EMAST Type of Microsatellite Instability-A Distinct Entity or Blurred Overlap between Stable and MSI Tumors.

Microsatellite instability (MSI) represents an accumulation of frameshifts in short tandem repeats, microsatellites, across the genome due to defective DNA mismatch repair (dMMR). MSI has been associated with distinct clinical, histological, and molecular features of tumors and has proven its prognostic and therapeutic value in different types of cancer. Recently, another type of microsatellite instability named elevated microsatellite alterations at selected tetranucleotide repeats (EMAST) has been reported across many different tumors. EMAST tumors have been associated with chronic inflammation, higher tumor stage, and poor prognosis. Nevertheless, the clinical significance of EMAST and its relation to MSI remains unclear. It has been proposed that EMAST arises as a result of isolated MSH3 dysfunction or as a secondary event in MSI tumors. Even though previous studies have associated EMAST with MSI-low phenotype in tumors, recent studies show a certain degree of overlap between EMAST and MSI-high tumors. However, even in stable tumors, (MSS) frameshifts in microsatellites can be detected as a purely stochastic event, raising the question of whether EMAST truly represents a distinct type of microsatellite instability. Moreover, a significant fraction of patients with MSI tumors do not respond to immunotherapy and it can be speculated that in these tumors, EMAST might act as a modifying factor.

Prognostic Factors for Post-Recurrence Survival in Stage II and III Colorectal Carcinoma Patients.

Background and objectives: This study aimed to evaluate prognostic factors for post-recurrence survival in local and locally advanced colorectal cancer patients. Materials and Methods: A total of 273 patients with stage III and high-risk stage II colorectal cancer were prospectively enrolled. All patients underwent operative treatment of the primary tumor and adjuvant fluorouracil-based chemotherapy. Results: Over the three-year period (2008-2010), a cohort of 273 patients with stage III and high-risk stage II colorectal cancer had been screened. During follow up, 105 (38.5%) patients had disease recurrence. Survival rates 1-, 3- and 5-year after recurrence were 53.9, 18.2 and 6.5%, respectively, and the median post-recurrence survival time was 13 months. Survival analysis showed that age at diagnosis (p < 0.01), gender (p < 0.05), elevated postoperative Ca19-9 (p < 0.01), tumor histology (adenocarcinoma vs. mucinous vs. signet ring tumors, p < 0.01) and tumor stage (II vs. III, p < 0.05) had a significant influence on post-recurrence survival. Recurrence interval and metastatic site were not related to survival following recurrence. Multivariate analysis showed that older age (HR 2.43), mucinous tumors (HR 1.51) and tumors expressing Ca19-9 at baseline (HR 3.51) were independently associated with survival following recurrence. Conclusions: Baseline patient and tumor characteristics largely predicted patient outcomes after disease recurrence. Recurrence intervals in local and locally advanced colorectal cancer were not found to be prognostic factors for post-recurrence survival. Older age, male gender, stage III and mucinous histology were poor prognostic factors after the disease had recurred. Stage II patients had remarkable post-recurrence survival compared to stage III patients.

Inflammation-related cytokines and their roles in gastroenteropancreatic neuroendocrine neoplasms.

Proinflammatory counterworks are important at different stages of tumor development, particularly during invasion and metastasis. Immune cells and their signal molecules can influence all stages of tumor progression, as well as therapeutic intervention. Proinflammatory cytokines are known triggers of growth in gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs). In this study, we explored the immunohistochemical expression of tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1ß), IL-2, and IL-6 in tissues from 43 GEP-NEN patients with tumors of gastric, duodenal, ileal, appendiceal, and colonic origin. The immunohistochemical expression of TNF-α was increased in tumor groups with high proliferation rates (Ki-67; p = 0.034), as well as in those with higher tumor grades (p = 0.05). Moreover, the immunohistochemical expression of TNF-α positively correlated with death outcomes (p = 0.016). Expression of IL-6, IL-1ß, and IL-2 displayed similar immunohistochemical expression patterns regardless of Ki-67, although the expression between the ILs differed. Most GEP-NENs had high levels of IL-6 and lower levels of IL-1ß and IL-2. Although further comprehensive studies are required for a complete understanding of activated mechanisms in proinflammatory protumoral microenvironment of GEP-NENs, TNF-α is a potential marker in the prognosis of those tumors.

Prothrombin 3'end Gene Variants in Patients With Sporadic Colon Adenocarcinoma.

