Abstract
The aim of the present study is to study the expressions of suppressor of cytokine signaling (SOCS)-1 in the tumor tissues and adjacent normal tissues of patients with breast cancer. The study was also planned to investigate the association of SOCS-1 gene expression with patients' clinical pathology, molecular subtype and prognosis. A total of 60 cases of frozen and paraffin-embedded specimens of tumor tissues and corresponding adjacent normal tissues of patients with breast cancer were selected. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression levels of SOCS-1 messenger RNA (mRNA) in the patients' tumor tissues and adjacent normal tissues. The immunohistochemical method was applied to detect the expressions of SOCS-1 proteins in the patients' breast cancer tissues and adjacent normal tissues. Moreover, the correlations of SOCS-1 protein expressions in breast cancer tissues with patients' pathological parameters, molecular subtypes and prognosis were analyzed in combination with the clinical data. The results of RT-qPCR showed that the SOCS-1 mRNA expression in breast cancer tissues was significantly lower than that in adjacent normal tissues (p<0.01). The immunohistochemical results indicated that the positive expression rate of the SOCS-1 proteins in breast cancer tissues (23.33%) was remarkably lower than that in adjacent normal tissues (88.33%) (p<0.01). The low expression of SOCS-1 in breast cancer tissues was related to lymph node metastasis and clinical staging. The positive expression rates of the luminal A SOCS-1 proteins were the highest (47.62%) (p<0.01). The 5-year overall survival rate of the breast cancer patients was 63.33% (38/60). The univariate survival analysis revealed that the patients with low expression of SOCS-1 had poorer prognosis. In conclusion, the low expression of SOCS-1 plays a key role in the pathogenesis of breast cancer; in particular, it is associated with the lymph node metastasis and clinical staging of the tumor; so, the SOCS-1 expression in breast cancer tissues can be regarded as an important reference for the prognostic estimation of breast cancer.