Abstract
Colorectal cancer (CRC) is one of the most common types of malignancy with high morbidity and mortality rates worldwide. This biologically heterogeneous disease results in diverse therapeutic responses, thus, novel prognostic biomarkers are required to improve CRC treatment. Estrogen-related receptor α (ERRα) is a nuclear orphan receptor, which is associated with estrogen receptor α. The present study aimed to investigate the expression of ERRα in patients with CRC, and explore the association between ERRα expression and clinicopathological factors, local recurrence and prognosis. In the present study, ERRα expression was detected in 15 fresh CRC tissues using quantitative real-time polymerase chain reaction (RT-qPCR) and in 128 paraffin-embedded CRC tissues using immunohistochemistry. The associations between ERRα expression and prognosis of CRC patients were evaluated by univariate, and multivariate (Cox proportional hazards model) analysis. RT-qPCR demonstrated that the mRNA expression of ERRα in CRC tissues was significantly higher compared with that in matched normal tissues. Immunohistochemistry revealed that ERRα high expression was detected in the nuclei of cancer cells from 39.1% (50/128) of CRC tissues. ERRα expression based on immunohistochemical staining was significantly associated with tumor differentiation, tumor invasion, lymph node status and Dukes stage (all P<0.05). Furthermore, patients with high ERRα expression were significantly associated with an increased risk of recurrence and poor prognosis, compared with patients with low ERRα expression. ERRα expression was identified as an independent prognostic factor for patients with CRC. In conclusion, ERRα serves important roles in the progression of CRC and is a potential prognostic factor for patients with CRC.