Expression of glutaminase 1 gene in breast cancer and its clinical significance in neoadjuvant chemotherapy

Objective: To analyze the expression of glutaminase 1 (GLS1) gene in breast cancer and its clinical significance in neoadjuvant chemotherapy. Methods: A total of 134 female patients with breast cancer who were treated in Department of Thyroid and Breast Surgery, Nanjing Drum Tower Hospital were selected. After being diagnosed by biopsy, they were randomly divided into two groups (n=67). Before modified radical mastectomy, the experimental group received a combined TEC (taxotere + epirubicin + cyclophosphamide) regimen. Then surgery was performed after three to four weeks of chemotherapy. Mammary glands of the control group were directly removed by modified radical mastectomy without receiving TEC regimen. After surgery, the cancerous tissues were subjected to immunohistochemical staining for GLS1 protein. Results: According to whether tumor cells penetrated the basement membrane, 5 patients had noninvasive carcinoma, and 129 had invasive carcinoma. According to the pathological morphology, 128 cases had ductal carcinoma, 2 had mucinous carcinoma (2 cases were complicated with ductal carcinoma), and 4 had lobular carcinoma. GLS1 gene was expressed differently in normal and cancerous tissues of the 134 patients, but the expression levels were significantly higher in cancerous ones (P<0.05). GLS1 gene expression level of the experimental group was significantly lower than that of the control group (P<0.05). Univariate analysis showed that GLS1 gene expression level was positively correlated with lymphatic metastasis and pathological stage (P<0.05). Conclusion: GLS1 gene was highly expressed in the tumor tissues of patients with breast cancer. Neoadjuvant chemotherapy before modified radical mastectomy significantly reduced such expression level. GLS1 gene expression level was positively correlated with lymphatic metastasis and pathological stage, which can thus be used as an evaluation index for therapeutic effects. GLS1 can be employed as one of the specific targets for breast cancer therapy and development of targeted therapy drugs.