Knockdown of Y­box­binding protein­1 inhibits the malignant progression of HT­29 colorectal adenocarcinoma cells by reversing epithelial­mesenchymal transition.

Y­box binding protein­1 (YB­1) has been identified as an oncoprotein in various malignancies. The aim of this study was to investigate the biological role of YB­1 and its association with epithelial­to­mesenchymal transition (EMT) in colorectal cancer (CRC). The expression of YB­1 and three EMT­related proteins (E­cadherin, N­cadherin and vimentin) was analyzed in 80 CRC and matched normal tissue samples, by immunohistochemistry. The results indicated that the expression of YB­1 was higher in CRC tissue samples than that in matched normal controls and was significantly correlated with tumor differentiation, tumor invasion, lymph node metastasis and distant metastases. Furthermore, analysis showed that YB­1 expression was negatively correlated with E­cadherin and positively correlated with N­cadherin and vimentin expression. In vitro assays showed that knockdown of YB­1 inhibited the proliferation, apoptosis resistance, invasion and migration of the HT­29 CRC cell line. Of note, following knockdown of YB­1, E­cadherin expression was elevated whereas N­cadherin and vimentin expression was reduced. Taken together, these results suggest that YB­1 promotes the malignant progression of CRC in part through the induction of EMT, and YB­1 may therefore be a potential novel target for CRC treatment.