ABSTRACT
Background: NOTCH1 pathway activation has been recently described to be a key player in gastric carcinogenesis, enhance the survival and proliferation of cancer stem cells (CSCs) and mediate chemoresistance in several malignancies. Aim: This study investigated the correlation between NOTCH1 and CSC marker OCT4 (octamer binding transcription factor-4) expression and the clinicopathological properties, survival and treatment outcome in patients with gastric carcinoma (GC) receiving adjuvant chemotherapy. Materials and Methods: NOTCH1 and OCT4 were immunohistochemically detected in 50 post-operated specimens of GC. Patients' data regarding disease-free survival (DFS), overall survival (OS), and the response to the chemotherapy was statistically analyzed. Results: NOTCH1 and OCT4 overexpression was detected in 60% and 52% of GC tissues, respectively, and that was significantly higher than the rates in adjacent non-neoplastic gastric mucosa (P < 0.05). A significant correlation was detected between overexpression of NOTCH1 and OCT4 in GC and aggressive clinicopathological features; poor differentiation (P = 0.021, P = 0.037, respectively), depth of tumor invasion (P < 0.001 for both), TNM stage (P < 0.001 for both), lymph node metastasis (P = 0.002, P = 0.003, respectively) and distant metastasis (P < 0.001 for both). NOTCH1 was positively correlated with OCT4 (P = 0.002). Survival analysis disclosed that upregulation of NOTCH1 and OCT4 was associated with worse DFS (P = 0.013, P < 0.001, respectively) and OS (P < 0.001 for both). Overexpression of NOTCH1 and OCT4 correlated with poor response to chemotherapy (P = 0.013, P = 0.005, respectively) and worse clinical outcome. Conclusion: Combined detection of these proteins might disclose even better predictive value for shorter survival and resistance to chemotherapy.