The overexpression of DBC1 in esophageal squamous cell carcinoma correlates with poor prognosis.

DBC1 (deleted in breast cancer 1) is a novel transcriptional coactivator that has been suggested to be a critical regulator of tumorigenesis. Recently, the overexpression of DBC1 in cancer cells has been reported to be strongly related with unfavorable clinical outcome in several cancers, including breast and gastric cancer. Despite the increasing significance of DBC1 in cancer, the expression of DBC1 and its clinical significance in esophageal squamous cell carcinoma (ESCC) have not been studied. In this study we aimed to investigate the role of DBC1 in ESCC. To this aim, we examined DBC1 expression in a total of 199 (165 ESCC and 34 normal esophageal epithelial) tissues by immunohistochemistry and assessed its prognostic value and correlation with patient survival. In addition, we measured DBC1 expression in three ESCC cell lines (TE1, TE8, and TE10). Also, we induced the loss of DBC1 expression by siRNA transfection and determined its effect on the migratory and invasive ability of cancer cells. DBC1 was expressed in all normal esophageal and ESCC tissues, whereas high expression was more prevalent in ESCC (90/165, 54.5%) than in normal esophageal (1/34, 2.8%) epithelium (P<0.001). Furthermore, DBC1 expression was significantly associated with poor prognosis in both univariate (relative ratio=2.889, P<0.001) and multivariate (relative ratio=2.655, P<0.001) analyses. DBC1 was also upregulated in all three ESCC cell lines, and the loss of DBC1 led to a significant reduction in the migration and invasion of tumor cells. Our study suggests that DBC1 may promote tumor progression, and DBC1 could be a prognostic biomarker in ESCC.