Expression of GLIS3 protein in triple negative breast cancer and its influence on prognosis of patients

To observe the expression of GLIS3 in triple negative breast cancer (TNBC) and analyze its relationship with the prognosis of TNBC patients.

Bioinformatic analysis was applied to analyze the expression level of GLIS3 in Gene Expression Omnibus (GEO). Kaplan-Meier survival curve was plotted to evaluate the impact of GLIS3 expression on the survival rate of patients based on DNA chip data. A total of 125 patients pathologically diagnosed as TNBC in the Fourth Hospital of Hebei Medical University from January to December 2014 were enrolled by cluster random sampling. Among them, 53 patients had complete tissue specimens, medical records and follow-up data. Immunohistochemical assay was used to detect the expression of GLIS3 in TNBC and adjacent tissues to tumors, while the relationships between GLIS3 protein expression in breast cancer tissues and clinicopathological parameters such as age, menstrual status, tumor size, clinical stage, histological grade, pathological type, axillary lymph node metastasis, vascular tumor thrombus, and expression of TP53 and Ki-67 were analyzed. Kaplan-Meier survival curve was plotted to analyze the effect of GLIS3 on the overall and disease-free survival of TNBC patients. Cox regression model was established to identify the risk factors impacting the prognosis of the patients.

Analysis of GEO data showed that the expression of GLIS3 in TNBC was significantly higher than that in paracancer tissues (P<0.05). The expression of GLIS3 was notably higher in the TNBC tissue than the adjacent tissue to tumor (P<0.05). A marked augmentation of GLIS3 expression was observed in both the advanced and larger-sized tumors (P<0.05). Univariate analysis of Cox regression model revealed that lymph node metastasis, TNM stage and GLIS3 expression were all related to disease-free survival of TNBC patients (P<0.05). Univariate and multivariate analyses displayed that TNM stage was related to the overall survival of TNBC patients (P<0.05). The patients with high expression of GLIS3 had significant shorter disease-free survival time than those with low expression (P<0.05), but had no statistical difference in overall survival (P>0.05).

GLIS3 protein is highly expressed in TNBC tissues, and tumor size and TNM stage are correlated with its high expression. The high expression of GLIS3 suggests that the patients have poor prognosis and low disease-free survival rate.