LncRNA AC008972.1 as a Novel Therapeutic Target for Prostate Cancer

Background: Prostate cancer is the leading cause of disease and death in men. Long non-coding RNAs (lncRNAs), microRNA (miRNAs) and mRNAs networks mediate prostate cancer progression. Here, we aim to investigate functions of lncRNA AC008972.1/miR-143-3p/thousand-and-one-amino acid 2 kinase (TAOK2) in prostate cancer. Methods: The expression levels of lncRNA AC008972.1, miR-143-3p and TAOK2 are detected in prostate cancer tissues and cell lines by RT-qPCR. PC3 and LNCaP cells are used to establish lncRNA AC008972.1-knockdown, miR-143-3p-overexpressing, and TAOK2-down-regulated cells. Cell viability is examined by MTT and cell proliferation is detected by clone formation assay. Cell migration and invasion are tested by wound scratch assay and transwell chamber assay. The rate of apoptosis was analyzed by flow cytometry. The protein expression is detected by western blot assay. The target is validated by RNA binding protein immunoprecipitation (RIP) assay and dual luciferase activity assay. A mouse xenograft model was conducted to investigate the oncogenic effect of lncRNA AC008972.1 on prostate cancer. Results: High expression of lncRNA AC008972.1 was associated with low overall survival in prostate cancer. Down-regulation of lncRNA AC008972.1 delayed prostate cancer process by inhibiting cell viability, proliferation, migration and invasion, as well as altering protein expression，whereas cell apoptosis was markedly promoted. LncRNA AC008972.1 negatively regulated miR-143-3p expression and miR-143-3p overexpression promoted prostate cancer process in vitro. TAOK2 expression was decreased by miR-143-3p through the complementary targeting of TAOK2 mRNA. Down-regulation of lncRNA AC008972.1 mitigated prostate cancer process in vitro based on miR-143-3p/TAOK2 node. Furthmore, the data of xenograft model experiment showed that inhibition of lncRNA AC008972.1 suppressed tumor growth in vivo. Conclusions: Collectively, knockdown of lncRNA AC008972.1 inhibits prostate cancer cell growth based on down-regulation of TAOK2 induced by miR-143-3p. Here, we identify that lncRNA AC008972.1 exerts essential roles in the progression of prostate cancer and serves as a novel therapeutic target for prostate cancer.