High expression of Y-box-binding protein 1 is associated with local recurrence and predicts poor outcome in patients with colorectal cancer.

Colorectal cancer (CRC) is one of the most common and fatal malignancies worldwide. Novel prognostic biomarkers are urgently warranted to help improve the treatment of CRC. Y-box-binding protein 1 (YB-1) has been identified as a multifunctional oncoprotein in various malignancies. Our previous study has suggested that YB-1 may promote malignant progression of CRC cells in vitro. However, its clinical and prognostic significance in CRC patients remains unclear. In this study, the expression of YB-1 was examined in 32 fresh CRC tissues using quantitative real-time polymerase chain reaction (qRT-PCR) and in 170 paraffin-embedded CRC tissues using immunohistochemistry. The result of qRT-PCR demonstrated mRNA expression of YB-1 was increased in 26 of 32 (81.25%) of CRC patients. The statistical analysis based on immunohistochemical staining suggested that YB-1 expression was significantly correlated with tumor differentiation, tumor invasion, lymph node metastasis and Dukes' classification (all P<0.05). Furthermore, we found that patients with high YB-1 expression had a poorer prognosis and were more likely to undergo local recurrence, compared to those with low YB-1 expression. We also identified that YB-1 expression, together with lymph node metastasis and Dukes' classification were independent prognostic factors for CRC patients. In conclusion, our study for the first time demonstrated the clinical and prognostic significance of YB-1 in CRC and suggested that YB-1 is of great potential to be an attractive therapeutic target as well as prognostic biomarker for CRC patients.