IL-18 serum level and IL-18 promoter gene polymorphism in Iranian patients with gastrointestinal cancers

Associations of mitochondrial DNA copy number with incident risks of gastrointestinal cancers: A prospective case-cohort study

Epidemiological investigations implied that mitochondrial DNA copy number (mtDNAcn) variations could trigger predisposition to multiple cancers, but evidence regarding gastrointestinal cancers (GICs) was still uncertain. We conducted a case-cohort study within the prospective Dongfeng-Tongji cohort, including incident cases of colorectal cancer (CRC, n = 278), gastric cancer (GC, n = 138), and esophageal cancer (EC, n = 72) as well as a random subcohort (n = 1173), who were followed up from baseline to the end of 2018. We determined baseline blood mtDNAcn and associations of mtDNAcn with the GICs risks were estimated by using weighted Cox proportional hazards models. Significant U-shaped associations were observed between mtDNAcn and GICs risks. Compared to subjects within the second quartile (Q2) mtDNAcn subgroup, those within the 1st (Q1), 3rd (Q3), and 4th (Q4) quartile subgroups showed increased risks of CRC (hazard ratio [HR] [95% confidence interval, CI] = 2.27 [1.47-3.52], 1.65 [1.04-2.62], and 2.81 [1.85-4.28], respectively) and total GICs (HR [95%CI] = 1.84 [1.30-2.60], 1.47 [1.03-2.10], and 2.51 [1.82-3.47], respectively], and those within Q4 subgroup presented elevated GC and EC risks (HR [95% CI] = 2.16 [1.31-3.54] and 2.38 [1.13-5.02], respectively). Similar associations of mtDNAcn with CRC and total GICs risks remained in stratified analyzes by age, gender, smoking, and drinking status. This prospective case-cohort study showed U-shaped associations between mtDNAcn and GICs risks, but further research works are needed to uncover underlying biological mechanisms.

Roles of Plasmacytoid Dendritic Cells in Gastric Cancer

Gastric cancer (GC) is the fifth most common neoplasm and the third most deadly cancer in humans worldwide. Helicobacter pylori infection is the most important causative factor of gastric carcinogenesis, and activates host innate and adaptive immune responses. As key constituents of the tumor immune microenvironment, plasmacytoid dendritic cells (pDCs) are increasingly attracting attention owing to their potential roles in immunosuppression. We recently reported that pDCs have vital roles in the development of immunosuppression in GC. Clarifying the contribution of pDCs to the development and progression of GC may lead to improvements in cancer therapy. In this review, we summarize current knowledge regarding immune modulation in GC, especially the roles of pDCs in GC carcinogenesis and treatment strategies.

Association of interleukin-18 genotypes (-607C > A) and (-137 G > C) with the hepatitis B virus disease progression to hepatocellular carcinoma

Chronic infection with HBV has been reported to be associated with the development of HCC. The inflammation mounted by cytokine-mediated immune system plays an important role in the pathogenesis of HBV-associated HCC. IL-18 is a pro-inflammatory cytokine whose role in the development of HBV-associated chronic to malignant disease state has not been much studied. The present study was conceived to determine the role of genetic polymorphisms in IL-18, serum levels of IL-18, and expression level of its signal transducers in the HBV disease progression. A total of 403 subjects were enrolled for this study including 102 healthy subjects and 301 patients with HBV infection in different diseased categories. Polymorphism was determined using PCR-RFLP. Genotypic distributions between the groups were compared using odd's ratio and 95% CI were calculated to express the relative risk. Circulating IL-18 levels were determined by ELISA. Expression levels of pSTAT-1 and pNFƙB was determined by western blotting. In case of IL-18(- 607C > A), the heterozygous genotype (CA) was found to be a protective factor while in case of IL-18(- 137G > C) the heterozygous genotype (GC) acted as a risk factor for disease progression from HBV to HCC. Moreover, serum IL-18 levels were significantly increased during HBV disease progression to HCC as compared to controls. Also the levels of activated signal transducers (pSTAT-1 and pNF-κB) of IL-18 in stimulated PBMCs were significantly increased during HBV to HCC disease progression. These findings suggest that IL-18 has the potential to act as a biomarker of HBV-related disease progression to HCC.

Targeting the NLRP3 Inflammasome as a New Therapeutic Option for Overcoming Cancer

Inflammasomes are multiprotein complexes that regulate the maturation and secretion of the proinflammatory cytokines interleukin-1beta (IL-1β and interleukin-18 (IL-18) in response to various intracellular stimuli. As a member of the inflammasomes family, NLRP3 is the most studied and best characterized inflammasome and has been shown to be involved in several pathologies. Recent findings have made it increasingly apparent that the NLRP3 inflammasome may also play a central role in tumorigenesis, and it has attracted attention as a potential anticancer therapy target. In this review, we discuss the role of NLRP3 in the development and progression of cancer, offering a detailed summary of NLRP3 inflammasome activation (and inhibition) in the pathogenesis of various forms of cancer. Moreover, we focus on the therapeutic potential of targeting NLRP3 for cancer therapy, emphasizing how understanding NLRP3 inflammasome-dependent cancer mechanisms might guide the development of new drugs that target the inflammatory response of tumor-associated cells.

IL‑33/ST2 promotes the malignant progression of gastric cancer via the MAPK pathway

Gastric cancer (GC) remains one of the commonest malignant tumors and the second leading cause of cancer-related deaths worldwide. IL-33 is highly expressed in tumor tissues and serum of patients with GC. However, the function of the IL-33 and IL-33 receptor ST2 in the malignant progression of GC is yet to be elucidated. The present study aimed to explore the effect of the IL-33/ST2 axis on the biological functions of GC cells. The expression of ST2 in GC tissues was measured by immunohistochemistry. GC cell lines (AGS and MKN45) were treated with IL-33, and the expression of ST2 was downregulated by using specific siRNA. The effects of the IL-33/ST2 axis on cell proliferation, migration, invasion, cell cycle and apoptosis was detected by CCK8, Transwell, wound healing, flow cytometry and western blotting assays. The present study found that ST2 was highly expressed in GC tissues compared with normal tissues. IL-33 promoted the proliferation and cell cycle progression of GC cells, and upregulated the expression levels of CDK4, CDK6 and cyclin D1. Furthermore, IL-33 inhibited the apoptosis of GC cells and regulated the expression of apoptosis-associated proteins. In addition, IL-33 stimulated the invasion and migration of GC cells. However, the transfection of ST2 small interfering (si)RNA attenuated the effects of IL-33. Finally, IL-33 stimulation increased the phosphorylation levels of ERK1/2, JNK and p38. The transfection of ST2 siRNA could significantly inhibit the IL-33-induced ERK1/2, JNK and p38 activation. In conclusion, it was found that ST2 was highly expressed in GC tissues. IL-33/ST2 promoted the malignant progression of GC cells by inducing the activation of ERK1/2, JNK and p38.

