High expression of COUP-TF II cooperated with negative Smad4 expression predicts poor prognosis in patients with colorectal cancer.

objectiveIn order to evaluate whether the role of chicken ovalbumin upstream promoter transcription factor II (COUP-TF II) could sever as a predictor to stratify risk of human colorectal cancer (CRC) patients, and to elucidate the preliminary molecular mechanisms of COUP-TF II involved in the development and advancement of CRC reflected by investigating the relationship of COUP-TF II with PTEN, Smad4.

methods112 cases tissue microarray and immunohistochemical SP method were used to detect the expression of COUP-TF II, PTEN and Smad4 in CRC tissues and adjacent non-tumorous tissues. The clinical relevance and prognosis of COUP-TF II, PTEN, Smad4 in CRC patients were analyzed. Furthermore, Cox proportional hazards model was performed to indicate the independent prognostic factors for CRC patients using various clinicopathological parameters and COUP-TF II, PTEN and Smad4.

resultsCOUP-TF II proteins were positively expressed in 65.2% of CRC tissues and 15.5% paired non-CRC tissues, respectively. The expression of COUP-TF II was significantly correlated with TNM stage and lymph node metastasis and a negative correlation with Smad4 expression. Patients bearing higher levels of COUP-TF II expression showed lower DFS and OS. Most importantly, Cox proportional hazards regression analyses showed COUP-TF II positive/Smad4 negative status (DFS, P=0.001; OS, P=0.005) were independent prognostic factors for CRC patients.

conclusionPositive COUP-TF II expression levels has significant value in determining CRC stage and metastasis and cooperates with negative Smad4 expression contributing to assess prognosis in patients with colorectal cancer, suggesting Smad4 may be involved in the above regulation progress probably.