Long noncoding RNA PCA3 regulates prostate cancer through sponging miR‐218‐5p and modulating high mobility group box 1

OBJECTIVE: The purpose of this study was to investigate the mechanism of long noncoding RNA (lncRNA) prostate cancer antigen 3 (PCA3) in prostate cancer (PCa) via regulating the miR-218-5p/high mobility group box 1 (HMGB1) axis. METHODS: The Cancer Genome Atlas database was used to divide differentially expressed lncRNAs, microRNAs, and messenger RNA (mRNAs). The mRNA expressions of lncRNA PCA3, miR-218-5p, and HMGB1 were determined by reverse transcription polymerase chain reaction. Cell propagation was evaluated using the Cell Counting Kit-8 assay and the apoptotic rate was examined by flow cytometry. Cell migration and invasion were observed through the wound healing assay and transwell assay. Target relationships among PCA3, miR-218-5p, and HMGB1 were validated via dual-luciferase reporter gene assay. A nude mouse model in vivo was designed to evaluate the effect of PCA3 on prostate tumor growth. RESULTS: PCA3 and HMGB1 were high-expressed in PCa, whereas miR-218-5p was low-expressed. PCA3 knockdown or miR-218-5p overexpression suppressed PCa cell proliferation, migration, and invasion, but promoted apoptosis. Besides, targeted relationships and interactions on the expression between miR-218-5p and PCA3 or HMGB1 were elucidated. PCA3 weakened cell viability and mobility whereas induced apoptosis through binding with miR-218-5p. Meanwhile, miR-218-5p also inhibited PCa tumorigenesis via downregulation of HMGB1. Knockdown of PCA3 impeded tumor growth by downregulating its downstream gene HMGB1. CONCLUSIONS: lncRNA PCA3 facilitated PCa progression through sponging miR-218-5p and regulating HMGB1.