BACKGROUND/AIM: Thrombin plays significant roles in various types of cancer. However, the expression levels of prothrombin, the thrombin precursor, in cancer remain unclear. Variants of the 3'end of the prothrombin gene lead to increased prothrombin expression. This study aimed to analyze prothrombin 3'end gene variants in colon tumor and adjacent normal tissue samples. MATERIALS AND METHODS: The study group consisted of 93 patients suffering from colon adenocarcinoma. The 3'end of the prothrombin gene was analyzed by DNA sequencing. RESULTS: Three variants, all previously associated with increased prothrombin expression were detected. Frequency of the FII 19911G allele was 46.77% and 47.85% in tumor and normal tissue, respectively. For the FII 20210A allele, the detected frequencies were 2.15% and 1.61%, respectively. The frequency of the FII c.1824T allele was 0.54% in both tissues. Four patients showed different genotypes in tumor and normal tissue. CONCLUSION: Prothrombin 3' end gene variants may play a role in colorectal cancer.

Analysis of MSH2 Loss of Heterozygosity, Expression, and IVS10+12G>A Polymorphism in Sporadic Colon Cancer.

BACKGROUND: mutS homolog 2 (MSH2) deficiency may be involved in the development of microsatellite instability found in certain sporadic colorectal tumors. In addition to mutations or loss of heterozygosity resulting in complete loss of MSH2 function, polymorphisms affecting MSH2 expression have been also identified. Therefore, the aim of this study was to examine MSH2 status in sporadic colon cancer. MATERIALS AND METHODS: MSH2 status was examined at the DNA, RNA and protein levels through loss of heterozygosity (LOH) analysis, quantitative real-time PCR and immunohistochemistry. MSH2 IVS10+12A>G polymorphism was examined by real-time single nucleotide polymorphism genotyping. RESULTS: MSH2 LOH was more frequent in tumors larger than 5 cm (p=0.032), mRNA expression was also significantly lower and the same expression pattern was present in the corresponding normal mucosa of the same patient (p=0.013 and p=0.008, respectively). No association was found between IVS10+12A>G polymorphism and susceptibility to sporadic colon cancer. CONCLUSION: Altered MSH2 expression detected in sporadic colon tumors pointing to its role in colorectal tumorigenesis without a hereditary component.

High VEGF serum values are associated with locoregional spread of gastroenteropancreatic neuroendocrine tumors (GEP-NETs).

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are highly vascularized neoplasms, capable of synthethisizing VEGF-A, a key mediator of angiogenesis. In pancreatic neuroendocrine tumors (pNETs) VEGF expression is higher in benign and low-grade tumors and associated with good prognosis (neuroendocrine paradox) while the VEGF role in gastrointestinal NETs (GI-NETs) is still unclear. In this study, we examined the VEGF-1154A/G polymorphism in 145 GEP-NET patients and 150 controls. Next, we measured VEGF serum levels and VEGF tumor protein expression, comparing it with Ki67 and tumor grade. Patients' VEGF serum levels were compared with VEGF -1145A/G genotypes and metastatic status as well as with chromogranin A (CgA) and 5-hydroxyindolacetic acid (5-HIAA) in case of GI-NET patients. In this study GEP-NET patients had elevated VEGF serum values when compared to healthy controls (p = 0.0013). VEGF-1145G allele correlated with higher VEGF serum levels (p = 0.002). Patients with metastatic tumors had higher VEGF serum values when compared to patients without metastases (p = 0.033), and highest levels were observed in case of lymph node metastases (p = 0.008). VEGF-1145G allele was more frequent in non-functional GI-NET patients than in healthy controls (p = 0.041). CgA was superior to VEGF in tumor detection, while VEGF was superior to 5-HIAA. A correlation was observed between VEGF immunohistochemical staining and Ki-67 (p = 0.028). Tumours with weaker VEGF protein expression were more aggressive than tumours with stronger VEGF expression, confirming a "neuroendocrine paradox" in GI-NETs. Our results suggest the role of VEGF in GI-NETs locoregional spread.

Mononucleotide repeats in the SMAD4 gene promoter in colon carcinoma tissue of Croatian patients.