Genetic variants and risk of thyroid cancer among Iranian patients

The definition of an exclusive panel of genetic markers is of high importance to initially detect among this review population. Therefore, we gave a summary of each main genetic marker among Iranian patients with thyroid cancer for the first time which were classified based on their cellular function. Due to the results, a significant relationship was found between SNP in codons 194, 280, and 399 (XRCC1), Allele 3434Thr (XRCC7), GC or CC genotype 31, G/C (Survivin), 399G>A (XRCC1), Tru9I (vitamin D receptor), G-D haplotype (MDM2), TT genotype, -656 G/T (IL-18), TAGTT haplotype (IL-18), G allele in +49 A>G (CTLA-4), +7146 G/A (PD-1.3), +7785 C/T (PD-1.5), rs1143770 (let7a-2), rs4938723 (pri-mir-34b/c) genes, and thyroid cancers. Moreover, SNP in 677C-->T (MTHFR), GG genotype Asp1312Gly (thyroglobulin), 2259C>T (Rad52), R188H, (XRCC2), T241M (XRCC3) had higher risks of thyroid cancer and lower risks were observed in -16 Ins-Pro (p53), rs3742330 (DICER1). At last, the protective effects were explored in 127 CC genotype (IL-18), rs6877842 (DROSHA). Conduct further studies on the types of DNA repair gene polymorphisms with a larger number in the thyroid cancer using modern methods such as SNP array so that these genes could be used as a biomarker in prediction, diagnosis, and treatment of thyroid cancer. This review presents for the first time a summary of important genetic markers in Iranian patients with thyroid cancer.

Association of Epidermal Growth Factor 61A>G, Survivin -31G>C, and EFNA1 -1732G>A Polymorphisms with Susceptibility to Colorectal Cancer

BACKGROUND

Genetic polymorphisms play an important role in the development of colorectal cancer (CRC). Functional variants in the epidermal growth factor (EGF), survivin, and Ephrin A1 (EFNA1) genes have been previously reported to play a potential role in susceptibility to CRC, but these polymorphisms have not been well replicated. The aim of this study was to assess the association of the EGF 61A>G, Survivin -31G>C, and EFNA1 -1732G>A polymorphisms with the susceptibility to CRC in an Iranian population.

METHODS

A total of 148 cases diagnosed with CRC and 160 healthy subjects were recruited. The EGF 61A>G, survivin -31G>C, and EFNA1 -1732G>A polymorphisms were genotyped using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay.

RESULTS

Our data revealed that the homozygous mutant genotype (CC: OR = 2.895, 95% CI = 1.092-7.673, p = 0.033) and mutant allele (C: OR = 1.629, 95% CI = 1.152-2.303, p = 0.006) of the survivin -31G>C were associated with an increased risk of CRC in the Iranian population. However, our results failed to show an association between the EGF 61A>G and EFNA1 -1732G>A polymorphisms and CRC risk.

CONCLUSION

Our results revealed that the survivin -31G>C polymorphism might play an important role in development of CRC in Iranian population. However, no association of EGF 61A>G and EFNA1 -1732G>A polymorphisms with CRC risk was found.

Epidemiologic Study of Gastric Cancer in Iran: A Systematic Review

BACKGROUND

Gastric cancer (GC) is one of the most common cancers in Iran. Knowledge of the epidemiology of the disease is essential in planning for prevention. So this study aimed to investigate the epidemiological aspects of gastric cancer including prevalence, incidence, mortality, and risk factors of Iran.

METHODS

This systematic review study was based on articles published in both English and Persian languages during the years of 1970-2020 in international databases (PubMed, Web of Science, Scopus) and national databases (including SID, Magiran, and IranDoc). Papers related to epidemiological aspects of the disease including mortality, prevalence, incidence, and risk entered the final review.

RESULTS

According to the studies, the minimum and maximum prevalence of gastric cancer in northwestern Iran (Ardabil) is between 0.2 and 100 per 100,000. Also, the death rate per 100,000 people ranged from 10.6 to 15.72 and the ASMR ranged from 4.2 to 32.2%. On the other hand, the incidence of GC was higher in men than in women (74.9 vs 4.6%). The GC risk ratio was 8-times higher in the elderly than in the other age groups (HR=8.0, 2.7-23.5). The incidence of gastric cancer in patients with H. pylori infection was 18-times and that of smokers 2-times higher than other populations. Low level of economic situation and food insecurity increased the odds of GC by 2.42- and 2.57-times, respectively. It should be noted that there was a direct relationship between consumption of processed red meat, dairy products, fruit juice, smoked and salty fish and legumes, strong and hot tea, and consumption of salt and gastric cancer incidence. There was also an inverse relationship between citrus consumption, fresh fruit, garlic, and gastric cancer. In addition, the mRNA genes are the most GC-related genes.

CONCLUSION

Given the high incidence of GC in Iran, changing lifestyle and decreasing consumption of preservatives in food, increasing consumption of fruits and vegetables, and improving the lifestyle can be effective in reducing the incidence of this disease.

Cumulative Evidence for Association Between IL-8 -251T>A and IL-18 -607C>A Polymorphisms and Colorectal Cancer Susceptibility: a Systematic Review and Meta-analysis

PURPOSE

The correlation of IL-8 and IL-18 gene polymorphisms with colorectal cancer (CRC) was investigated by previous studies, though the results remained conflicting. Thus, the meta-analysis was performed to investigate the association of IL-8 -251T>A and IL-18 -607C>A polymorphisms with CRC risk.

METHODS

A comprehensive search of the PubMed, Web of Science, CNKI, SciELO, and Wanfang databases was performed up to February 20, 2020. The strength of the associations was calculated with odds ratios (ORs) and their corresponding 95% of confidence intervals (CIs).

RESULTS

A total of 16 case-control studies including 13 studies with 3908 cases and 5005 controls on IL-8 -251T>A polymorphism and three studies with 396 cases and 560 controls on IL-18 -607C>A polymorphism were selected. Pooled data revealed that the IL-8 -251T>A and IL-18 -607C>A polymorphisms were not significantly associated with an increased risk of CRC in global population. When stratified by ethnicity, source of controls, sample size, and Hardy-Weinberg equilibrium (HWE), there were still no significant association between IL-8 -251T>A polymorphism and risk of CRC.

CONCLUSIONS

Our results revealed that the IL-8 -251T>A and IL-18 -607C>A polymorphisms were not associated with an increased susceptibility to CRC. We strongly call for further studies with larger sample sizes and different ethnicities to confirm our findings.

