Prostate cancer (PCa) remains the leading cancer among men worldwide. There is a critical need for new biomarkers to predict PCa progression and emerging mechanisms of resistance. Long non-coding RNAs(lncRNAs) play pivotal roles in a plethora of cellular processes. Understanding the molecular mechanisms of lncRNAs implicated in the progression of PCa could have an important impact on cancer detection, diagnosis and prognosis.

We previously identified 17 lncRNAs that were found to be differentially expressed in oriental PCa patients. Here, We focused on one uncharacterized lncRNA, which is highly expressed in locally advanced or metastatic PCa, and named it lncAPP. Silencing of lncAPP in PCa inhibitied proliferation and tumour invasion both in vitro and in vivo, resulting in a less aggressive phenotype. In addition, we found that expression of lncAPP in PCa correlated with epithelial-to-mesenchymal-transition(EMT). Using miRDB and Target Scan prediction algorithm, we identified a list of putative lncAPP-binding miRNAs. Specifically, using RNA immunoprecipitation assay and luciferase reporter assay, we demonstrated that lncAPP functions as a molecular sponge for miR218 to facilitate expression of ZEB2 and CDH2.

In conclusion, we discovered a novel lncRNA which is highly expressed in PCa patients of poor prognosis. The expression of lncAPP is associated with tumor progression. We conclude that lncAPP is an intriguing therapeutic target in PCa.

Citation Format: Xiao-Lei Shi, Yu-Tian Xiao, Fei Liu, Yue Yang, Xin-Wen Nian, Ya-Sheng Zhu, Shancheng Ren, Yinghao Sun. A novel long non-coding RNA competes with endogenous RNA and mediates prostate cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4421.