Overexpression of kin of IRRE-Like protein 1 (KIRREL) as a prognostic biomarker for breast cancer

Objectives: The purpose of this study was to investigate the expression of Kin of IRRE-Like Protein 1 (KIRREL) and its clinicopathologic significance in breast cancer.

Materials and methods: The mRNA and protein expressions of KIRREL in fresh breast cancer tissue specimens and the corresponding noncancerous tissue specimens were examined by western blot analysis (n = 24) and RT-qPCR (n = 48). KIRREL was detected by immunohistochemistry (IHC) using breast cancer tissue microarrays (TMAs) in 302 patients. The prognostic roles and clinicopathologic significances in breast cancer were statistically analyzed.

Results: Compared with para-carcinoma tissues, KIRREL mRNA and protein were overexpressed in breast cancer tissues. Immunohistochemical results showed that the high expression rate of KIRREL staining in breast cancer was 43.7% (132/302). Moreover, Expression of KIRREL was significantly correlated with Her2 status and survival outcomes of patients. Patients with both positive expression of KIRREL showed shorter overall survival (OS) and progression free survival (PFS). Additionally, Cox multivariate survival analysis revealed that KIRREL level, age, primary tumor size, tumor stage and distant metastasis were the independent parameter predicting the prognosis of breast cancer patients.

Conclusions: KIRREL was overexpressed in breast cancer and the overexpression of KIRREL could serve as an independent predictor of poor prognosis in breast cancer patients.