MiRNA expression profiles in high-grade prostatic intraepithelial neoplasia.

Abstract

45 Background: High-grade prostatic intraepithelial neoplasia (HGPIN) is widely believed to be a precursor of prostate cancer (PCa). However, little is known about the expression of miRNAs variations in HGPIN compared to normal tissues and PCa. Methods: The expression data of 1054 miRNAs from TCGA were applied to identify relevant miRNAs associated with tumor progression (i.e., miR-98-5p, miR-183-5p, 345-5p, miR-143 miR-210-3p and miR-378-3p). miRNA were isolated by miRNeasy FFPE kit (Qiagen, Hilden, Germany) from paraffin-embedded tissues (FFPE) of prostate specimens with PCa, HGPIN and normal tissues. Early-stage PCa was defined as PCa with pT2 tumor stage, Gleason score <=7a (3+4) and PSA level <10 ng/ml. Quantitative miRNA expression data were acquired and analyzed using a real-time TaqMan-based PCR with the ABI Prism 7900HT (Life Technologies, Darmstadt, Germany). ANOVA analysis were performed to evaluate the expression of miRNAs between HGPIN, Normal and PCa tissues. All statistical analysis was performed using SPSS (IBM, Armonk, USA). P values were adjusted using the false discovery rate for multiple comparisons. The small nuclear U6 RNA was used as an endogenous control. Results: The expression of miR-143-3p, miR-210-3p and miR-345-5p and miR-98-5-p were varied between normal tissue, HGPIN and early-stage PCa. Interestingly, decrease in expression of miR-143.-3p, miR-98-5p and miR-210-3p was associated with tumor development (Normal tissues > HGPIN > early-stage PCa) (FDR<0.001). Furthermore, overexpression of miR-345-5p was observed in normal tissues compared to HGPIN and early-stage PCa, which both showed similar expression level of miR-345-5p. No significant differences in expression of miR-375, miR-183-5p and miR-378-3p were observed between HGPIN and PCa. These miRNAs were interacted with genes related to HIF-1 signaling pathway, p53 signaling pathway, androgen receptor signaling pathway, intrinsic apoptotic signaling pathway, RNA transcription, homologous recombination and non-homologous end-joining. Conclusions: HGPIN shows an altered expression of miRNAs interact with genes related to hypoxia, androgen receptor signaling pathway, cell cycle and epigenetic regulation.