Gil1 is a potential cancer stem cell marker and predicts poor prognosis in ductal breast carcinoma

Glioma-associated oncogene homolog 1 (Gil1) maintains the cancer stem cell like characteristics in various tumors. However, its expression in cancer stem cells (CSC) in ductal breast carcinoma has not been well studied. We aimed to characterize Gli1 as a potential CSC marker and investigate its clinical significance in ductal breast carcinoma. Immunohistochemical staining was used to study the relationship of Gli1 to clinicopathologic features, cell cycle regulation related genes, and CSC markers. Gli1 was expressed to a greater extent in ductal breast carcinoma than in normal breast tissues (P = .002). Its expression was significantly correlated with tumor grade (P = .044), pT stage (P = .017), and molecular subtype (P = .008). Expression was associated, not only with the expression of HIF-1 alpha (P < .001), but also with greater microvessel density (MVD; P = .012). Kaplan-Meier survival analysis revealed that Gli1 was significantly associated with lower overall survival (OS; P = .02). Univariate Cox regression analysis confirmed that Gli1 was a poor prognostic factor for OS (P = .037) and was associated with the expression of the cell cycle related genes cyclin D1 (P = .011), p21 (P = .009), and pAkt-Thr308 (P = .038). Moreover, Gli1 expression correlated significantly with the expression of two CSC markers, Sox2 (P = .01) and LSD1 (P = .01). Gli1 could be a stem cell marker and an indicator of poor prognosis in patients with ductal breast carcinoma. (c) 2017 Elsevier Inc. All rights reserved.