This study was aimed at the analysis of mononucleotide repeats -462T(15) and -4T(12) in the SMAD4 gene promoter in sporadic colon adenocarcinoma tissue of Croatian patients. The analysis has included 60 pairs of samples of colon tumor and adjacent normal tissue. The number of thymidines in the tracts -462T(15) and -4T(12) of the SMAD4 gene promoter was determined by PCR with fluorescently labeled primers followed by the analysis of obtained DNA fragments by capillary electrophoresis. In the normal colon tissue two haplotypes were present: -462T(15)/-4T(12) in 51 patients (85%) and -462T(16)/-4T(12) in 9 patients (15%). Among the cases with haplotype -462T(15)/-4T(12) detected in normal colon tissue, in 5 cases (8%) malignant tissue displayed different haplotypes: 462T(10)/-4T(10), -462T(12)/-4T(12), 462T(13)/-4T(11), -462T(14)/-4T(10) and -462T(15)/-4T(11). Haplotype -462T(14)/-4T(10) was previously found to be associated with significantly decreased SMAD4 gene promoter activity in comparison to the wild type, while the other detected haplotypes remain to be functionally characterized. This study has shown that functionally relevant somatic alterations of the SMAD4 gene promoter are found in some colon cancer tumors. Although not as frequent in colon as in pancreatic cancer, they may be of significance for certain cases and their role in colon tumorigenesis should be investigated further.

TNFα gene/protein in tumorigenesis of sporadic colon adenocarcinoma.

PURPOSE: Inherited polymorphisms in immunomodulatory genes such as cytokines may contribute to variation in immunological response and genetic susceptibility for complex diseases, including cancer. TNFα can mediate tumor progression by inducing proliferation, invasion and metastasis of tumor cells. The aim of our study was to examine the allelic frequencies of TNFα promoter SNPs, -1031 T/C, -857 C/T, -308 G/A and -238 G/A, in patients with sporadic colon adenocarcinoma in order to investigate the possible role of these SNPs in susceptibility to sporadic colon cancer. Another aim of this study was to examine the influence of TNFα SNPs on TNFα mRNA and protein expression in colon tumors and their possible role in the development and progression of this type of tumor. RESULTS: The distribution of all four TNFα SNP genotypes in patients showed no significant difference compared to controls. No statistically significant difference in TNFα mRNA expression in tumors and corresponding normal mucous tissue was found (p=0.14). A statistically significant (p=0.028) difference was found in TNFα mRNA expression between histological grade 1 and histological grade 2 and 3 tumors. Additionally, a statistically significant correlation (p=0.03) was found between TNFα-857 C/T genotypes and TNFα mRNA expression in tumor tissue. TNFα mRNA expression was significantly higher in the tumor tissue of patients with -857 CT and -857 TT genotypes. Most of the tumors (78.26%) were positive for TNFα protein. No correlation was found between the TNFα protein expression and clinicopathological characteristics as well as TNFα genotypes. However, patients with TNFα protein negative tumors had longer survival but the result was not statistically significant (p=0.365). CONCLUSION: Our results suggest the role of TNFα as one of the immunomodulatory genes in the progression of sporadic colon cancer.

New insights into the role of chronic inflammation and cytokines in the etiopathogenesis of gastroenteropancreatic neuroendocrine tumors.

Although previously considered rare, recent epidemiological studies have revealed that the incidence (3.6/100,000) and prevalence (35/100,000) of gastroenteropancreatic neuroendocrine tumors (GEP-NETs) has increased over the past few decades. Despite the progress in the understanding of GEP-NET molecular biology, there is still little advance in the early diagnosis due to lack of specific tumor markers. As the tumors are mostly detected in their late stage, they are not well controlled by either biotherapy or conventional chemotherapy, and thus represent a significant clinical issue. Chronic inflammation has been implicated in the development of GEP-NETs. This review presents recent findings that link pro-inflammatory cytokines to the molecular basis of GEP-NET tumorigenesis, leading to a more personalized approach to disease management and therapy.

Loss of NF2/Merlin expression in advanced sporadic colorectal cancer.

PURPOSE: NF2/Merlin was first identified through its association with neurofibromatosis type 2 (NF2). However, accumulating evidence suggests a more general involvement in tumorigenesis and, in particular, a broader role in tumor suppression. The aim of this study was to examine NF2/Merlin involvement in sporadic colorectal cancer. METHODS: This study is the first to examine the role of NF2/Merlin in sporadic colorectal cancer through LOH analysis at the NF2 locus and mRNA expression analysis via quantitative RT-PCR of total NF2, NF2 isoform I and II. In addition, Merlin protein expression was assessed by immunohistochemistry and Western blotting. RESULTS: NF2 LOH was detected in 20.0 % of heterozygous cases and was found to be more frequent in tumors larger than 5 cm in diameter (p = 0.041) and in tumors with a less differentiated phenotype (p = 0.027). No differences were observed in total NF2 and NF2 isoform I/isoform II mRNA expression between the tumors and their corresponding normal mucous tissues. NF2 isoform II was the most predominant isoform in all samples analyzed. mRNA expression levels of total NF2 and isoforms I and II were significantly lower in poorly differentiated tumors (p = 0.033, p = 0.036 and p = 0.044, respectively). Weak Merlin immunostaining was more frequent in poorly differentiated tumors (p = 0.034) and tumors classified as Dukes' C (p = 0.023). A distinct pattern of Merin phosphorylation was observed in tumors compared to normal mucous tissues. CONCLUSION: Our data indicate that NF2/Merlin may serve as a potential target in the management of colorectal cancer.

