PRKAR2B Plays The Oncogenic Roles In The Castration-resistant Prostate Cancer

Purpose: Identification of the critical genes causing the growth of CRPC is urgent for developing effective therapeutic and diagnosis markers for the treatment of CRPC.Materials and methods: In order to identify the target genes playing important roles in the development of CRPC,we analyzed GEO and other relatedonline databases through bioinformatic methods and identified PRKAR2B(protein kinase CAMP-dependent type II regulatory subunit beta),which is a gene encoding c AMP-dependent protein kinase type II-beta regulatory subunit,to be significantly upregulated in CRPC of mouse model and patients.Then castration-resistant and castration-sensitive prostate cancer tissues were studied by immunohistochemistry(IHC)to investigate the expression of PRKAR2 B in paraffin section.Knock-down of PRKAR2 B by using si RNA in castration-resistant human prostate cancer(Pca)cell and overexpression of PRKAR2 B by plasmid transfection in human Pca cell showed PRKAR2 B regualted prostate cancer cell proliferation,invasion and apotosis.Whole genome transcriptome analysis and GO enrichment analysis identified the top changed biological pathway regualted by PRKAR2 B in CRPC and its down-stream genes.Results:(1)Dataset GSE21887 was used in our study.Differential expressed genes and Oncomine analysis were performed.We found that PRKAR2 B to be significantly upregulated in CRPC of mouse models and patients,indicating it might be a potential target regulating CRPC.(2)By using IHC,PRKAR2 B was mostly found in cytoplasm.The expression of PRKAR2 B was significantly higher in castration-resistant prostate cancer tissue compared to castration-sensitive prostate cancer and normal prostate tissue(P<0.05).In addition,a statistical difference in PRKAR2 B expression among Gleason?6,Gleason 7 and Gleason?8prostate cancer tissue was noted(P<0.001).The PRKAR2 B expression rose up along with up-grading of prostate cancer.(3)si RNA interference and PRKAR2 B plasmid transfection was used to regulate the expression of PRKAR2 B in prostate cancer cells.We found that PRKAR2 B promoted CRPC cell proliferation and invation,and inhibited CRPC cell apoptosis.(4)We knocked-down PRKAR2 B in DU-145 cells,and then performed RNA-SEQ to examine the whole genomic gene expression pattern after inhibition of PRKAR2 B.We identified 385 genes which had significant changes after knock-down of PRKAR2 B in DU145 cells.GO biological process analysis indicated that those genes were significantly involved in cell cycle process and cell mitosis.KEGG pathway analysis also showed those genes mainly played roles in cell cycle and DNA replication signaling pathways.These results indicated there's strong correlation between PRKAR2 B and cell cycle as well as cell proliferation process.In DU145 cells,the expression of those target genes,MCM2(mini-chromosome maintenance complex component 2),PLK1(polo like kinase 1),AURKB(aurora kinase B)and CCNB1(cyclin B1),was decreased after knock-down of PRKAR2 B.Meanwhile,overexpression of PRKAR2 B in 22RV1 led to up-regulation of MCM2,PLK1,AURKB and CCNB1 expression.These results indicate that those hub genes,such as MCM2,PLK1,AURKB and CCNB1,might be the key downstream genes of PRKAR2 B to regulate the development of CRPC.Conclusions: The expression of PRKAR2 B was significantly higher in castration-resistant prostate cancer tissue than in castration-sensitive prostate cancer and normal prostate tissue and its expression level increased along with the tumor malignancy.PRKAR2 B was significantly up-regulated in CPRC and promoted cell proliferation,invasion and inhibited cell apotosis.The whole genome transcriptomic gene profile analysis showed that PRKAR2 B modulated cell cycle-related gene expression in CRPC,such as MCM2,PLK1,AURKB and CCNB1.