Browsing by Author "Arikan S."

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Individual and combined effects of CTLA4-CD28 variants and oxidant-antioxidant status on the development of colorectal cancer
(2015-10-01) Kucukhuseyin O.; Turan S.; Yanar K.; Arikan S.; Duzkoylu Y.; Aydin S.; Cakatay U.; Mezani B.; Farooqi A.A.; Aydinoʇlu Isitmangil G.; Kiran B.; Cacina C.; Nurdan Yenilmez E.; Ergen A.; Zeybek U.; Yaylim I.
Background: Colorectal cancer (CRC) is the third most frequent cancer worldwide. Research has revealed the contributions of the immune system and anti-inflammatory pathways in the development of cancer. The balance between cluster of differentiation 28 (CD28) and cytotoxic Tlymphocyte- associated protein 4 (CTLA4) signaling is important for the regulation of immune responses. The oxidant-antioxidant balance by sustaining redox control via several defense mechanisms is also an important factor for the progression of cancer. The aim of the present study was to determine the distribution of CTLA4/CD28 variants and oxidant-antioxidant status in patients with CRC. Materials and Methods: This study enrolled 80 patients with CRC and 115 healthy controls. We used a spectrophotometric assay to detect the levels of lipid peroxidation products malon dialdehyde (MDA) and lipid hydroperoxide (LHP), and measured the concentration of protein damage products, advanced oxidation protein products (AOPP) and protein carbonyl (PCO). Additionally, antioxidant levels were detected by measuring copper, zinc, superoxide dismutase (Zn-Cu SOD) and total thiol (T-SH) levels, and advanced glycation end-products (AGEs). The CTLA4 -318C>T, CTLA4 49A>G and CD28C>T genotypes were determined by using restriction enzymes. Results: AOPP and PCO levels were increased in patients with CRC as well as those of LHP, MDA and AGE, while the levels of antioxidants such as Cu-Zn SOD and T-SH were lower. Lower serum levels of CTLA4 and higher serum levels of CD28 were detected in patients and, an association of the CTLA4 -318C/T polymorphism was found in patients with CRC. Conclusion: Our oxidative stress was increased in patients with CRC, suggesting the contribution of this disturbed oxidative status to serum CTLA4 and CD28 levels, and to the pathogenesis of CRC.
The effect of CTLA-4 and CD28 gene variants and circulating protein levels in patients with gastric cancer
(2017-10-01) Arikan S.; Gümüş A.; Küçükhüseyin Ö.; Coşkun C.; Turan S.; Cacina C.; Talu C.K.; Akyüz F.; Farooqi A.A.; Kıran B.; Yaylım İ.
Objective: Gastric cancer is one of the most common malignancies worldwide. The risk factors for gastric cancer include environmental and genetic factors. Inflammation and the immune system are known to contribute to the development of the gastric cancer. We examined the influence of critical polymorphisms of CTLA-4 and CD28 genes and circulating protein levels on the etiology of gastric cancer. Methods: Genotyping of SNPs was performed in 55 gastric cancer patients and 105 healthy individuals using the PCR-RFLP method, and circulating levels of sCTLA-4 and sCD28 were measured. Results: There were no significant differences in the genotype and allele distributions of the evaluated SNPs [CTLA- 4-318 C > T (rs5742909), CTLA-4 + 49 A > G (rs231775), CD28 C > T (rs3116496)] between gastric cancer patients and controls (p = 0.36, p = 0.78, and p = 0.80, respectively). The circulating levels of sCTLA-4 and sCD28 were significantly different between the gastric cancer group and the control group (p < 0.001 and p < 0.001, respectively). Conclusion: The present results suggest that the CTLA-4 and CD28 gene polymorphisms that were evaluated do not play an important role in Turkish patients with gastric cancer. However, sCTLA4 and sCD28 levels were higher in cancer patients and may be useful as an auxiliary parameter in the diagnosis and monitoring of gastric cancer.