Numerous previous studies have revealed that pleomorphic adenoma gene-like 2 (PLAGL2) is a transcription factor that is active in cancer progression. The aim of this study was to investigate the role of PLAGL2 in the development, progression and prognosis of gastrointestinal cancer. Immunohistochemical analysis revealed that PLAGL2 was expressed in gastrointestinal tumors and adjacent normal tissues. The expression of PLAGL2 was significantly higher in 225 colorectal cancer tissues than in 66 adjacent non-tumor tissues (P = 0.037). However, expression was not significantly different between 286 gastric tumors and 57 adjacent non-tumor tissues (P = 0.352). Moreover, the PLAGL2 expression level significantly correlated with the depth of tumor invasion in colorectal cancer (P = 0.030). However, the PLAGL2 expression level significantly correlated with tumor size in gastric cancer (P = 0.046). Furthermore, we performed survival analyses and found that neither higher nor lower PLAGL2 expression was a prognostic factor in gastrointestinal cancer. Our findings indicate that PALGL2 serves as a tumor oncoprotein in the development and progression of colorectal cancer. However, the role of this protein in the development, progression and prognosis of gastric cancer is uncertain. Further investigation into the molecular mechanisms of PLAGL2 activity in gastrointestinal cancer is warranted.
Keywords: Gastrointestinal cancer; PLAGL2; immunohistochemistry; prognosis; tumor invasion.