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Regulatory Cytokine Gene Polymorphisms and Risk of Colorectal Carcinoma

Abstract:  It is well established that cancer arises in chronically inflamed tissue, and this is particularly notable in the gastrointestinal tract. Classic examples include Helicobacter pylori–associated gastric cancer, hepatocellular carcinoma, and inflammatory bowel disease–associated colorectal cancer. Growing evidence suggests that these associations might be not casual findings. Focusing on individual cytokines has generated evidence that anti‐inflammatory cytokine interleukin (IL)‐10 and transforming growth factor‐beta1 (TGF‐β1) may have a complex role in gastrointestinal carcinogenesis. As an example, IL‐10‐deficient mice develop severe atrophic gastritis and a chronic enterocolitis, developing colorectal cancer similar to human inflammatory bowel disease–associated neoplasia. TGF‐β1 is a multifunctional signaling molecule with a wide array of roles. Animal experiments suggest that TGF‐β1 plays a biphasic role in carcinogenesis by protecting against the early formation of benign epithelial growths, but promoting a significant stimulation of tumor growth invasion and metastasis during tumor progression. We assessed association of functional polymorphisms (–1082G/A; –592C/A) and TGF‐β1 (–509C/T; +869C/T) influencing the IL‐10 production to colorectal cancer risk in a case–control study of 62 patients and 124 matched controls. No significant differences were observed among cancer patients and controls for IL‐10 –1082G/A; –592C/A genotype frequencies. Evaluation of odds ratios (OR) for the TGF‐β1 +869C/T genotypes showed a significant increased risk for individuals bearing +869CC genotype compared to +869CT‐ and +869TT‐positive individuals. These results suggest that the +869C allele, responsible for a Leu→Pro substitution in the signal peptide sequence of the TGF‐β1 protein, may have a predisposing role in the development of colorectal cancer.

Cytokine gene polymorphisms and breast cancer susceptibility

Abstract:  Human breast cancer (BC) is characterized by a considerable clinical heterogeneity. Steroid hormone receptor expression and growth factor receptor expression have been considered suitable diagnostic and prognostic markers, whereas mutations of oncosuppressor and gatekeeper genes have been found associated with an increased risk for this malignancy. To evaluate the role that polymorphisms of genes involved in the regulation of inflammatory response might play in BC susceptibility, we investigated associations between cytokine functionally relevant polymorphisms in 84 BC patients compared to 110 age‐ and sex‐matched controls. TNF‐α (‐308G/A), TGF‐β1 (+869C/T), IL‐10 (−1117G/A; −854C/T; −627C/A), and IFN‐γ (874T/A) single nucleotide polymorphisms (SNPs) were identified by sequence‐specific primers (SSP)‐PCR or restriction fragment length polymorphism (RFLP)‐PCR. Genotype or haplotype distributions for each polymorphisms were consistent with the HWE in these populations. We were unable to demonstrate differences in genotype or allele frequencies between patient and control groups. Data obtained in this study indicate that none of the cytokine SNPs studied is likely to have predisposing or protective effects on BC susceptibility. On the other hand, both positive and negative association with BC have been reported for some of the studied genotypes by different research groups. In conclusion, further studies involving larger numbers of subjects are required.

IL-6 -174G/C polymorphism and IL-6 serum levels in patients with liver cirrhosis and hepatocellular carcinoma

Recently, a link between high levels of circulating IL-6 and hepatocellular carcinoma (HCC) has been proposed. In addition, single nucleotide polymorphisms (SNPs) in the promoter region of the IL-6 gene have been reported to be related to several inflammatory-related conditions, including cancer. The purpose of this article is: (1) to evaluate the frequencies of SNPs in the IL-6 promoter region at position -174 and IL-6 serum levels in a group of patients with HCC and underlying liver cirrhosis (LC), and compare them with a group of LC patients without HCC; (2) to determine whether a possible correlation exists between the allelic variations, IL-6 serum levels, and the risk of developing HCC. The study included 105 HCC and 95 LC patients. Genomic DNA was isolated using commercially available kits. DNA samples were typed for relevant SNPs of the IL-6 promoter region (-174 G>C, G allele being associated with higher levels of the cytokine). The Restriction Fragment Length Polymorphism (RFLP-PCR) method was used to type the SNPs. IL-6 serum levels were determined using an ultrasensitive commercially available ELISA kit. IL-6 serum levels were higher in G/G compared to C/C genotypes only in HCC (z=2; p=0.04) and G/G versus G/C (z=1.8; p<0.03). IL-6 serum levels in G carriers (G/G+G/C) were higher in HCC 4.8 (0.2-17.5) versus LC patients 2.2 (0.07-11.5) (z=2.8; p=0.004). There was no difference for genotype C/C. IL-6 serum levels in HCC correlated with G carriers (G/G+G/C) (ρ=0.25, p=0.05). A positive correlation was also found between sIL-6 levels and some parameters of liver function both in LC and in HCC patients.

