechanisms involved in the inhibition of HCMV by TNF-α, in the present study we have analyzed ceramide production by U373 MG astrocytoma cells and the effects of TNF-α versus ceramides on HCMV replication. Our results show that U373 MG cells did not produce ceramides upon incubation with TNF-α. Moreover, long-chain ceramides induced by treatment with exogenous bacterial sphingomyelinase inhibited HCMV replication in synergy with TNF-α. Surprisingly, short-chain permeant C6-ceramide increased viral replication. Our results show that the anti-HCMV activity of TNF-α is independent of ceramides. In addition, our results suggest that TNF-α and endogenous long-chain ceramides use separate pathways of cell signalling to inhibit HCMV replication, while permeant C6-ceramide appears to activate a third pathway leading to an opposite effect.Human cytomegalovirus (HCMV) infections are well controlled in the immunocompetent host. Cellular immune responses (CD4⁺ and CD8⁺ T cells and NK cells) which accompany both acute and latent infections (for a review, see reference 4) are thought to be the main components of this control. HCMV infection during immunosuppression such as in cancer, transplantations, or AIDS results in severe pathology (4). We have previously shown that tumor necrosis factor alpha (TNF-α), in synergy with gamma interferon (IFN-γ), inhibits the replication of HCMV (7). In mice, TNF-α is involved in the clearance of CMV infection (25). TNF-α is a cytokine with multiple effects which is produced by many cell types, including macrophages and CD8⁺ and CD4⁺ T lymphocytes (for a review, see reference 40), and is known to possess antiviral effects (20, 47). The molecular mechanisms involved in the signalling by TNF-α depend on the type of receptor, p55 (TNF-R1) or p75 (TNF-R2) (5), to which it binds. Some cells express only one type of TNF-α receptor; however, expression of these receptors is not always mutually exclusive (5). The cytotoxicity of TNF-α has been reported to be mediated by TNF-R1 (38), whose intracellular region carries a death domain which signals for programmed cell death (39). Signalling through TNF-R1 with specific antibodies can also protect Hep-G2 cells from vesicular stomatitis virus-mediated cytopathic effects (48). Ceramide production after TNF-α treatment has been widely reported (16, 19, 31) and has also been shown to depend on signalling through the TNF-R1 receptor (45). In these experiments concerning myeloid cells, TNF-α induced the activation of a sphingomyelinase, which cleaved sphingomyelin to release ceramide and phosphocholine. The production of ceramides can lead to cell apoptosis (11, 14, 23) or cell cycle arrest (13). Induction of apoptosis by TNF-α has been mimicked by exogenous sphingomyelinase and by synthetic, short-chain, permeant ceramides, which suggests that ceramides, as second messengers, are sufficient to induce the cytotoxic effects of TNF-α (11, 23). Acidic and neutral sphingomyelinases activated in different cell compartments may be responsible for the diverse effects of TNF-α (46), with the former being involved in signalling through NF-κB (34) and the latter being involved in signalling through a ceramide-activated protein kinase and phospholipase A₂ (46).One of the characteristics of HCMV infection is the increase in the content of intracellular DNA, reported to be of viral (3, 8, 18) or cellular (12, 37) origin. Since TNF-α has been known to display antiproliferative properties and to block cells in the G₁ phase (29), we initially tested its effects on the cell cycle of infected cells. Then, based on studies reporting that TNF-α induces ceramides in cells (16, 19, 31) and on a study showing the role of ceramide in cell cycle blockade (13), we originally postulated that ceramide was responsible for the antiviral effect of TNF-α. In the present study, we used astrocytoma cells (U373 MG) as a model for brain cells, which are important targets of HCMV in vivo (22). In contrast to fibroblasts, infected U373 MG cells release smaller quantities of virus particles even though all the cells were infected in our experiments. We believe that the U373 MG model is closer to HCMV infection in vivo. We show that ceramides are not produced by U373 MG cells upon incubation with even high concentrations of TNF-α. In addition, we demonstrate that exogenously added sphingomyelinase induces anti-HCMV effects whereas permeant C6-ceramide increases HCMV proliferation in U373 MG cells. This suggests that lipid second messengers can modulate HCMV infection and that TNF-α and ceramides use distinct signalling pathways in the control of HCMV infection. This is supported by our observation that the protein kinase JNK1 is activated exclusively by TNF-α in U373 MG cells and that TNF-α and exogenous sphingomyelinase act in synergy on HCMV infection.     

Association of SMAD7 rs12953717 Polymorphism with Cancer: A Meta-Analysis

Background

Accumulating evidence has suggested that Mothers against decapentaplegic homolog 7 (SMAD7) rs12953717 polymorphism might be related to cancer risk. However, epidemiologic findings have been inconsistent. We therefore performed a meta-analysis to clarify the association between the SMAD7 rs12953717 polymorphism and cancer risk.

