Elevated Expression of NOP16 as a Novel Prognostic Biomarker of Prostate Cancer

Objective. To investigate the role of NOP16, a target gene of estrogen and c-Myc, in prostate cancer (PCa). Methods. The expressions of NOP16 in PCa and benign prostate hyperplasia (BPH) tissues, PC-3 and RWPE-1 cell lines were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot respectively. The expressions of NOP16 in BPH and PCa paraffin-embedded tissues were assessed by immunohistochemistry (IHC). The Cancer Genome Atlas (TCGA) database was used to analyze the effect of NOP16 gene expression on the disease-free survival of PCa patients. CCK-8, wound healing, transwell assays and flow cytometric analysis were used to assess the changes of proliferation, migration, invasion and apoptosis of PC-3 cells respectively after knocking down NOP16 in vitro. Gene ontology (GO) and gene set enrichment analysis (GSEA) were used to analyze the RNA sequencing data followed by knocking down NOP16 in PC-3 cells. Mouse models were used to explore the effect of NOP16 on PC-3 subcutaneous tumor growth in vivo. Results. The NOP16 expression was significantly higher in PCa tissues than that in BPH tissues and significantly higher in PC-3 cells than in RWPE-1 cells. PCa patients with low NOP16 expression have a longer disease-free survival than that with high NOP16 expression. Ribosome biogenesis in eukaryotes, ECM-receptor interaction, PTEN and VEGF signaling pathways may be changed in the NOP16 knockdown group than control. Knockdown of NOP16 could significantly inhibit the pro-liferation, migration and invasion of PC-3 cells in vitro and in vivo. Low expression of NOP16 could reduce the total protein synthesis and induce the apoptosis of PC-3 cells. Conclusion. NOP16 may be expected to be a novel biomarker for predicting the occurrence and development of PCa, and may become a target for the treatment of PCa.