Single Nucleotide Variants Associated with Colorectal Cancer Among Iranian Patients: A Narrative Review

Colorectal cancer has been considered as one of the complicated multi-stage processes after adenoma-carcinoma sequence. Therefore, studies of the molecular dysregulation basis could present information on the recognition of the potent biomarkers and treatment targets for this disease. Even though outcomes of the patients with colorectal cancer have been improved largely with current annual screening plans, it is necessary to have reliable prognostic biomarkers because of the disease heterogeneity. There is a significant relationship between SNP in IL1RN* 2 (IL1ra), −509 C/T (TGFB1), rs11556218 T>G and rs4778889 T/C (IL16), miRNA-binding site polymorphisms in IL16, rs4464148 (SMAD7), rs6983267 (EGF), GSTT1, TACG haplotype (CTLA4), 1793G> A (MTHFR), Leu/Leu genotype of (EXO1), −137 G/C (IL18), C/T genotype (XRCC3), I3434T (XRCC7), MGMT, C3435T (MDR1), ff genotype of FokI, 677CT+TT (MTHFR), G2677T/A (MDR1) and CRC. Increased risk has been observed in VDR ApaI genotype “aa”. Finally, the protective effect has been explored in the TACA haplotype (CTLA4). According to the findings, the genetic polymorphisms in the immunity-associated genes are related to the CRC amongst the Iranian patients. Therefore, more large-scale functional investigations are necessary for confirming the results.

Emerging Roles for Interleukin-18 in the Gastrointestinal Tumor Microenvironment

Interleukin (IL)-18, a member of the IL-1 family of cytokines, has emerged as a key regulator of mucosal homeostasis within the gastrointestinal tract. Like other members of this family, IL-18 is secreted as an inactive protein and is processed into its active form by caspase-1, although other contributors to precursor processing are emerging.Numerous studies have evaluated the role of IL-18 within the gastrointestinal tract using genetic or complementary pharmacological tools and have revealed multiple roles in tumorigenesis. Most striking among these are the divergent roles for IL-18 in colon and gastric cancers. Here, we review our current understanding of IL-18 biology and how this applies to colorectal and gastric cancers.

Dual roles of IL-18 in colitis through regulation of the function and quantity of goblet cells

The main aim of the present study was to investigate the dual roles and mechanism of interleukin (IL)‑18 in dextran sulfate sodium (DSS)‑induced colitis. Firstly, meta‑analysis was used to explore whether the levels of IL‑18 were different in patients with colon cancer or inflammatory bowel disease. The results demonstrated that IL‑18 (rs187238, ‑137G/C) increased the incidence rate of colon cancer in patients, while IL‑18 (rs187238, ‑137G/C) decreased the incidence rate of ulcerative colitis or Crohn's disease in patients. Therefore, IL‑18 (rs187238, ‑137G/C) may have a dual function in colitis. Next, the functional role of IL‑18 in colitis was further investigated, by use of a DSS‑induced colitis mouse model. Pre‑treatment of the mice with IL‑18 increased body weight, augmented colon length, reduced inflammatory infiltration, promoted mucin (Muc)‑2 expression, increased the function and quantity of goblet cells and increased the mRNA levels of resistin‑like molecule (RELM) β and trefoil factor family (TFF) 3 in mice with DSS‑induced colitis, through the IL‑22/STAT3 pathway. By contrast, treatment with IL‑18 at later stages of the disease reduced body weight, decreased colon length, enhanced inflammatory infiltration and reduced Muc‑2 expression, decreased the function and quantity of goblet cells and inhibited the mRNA levels of RELMβ and TFF3 in mice with DSS‑induced colitis. In conclusion, IL‑18 served a dual function in colitis by regulating the function of goblet cells. The anti‑inflammatory effects of IL‑18 were observed in the early stage of colitis‑induced inflammation, while the pro‑inflammatory effects were observed in the later stages of the disease.

Predictive value of IL-18 and IL-10 in the prognosis of patients with colorectal cancer

Predictive value of serum interleukin 10 (IL-10) and interleukin 18 (IL-18) expression in patients with colorectal cancer (CRC) was investigated. This study retrospectively analyzed the medical records of 146 patients with CRC admitted to the Binzhou Medical University Hospital as the study group, and collected the physical examination data of 82 volunteers as the control group. The expression levels of IL-10 and IL-18 in the serum were measured by enzyme-linked immunosorbent assay (ELISA). A 60-month follow-up on patients in the study group was performed to make records of their prognosis. The expressions of IL-10 and IL-18 were statistically different in patients with different Dukes stages, tumor sizes, histological grades, and different situations of distant metastasis of cancer cells (P<0.05); with a gradual downward trend following the operation. The expression levels of serum IL-10 and IL-18 in the study group 7 days after the operation were lower than the levels before the operation (P<0.05), and the expression levels of IL-10 and IL-18 of patients in the study group on the day of discharge were lower than the expression levels 7 days after the operation (P<0.05). The expressions of IL-10 and IL-18 of patients with reoccurred CRC after the operation were significantly higher than that of patients without recurrence of CRC in the study group (P<0.05). Thus, IL-10 and IL-18 are highly expressed in the serum of CRC patients, which makes IL-10 and IL-18 useful to serve as indicators to determine the prognosis of CRC patients. The lower the expression levels of IL-10 and IL-18, the lower the cancer recurrence rate, the better the prognosis and the longer the survival time.

Contribution of Inflammatory Cytokine Interleukin-18 Genotypes to Renal Cell Carcinoma

Interleukin-18 (IL-18) is a multi-functional immuno-mediator in the development and progression of many types of infectious and inflammatory diseases. In this study, we evaluated the contribution of IL-18 genotypes to renal cell carcinoma (RCC) in Taiwan via the genotyping of IL-18 -656 (A/C), -607 (A/C), and -137 (G/C). Moreover, we analyzed their interactions with smoking, alcohol drinking, hypertension, and diabetes status. The results showed an association of the AC and CC genotypes of IL-18 -607 with a significant decrease in the risk of RCC compared with the AA genotype (odds ratio (OR) = 0.44 and 0.35, 95% confidence interval (CI) = 0.27⁻0.72 and 0.18⁻0.66, p = 0.0008 and 0.0010, respectively). Furthermore, a significantly lower frequency of the C allele at -607 was observed in the RCC group (35.3% vs. 49.8%; OR = 0.53; 95% CI = 0.35⁻0.71, p = 0.0003). However, IL-18 -656 and -137 did not exhibit a likewise differential distribution of these genotypes between the control and case groups. Stratifying the population according to smoking, alcohol drinking, hypertension, and diabetes status revealed a different distribution of IL-18 -607 genotypes among non-smokers, non-drinkers, and patients without diabetes, but not among smokers, drinkers, or patients with diabetes. These findings suggest that IL-18 -607 genotypes may play a role in the etiology and progression of RCC in Taiwan and may serve as a useful biomarker for early detection.

Could the inhibition of IL-17 or IL-18 be a potential therapeutic opportunity for gastric cancer?

Chronic inflammation is recognized as a key tumor-promoting factor in a number of epithelial cancers, including gastric cancer (GC). The production of pro-inflammatory cytokines in the tumor microenvironment by both the innate and the adaptive immune response can activate signaling pathways that are associated with increased cell survival and proliferation of cancer cells. Among the cytokines that have most commonly been linked to inflammation-associated cancers, are the Th17 cell-associated cytokines IL-17A, IL-23, IL-22, and the IL-1 family members IL-1β and IL-18. However, whether their contribution to inflammation-associated cancers is universal, or specific to individual types of cancers, remains to be elucidated. This review will explore our current understanding of the known roles of these cytokines in gastritis and discuss how their therapeutic inhibition may be useful for GC.

