Associations between cytokine gene polymorphisms and rheumatoid arthritis in Turkish population.

OBJECTIVE: Various cytokine polymorphisms have been associated with genetic risk factors predisposing to Rheumatoid Arthritis (RA) in different populations. To predict the clinical outcome as well as response to therapy in RA, studies aimed to describe genetic markers. The present study aims to search for polymorphisms of 13 cytokine coding genes in the Eastern Black Sea Region of Turkey. METHODS: DNAs of 49 patients and 96 healthy bone marrow and kidney donors were isolated from peripheral blood samples. Genotyping was performed using the Heidelberg Cytokine Typing Tray kit. PCR products were visualized on an agarose gel, and results were analyzed using the interpretation scheme provided with the kit. Arlequin 3.5 software was used for statistical analysis. RESULTS: No positive association was found between allele frequencies and the disease. However, a negative association was found for the IL-A -889 C allele (p=0.02, OR=0.533, Wald's 95% CI=0.318-0.893). IL-12 -1188 CC (p=0.01, OR=3.667, Wald's 95% CI=1.246-10.786), IL-4 -1098 GT (p=0.02, OR=2.405, Wald's 95% CI=1.129-5.125) genotypes were found positively associated with the RA, while IL-4 -590 CT (p=0.02, OR=0.422, Wald's 95% CI=0.201-0.886) was found negatively associated with the disease. In addition, IL-6 GG haplotype was found positively associated with the RA (p=0.02, OR=1.880, Wald's 95% CI=1.086-3.254). CONCLUSION: Our findings suggest that some polymorphisms of the IL-1A, IL-2, IL-4, IL-6 and IL-12 could be responsible for the susceptibility or protective to RA in our study population. Multi-centered and large numbers of subjects containing studies that search for cytokine polymorphisms will gather more information regarding the susceptibility to RA of Turkish patients.

Genetic polymorphisms variants in interleukin-6 and interleukin-1beta patients with obstructive sleep apnea syndrome in East Northern Turkey.

AIM: To investigate the relationship of IL-1ß and IL-6 cytokine gene polymorphisms with obstructive sleep apnea syndrome (OSAS) in 61 patients admitted to the neurology clinic in Kafkas University Hospital with insomnia problem who were diagnosed with OSAS in sleeping labs, and 80 healthy subjects not associated with the syndrome. METHODS :Blood samples were taken to isolate DNA from patients diagnosed with OSAS based on polysomnography results and healthy controls. DNA amplification of the genes was performed with PCR. Amplification products were cut with the restriction enzymes in order to determine IL-1 gene (TaqI) and IL-6 gene (Lwel) polymorphisms. The cut DNA fragments were carried out in agarose gel electrophoresis, and RFLP analysis was performed by utilizing the images with gel imaging system. PCR products were sequenced with an Applied Biosystems Automated Sequencer. RESULTS: Polymorphic changes were observed for IL-1ß gene in 26 of 62 patients (41.9%), and 16 of the 80 (25.8%) in the control group. The incidence of polymorphic changes in IL-6 gene was in seen in seven (of the 62 patients) (11.3%), and in the 16 (20%) controls. CONCLUSION: The findings on the genomic level in OSAS may provide an important contribution to diagnosis of obstructive sleep apnea syndrome in clinical practice, as well as it helps to obtain the results easily about environmental and genetic interaction of OSAS patients.

The effect of polymorphism in DNA repair genes RAD51 and XRCC2 in colorectal cancer in Turkish population.

