The functional 4-bp insertion/deletion ATTG polymorphism in the promoter region of NF-KB1 reduces the risk of BC.

Nuclear factor kappaB (NF-kB) plays a key role in mammary gland development and breast cancer (BC) progression. A functional -94 insertion/deletion ATTG polymorphism (rs28362491) in the promoter of the NFKB1 gene was reported to affect NF-KB1 expression and confer susceptibility to different types of cancer. The current study aimed to assess the association of NFKB1 -94 insertion/deletion ATTG promoter polymorphism and BC risk in an Iranian population. A total of 439 subjects including on 236 BC patients and 203 healthy women were recruited. The NF-KB1 -94ins/del ATTG polymorphism was genotyped by Allele-Specific polymerase chain reaction (AS-PCR) method. Our results demonstrated that the NF-KB1 -94ins/del ATTG polymorphism was associated with a reduced risk of BC in Codominant (Ins/Ins vs. Del/Del: OR = 0.33, 95%CI = 0.17-0.64; P= 0.001), dominant (Ins/Ins vs. Ins/Del+Del/Del: OR = 0.64, 95%CI = 0.42-0.97; P= 0.027) and recessive (Ins/Del+Del/Del vs. Del/Del: OR = 0.40, 95%CI = 0.21-0.75; P= 0.002) tested inheritance models. Additionally, the Del allele of NF-KB1 -94ins/del ATTG variation with a higher prevalence in the control group compared to the BC patients (43.3% vs. 33.5%) was associated with a decreased risk of BC (OR = 0.66, 95%CI = 0.50-0.86, P= 0.003). In conclusion, our findings for the first time, suggest that the NF-KB1 -94ins/del Del allele and Del/Del genotype were associated with a reduced risk of BC which may contribute as protective factors against BC.