Methods

A comprehensive search was conducted to identify all eligible studies of SMAD7 rs12953717 polymorphism and cancer risk. We used odds ratios (ORs) to assess the strength of the association, and 95% confidence intervals (CIs) to give a sense of the precision of the estimate. Heterogeneity, publication bias, and sensitivity analysis were also explored.

Results

A total of 14 case-control studies, including 16928 cases and 14781 controls, were included in the present meta-analysis. The overall results showed that the variant genotypes were associated with a significantly increased risk of all cancer types (homozygote comparison, OR = 1.23, 95%CI = 1.10–1.38, P<0.01; heterozygote comparison, OR = 1.12, 95%CI = 1.02–1.22, P = 0.02; recessive model, OR = 1.17, 95%CI = 1.07–1.29, P<0.01; dominant model, OR = 1.15, 95%CI = 1.06–1.25, P<0.01; allelic model, OR = 1.12, 95%CI = 1.06–1.18, P<0.01). Further sensitivity analysis confirmed the significant association. In the subgroup analysis by ethnicity, SMAD7 rs12953717 polymorphism was significantly associated with cancer risk in both Caucasians and Asians. In the subgroup analysis by cancer types, SMAD7 rs12953717 polymorphism was significantly associated with colorectal cancer.

Conclusions

Our investigations demonstrate that rs12953717 polymorphism is associated with the susceptibility of cancer. Large-scale and well-designed case-control studies are necessary to validate the risk identified in the present meta-analysis.     

African Swine Fever Virus Infection Induces Tumor Necrosis Factor Alpha Production: Implications in Pathogenesis

We have analyzed the production of tumor necrosis factor alpha (TNF-α) induced by in vitro infection with African swine fever (ASF) virus (ASFV) and the systemic and local release of this inflammatory cytokine upon in vivo infection. An early increase in TNF-α mRNA expression was detected in ASFV-infected alveolar macrophages, and high levels of TNF-α protein were detected by ELISA in culture supernatants from these cells. When animals were experimentally infected with a virulent isolate (E-75), enhanced TNF-α expression in mainly affected organs correlated with viral protein expression. Finally, elevated levels of TNF-α were detected in serum, corresponding to the onset of clinical signs. TNF-α has been reported to be critically involved in the pathogenesis of major clinical events in ASF, such as intravascular coagulation, tissue injury, apoptosis, and shock. In the present study, TNF-α containing supernatants from ASFV-infected cultures induced apoptosis in uninfected lymphocytes; this effect was partially abrogated by preincubation with an anti-TNF-α specific antibody. These results suggest a relevant role for TNF-α in the pathogenesis of ASF.     

Tumor Necrosis Factor Alpha Exerts Powerful Anti-Influenza Virus Effects in Lung Epithelial Cells

Previous studies have associated influenza virus-induced expression of inflammatory cytokines, including tumor necrosis factor alpha (TNF-alpha), with influenza pathogenesis in the human respiratory tract and have suggested that alpha and beta interferons are the first cytokines recruited to counteract such infection. However, we report here that TNF-alpha has powerful anti-influenza virus activity. When infected with influenza virus, cultured porcine lung epithelial cells expressed TNF-alpha in a dose-dependent manner. Expression of TNF-alpha was induced only by replicating virus. TNF-alpha showed strong antiviral activity against avian, swine, and human influenza viruses, and the antiviral effect of TNF-alpha was greater than that of gamma or alpha interferon. These findings suggest that TNF-alpha serves as the first line of defense against influenza virus infection in the natural host.     

LARP4 Is Regulated by Tumor Necrosis Factor Alpha in a Tristetraprolin-Dependent Manner

LARP4 is a protein with unknown function that independently binds to poly(A) RNA, RACK1, and the poly(A)-binding protein (PABPC1). Here, we report on its regulation. We found a conserved AU-rich element (ARE) in the human LARP4 mRNA 3′ untranslated region (UTR). This ARE, but not its antisense version or a point-mutated version, significantly decreased the stability of β-globin reporter mRNA. We found that overexpression of tristetraprolin (TTP), but not its RNA binding mutant or the other ARE-binding proteins tested, decreased cellular LARP4 levels. RNA coimmunoprecipitation showed that TTP specifically associated with LARP4 mRNA in vivo. Consistent with this, mouse LARP4 accumulated to higher levels in TTP gene knockout (KO) cells than in control cells. Stimulation of WT cells with tumor necrosis factor alpha (TNF-α), which rapidly induces TTP, robustly decreased LARP4 with a coincident time course but had no such effect on LARP4B or La protein or on LARP4 in the TTP KO cells. The TNF-α-induced TTP pulse was followed by a transient decrease in LARP4 mRNA that was quickly followed by a subsequent transient decrease in LARP4 protein. Involvement of LARP4 as a target of TNF-α–TTP regulation provides a clue as to how its functional activity may be used in a physiologic pathway.     