Reduced FHIT expression is associated with tumor progression in sporadic colon adenocarcinoma.

PURPOSE: Tumor supressor gene FHIT was identified at chromosome 3p14.2 spanning the FRA3B fragile site and is very often inactivated in different types of cancer. The aim of this study was to examine the frequency of FHIT gene LOH as well as FHIT mRNA and protein expression in sporadic colon adenocarcinoma. METHODS: The results of LOH, real-time qRT-PCR and imunohistochemical analyses were correlated with clinico-pathological characteristics of patients and their tumors in order to evaluate the role of FHIT gene/protein in sporadic colon adenocarcinoma tumorigenesis. RESULTS: One hundred and thirty one (96.3%) samples were informative for both markers and 33/131 (25.2%) demonstrated LOH. Expression of FHIT mRNA was significantly decreased in colon tumors relative to that in corresponding normal tissue (p = 7.2×10(-6)). Most of the samples (54.0%) were negative for FHIT protein, 26.4% adenocarcinomas showed a weak to moderate immunostaining and 19.6% adenocarcinomas showed strong FHIT immunostaining. No correlation was found between FHIT gene LOH status, mRNA expression or FHIT protein immunostaining and clinico-pathological characteristics. Expression of FHIT mRNA was significantly decreased in FHIT LOH positive tumors (p = 0.027). Patients with LOH negative tumors or FHIT protein positive tumors had longer survival but this findings were not statistically significant. CONCLUSIONS: Our overall results suggest that reduced expression of FHIT gene may be associated with the progression of these malignant tumors.

Even stressed cells are individuals: second messengers of free radicals in pathophysiology of cancer.

Pathophysiological processes associated with disturbances in cell and tissue oxidative homeostasis, are associated with self-catalyzed process of lipid peroxidation. The end products of lipid peroxidation are reactive aldehydes such as 4-hydroxy-2-nonenal (HNE), acting as "second messengers of free radicals." Although reactive aldehydes were first recognized only as cytotoxic, new evidence has come to light, related to their cell growth regulatory functions achieved through cell signaling. The variable appearance of HNE in several organs indicates that its mode of action might be related to an individual cell stress adaptation. The underlying mechanism could be that specific mutations and epigenetic changes on one hand interfere with hormesis on the other. The precise role of oxidative stress and lipid peroxidation in these processes still needs more clarification at molecular level. Finally, an individual approach to each patient, based on the individual cell response to stress, opens a new possibility of integrative medicine in cancer treatment and strongly supports modern concepts of personalized medicine.

Interleukin-6-174 G/C polymorphism is not associated with IL-6 expression and susceptibility to sporadic colon cancer.

Interleukin-6 (IL-6) has been implicated in tumorigenesis; however, its role is still far from being clearly defined. Regulation of IL-6 expression is highly complex, and additional complexity is introduced by single-nucleotide polymorphisms in the IL-6 gene. These single-nucleotide polymorphisms might influence mRNA transcription, which might in turn result in increased susceptibility to certain tumors. The aim of this study was to analyze IL-6 mRNA and protein expressions in sporadic colon cancer. Influence of IL-6-174 G/C polymorphism on IL-6 mRNA expression and sporadic colon cancer susceptibility was evaluated as well. The frequency of IL-6-174 G/C was analyzed by polymerase chain reaction-restriction fragment length polymorphism analysis. IL-6 mRNA and protein expressions were analyzed by real-time reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry. No statistically significant difference in IL-6 mRNA expression in tumor tissue compared with the corresponding normal tissue was observed (p = 0.116). No correlation was found between IL-6 mRNA and protein expressions and clinicopathological features of sporadic colon tumors. There was no association of IL-6-174 G/C genotypes with IL-6 mRNA expression in colon tumors and corresponding normal mucous tissue (p = 0.355; p = 0.152). Finally, there was no association of IL-6-174 G/C with susceptibility to sporadic colon cancer.

