NFKB1 -94 insertion/deletion ATTG polymorphism in gastroenteropancreatic neuroendocrine tumors

Nuclear factor-kappaB (NF-kappaB) is a transcription factor responsible for modulating the expression of many genes involved in immune response, inflammatory process, cell growth and survival. A functional and common promoter polymorphism of the NF-kappaB1 (NFKB1) gene leads to alteration in the activation pattern and expression of NF-kappaB, and thus, is probably associated with carcinogenesis. The aim of this study was to detect the importance and the frequency of NFKB1 -94 insertion/deletion ATTG promoter polymorphism in patients with gastroenteropancreatic neuroendocrine tumor. A case-control cohort including 50 patients with gastroenteropancreatic neuroendocrine tumor and 100 healthy controls was genotyped with the polymerase chain reaction method. Polymerase chain reaction products were analyzed in agarose gel electrophoresis and processed with the Van91I restriction enzyme. There are 2 cleavage points on the amplified region. When ATTG insertion or deletion is present, the function of restriction enzyme changes. Thirty patients (60%) had ID (insertion/deletion), 18 (36%) had II (insertion/insertion) and 2 (4%) had DD (deletion/deletion) genotypes. Fifty-eight of the control group (58%) had ID, 30 (30%) had II and 12 (12%) had DD genotypes. The frequencies of D and I alleles were 34 and 66 in the study group, and 82 and 118 in the control group, respectively. Although the frequencies of I and D alleles and genotype distribution did not differ between the study and control groups, there seem to be important differences concerning the DD genotype analyses of the NFKB1 -94ins/delATTG promoter polymorphism between patients with pancreatic neuroendocrine tumor and those with carcinoid tumor. This may support the view that the genetics of carcinoid tumors and pancreatic neuroendocrine tumors are different and should be further studied.