Y‑box‑binding protein 1 inhibits apoptosis and upregulates EGFR in colon cancer.

Y‑box‑binding protein 1 (YB‑1) is a DNA/RNA‑-binding protein and an important transcription and translation factor in carcinogenesis. However, the biological function and molecular correlation of YB‑1 in colorectal cancer are not fully understood. The aim of the present study was to determine the significance of YB‑1 expression and its biological role in colorectal cancer. Cell proliferation, migration and apoptosis were examined upon knockdown of YB‑1 expression in different colon cancer cell lines that had different genetic backgrounds. Since the properties of different colon cancer cell lines with specific RAS/RAF gene mutations downstream epidermal growth factor receptor (EGFR) may differ from wild‑type colorectal cancer, it is critical to study the role of YB‑1 with respect to the mutational status of RAS. The results indicated that the suppression of YB‑1 decreased cell proliferation (P<0.05) and migration (P<0.05) regardless of the status of RAS/RAF in the HT29, HCT116 and CaCo2 cell lines. In contrast, YB‑1 knockdown altered the expression of apoptosis‑related genes and the expression of EGFR was detected in the cell lines expressing wild‑type RAS/RAF but not in those expressing mutated RAS/RAF. These results indicated that YB‑1 plays an important role in cell proliferation, migration, apoptosis and EGFR expression in colorectal cancer. Furthermore, apoptosis and EGFR expression may be affected by the mutational status of RAS/RAF and controlled through YB‑1.