LncRNA-PAGBC acts as a microRNA sponge and promotes gallbladder tumorigenesis

Long noncoding RNAs (lncRNAs) play roles in the development and progression of many cancers; however, the contributions of lncRNAs to human gallbladder cancer (GBC) remain largely unknown. In this study, we identify a group of differentially expressed lncRNAs in human GBC tissues, including prognosis-associated gallbladder cancer lncRNA (lncRNA-PAGBC), which we find to be an independent prognostic marker in GBC. Functional analysis indicates that lncRNA-PAGBC promotes tumour growth and metastasis of GBC cells. More importantly, as a competitive endogenous RNA (ceRNA), lncRNA-PAGBC competitively binds to the tumour suppressive microRNAs miR-133b and miR-511. This competitive role of lncRNA-PAGBC is required for its ability to promote tumour growth and metastasis and to activate the AKT/mTOR pathway. Moreover, lncRNA-PAGBC interacts with polyadenylate binding protein cytoplasmic 1 (PABPC1) and is stabilized by this interaction. This work provides novel insight on the molecular pathogenesis of GBC.