Inflammasome Adaptor ASC Suppresses Apoptosis of Gastric Cancer Cells by an IL18-Mediated Inflammation-Independent Mechanism

Inflammasomes are key regulators of innate immunity in chronic inflammatory disorders and autoimmune diseases, but their role in inflammation-associated tumorigenesis remains ill-defined. Here we reveal a protumorigenic role in gastric cancer for the key inflammasome adaptor apoptosis-related speck-like protein containing a CARD (ASC) and its effector cytokine IL18. Genetic ablation of ASC in the gp130^F/F spontaneous mouse model of intestinal-type gastric cancer suppressed tumorigenesis by augmenting caspase-8-like apoptosis in the gastric epithelium, independently from effects on myeloid cells and mucosal inflammation. This phenotype was characterized by reduced activation of caspase-1 and NF-κB activation and reduced expression of mature IL18, but not IL1β, in gastric tumors. Genetic ablation of IL18 in the same model also suppressed gastric tumorigenesis, whereas blockade of IL1β and IL1α activity upon genetic ablation of the IL1 receptor had no effect. The specific protumorigenic role for IL18 was associated with high IL18 gene expression in the gastric tumor epithelium compared with IL1β, which was preferentially expressed in immune cells. Supporting an epithelial-specific role for IL18, we found it to be highly secreted from human gastric cancer cell lines. Moreover, IL18 blockade either by a neutralizing anti-IL18 antibody or by CRISPR/Cas9-driven deletion of ASC augmented apoptosis in human gastric cancer cells. In clinical specimens of human gastric cancer tumors, we observed a significant positive correlation between elevated mature IL18 protein and ASC mRNA levels. Collectively, our findings reveal the ASC/IL18 signaling axis as a candidate therapeutic target in gastric cancer.Significance: Inflammasome activation that elevates IL18 helps drive gastric cancer by protecting cancer cells against apoptosis, with potential implications for new therapeutic strategies in this setting. Cancer Res; 78(5); 1293-307. ©2017 AACR.

Genetic host factors in Helicobacter pylori-induced carcinogenesis: Emerging new paradigms

Helicobacter Pylori is a gram negative rod shaped microaerophilic bacterium that colonizes the stomach of approximately half the world's population. Infection with c may cause chronic gastritis which via a quite well described process known as Correas cascade can progress through sequential development of atrophic gastritis, intestinal metaplasia and dysplasia to gastric cancer. H. pylori is currently the only bacterium that is classified as a class 1 carcinogen by the WHO, although the exact mechanisms by which this bacterium contributes to gastric carcinogenesis are still poorly understood. Only a minority of H. pylori-infected patients will eventually develop gastric cancer, suggesting that host factors may be important in determining the outcome of H. pylori infection. This is supported by a growing body of evidence suggesting that the host genetic background contributes to risk of H. pylori infection and gastric carcinogenesis. In particular single nucleotide polymorphisms in genes that influence bacterial handling via pattern recognition receptors appear to be involved, further strengthening the link between host risk factors, H. pylori incidence and cancer. Many of these genes influence cellular pathways leading to inflammatory signaling, inflammasome formation and autophagy. In this review we summarize known carcinogenic effects of H. pylori, and discuss recent findings that implicate host genetic pattern recognition pathways in the development of gastric cancer and their relation with H. pylori.

Clinical Significance of Serum Interleukin-31 and Interleukin-33 Levels in Patients of Endometrial Cancer: A Case Control Study

Aims. Previous evidence has proved that interleukin-31 (IL-31) and interleukin-33 (IL-33) can be potential markers in some cancers' formulation. We aimed to determine the potential role of IL-31 and IL-33 in prognosis of endometrial cancer patients. Methods. Serum samples were collected from 160 patients with endometrial cancer and 160 healthy controls. The ELISA kits (Raybio® Systems) specific for human IL-31 and human IL-33 were used. Serum levels of tumor markers (CEA, CA-125, and CA19-9) were measured by chemiluminescence immunoassay. A two-side P value < 0.05 was indicated to be significant. Results. Serum levels of IL-31 and IL-33 in patients were significantly elevated compared to those of healthy controls. The interleukin levels were also related to clinical characteristics, including tumor stages, depth of invasion, and existence of node metastases and distant metastases. The sensitivity and specificity of IL-31 and IL-33 were higher than the counterparts of tumor markers, both separately and in combination of IL-31, IL-33, and the clinical markers. Conclusions. This report is the first one mentioning the possible association between serum IL-31 and IL-33 and endometrial cancer. With their sensitivity and specificity, the interleukins may be useful biomarkers for endometrial cancer's prognosis.

A gene-disease association study of IL18 in thyroid cancer: genotype and haplotype analyses

Thyroid cancer is the most common malignancy of the endocrine system, and genetic factors have been shown to be associated with its risk. Interleukin-18 (IL-18) is a pleiotropic pro-inflammatory cytokine that induces IFN-γ production and is involved in T helper type 1 development. To determine the role of IL-18 gene in thyroid cancer susceptibility, we conducted a case-control study, and genotyped five single nucleotide polymorphisms (SNPs) in IL-18 gene (-656 G/T (rs1946519), -607 C/A (rs1946518), and -137 G/C (rs187238) in the promoter region and +113 T/G (rs360718) and +127 C/T (rs360717) in 5'-untranslated region) in 105 patients with thyroid cancer and 148 healthy controls from Iranian population. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and allele-specific primer-PCR were used for genotyping. The association of different genotypes with thyroid cancer, tumor type, and the tumor stage was analyzed. Comparing all of the patient population with the controls, TT genotype at position -656 G/T was observed to be associated with a significantly increased risk of thyroid cancer [31/105 (30.1 %) vs 19/148 (13.1 %), p = 0.002, OR 2.90, CI 1.40-5.70]. No association with thyroid cancer was found at other positions (-607 C/A, -137 G/C, +113 T/G, and +127 C/T). Excluding the patients with medullary carcinoma, and including only the ones with thyroid cancer derived from the follicular epithelium, nearly the same results were observed regarding the genotypes at position -656 G/T. Furthermore, significantly decreased risk of thyroid cancer derived from the follicular epithelium was observed upon inheritance of the homozygote genotype (CC) at position +127 C/T (40/94 (42.5 %) versus 84/148 (56.8 %) in patients and controls, respectively (OR 0.56, 95 % CI for OR 0.32-0.98, p = 0.04). Haplotype analysis indicated that among 32 possible haplotypes, TAGTT haplotype frequency was significantly higher in patients than in controls [12/188 (6.4 %) vs 2/292 (0.7 %), p = 0.0008] and this difference resisted Bonferroni correction (n = 19) and significant level set at 0.003. Nearly the same results were observed after excluding the patients with medullary carcinoma. No association was found between the SNPs and the stage of tumor. Our results suggest the increased susceptibility to thyroid cancer in subjects with TT genotype at position -656 G/T of the promoter of IL-18 gene, as well as TAGTT haplotype emerged from five studied SNPs in IL-18 gene. The data also suggest that the inheritance of +127 CC genotype may protect individuals from thyroid cancer derived from follicular epithelium.

