ASS1 expression and its correlation with clinicopathological features and prognosis in breast cancer

To determine the key molecule in breast cancer pathology and clinical prognosis by data analysis as well as surgical specimens immunohistochemical staining analysis. TCGA and GTEx databases were used to screen key molecules in the urea cycle with differential expression in breast, and their relationship with the prognosis of breast cancer patients was also analyzed. Then, the surgical specimens of 97 breast cancer patients and 54 non-neoplastic (mammary gland disease) patients who underwent surgical treatment in Xijing Hospital from November 2010 to December 2016 were collected to produce breast cancer tissue chips. Immunohistochemical staining was employed to determine the expression of ASS1 (argininosuccinate synthase 1) in breast cancer and adjacent normal tissues, and to verify its relationship with pathological features and prognosis of breast cancer. TCGA and GTEx database analysis showed that the expression of ASS1 decreased in breast cancer, significantly correlated with the prognosis of patients (p < 0.05). Immunohistochemical results demonstrated that ASS1 is mainly located in cytoplasm. Its expression decreased in breast cancer, and significantly correlated with Ki-67 level and molecular typing (p = 0.0215, p = 0.0005). The expression of ASS1 significantly decreased in breast cancer, and closely related to molecular typing and Ki-67 level, suggesting that ASS1 plays an important role in the occurrence and development of tumor. Therefore, low ASS1 expression can be used as a potential indicator to evaluate the prognosis of breast cancer.