Abstract
Background:
Dysregulated lncRNA PCAT6 was discovered in many cancers excluding pituitary adenomas (PA). Therefore, we explored the role of PCAT6 in PA in this research.
Methods:
Abnormally expressed miRNAs were analyzed by bioinformatics and RT-qPCR. The target and regulator of miR-139-3p were determined by bioinformatics, dual-luciferase reporter assay, or RIP. The correlation among PCAT6, miR-139-3p, and BRD4 was further analyzed. The viability, apoptosis, cell cycle distribution of PA cells, as well as their ability to invade, migrate, and proliferate, were tested after transfection through CCK-8, flow cytometry, transwell, wound healing, and colony formation assays. After construction of transplanted-tumor model in nude mice, cell apoptosis in the tumor was detected by TUNEL. The expressions of PCAT6, BRD4, miR-139-3p, and apoptosis-related factors in PA tissues, cells, or tumor tissues were detected by RT-qPCR, Western blot, or IHC.
Results:
PCAT6 and BRD4 were high-expressed but miR-139-3p was low-expressed in PA. Both the 3'-untranslated regions of PCAT6 and BRD4 mRNAs were demonstrated to contain a potential binding site for miR-139-3p. PCAT6 was positively correlated to BRD4, and miR-139-3p was negatively correlated to PCAT6 and BRD4. MiR-139-3p mimic, shPCAT6 and siBRD4 inhibited the viability, migration, invasion, and proliferation of PA cells while inducing apoptosis. MiR-139-3p mimic and shPCAT6 inhibited the cell cycle progression of PA cells, decreased the weight and volume of the xenotransplanted tumor, and reduced the levels of Bcl-2 and BRD4 while enhancing the levels of Bax, miR-139-3p, and Cleaved caspase-3. MiR-139-3p inhibitor caused the opposite effect of miR-139-3p mimic and further reversed the effect of shPCAT6 on on PA cells.
Conclusion:
PCAT6 regulated the progression of PA via modulating the miR-139-3p/BRD4 axis, which might provide a novel biomarker for the prevention, diagnosis, and treatment of PA.
Keywords:
BRD4; Pituitary adenomas; Xenotransplanted-tumor; lncRNA PCAT6; miR-139-3p.