LncRNA TP73-AS1 predicts poor prognosis and functions as oncogenic lncRNA in osteosarcoma.

TP73 antisense RNA 1 (TP73-AS1), a novel long noncoding RNA (lncRNA), has been suggested to be deregulated in various human cancers and serve as a tumor suppressor or promoter, depending on tumor types. The role of TP73-AS1 in osteosarcoma is still unknown. In our results, TP73-AS1 was highly expressed in osteosarcoma tissue samples and cell lines compared with matching adjacent nontumor tissue specimens and a normal human osteoblast cell line, respectively. Moreover, high expression of TP73-AS1 was statistically associated with advanced Enneking stage, large tumor size, present distant metastasis, and poor histological grade, while exhibiting no statistical association with age, sex, and tumor site. The survival analyses showed that patients with osteosarcoma with high expression of TP73-AS1 obviously had lower overall survival than osteosarcoma patients with low expression of TP73-AS1, and high expression of TP73-AS1 was an independent poor prognostic factor for osteosarcoma patients. The experiments in vitro indicated that inhibition of TP73-AS1 expression depressed osteosarcoma cell viability, migration, and invasion, and arrested cell cycle. In conclusion, TP73-AS1 serves as oncogenic lncRNA participated in osteosarcoma progression.