Search for Genetic Factors Associated with Susceptibility to Multiple Sclerosis

Abstract:  Multiple sclerosis (MS) is a cell‐mediated autoimmune disease characterized by type‐1 cytokine production. Environmental and individual genetic background might influence this response particularly in cytokine gene polymorphisms. We evaluated whether polymorphisms of interleukin (IL)‐10, IL‐12, and tumor necrosis factor (TNF)‐α genes, which might play a role in MS pathogenesis, are associated with MS susceptibility. Genotype frequencies for all the analyzed polymorphisms were not differently distributed between cases and controls. It is reasonable to suppose that the cytokine single‐nucleotide polymorphisms (SNPs) studied must be considered against a larger genetic background involving other functional SNPs of Th1 regulator elements such as IL‐21 and IL‐23.

Genetic determined downregulation of both type 1 and type 2 cytokine pathways might be protective against pancreatic cancer.

Many cytokine polymorphisms have been studied for associations with susceptibility to breast, gastric, liver, lung, prostate, and ovarian cancer without conclusive results. The cytokine network, indeed, is characterized by complex interactions, and the final biological effect of a single genetic variation depends on the balance among different molecular signals. As is well known, Th1/Th2 cytokine unbalanced production might predispose to different pathologies, cancer included. In general, a prolonged type 1 inflammatory response might allow that cells accumulating enough “genetic hits” are promoted to neoplastic transformation. On the other hand, IL‐13‐producing cells through the IL‐13/IL‐4 receptor‐alpha (R‐α) pathway might facilitate escape from tumor immunosurveillance. Here are reported data on the evaluation of the influence of some type 2 and type 1 cytokine genetic polymorphisms as risk factors for pancreatic cancer. There was no overall association between pancreatic cancer risk and single cytokine SNPs. On the other hand, in evaluating the influence of combined cytokine genotypes we found that the combined IL‐10‐1082GA heterozygous and IL‐4 Rα‐1902AA homozygous genotype is underrepresented in the pancreatic cancer subject group. As is well known, the IL‐10‐1082GA genotype is associated with an intermediate production of this regulatory cytokine, whereas the IL‐10‐1902AA genotype of the IL‐4Rα gene is associated with a reduced efficiency in signal transduction when the receptor is engaged by IL‐13 or IL‐4. These results strongly suggest that a genetic background associated to a mild downregulation of type 1 and type 2 inflammatory signals might be protective against pancreatic cancer.

Association between single nucleotide polymorphisms in the cyclooxygenase-2, tumor necrosis factor-α, and vascular endothelial growth factor-A genes, and susceptibility to hepatocellular carcinoma.

Cyclooxygenase-2 (COX-2), vascular endothelial growth factor-A (VEGF-A), and tumor necrosis factor-α (TNF-α) are mediators of inflammation and angiogenesis; all of them are produced in liver cirrhosis (LC) and in hepatocellular carcinoma (HCC). It was proposed that there is an association between single nucleotide polymorphisms (SNPs) and HCC. These allelic variants influence the transcriptional activity of these genes, and therefore the proteins levels. The VEGF-A pathway is a potential therapeutic target in HCC, and several antiangiogenic agents have entered clinical trials in HCC. We evaluated the frequency of SNPs of COX-2, TNF-α, and VEGF-A genes in patients with HCC versus LC patients and a control group. The aim of this article was to verify the correlation between the allelic variations and the risk of developing HCC. The study included 96 HCC, 79 LC patients, and 162 healthy subjects. The evaluation of SNPs was performed by the restriction fragment length polymorphism (RFLP-PCR) method. The SNPs analyzed were: -1195 G>A of the COX-2 gene, -308 G>A of the TNF-α gene, and +936 C>T of the VEGF-A gene. Chi-square and Fisher exact tests were used for statistical analysis. Our results confirm that carriers with the C allele in the VEGF-A gene are more frequent in HCC versus LC (p=0.039), suggesting that this SNP may predispose to the development of HCC.

