Trop2 is a potential biomarker for the promotion of EMT in human breast cancer

Trop2 is considered to have an important function in tumor metastasis and the promotion of epithelial-mesenchymal transition (EMT). E-cadherin is a crucial factor in intercellular adhesion and EMT transformation. In the present study, we detected the expression of Trop2 and E-cadherin in breast cancer (BC) to better define their prognostic value. The mRNA expression levels of these two genes in 20 cases of fresh BC tissues were detected by quantitative real-time polymerase chain reaction (qRT-PCR). We also detected the expression levels of these two genes by immunohistochemistry (IHC) in 312 BC tissues, and the correlations between the expression of these two genes and the clinicopathological characteristics in BC patients were analyzed. The mRNA and protein expression levels of the two genes in BC cell lines were studied by qRT-PCR and western blotting. The results indicated that Trop2(+)/E-cadherin(-) was expressed in BC tissues more than that in the matched adjacent tissues. The protein expression results obtained via IHC were similar to the mRNA expression results. Trop2(+)/E-cadherin(-) that was expressed in BC was associated with lymph node status, metastasis, tumor-node-metastasis (TNM) stage, and ER-/PR-/HER2(-) expression. BC patients that expressed Trop2(+)/E-cadherin(-) had poor overall survival rates. The results of Trop2 and E-cadherin expression levels obtained in the BC cell lines were the same as those obtained in the BC tissues. Overall, Trop2 has a potential role in the promotion of EMT in BC and it could be considered as a therapeutic target in the future.