Expression of PEBP4 protein correlates with the invasion and metastasis of colorectal cancer.

This study aimed to investigate the expression of PEBP4 protein in colorectal carcinoma tissues and its correlation with the clinical pathology of colorectal cancer and to investigate the relationship between PEBP4 expression and the invasion and metastasis of colorectal cancer cells, which could provide an experimental basis for future biological treatments of human colorectal cancer. RT-PCR and western blot methods were applied to detect the mRNA and protein expressions, respectively, of PEBP4 in colorectal cancer tissues and normal pericarcinoma tissues, and their correlations with the tumorigenesis and development of colorectal cancer, as well as its clinical pathology, were analyzed. Using the RNA interference technology, the expression of PEBP4 was knocked down in the human colorectal cancer cell HCT116, and the changes of the invasion capability of HCT116 were monitored. The positive mRNA expression rate of PEBP4 in colorectal cancer tissue was significantly higher than that in the normal pericarcinoma tissue (p < 0.05). Also, the positive expression rate in the cancer tissues from patients with positive lymph node and distant metastasis was significantly higher than that from the patients negative for lymph node and distant metastasis (p < 0.05). The positive expression rate of PEBP4 in the cancer tissues from the patients in early stages (I, II) was significantly lower than the expression rate in patients in advanced stages (III, IV) (p < 0.05). A lower degree of differentiation in colorectal cancer corresponded to a higher positive mRNA expression rate of PEBP4 (p < 0.05). However, this was independent of the patient's gender, age, and tumor size (p > 0.05). In colorectal cancer tissue, the expression of PEBP4 protein was consistent with its mRNA. Namely, PEBP4 protein expression in colorectal cancer tissues was significantly higher than that in the normal pericarcinoma tissues (p < 0.05), the expression in the cancer tissues from the patients with positive lymph node and distant metastasis was significantly higher than that from the patients who were negative for these metastases (p < 0.05), and a lower degree of differentiation in colorectal cancer corresponded to a higher TNM staging along with a higher PEBP4 protein expression (p < 0.05). After HCT116 cells transfected with PEBP4 siRNA, they showed a significantly lower expression level of PEBP4 protein (p < 0.05), and the number of cells that passed through the Transwell chamber was significantly lower compared to the non-transfected or the transfected controls (p < 0.05). The over-expression of PEBP4 protein may be related to the tumorigenesis, development, metastasis, and invasion of colorectal cancer.