Functional IL-23R rs10889677 Genetic Polymorphism and Risk of Multiple Solid Tumors: a Meta-Analysis

Interleukin-23 receptor (IL23R) can interact with IL-23 and, thus, is involved in the T-helper 17 (Th17) cell-mediated inflammatory process as well as tumorigenesis. Recently, a functional single nucleotide polymorphism (SNP) rs10889677 has been identified in the 3’-untranslated region of IL-23R. It has been showed that the rs10889677AC SNP could increase the binding affinity of microRNA let-7f and downregulate IL-23R expression. Several case-control studies have examined the association between this SNP and genetic susceptibility of multiple solid tumors. However, the conclusions are conflicting. Therefore, we conducted this meta-analysis to systematically study the role of this functional IL-23R SNP in development of multiple solid tumors. There are a total of 5 studies are eligible (6731 cases and 7296 healthy controls). Either fixed-effect model or random-effect model was used to calculate pooled odds ratios (ORs) and the 95% confidence interval (95% CI). Significant association between this functional rs10889677 genetic variant and risk of multiple solid tumors were observed (CC genotype vs. AA genotype: OR = 0.59, 95% CI = 0.53-0.66, P < 0.001). These findings demonstrated that the IL-23R rs10889677 genetic variant might play an important part during malignant transformation of multiple solid tumors.     

Stable Escherichia coli-Clostridium acetobutylicum Shuttle Vector for Secretion of Murine Tumor Necrosis Factor Alpha

Recombinant plasmids were constructed to secrete mouse tumor necrosis factor alpha (mTNF-α) from Clostridium acetobutylicum. The shuttle plasmids contained the clostridial endo-β1,4-glucanase (eglA) promoter and signal sequence that was fused in frame to the mTNF-α cDNA. The construction was first tested in Escherichia coli and then introduced in C. acetobutylicum DSM792 by electroporation. Controls confirmed the presence and stability of the recombinant plasmids in this organism. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and an in vitro cytotoxic assay were used to monitor expression and secretion of mTNF-α during growth. Significant levels of biologically active mTNF-α were measured in both lysates and supernatants. The present report deals with investigations on the elaboration of a gene transfer system for cancer treatment using anaerobic bacteria.     

Engineered Lactic Acid Bacterium Lactococcus lactis Capable of Binding Antibodies and Tumor Necrosis Factor Alpha

We have optimized the display of the B domain of staphylococcal protein A on the surface of Lactococcus lactis. The maximum binding capacity was estimated at 0.146 μg of antibody per 10⁸ cells and was sustained at 86% after treatment with simulated gastric juice. A tumor necrosis factor alpha (TNF-α)-binding affibody was also displayed and bound TNF-α, which could be useful in the treatment of inflammatory bowel disease.Lactic acid bacteria (LAB) have received considerable attention in recent years, based on their record of safe usage as a constituent of fermented foods and their health-promoting effects as probiotics (5). Recombinant LAB could also be used in therapy, with most applications aimed at the delivery of antigens or therapeutic proteins to human mucosal surfaces (27). Another potential application of recombinant LAB involves surface attachment of affinity molecules, such as antibodies, single-chain variable fragments (scFv), or specific oligosaccharides, which can target pathogens, toxins, or inflammatory mediators in the human intestine (9, 22).We describe the surface display of two types of affinity molecule, the B domain and the tumor necrosis factor alpha (TNF-α)-binding affibody, on a model LAB, Lactococcus lactis. The B domain, which is one out of five antibody-binding domains of staphylococcal protein A (15), was already used as a model protein (2). The surface display of the B domain was reported for Escherichia coli in a biosensor application (8), for Saccharomyces cerevisiae as a whole-cell immunoadsorbent (16), and for certain viruses for specific cell targeting (20).The affinity of the B domain or its synthetic homologue, the Z domain (17), for the antibody Fc region has been redirected to several other proteins by randomization of amino acids involved in the interaction, using the genetic combinatorial library and phage display (18). The variants of the Z domain were termed “affibodies” and were directed against various proteins (reviewed in reference 19) and also against TNF-α (7).TNF-α is well established as a proinflammatory cytokine in the pathology of inflammatory bowel disease (IBD), and monoclonal antibodies against TNF-α are routinely used in parenteral therapy (23) but can have systemic side effects. The abundant presence of TNF-α in the stool samples of IBD patients (4) and the successful treatment of experimental colitis in rats by oral administration of avian IgY (28) justify the oral delivery of an agent with the capability of removing TNF-α in IBD. We have therefore replaced the B domain in our surface-displayed fusion protein with an affibody against TNF-α (7) as a second type of binding molecule. LAB with surface-displayed affibody against TNF-α could be used to bind TNF-α in the intestine, with the potential for use in the treatment of IBD. This novel approach could also overcome the problems with the gastrointestinal stability of antibodies.