An integrated proteomics approach for studying the molecular pathogenesis of Dupuytren's disease.

Dupuytren's disease (DD) is a fibromatosis characterized by non-malignant transformation of palmar fascia leading to permanent contraction of one or more fingers. Despite the extensive knowledge of its clinical pathogenesis, the aetiology of this disease remains obscure. In the present paper, we report for the first time on the proteomic profiling of diseased versus unaffected patient-matched palmar fasciae tissues from DD patients using two-dimensional gel electrophoresis coupled with mass spectrometry analysis. The herein identified proteins were then used to create the protein-protein interaction network (interactome). Such an integrated approach revealed the involvement of several different molecular processes related to DD progression, including extra- and intra-cellular signalling, oxidative stress, cytoskeletal changes, and alterations in cellular metabolism. In particular, autocrine regulation through ERBB-2 and IGF-1R receptors and the Akt signalling pathway have emerged as novel components of pro-survival signalling in Dupuytren's fibroblasts and thus might provide a basis for a new therapeutic strategy in Dupuytren's disease.

Vascular endothelial growth factor polymorphisms -1154 G/A and -460 C/T are not associated with VEGF mRNA expression and susceptibility to sporadic colon cancer.

Vascular endothelial growth factor (VEGF) is important mediator of angiogenesis, and its expression in colorectal tumors is related to tumor progression. VEGF expression has been detected in normal mucosa, primary colon cancers, and metastatic tumors, and patients with low VEGF expression have a better survival rate. In addition, anti-VEGF monoclonal antibody improves overall survival when used in combination with existing metastatic colorectal cancer therapy. Therefore, prediction of VEGF production based on individual genetic background might be important for predicting the course of the disease and the efficacy of anticancer treatment. The number of studies evaluating the influence of VEGF polymorphisms on cancer susceptibility is growing; however, their results are often conflicting. In addition, these studies are rarely accompanied with the expression analysis examining the influence of these polymorphisms on mRNA expression in tumor tissue. In this study, we have examined the influence of VEGF polymorphisms -1154 G/A and -460 C/T on VEGF mRNA expression and susceptibility to sporadic colon cancer by real-time PCR-SNP and mRNA expression analysis. The study included population control group consisting of 160 unrelated volunteers and a group of 160 patients with sporadic colon cancer. According to our results, -1154 G/A and -460 C/T do not influence VEGF mRNA expression in colorectal tumors and susceptibility to sporadic colon cancer, although the role of other polymorphisms cannot be excluded.

Influence of interleukin-8 and interleukin-10 on sporadic colon cancer development and progression.

Cytokines produced in the tumour microenvironment have an important role in cancer pathogenesis. Altered cytokine expression may result in increased susceptibility to and/or poor prognosis in certain cancers. Therefore, the aim of this study was to investigate the influence of interleukin (IL)-8 and IL-10 on sporadic colon cancer development and progression. In our study, a statistically significant increase in IL-8 messenger RNA (mRNA) expression and decrease in IL-10 mRNA expression in tumour tissue compared with normal mucous tissue was observed (P = 0.003; P = 1.3 x 10(-9)). No association was found between IL-8 -251 A/T genotypes and IL-8 mRNA expression in tumour and corresponding normal mucous tissue, as well as susceptibility to sporadic colon cancer. Positive immunohistochemical IL-8 staining was more frequent in moderately and poorly differentiated tumours compared with well-differentiated tumours (P = 0.024). Finally, IL-8 significantly stimulated invasion of HT-29 cells in vitro (P = 0.000172). Significant association of IL-10 -1082 A/G, -819 T/C and -592 A/C genotypes and IL-10 mRNA expression in tumour tissue was observed (P = 0.022; P = 0.013; P = 0.02). Significant association of -819 T/C and -592 A/C genotypes and IL-10 mRNA expression in corresponding normal mucous tissue was observed (P = 0.01; P = 0.04) as well. IL-10 single-nucleotide polymorphism (SNP) promoter genotypes associated with low IL-10 mRNA expression (-819 TT; -592 AA) were also associated with increased risk of sporadic colon cancer compared with high-expression genotypes [odds ratio, 5.53; 95% confidence interval (CI), 1.53-20.1; odds ratio, 4.07; 95% CI, 1.28-12.96]. Positive IL-10 immunohistochemical reaction was more frequent in well-differentiated and moderately differentiated tumours compared with poorly differentiated tumours (P = 0.036). In Dukes' C tumours, positive IL-10 immunohistochemical reaction was less frequent compared with Dukes' A and B tumours (P = 0.023). Taken together, our results point to possible tumour promoting role of IL-8 and potential protective role of IL-10 in sporadic colon cancer.