The genes RAD51 and XRCC2 encode proteins that are important for the repair of double-strand DNA breaks by recombination. Therefore, genetic variability in these genes may contribute to the occurrence and progression of carcinoma. We investigated the association of polymorphisms in the DNA repair genes XRCC2-A/G and RAD51-135G/C with the colorectal cancer risk. Genotypes were determined by PCR-RFLP assays in 71 patients with colorectal cancer and 86 age-matched healthy controls. After amplification, we used a restriction enzyme (RAD51; MvaI and XRCC2; HphI) and digested the PCR product. Then, this DNA fragments were passed through gel electrophoresis. By examining these images, we identified changes in the nucleotides in these specific regions. To clarify fragments polymorphisms, the PCR products were sequenced with an Applied Biosystems Automated Sequencer. We observed the Arg188His polymorphism of XRCC2 genes in 42.2%, as shown in 30 of the 71 cancer patients. Only 21 out of 86 controls showed this polymorphism (24.2%). We also observed that 21 of the 71 patients (29.5%) carried the RAD51135G/C polymorphism of this gene. The same polymorphism was observed in 11 of the 86 controls (12.7 %; p < 0.05). The obtained results indicate that the polymorphism of RAD51 and XRCC2 genes may be associated with the incidence of colon cancer in the Turkish population. Further studies, including those on a larger group of patients, are required to further clarify this point.

Inflammatory cytokine gene polymorphism profiles in Turkish patients with ulcerative colitis.

AIM: To investigate IL-1α, IL-1ß, IL-1R , IL-4RA, TGF-ß, TNF-α and IFN-γ, genes polymorphism in Turkish patients with ucerative colitis (UC). METHODS: An analysis was carried out at Trabzon Karadeniz Technical University Medicine Faculty Gastroenterology polyclinics between March 2005 and May 2011 on 51 patient with UC (cases) and 100 healthy individuals (controls). PCR-SSP and cytokine gene panel (Helderberg kits) based techniques for analysis of gene polymorphisms were used. RESULTS: Changes in allelic frequencies of each of the investigated eight cytokine genes polymorphisms in patient with ulcerative colitis were found. Among the allelic genes analyzed here, the highest statistically significant change was observed in the position TNF-α -308 G/A (339.7%). The following increases were observed in IL-IR mspa T/C variation (179.4%), IFN-γ 5644A/T variation (77.4%), and in IL-1ß -511T/C SNPs (35.9% ). In other analyzed genes, allelic changes were found to be decreasing for TGF- ß codon10C / T (-71.9%), IL4RA + 1902G / A (-47.3 %), and for IL- 1α -889T / C (-37.7%). The lowest negative change (-25.9%) was observed in the allele frequency in IL- 1ß 3962T / C (p les than 0.000). In addition, there were changes in genotypic frequencies investigated seven gene polymophic site and only one of cytokine gene IL-1ß 3962TT/TC/CC was not changed. CONCLUSION: Genes polymorphism is not itself the only determining factor for clinical diagnoses. However, it can be used in the clinical diagnosis of UC in order to determine the low level or high level variations in cytokine gene polymorphisms.

Polymorphisms in DNA repair genes XRCC2 and XRCC3 risk of gastric cancer in Turkey.

We studied the prevalence of polymorphisms in genes XRCC2 and XRCC3 in stomach cancer patients who lived in North Eastern Turkey. A total of 61 cancer patients and 78 controls were included in this study. Single nucleotide changes were studied in XRCC2 and XRCC3 genes at locus Arg188His and Thr241Met. Blood samples were taken from the patients and controls, and DNA was isolated. The regions of interest were amplified using a polymerase chain reaction method. After amplification, we used restriction enzymes (HphI and NcoI) to digest the amplified product. Digested product was then run through gel electrophoresis. We identified changes in the nucleotides in these specific regions. It was found that the Arg188His polymorphism of the XRCC2 gene was about 39% (24 out of the 61) among cancer patients. However, only 15% (12 out of 78) of the control group indicated this polymorphism. We also observed that 18 of the 61 cancer patients (29%) carried the Thr241Met polymorphism of the XRCC3 gene whereas 11 of the 78 (14%) individuals in the control group had the polymorphism. Our results showed a significant difference in polymorphism ratios between the cancer patients and health control group for the regions of interest. This result clearly showed that these polymorphisms increase the risk of stomach cancer and might be a strong marker for early diagnosis of gastric cancer.