Gene Expression of OCT4 and NANOG Correlated with Advanced Stage and Worse Survival in Breast Cancer Patients

Abstract

The present study aimed to show the correlation between expression of cancer stem cell markers (OCT4 and NANOG) with both clinicopathological features and survival of breast cancer (BC) patients. Methods: The gene expressions of OCT4 and NANOG were quantified using real time polymerase chain reaction, clinicopathological data have been collected from patients' data records and patients were followed-up with a median duration of 110 months. Results: OCT4 (p<0.001), and NANOG (p<0.001) expressions were upregulated in BC tissues compared to adjacent normal tissues. OCT4 and NANOG were associated with poor histological grade (p=0.029, 0.025) and advanced clinical stage (p=0.001, 0.042 respectively). OCT4 alone showed a significant association with lymph nodes involvement (p=0.006), metastasis (p=0.024) and was significantly correlated to patients' age (p=0.009). NANOG also showed a significant positive correlation with ERα and PR receptors expression (p=0.004 and 0.005 respectively). Kaplan–Meier curves disclosed that NANOG (p=0.028, 0.050) positive expression was associated with worse DFS and OS, while OCT4 (p=0.200, 0.205) was correlated with poor DFS and OS but not significant statistically. Univariate analysis using Cox proportional hazards regression model analysis showed that OCT4 (p = 0.002), NANOG (p = 0.021), and ERα status (p = 0.004) had significant predictive values for poor DFS. However, the multivariate analysis did not show that any of them can be used as independent prognostic markers for DSF. Conclusions: From these findings, it may be concluded that the upregulated expressions of OCT4 and NANOG were associated with worse clinical outcome and could be used as predictive markers for poor DFS in BC patients.