Association of WNT Antagonist Gene Polymorphisms with Breast Cancer in a Turkish Population

Introduction: Changes in protein encoding genes involved in various signalling pathways are effective in the development of breast cancer. The (WNT)/β-catenin pathway is known to have a role in many cancer types, including breast cancer. In this study we aimed to investigate the relationship between the risk of breast cancer development and WNT antagonist gene polymorphisms in a selected Turkish population.
Methods: In total, 100 patients who were diagnosed with breast cancer and 100 age-matched and sex-matched healthy individuals were evaluated in this study. We genotyped 4 single nucleotide polymorphisms including DKK3 non-synonymous (Exon7 Arg335Gly), DKK3 (Intron4 G/C), DKK4 synonymous (Exon4 V169V), sFRP4 non-synonymous (Exon6 R340K) by performing polymerase chain reactions (PCR) and restriction fragment length polymorphism (RFLP).
Results: In statistical analysis using Chi-square (χ2) test, we observed that there was no significant difference between case and control groups for distribution of DKK3 nonsynonymous exon 7 Arg335Gly, DKK3 intron 4 G/C polymorphisms and sFRP4 non-synonymous (Exon6 R340K) (p>0.05). On the other hand, distribution of DKK4 synonymous exon 4 V169V polymorphism between case and control groups was significantly different (p<0.05). However, a statistically significant correlation between breast cancer risk and CC genotype of DKK4 synonymous exon 4 V169V polymorphism (adjusted for BMI and sFRP4) has been defined [p=0.001, OR: 16.38 CI: 95% (6.37–42.12)].
Discussion and Conclusion: These results suggest that the CC genotype of DKK4 synonymous exon 4 V169V polymorphism is associated with the development of breast cancers in Turkish population.

Keywords: Breast cancer; Polymorphism; Turkish population; WNT antagonists