Identification and functional activity of Nik related kinase (NRK) in benign hyperplastic prostate

Benign prostatic hyperplasia (BPH) is common in elder men. The current study aims to identify differentially expressed genes (DEGs) in hyperplastic prostate and to explore the role of Nik related kinase (NRK) in BPH.

Four datasets including three bulk and one single cell RNA-seq (scRNA-seq) were obtained to perform integrated bioinformatics. Cell clusters and specific metabolism pathways were analyzed. The localization, expression and functional activity of NRK was investigated via RT-PCR, western-blot, immunohistochemical staining, flow cytometry, wound healing assay, transwell assay and CCK-8 assay.

A total of 17 DEGs were identified by merging three bulk RNA-seq datasets. The findings of integrated single-cell analysis showed that NRK remarkably upregulated in fibroblasts and SM cells of hyperplasia prostate. Meanwhile, NRK was upregulated in BPH samples and localized almost in stroma. The expression level of NRK was significantly correlated with IPSS and Q_max of BPH patients. Silencing of NRK inhibited stromal cell proliferation, migration, fibrosis and EMT process, promoted apoptosis and induced cell cycle arrest, while overexpression of NRK in prostate epithelial cells showed opposite results. Meanwhile, induced fibrosis and EMT process were rescued by knockdown of NRK. Furthermore, expression level of NRK was positively correlated with that of α-SMA, collagen-I and N-cadherin, negatively correlated with that of E-cadherin.

Our novel data identified NRK was upregulated in hyperplastic prostate and associated with prostatic stromal cell proliferation, apoptosis, cell cycle, migration, fibrosis and EMT process. NRK may play important roles in the development of BPH and may be a promising therapeutic target for BPH/LUTS.