title: Investigation of   CTLA-4   and   CD28   gene polymorphisms in a group of   Turkish patients with colorectal cancer.
abstract: Colorectal cancer (CRC), also called colon cancer or bowel cancer, includes cancerous growths in the colon, rectum and appendix. The immune system is an important defence mechanism against cancer and is often dysfunctional in patients with malignancies. Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) and CD28 genes encode receptors that provide negative and positive signals, respectively. Polymorphisms in these genes can affect their functions. In this study, we aimed to investigate the association of cancer with the frequencies and roles of CTLA-4/+49A > G (exon 1) and -318C > T (promoter), and CD28/IVS3 + 17T > C (intron 3 position + 17). These polymorphisms were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 218 Turkish subjects (56 patients with CRC and 162 healthy controls). No statistically significant differences in the genotype distributions of CTLA-4/+49GG (1.8% vs. 6.8%, odds ratio (OR) = 0.250, P = 0.305) and CTLA-4/-318TT (0% vs. 0.6%, OR = 1.006, P = 1.000), and CD28/IVS3 + 17CC (8.9% vs. 3.7%, OR = 0.2411, P = 0.155) between patients with CRC and healthy controls, were observed. We also found that there were no significant differences in the frequencies of CTLA-4/+49G (18.8% vs. 20.1%, OR = 0.920, P = 0.891) and CTLA-4/-318T (7.1% vs. 4.3%, OR = 1.653, P = 0.314), and CD28/IVS3 + 17C alleles (25.9% vs. 19.1%, OR = 1.353, P = 0.139) between two study groups. Present results suggested that CTLA-4 and CD28 gene polymorphisms did not play an important role in Turkish patients with CRC.
authors.affiliation: Department of Medical Biology, Faculty of Medicine, Harran University, Sanliurfa, Turkey. fdilmec@harran.edu.tr
authors.forename: F
authors.initials: F
authors.lastname: Dilmec
authors.forename: A
authors.initials: A
authors.lastname: Ozgonul
authors.forename: A
authors.initials: A
authors.lastname: Uzunkoy
authors.forename: F
authors.initials: F
authors.lastname: Akkafa
mesh_terms: D015703:Antigens, CD / Q000235:genetics*; D018106:CD28 Antigens / Q000235:genetics*; D060908:CTLA-4 Antigen; D015179:Colorectal Neoplasms / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic / Q000235:genetics*; D014421:Turkey
chemical_list: D015703:Antigens, CD; D018106:CD28 Antigens; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human