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

The expression level of CLDN1 was found to be associated with tumor differentiation and age in several kinds of cancers. In OSCCs, the highest expression of CLDN1 was observed in well-differentiated OSCCs, whereas poorly differentiated OSCCs exhibited mostly negative staining for CLDN1 [40] . In hepatocellular cancer, down-regulation of CLDN1 was associated with poor differentiation [41] . In basal-like breast cancer patients, the highest level of CLDN1 protein expression was observed in patients who were older than 55 years of age [42] . So, we assume that polymorphisms in CLDN1 might influence the expression level of CLDN1 protein and then influence the tumor differentiation. However, the underlying mechanisms need to be further investigated. Our results also suggested that polymorphisms in CLDN1 might help us to identify subtypes of TNBC, as TNBC patients with different age and grade were proved to have unique molecular features [32, 43] .