High expression of TAZ indicates a poor prognosis in retinoblastoma

BACKGROUND The transcriptional co-activator, TAZ, is an important effector of the Hippo pathway and is critical for the development of human cancers. However, the expression and prognostic significance of TAZ in retinoblastoma is currently unclear. METHODS TAZ expression was examined in 43 retinoblastoma samples by immunohistochemistry. The relationship between TAZ expression and the clinicopathological features of retinoblastoma was also analyzed. Cox regression and Kaplan-Meier survival analyses were used to identify the prognostic factors for retinoblastoma patients. Finally, the effects of TAZ on cell proliferation were explored through lentivirus-mediated downregulation of TAZ in retinoblastoma cells. RESULTS TAZ was highly expressed in retinoblastoma tissues and was associated with regional lymph node classification (P = 0.013), largest tumor base (P = 0.045), and differentiation (P = 0.019). Moreover, patients with high TAZ expression had shorter overall survival (OS), progression-free survival (PFS), loco-regional relapse-free survival (LRRFS), and distant metastasis-free survival (DMFS) time than patients with low TAZ expression (P < 0.05). Multivariate analysis showed that high TAZ expression was an important prognostic factor for retinoblastoma patients. In addition, downregulation of TAZ expression significantly suppressed tumor cell proliferation by blocking the transition of the cell cycle from G1 to S phase. CONCLUSIONS Our findings suggest that the high expression of TAZ plays a significant role in retinoblastoma's aggressiveness, and predicts poor prognosis for patients with retinoblastoma.