IL-18 polymorphisms in hepatitis B virus related liver disease

Interleukine-18 (IL-18) was originally called interferon (INF-γ) inducing factor and plays a critical dual role in Th1 polarization and viral clearance. We aimed to explore whether single-nucleotide promoter polymorphisms (SNPs) are associated with the outcome of hepatitis B virus (HBV) infection. 271 HBV infected patients were recruited in this study out of these 109 were spontaneously recovered and 162 were diagnosed to be having persistent HBV infection which includes 48 chronic hepatitis, 84 liver cirrhosis, 30 HCC cases and were compared with 280 healthy controls. IL-18 promoter genotyping was performed with sequence-specific primers. The results demonstrated the significant involvement of genotype AA at position -607 in healthy controls (38.6%) when compared to cases (26.0%) (OR=0.54 (0.385-0.797)) and also associated with spontaneous clearance (37.6%) compared to persistent HBV infections (17.9%) (OR=2.76 (1.582-4.832)). Whereas, genotype CC at position -607 in cases (18.0%) when compared to healthy controls (6.7%) (OR=3.03 (1.734-5.303)) also associated with persistent HBV infections (24.1%) compared to spontaneous clearance (9.2%) (OR=0.31 (0.151-0.67)). And genotype GC at position -137 in cases (49.5%) compared to healthy controls (38.5%) (OR=1.55 (1.11-2.18)). Whereas, genotype GG at position -137 in healthy controls (56.8%) compared to cases (45.4%) (OR=0.63 (0.451-0.885)). No significant difference at position -137 was observed between spontaneous clearance and persistent HBV infections. These polymorphisms of the IL-18 gene promoter region at position -607 and -137 could be associated with different outcomes of HBV infection. The people with allele A at position -607 may be protected against HBV infection; moreover AA genotype is associated with spontaneous clearance.

Clinical significance of serum interleukin-18 (IL-18) levels in patients with gastric cancer

An inappropriate production of interleukin-18 (IL-18) contributes to the pathogenesis of malignancies and may influence the clinical outcome of patients. The objective of this study was to determine the clinical significance of the serum levels of IL-18 in patients with gastric cancer. A total of 63 patients with a pathologically confirmed diagnosis of gastric cancer were enrolled into this study. Serum IL-18 concentrations were determined by the solid-phase sandwich Elisa method. Age- and sex-matched 30 healthy controls were included in the analysis. The median age at diagnosis was 62 years, range 28 to 82 years. The baseline serum IL-18 levels of the gastric cancer patients were a significantly higher than those in the control group (median values 1436.4 vs. 638.4 pg/mL, respectively, P<0.001). The known clinical variables including age of patient, gender, site of lesion, histology, histological grade, stage of disease, and serum tumor markers such as LDH, CEA, and CA 19.9 were not found to be correlated with serum IL-18 concentrations (P>0.05). Moreover, no correlation was found between serum IL-18 level and response to chemotherapy (P=0.34). Serum IL-18 concentration was also found no prognostic role on survival (P=0.21). In conclusion, serum levels of IL-18 may have a good diagnostic marker in patients with gastric cancer. However, its predictive and prognostic values were not determined.

Helicobacter pylori-induced IL-1β secretion in innate immune cells is regulated by the NLRP3 inflammasome and requires the cag pathogenicity island

Infection with the gram-negative bacterium Helicobacter pylori is the most prevalent chronic bacterial infection, affecting ∼50% of the world's population, and is the main risk factor of gastric cancer. The proinflammatory cytokine IL-1β plays a crucial role in the development of gastric tumors and polymorphisms in the IL-1 gene cluster leading to increased IL-1β production have been associated with increased risk for gastric cancer. To be active, pro-IL-1β must be cleaved by the inflammasome, an intracellular multiprotein complex implicated in physiological and pathological inflammation. Recently, H. pylori was postulated to activate the inflammasome in murine bone marrow-derived dendritic cells; however, the molecular mechanisms as well as the bacterial virulence factor acting as signal 2 activating the inflammasome remain elusive. In this study, we analyzed the inflammasome complex regulating IL-1β upon H. pylori infection as well as the molecular mechanisms involved. Our results indicate that H. pylori-induced IL-1β secretion is mediated by activation of the nucleotide-binding oligomerization domain-like receptor family, pyrin domain-containing 3 inflammasome. We also show that reactive oxygen species, potassium efflux, and lysosomal destabilization are the main cellular mechanisms responsible of nucleotide-binding oligomerization domain family, pyrin domain-containing 3 inflammasome activation upon H. pylori infection, and identify vacuolating cytotoxin A and cag pathogenicity island as the bacterial virulence determinants involved. Moreover, in vivo experiments indicate an important role for the inflammasome in the onset and establishment of H. pylori infection and in the subsequent inflammatory response of the host.

Pattern-recognition receptors and gastric cancer

Chronic inflammation has been associated with an increased risk of several human malignancies, a classic example being gastric adenocarcinoma (GC). Development of GC is known to result from infection of the gastric mucosa by Helicobacter pylori, which initially induces acute inflammation and, in a subset of patients, progresses over time to chronic inflammation, gastric atrophy, intestinal metaplasia, dysplasia, and finally intestinal-type GC. Germ-line encoded receptors known as pattern-recognition receptors (PRRs) are critical for generating mature pro-inflammatory cytokines that are crucial for both Th1 and Th2 responses. Given that H. pylori is initially targeted by PRRs, it is conceivable that dysfunction within genes of this arm of the immune system could modulate the host response against H. pylori infection, and subsequently influence the emergence of GC. Current evidence suggests that Toll-like receptors (TLRs) (TLR2, TLR3, TLR4, TLR5, and TLR9), nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) (NOD1, NOD2, and NLRP3), a C-type lectin receptor (DC-SIGN), and retinoic acid-inducible gene (RIG)-I-like receptors (RIG-I and MDA-5), are involved in both the recognition of H. pylori and gastric carcinogenesis. In addition, polymorphisms in genes involved in the TLR (TLR1, TLR2, TLR4, TLR5, TLR9, and CD14) and NLR (NOD1, NOD2, NLRP3, NLRP12, NLRX1, CASP1, ASC, and CARD8) signaling pathways have been shown to modulate the risk of H. pylori infection, gastric precancerous lesions, and/or GC. Further, the modulation of PRRs has been suggested to suppress H. pylori-induced inflammation and enhance GC cell apoptosis, highlighting their potential relevance in GC therapeutics. In this review, we present current advances in our understanding of the role of the TLR and NLR signaling pathways in the pathogenesis of GC, address the involvement of other recently identified PRRs in GC, and discuss the potential implications of PRRs in GC immunotherapy.

