Prognostic significance of a component of the Hippo pathway, TAZ, in human uterine endometrioid adenocarcinoma

Transcriptional coactivator with PDZ-binding motif (TAZ) is a crucial component of the Hippo tumor suppressor pathway, interacting with transcriptional factors to regulate cell proliferation, apoptosis and tumorigenesis. TAZ and its paralog, Yes-associated protein (YAP), are activated at high frequencies during the progression towards malignancy in various tumors. Recently, YAP has been identified to modulate oncogenic features in endometrial adenocarcinoma, and it has also been reported that the nuclear expression of YAP is correlated with the poorly-differentiated form of endometrioid adenocarcinoma. In contrast to YAP, no studies have investigated TAZ expression in endometrioid adenocarcinoma. In the present study, TAZ expression was immunohistochemically examined in 55 clinical samples of endometrioid adenocarcinoma, and the clinical implications were evaluated. The results demonstrated that TAZ was located primarily in the cell nuclei, and that high TAZ expression was significantly correlated with high tumor-factor (P=0.024), stage (P=0.041) and histological grade (P=0.001), lymph node metastasis (P=0.046), recurrence (P=0.002) and a poor prognosis (P=0.007). Furthermore, univariate analysis identified that high TAZ expression was a poor prognostic factor for overall and disease-free survival. To the best of our knowledge, the present case is the first to report the clinical implications of TAZ in endometrioid adenocarcinoma of the uterus. TAZ may become a marker of a poor prognosis in endometrioid adenocarcinoma.