title: HLA-Cw polypmorphism and killer cell immunoglobulin-like receptor (KIR) gene analysis in Korean colorectal cancer patients.
abstract: OBJECTIVE
  Natural killer cells (NK cells) play important roles in protecting the patient from the early development of cancers, and are activated or inhibited by killer cell immunoglobulin-like receptors (KIR), which bind to HLA class I. In the present study, we investigated the KIR genotype of Korean colorectal cancer patients.
  
  
  METHODS
  DNA samples were extracted from peripheral blood cell samples taken from Korean colorectal cancer patients and a control group. KIR genes were amplified using PCR-SSP methods, and HLA-Cw genes were characterized using PCR methods. The results were analyzed to assess the difference between colorectal cancer patients and the normal control group.
  
  
  RESULTS
  In the present study, the frequency of KIR2DS5 (33.2% vs. 20.8%, p-value < 0.007) was higher in the colorectal cancer group, and in the rectal cancer subgroup, the frequencies of KIR3DL1 (93.2%, vs. 98.1%, p-value < 0.05), KIR2DS2 (7.8% vs. 19.5%, p-value < 0.01), and KIR2DS4 (93.2% vs. 98.1%, p-value < 0.05) were lower significantly. The frequencies of HLA-Cw6 (9.1% vs. 15.7%, p-value < 0.05) and HLA-Cw7 (17.4% vs. 27.7%, p-value < 0.02) were lower in the colorectal cancer group. Of the patients with HLA-C1 homozygote, the frequency of KIR2DS2 was decreased significantly (5.8% vs. 14.5%, p-value < 0.004).
  
  
  CONCLUSIONS
  The frequency of KIR2DS5 is higher in Korean colorectal cancer patients, and in the rectal cancer subgroup, the frequencies of KIR3DL1, KIR2DS2 and KIR2DS4 are lower. Among the patients with HLA-C1 homozygote, the frequency of KIR2DS2 is decreased. Therefore, KIR2DS2 in presence of its ligand (HLA-C1 group) may have a protective effect against colorectal cancer.
authors.affiliation: Department of Surgery, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Hyung-Jin
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Hematopoietic Stem Cell Bank, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Hae-Baeg
authors.initials: HB
authors.lastname: Choi
authors.affiliation: Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Jung-Pil
authors.initials: JP
authors.lastname: Jang
authors.affiliation: Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: In-Cheol
authors.initials: IC
authors.lastname: Baek
authors.affiliation: Hematopoietic Stem Cell Bank, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Eun-Jeong
authors.initials: EJ
authors.lastname: Choi
authors.affiliation: Hematopoietic Stem Cell Bank, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Miyoung
authors.initials: M
authors.lastname: Park
authors.affiliation: Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea; Hematopoietic Stem Cell Bank, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea. Electronic address: kimtg@catholic.ac.kr.
authors.forename: Tai-Gyu
authors.initials: TG
authors.lastname: Kim
authors.affiliation: Department of Surgery, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea. Electronic address: stoh@catholic.ac.kr.
authors.forename: Seong-Taek
authors.initials: ST
authors.lastname: Oh
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D003110:Colonic Neoplasms / Q000235:genetics* / Q000276:immunology; D005260:Female; D005838:Genotype; D015236:HLA-C Antigens / Q000032:analysis / Q000235:genetics*; D006801:Humans; D007694:Killer Cells, Natural / Q000737:chemistry*; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D054340:Receptors, KIR / Q000032:analysis / Q000235:genetics*; D012004:Rectal Neoplasms / Q000235:genetics* / Q000276:immunology; D056910:Republic of Korea
chemical_list: D015236:HLA-C Antigens; C528994:HLA-C*06 antigen; C040178:HLA-C*70 antigen; D054340:Receptors, KIR
keywords: Colorectal cancer; HLA-Cw; KIR; NK cells