The -137G/C Polymorphism in Interleukin-18 Gene Promoter Contributes to Chronic Lymphocytic and Chronic Myelogenous Leukemia Risk in Turkish Patients

Objective:

Interleukin-18 (IL-18) is a cytokine that belongs to the IL-1 superfamily and is secreted by various immune and nonimmune cells. Evidence has shown that IL-18 has both anticancer and procancer effects. The aim of this study was to evaluate the relationship between IL-18 gene polymorphisms and susceptibility to chronic lymphocytic leukemias (CLL) and chronic myelogenous leukemias (CML) in Turkish patients.

Materials and Methods:

The frequencies of polymorphisms (rs61667799(G/T), rs5744227(C/G), rs5744228(A/G), and rs187238(G/C)) were studied in 20 CLL patients, 30 CML patients, and 30 healthy individuals. The genotyping was performed by polymerase chain reaction and DNA sequencing analysis.

Results:

Significant associations were detected between the IL-18 rs187238(G/C) polymorphism and chronic leukemia. A higher prevalence of the C allele was found in CML cases with respect to controls. The GC heterozygous and CC homozygous genotypes were associated with risk of CML when compared with controls. However, prevalence of the C allele was not significantly high in CLL cases with respect to controls. There was only a significant difference between the homozygous CC genotype of CLL patients and the control group; thus, it can be concluded that the CC genotype may be associated with the risk of CLL. Based on our data, there were no significant associations between the IL-18 rs61667799(G/T), rs5744227(C/G), or rs5744228(A/G) polymorphisms and CLL or CML.

Conclusions:

IL-18 gene promoter rs187238(G/C) polymorphism is associated with chronic leukemia in the Turkish population. However, due to the limited number of studied patients, these are preliminary results that show the association between -137G/C polymorphism and patients (CLL and CML). Further large-scale studies combined with haplotype and expression analysis are required to validate the current findings.

The -607C/A polymorphisms in interleukin-18 gene promoter contributes to cancer risk: evidence from a meta-analysis of 22 case-control studies

BACKGROUND

Several observational studies have investigated the association between -607 C/A polymorphism of IL-18 gene and cancer risk; however, the results were inconsistent. Therefore, we performed a meta-analysis to derive a more precise estimation of the association to help us better understand the relationship between -607 C/A polymorphism of IL-18 gene promoter and risk of cancer.

METHODS

A literature search was carried out using PubMed, EMBASE, and China National Knowledge Infrastructure (CNKI) database between January 1966 and February 2013. Fixed-effect and random-effect models were used to estimate the pooled odds ratio (OR) and the corresponding 95% confidence intervals (CIs).

RESULTS

A total of 22 case-control studies including 4100 cancer cases and 4327 controls contributed to the analysis. Significant association between -607C/A polymorphism in IL-18 gene promoter and cancer risk was observed (CA vs CC:OR =1.221, 95% CI: 1.096, 1.360; P(heterogeneity)=0.219; AA/CA vs. CC:OR =1.203, 95% CI: 1.057, 1.369; P(heterogeneity)=0.064). In the subgroup analysis by ethnicity, -607C/A polymorphism significantly increased risk of cancer among Asian population (AA/CA vs. CC:OR =1.197, 95% CI: 1.023,1.401; P(heterogeneity)=0.088); however, no significant association was found in Caucasian or African population. The -607C/A polymorphism was associated with a significantly increased risk of nasopharyngeal carcinoma (CA vs CC:OR =1.330, 95% CI: 1.029,1.719; P(heterogeneity)=0.704; AA/CA vs. CC:OR =1.323, 95% CI: 1.037,1.687; P(heterogeneity)=0.823) and esophageal cancer (AA/CA vs. CC:OR =1.289, 95% CI: 1.002,1.658; P(heterogeneity)=0.700).

CONCLUSIONS

The present meta-analysis suggests that the -607C/A polymorphisms in IL-18 gene promoter is associated with a significantly increased risk of cancer, especially for nasopharyngeal carcinoma and esophageal cancer and in Asian population. More studies with larger sample size, well controlled confounding factors are warranted to validate this association.

Association of interleukin-18 gene promoter -607 C>A and -137G>C polymorphisms with cancer risk: a meta-analysis of 26 studies

BACKGROUND

Evidence suggest that IL-18 gene polymorphisms may be risk factors for several cancers. Increasing studies investigating the association between IL-18 gene promoter polymorphisms (-607 C>A and -137G>C) and cancer risk have yielded conflicting results.

METHODOLOGY/PRINCIPAL FINDINGS

We performed a meta-analysis of 26 studies including 4096 cases and 5222 controls. We assessed the strength of the association of IL-18 gene promoter -607 C>A and -137G>C polymorphisms with cancer risk and performed sub-group analyses by cancer types, ethnicities, source of controls and sample size. The pooled results revealed a significant increased risk of cancer susceptibility for -607 C>A (CA vs. CC: OR = 1.19, 95%CI: 1.04, 1.37, Pheterogeneity = 0.033; CA/AA vs. CC: OR = 1.17, 95% CI: 1.01, 1.34, Pheterogeneity = 0.007), but no significant association for -137 G>C was observed with overall cancer risk. Sub-group analyses revealed that an increased risk of nasopharyngeal carcinoma was both found for -607 C>A (CA/AA vs. CC: OR = 1.32, 95% CI: 1.04, 1.69, Pheterogeneity = 0.823) and -137G>C (GC/CC vs. GG: OR = 1.57, 95%CI: 1.26, 1.96, Pheterogeneity = 0.373). Consistent with the results of the genotyping analyses, the -607A/-137C and -607C/-137C haplotypes were associated with a significantly increased risk of nasopharyngeal carcinoma as compared with the -607C/-137G haplotype (-607A/-137C vs. -607C/-137G: OR = 1.26, 95%CI: 1.13, 1.40; Pheterogeneity = 0.569; -607C/-137C vs. -607C/-137G: OR = 1.14, 95%CI: 1.03, 1.27; Pheterogeneity = 0.775). As for gastrointestinal cancer, we also found that -607 C>A polymorphism was significantly associated with increased cancer risk (CA/AA vs. CC: OR = 1.25, 95% CI: 1.05, 1.50, Pheterogeneity = 0.458). Further sub-group analysis revealed that -137G>C polymorphism contributed to cancer risk in Asians but not in Caucasians (GC/CC vs. GG: OR = 1.31, 95%CI: 1.05, 1.64, Pheterogeneity<0.001).

CONCLUSIONS

The meta-analysis results suggest that IL-18 gene promoter -607 C>A polymorphism is significantly associated with overall cancer risk, especially in nasopharyngeal carcinoma and gastrointestinal cancer; and the -137 G>C polymorphism is associated with increased overall cancer risk in Asian populations and also significantly increases the risk of nasopharyngeal carcinoma.

