Effect of TP53 16-bp and β-TrCP 9-bp INS/DEL polymorphisms in relation to risk of breast cancer.

Abstract P53 as a tumor suppressor and an apoptosis modulator, is the regulator of the cell cycle and apoptosis, and contributes to mammary gland development and breast cancer (BC) progression. BTRC gene ( Homo sapiens beta-transducing repeat containing E3 ubiquitin protein ligase) encoded protein, β-TrCP, is a novel regulator of p53. The current study aimed to assess the possible effects of TP53 IVS3 16 bp (rs17878362) and β-TrCP 9 bp (rs16405) INS/DEL polymorphisms on BC risk in an Iranian population. A total of 439 women including 236 BC patients and 203 healthy women were recruited. The TP53 and β-TrCP INS/DEL polymorphisms were genotyped by allele-specific polymerase chain reaction method. Our data demonstrated that the TP53 16-bp INS/DEL variation was associated with an increased risk of BC in codominant (INS/INS vs. DEL/DEL: OR = 1.82; 95% CI = 1.02–3.23; P = 0.042) and dominant (Del/INS + INS/INS vs. DEL/DEL: OR = 1.48; 95% CI = 1.03–2.21; P = 0.044) models. Additionally, the variant allele (INS) of TP53 DEL/INS polymorphism with a relatively higher frequency in cases than in controls (35.6 vs. 27.8) was a risk factor for BC (OR = 1.43; 95% CI = 1.06–1.93; P = 0.017). With respect to β-TrCP INS/DEL polymorphism, our study failed to find any difference in allele and genotype distribution between BC patients and controls in codominant, dominant and recessive tested inheritance models (P > 0.05). Furthermore, no significant association among the β-TrCP and TP53 genotype distribution and clinical characteristics of BC patients were found (P > 0.05). Our findings suggest that the TP53 16-bp INS/INS and DEL/INS + INS/INS genotypes as well as the INS allele could be genetic factors related to BC risk.