TNF alpha promoter polymorphisms analysis in benign and malignant breast lesions.

Polymorphisms in genes involved in the complex mechanisms of carcinogenesis may affect the susceptibility to cancer. The multifunctional cytokine tumor necrosis factor alpha (TNF alpha) has an important role in the pathogenesis of inflammatory, autoimmune and malignant diseases. It has a large spectrum of activities, including both antitumorigenic and protumorigenic. In recent years, several TNF alpha promoter polymorphisms have been identified and related to the expression level of cytokine and to the susceptibility to solid tumors. The aim of our study was to investigate the frequency of three TNF alpha promoter polymorphisms (-1031, -308 and -238) in benign (fibrocystic changes) and malignant (invasive carcinoma) breast lesions. Using "real-time" PCR SNP analysis these polymorphisms were determined in 76 patients with benign and 158 patients with malignant breast lesions. The high expression genotypes at any of the three SNP polymorphisms were more frequent in invasive breast carcinoma (in 81 of 158 examined, 51.3%) than in fibrocystic changes (in 33 of 76 examined, 43.4%). The combined frequency of high production genotypes (-1031 T/C and C/C, -308 G/A and A/A and -238 G/A and A/A) was higher in patients with invasive breast carcinoma than in those with fibrocystic changes. However, these results were not statistically significant. Further studies on a larger group of patients are needed to evaluate the significance of potential differences in TNF alpha genotypes in different breast lesions.

TNF-alpha promoter single nucleotide polymorphisms in gastroenteropancreatic neuroendocrine tumors.

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) secrete biogenic amines, hormones and growth factors, tumor necrosis factor-alpha (TNF-alpha) being one of them. As the expression of TNF-alpha is mostly regulated at the transcriptional level, its promoter polymorphisms have been intensively studied as a potential determinant of TNF-alpha production and cancer susceptibility. We have analyzed for the first time the potential association between -238, -308, -857 and -1031 TNF-alpha promoter polymorphisms and GEP-NETs. The study included 65 individuals diagnosed with GEP-NET and 154 healthy age- and sex-matched controls. Although most of the patients had solitary GEP-NETs, 6 were diagnosed with GEP-NET as a part of multiple endocrine neoplasia type 1 and 1 as a part of neurofibromatosis type 1. The C allele at the -1031 position was more frequent in GEP-NET patients (p < 0.0005), suggesting its possible role in GEP-NET development. The significant difference between foregut and midgut GEP-NET patients was observed in the -308 high expression genotypes and -308A allele (high expression) which tend to occur more frequently in the foregut GEP-NETs (p = 0.0392 and p = 0.0350, respectively). When functional and nonfunctional pancreatic endocrine tumors were compared, there were no significant differences in the researched TNF-alpha SNPs. The results suggest the putative role of TNF-alpha -1031 polymorphism in the development of GEP-NET.

NeuroD1 gene and interleukin-18 gene polymorphisms in type 1 diabetes in Dalmatian population of Southern Croatia.

AIM: To evaluate the frequency of known polymorphisms in the exon 2 of the NeuroD1 gene and in the interleukin (IL)-18 promoter region in patients with type 1 diabetes mellitus (T1DM) and in healthy control subjects in Dalmatia, Southern Croatia. METHODS: A total of 134 unrelated patients (73 men and 61 women) and 132 consecutive unrelated healthy controls (61 men and 71 women) from the Dalmatian region of southern Croatia were recruited for the study. NeuroD1 genotypes (GG, GA, AA) were identified by means of polymerase chain reaction followed by restriction fragment length polymorphism (PCR/RFLP). IL-18 polymorphism in the position -137 of the promoter region was detected by using PCR sequence-specific primers. RESULTS: Genotype distributions of both genes did not show significant difference between patients and controls. CONCLUSION: Our results suggest that NeuroD1 exon 2 and IL-18 promoter gene polymorphisms are not associated with development of T1DM susceptibility in the population of South Croatia. In addition to previously published positive correlations of these polymorphisms with development of T1DM among different world populations, our findings indicate the existence of ethnic variations in the association of these genes with disease development.