Opposing Functions of Classic and Novel IL-1 Family Members in Gut Health and Disease

In addition to their well-established role(s) in the pathogenesis of gastrointestinal (GI)-related inflammatory disorders, including inflammatory bowel disease (IBD) and inflammation-associated colorectal cancer (CRC), emerging evidence confirms the critical involvement of the interleukin-1 (IL-1) cytokine family and their ligands in the maintenance of normal gut homeostasis. In fact, the paradigm that IBD occurs in two distinct phases is substantiated by the observation that classic IL-1 family members, such as IL-1, the IL-1 receptor antagonist (IL-1Ra), and IL-18, possess dichotomous functions depending on the phase of disease, as well as on their role in initiating vs. sustaining chronic gut inflammation. Another recently characterized IL-1 family member, IL-33, also possesses dual functions in the gut. IL-33 is upregulated in IBD and potently induces Th2 immune responses, while also amplifying Th1-mediated inflammation. Neutralization studies in acute colitis models, however, have yielded controversial results and recent reports suggest a protective role of IL-33 in epithelial regeneration and mucosal wound healing. Finally, although little is currently known regarding the potential contribution of IL-36 family members in GI inflammation/homeostasis, another IL-1 family member, IL-37, is emerging as a potent anti-inflammatory cytokine with the ability to down-regulate colitis. This new body of information has important translational implications for both the prevention and treatment of patients suffering from IBD and inflammation-associated CRC.

Immunotherapeutic approach for better management of cancer--role of IL-18

Interleukin-18 (IL-18) is an immune-stimulatory cytokine with antitumor activity in preclinical models. It plays pivotal roles in linking inflammatory immune responses and tumor progression and is a useful candidate in gene therapy of lymphoma or lymphoid leukemia. A phase I study of recombinant human IL-18 (rhIL-18) in patients with advanced cancer concluded that rhIL-18 can be safely given in biologically active doses to patients with advanced cancer. Some viruses can induce the secretion of IL-18 for immune evasion. The individual cytokine activity might be potentiated or inhibited by combinations of cytokines. Here we focus on combinational effects of cytokines with IL-18 in cancer progression. IL-18 is an important non-invasive marker suspected of contributing to metastasis. Serum IL-18 may a useful biological marker as independent prognostic factor of survival. In this review we cover roles of IL-18 in immune evasion, metastasis and angiogenesis, applications for chemotherapy and prognostic or diagnostic significance.

The -137G>C polymorphism in interleukin-18 promoter region and cancer risk: evidence from a meta-analysis of 21 studies

Interleukin-18 (IL-18) is a key cytokine responsible for immune response and involved in the process of cancer development. The association of -137G>C polymorphism in the promoter region of IL-18 with cancer risk is still elusive based on current genetic association studies. We performed this meta-analysis to determine whether the -137G>C polymorphism is associated with cancer risk. A comprehensive search was conducted for databases of PubMed, EMBASE, and China National Knowledge Infrastructure. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate the association strength. Publication bias was detected by Egger's and Begg's test. Twenty-one eligible studies including 3,498 cancer patients and 5,222 controls were identified and analyzed. In the overall analysis, no significant association between -137G>C polymorphism and cancer risk was observed. In the sub-group analyses of ethnicities, the -137G>C polymorphism significantly increased cancer risk in Asian population (GC/CC vs. GG: OR = 1.313, 95% CI = 1.053-1.638, heterogeneity P < 0.001) but not in Caucasian population. Further stratified analyses showed that the variant -137C allele was significantly associated with increased risk of nasopharyngeal carcinoma (C vs. G: OR = 1.484, 95% CI = 1.193-1.847, heterogeneity P = 0.213). No publication bias was detected. We provide evidence that the -137G>C polymorphism in IL-18 promoter region significantly increases cancer risk in Asian population but not in Caucasian population, and the variant -137C allele is associated with increased risk of nasopharyngeal carcinoma.

The association of interleukin-18 promoter polymorphisms and serum levels with duodenal ulcer, and their correlations with bacterial CagA and VacA virulence factors

BACKGROUND

We analyzed the impact of interleukin (IL)-18 promoter polymorphisms on IL-18 serum levels in Helicobacter pylori-infected duodenal ulcer (DU) patients and healthy asymptomatic (AS) carriers. We also aimed to determine the association of the H. pylori virulence factors CagA and VacA antibodies with serum concentrations of IL-18 in order to elucidate any correlation between them.

METHODS

Three groups of patients were enrolled: DU patients (67 individuals), AS carriers (48 individuals), and H. pylori-negative subjects (26 individuals). Serum concentrations of IL-18 were determined by ELISA. Patient sera were tested by Western blot method to determine the presence of serum antibodies to bacterial CagA and VacA. Genotyping of IL-18 promoter polymorphisms at positions - 137G/C and - 607C/A were performed by allele-specific primer PCR protocol.

RESULTS

Our study revealed that serum IL-18 levels are positively influenced by CagA-positive H. pylori strains, so that maximum levels of IL-18 were detected in DU patients with the CagA(+) phenotype, regardless of the presence of the anti-VacA antibody. Regarding IL-18 promoter polymorphisms, the AA genotype and A allele at position - 607C/A were found to be significantly lower in DU patients than in AS carriers and H. pylori-negative subjects (p = 0.032 and 0.043, respectively).

CONCLUSIONS

The IL-18 - 607C variant was associated with higher levels of serum IL-18 and an increased risk of DU. Moreover, our findings indicated that serum concentrations of IL-18 were influenced by CagA factor, irrespective of the VacA status, suggesting that high levels of IL-18 in CagA-positive subjects predisposes to susceptibility to DU.

Alleles and genotypes of polymorphisms of IL-18, TNF-α and IFN-γ are associated with a higher risk and severity of hepatocellular carcinoma (HCC) in Brazil

Hepatocellular carcinoma (HCC) is a primary malignant tumor of the liver. We evaluated the association of alleles and genotypes of polymorphisms of IL-18 (-607C/A and -137G/C), IFN-γ (+874T/A) and TNF-α (-238G/A and -308G/A) with the risk and severity of HCC. One-hundred-and-twelve patients with HCC and 202 healthy controls were studied. Single nucleotide polymorphisms (SNPs) were amplified by PCR with specific primers and the products were submitted to polyacrylamide gel electrophoresis and stained with silver. We evaluated tumor presentation, tumor size and presence of metastasis. Significant higher risk of HCC was associated with: alleles IL-18 -607(*)A (P=0.0235; OR=1.48; 95%CI=1.06-2.08); TNF-α -238(*)A (P=0.0025; OR=2.12; 95%CI=1.32-3.40) and TNF-α -308(*)A (P=0.0351; OR=1.82; 95%CI=1.07-3.08); and genotypes IL-18-607AA (P=0.0048; OR=3.03; 95%CI=1.40-6.55); TNF-α -238GA (P=0.0011; OR=2.44; 95%CI=1.45-4.12); and TNF-α -308GA (P=0.0031; OR=2.51; 95%CI=1.39-4.51). Significant association was found between multinodular HCC and IL-18 -607(*)C allele (P=0.029; OR=2.40, 95%CI: 1.09-5.28), and IL-18 -607CC genotype (P=0.028; OR=3.5, 95%CI: 1.24-9.86). Diffuse HCC was significantly associated with IFN-γ +874TA genotype (P=0.044; OR=3.6, 95%CI: 1.03-12.47). The IL-18 -137(∗)C allele showed a significant association with the presence of metastasis. Thus, IL-18 -607(*)A and TNF-α (-238(*)A and -308(*)A) alleles may confer susceptibility to HCC, while IL-18 -607(*)C and -137(*)C alleles more severe disease.

