Polymorphisms in CLDN1 are associated with age and differentiation of triple-negative breast cancer patients

Hu, Aimin; Li, Junyu; Ruan, Shufang; Fan, Ying; Liao, Yuqian

Down-regulation of CLDN1 was associated with shorter DFS of breast cancer patients [9] . In TNBC, CLDN1-negative phenotype also predicted poor prognosis [36, 37] . In our study, no association between polymorphisms in CLDN1 and survival of TNBC patients was observed. There are some explanations. First, the sample size was relatively small and we did not do subgroup analysis. Second, though polymorphisms in CLDN1 might influence the expression level of CLDN1 protein, the complex interactions between CLDN family members could also affect the results. By using STRING, we found that CLDN1 interacts with some other proteins in CLDN family, such as CLDN2, CLDN3, CLDN6, CLDN12 and so on (Figure 1 ). CLDN 12 expression could be clinically useful for predicting the survival of the ER-negative subgroup of patients with breast cancer [38] . High expression of CLDN6 confers chemoresistance on breast cancer [39] . So, combination analysis of CLDN1 and other related proteins might help us to better understand the role of CLDN1 in TNBC.