In conclusion, significant changes in the expression of claudin-1 and -3 but not in the expression of claudin-4, E- and N-cadherin were observed in samples taken from patients with BC following chemotherapy.
Our results might contribute to understanding the mechanisms of CLDN4 regulation and suggest PAK4-CEBPB-CLDN4 axis as a potential therapeutic target for breast cancer.
BRCAmut tumors bear stem cell characteristics displaying a distinct cell adhesion molecule profile characterized by high expression of CDH1 and CLDN4 according to public gene expression data set analysis, and higher claudin-3 expression as detected by IHC; thus, BRCAmut breast carcinomas are not identical with the previously identified claudin-low subtype of breast cancer.
Western blot analysis revealed a possible correlation between claudin-4 and -6 expression in breast cancer cell lines and tumor aggressiveness, with protein levels correlating with the ability to form vascular channels.
Claudin-4 is frequently expressed in primary breast cancers but especially in their metastases and is thereby an attractive membrane bound molecular imaging and drug target.
High claudin-4 expression was also associated with worse breast cancer-specific survival (p = 0.003), recurrence-free survival (p = 0.025) and overall survival (p = 0.034).
High claudin-4 expression was also associated with worse breast cancer-specific survival (p = 0.003), recurrence-free survival (p = 0.025) and overall survival (p = 0.034).