Gender-specific association of the interleukin 18 gene with symptomatic gallstone disease

BACKGROUND AND AIM

Symptomatic gallstone disease (SGSD) induced several inflammatory responses and affected extrahepatic bile ducts. Although the pathology and environmental risk factors of gallstone disease are well documented, immune or inflammatory responses in SGSD development are still inconclusive. Interleukin 18 (IL18) is a pro-inflammatory cytokine that plays an important role in immune, infectious, and inflammatory diseases because of the induction of interferon-γ. In this study, we investigated whether polymorphisms of the IL18 gene were associated with SGSD susceptibility.

METHODS

Genomic DNA was isolated from the whole blood samples of 445 patients with SGSD and 1121 gallstone-free controls. The IL18 rs549908T>G, rs5744247C>G, rs187238G>C, rs1946518T>G, and rs360719A>G polymorphisms were genotyped using predeveloped TaqMan allelic discrimination assay.

RESULTS

We found IL18 rs5744247G allele conferred protection against SGSD in female patients (odds ratio = 0.75, corrected P-value = 0.015). Haplotype analysis revealed that TGGTA protected females from SGSD development (odds ratio = 0.75, corrected P-value = 0.02).

CONCLUSIONS

Based on our findings, IL18 rs5744247C>G polymorphism could be a potential genetic marker to predict SGSD susceptibility in Han Chinese women.

Specific inflammasomes in complex diseases

Blocking the cytokines Interleukin-1beta (IL-1β) and Interleukin-18 (IL-18) benefits a diverse range of inflammatory pathologies. In each of these diseases, different cytoplasmic innate immune receptors nucleate individual protein complexes known as inflammasomes, to regulate the production of active IL-1β or IL-18. This review will outline the complex diseases where these cytokines are pathogenic, and explain which inflammasome(s) may be responsible. For example, inflammasomes nucleated by NLRP3 and NLRP6 integrate signals from metabolic and commensal systems contributing to metabolic dysfunction and type 2 diabetes. On the other hand, NLRP1 and AIM2 are more broadly implicated in autoimmunity and allergy. Furthermore, each inflammasome has unique roles in pathogen recognition, which may determine the outcome of polymicrobial infection and link different infectious co-morbidities to chronic inflammatory disease. We can now imagine a time when targeted inflammasome inhibitors will be employed in the clinic, tailoring treatments to particular diseases, and perhaps individual patients.

Mitochondrial copy number is associated with colorectal cancer risk

BACKGROUND

Mitochondria are eukaryotic organelles responsible for energy production. Quantitative changes in human mitochondrial DNA (mtDNA) copy number have been implicated in various cancer types. Data from prospective cohort studies on mtDNA copy number and colorectal cancer risk have been lacking.

METHODS

We evaluated the association between mtDNA copy number in peripheral blood and colorectal cancer risk in a nested case-control study of 422 colorectal cancer cases (168 cases with pre-diagnostic blood and 254 cases with post-diagnostic blood) and 874 controls who were free of colorectal cancer among participants of the Singapore Chinese Health Study. The relative mtDNA copy number was measured using real-time PCR. Unconditional logistic regression methods were employed to examine the association between mtDNA copy number and colorectal cancer risk.

RESULTS

There was a U-shaped relationship between the relative mtDNA copy number and colorectal cancer risk. Compared with the 2nd quartile, the OR (95% confidence intervals) for subjects in the lowest and highest quartiles of relative mtDNA copy numbers were 1.81 (1.13-2.89) and 3.40 (2.15-5.36), respectively (P(curvilinearity) <0.0001). This U-shaped relationship was present in both men and women, similar for colon cancer and rectal cancer, and independent of the timing of blood draw with regard to cancer diagnosis.

CONCLUSIONS

This is the first prospectively designed study to show a U-shaped association between the relative mtDNA copy number and risk of colorectal cancer.

IMPACT

The findings of the present study support that mtDNA may play a critical role in the colorectal carcinogenesis in humans.

Serum interleukin-33 levels in patients with gastric cancer

BACKGROUND

Interleukin-33 (IL-33) is a novel member of the IL-1 family of cytokines, and it is closely related to IL-18, one of the best characterized members of the IL-1 family. It's been demonstrated that elevated levels of IL-18 are involved in a wide variety of tumors, especially in gastric cancer.

AIMS

The purpose of this study was to determine the correlations between serum IL-33 levels and the clinicopathologic features in gastric cancer patients.

METHODS

Serum samples were collected from 68 patients with gastric cancer and 57 controls. Serum IL-33 levels were measured by ELISA. Classical tumor markers of CEA and CA19-9 levels were routinely detected by chemiluminescence immunoassay. Western blot analysis was used to detect IL-33 expression in gastric cancer tissue samples and cell lines. The relationship between serum levels of IL-33 and clinical characteristics in patients was analyzed.

RESULTS

IL-33 levels in the serum of gastric cancer patients were significantly elevated in comparison with that of healthy volunteers. Furthermore, higher serum levels of IL-33 in gastric cancer patients were found to correlate with several poor prognostic factors like depth of invasion, distant metastasis and advanced stage (stage III/IV). On the other hand, serum IL-33 levels did not correlate with CEA and CA19-9. The expression of IL-33 protein was upregulated in carcinoma tissues in comparison with matched normal tissues, and no statistically significant difference was found between the four gastric cancer cell lines and human gastric epithelial cell line GES-1.

CONCLUSIONS

Serum IL-33 may be a useful biomarker for predicting the prognosis of gastric cancer.

Review and pooled analysis of studies on -607(C/A) and -137(G/C) polymorphisms in IL-18 and cancer risk

Interleukin-18 (IL-18) is a pleiotropic, pro-inflammatory cytokine with dual effects on tumor development and progression. The -607(C/A) and -137(G/C) polymorphisms in IL-18 gene region have been implicated in cancer risk; however, data from published studies with individually low statistical power are conflicting. To clarify the role of IL-18 -607(C/A) and -137(G/C) genotype in global cancer, we examined all the available published studies through a pooled analysis approach. Overall, IL-18 -607A allele was associated with increased total cancer risk when compared with -607C allele (OR=1.14, 95% CI=1.01-1.28, P=0.010), as well as in the heterozygote comparison (OR=1.10, 95% CI=1.04-1.15, P=0.256) and the dominant model (OR=1.07, 95% CI=1.03-1.11, P=0.124). Furthermore, IL-18 -137(G/C) polymorphism was associated with increased nasopharyngeal carcinoma risk. In the stratified analysis for -607(C/A) polymorphism, a significantly increased cancer risk in Asian population was found, as well as subgroup in source of control. Similar results were found in the stratified analysis for -137(G/C) polymorphism. Our pooled analysis supported that IL-18 is a good candidate for large-scale epidemiological case-control studies that may be a low-penetrance susceptibility biomarker for cancer.