LncRNA TPT1-AS1 promotes tumorigenesis and metastasis in epithelial ovarian cancer by inducing TPT1 expression.

Increasing numbers of studies have confirmed that long noncoding RNA (lncRNA) play a critical role in epithelial ovarian cancer (EOC) progression. However, the potential function of the lncRNA tumor protein translationally controlled 1 (TPT1) antisense RNA 1 (TPT1-AS1) in EOC is unclear. In this study, we aimed to uncover the biological roles and regulatory mechanisms of TPT1-AS1 in EOC progression and metastasis. First, TPT1-AS1 expression was significantly higher in EOC metastatic tissue and cell lines than in their respective control counterparts. In addition, ectopic TPT1-AS1 expression was strongly associated with unfavorable EOC clinicopathological features, including FIGO stage, tumor size and tumor differentiation. TPT1-AS1 overexpression remarkably induced cell proliferation, migration and invasion, and significantly attenuated cell adhesion ability in vitro and facilitated nude mouse subcutaneous xenograft growth and intraperitoneal metastasis in vivo, while the downregulation of TPT1-AS1 expression produced the opposite effect in vitro. Mechanistically, TPT1-AS1 was proven to be primarily distributed in EOC cell nuclei and positively modulated TPT1 promoter activity and transcription. Moreover, the oncogenic effects of TPT1-AS1 could be reversed by TPT1 depletion, and the PI3K/AKT signaling pathway downstream of TPT1 was also altered. These results suggested that TPT1-AS1 induced EOC tumor growth and metastasis through TPT1 and downstream PI3K/AKT signaling and that TPT1-AS1 may be a promising therapeutic target for EOC.