Role of environmental and genetic factor interaction in age-related disease development: the gastric cancer paradigm.

The association of Helicobacter pylori (Hp) infection with gastric cancer is well known and might be considered a paradigmatic example of the role that interaction among environmental factors and individual background might play in inducing age-associated disease. To evaluate the role of interaction of Hp infection with genetic background, gastric cancer and chronic gastritis patients as well as random selected controls were typed for five inflammation-related polymorphisms of IL-1 and IL-10 cytokine genes. No association among IL-10 or IL-1 variants with an increased risk of gastric cancer was found, whereas an Hp-independent association of IL-1beta -511T positive genotypes to an increased risk of chronic gastritis was found (Hp-/511T+ OR 1.89, 95% CI: 1.01-3.54; Hp+/-511T+ OR 1.83, 95% CI: 1.05-3.19). Stratification of gastric cancer group according to Hp infection does not allow finding a statistically significant association of Hp+ to the higher histological grading (G3) of gastric cancer (OR 1.54, 95% CI: 0.46-5.11). Our findings seem to confirm that cytokine genetic variants might contribute to determining the background for inflammaging in which H. pylori infection might facilitate cancer development.

Frequency of polymorphisms of signal peptide of TGF-beta1 and -1082G/A SNP at the promoter region of Il-10 gene in patients with carotid stenosis.

Abstract:  The role of inflammation in atherosclerosis is well recognized. We have evaluated the allele frequencies of the +869T/C and +915G/C polymorphisms (SNPs) at the TGF‐β1 gene and −1082G/A SNP at IL‐10 promoter sequence, two well‐known immunosuppressive and anti‐inflammatory cytokines, in patients with carotid stenosis. Our data suggest a lack of association between these SNPs and the susceptibility to atherosclerosis although other reports have demonstrated this association. These results may be due to the pleiotropic effects of the cytokines and/or differences in haplotype combination that should be investigated to elucidate the role of TGF‐β1 and IL‐10 polymorphisms in atherosclerosis.

503 ALLELIC VARIANTS OF CYP2E1 GENE IN HEPATOCARCINOMA PATIENTS AND IN HEPATIC TUMOR CELL LINES

Scores were considered useful if AUROC was >0.7 and excellent if >0.8. Results: 332 patients with severe AH were treated with prednisolone 40mg/day. At first day of treatment, patients had the following characteristics (results in medians): male gender 55.9%, ascites 74.2%, encephalopathy 24.3%, age 50.5years (95%CI: 49.2–51.7), alcohol consumption 100g/day (80–100), prothrombin time 20.9sec (20.3–21.8), INR 1.9 (1.85–2), AST 109 IU/l (102–117), albumin 25g/l (24.1–26), bilirubin 15.6mg/dl (13.4–18), creatinine 0.86mg/dl (0.8–0.9). At first day of treatment with steroids, median of prognostic functions were: ABIC 8.3 (8–8.5), Glasgow 9 (8–9), Lille 0.31 (0.25–0.37), Maddrey 60.3 (56.2–63.4) and MELD 22.5 (21.2–23.6). The AUROC (0.84) of the Lille score was significantly higher than the AUROC of other scores: ABIC (0.76, p = 0.008), Glasgow (0.68, p = 0.0004), Maddrey (0.65, p < 0.00001) and MELD (0.7, p = 0.0002). The AUROC for ABIC score was higher than for Glasgow (p=0.003), Maddrey (p < 0.0001) and MELD (p =0.002). The diagnostic accuracy of the scores using baseline variables was not improved by their evolution between 1st and 7th day of treatment: ABIC 0.68, Glasgow 0.65, Maddrey 0.65, MELD 0.64. We compared the ability of the Lille, Glasgow and ABIC scores to classify patients according to their proposed cut-offs (9 for the ABIC and Glasgow scores, 0.45 for the Lille score). Percentage of patients correctly classified by these cut-offs was higher for the Lille score than for the ABIC (79.2% vs. 72%, p = 0.01) and of the Glasgow scores (62.8%, p < 0.01). Conclusion: In a prospective cohort of more than 300 patients, the ABIC and the MELD scores are clinically useful and the Lille score has an excellent diagnostic accuracy for predicting deaths at 6 months. In addition, the 0.45 cut-off of Lille score is superior in terms of patients correctly classified.