How hsa-miR-495 performed in the tumorigenesis of pancreatic adenocarcinoma by bioinformatics analysis.

Introduction: Pancreatic adenocarcinoma (PAAD) is one of the most fatal cancers in the world for early metastasis, extensive invasion, and poor prognosis with a 5-year survival rate less than 5%. However, the underlying mechanisms are poorly understood. Therefore, it is urgent to explore molecular markers for early diagnosis or therapy target to improve the outcome of PAAD.

Methods: We retrieved transcriptome data as well as clinical information from patients with PAAD in The Cancer Genome Altas (TCGA) database. Survival time associated microRNAs (miRNAs) and messenger RNAs (mRNAs) were initially identified, followed by enrichment analysis (Gene Ontology [GO] and pathway). The relationship between survival time associated miRNAs-mRNAs was also investigated to discover putative transcriptional control mechanisms of PAAD. Finally, by consulting the literature and retrieving the database, we found that hsa-miR-495 might have played an important role in PAAD.

Results: In total, 146 miRNAs from 378 miRNAs and 580 mRNA from 17 100 mRNA, including 328 risk mRNA and 252 protective mRNA, were found to be associated with the survival time of PAAD. Eight hundred eighty-eight mRNA-miRNA pairs were related to the survival time of PAAD, involving in 755 mRNAs and 35 miRNAs. We chose 13 miRNAs predicted by target gene in the miRanda database for further research. Among these 13 miRNAs, hsa-miR-495 was identified as a good biomarker. Through GO and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, the significantly enriched pathways involved in focal adhesion, Staphylococcus aureus infection, and Intestinal immune network for immunoglobulin A production. And four target genes and 87 pathways of the hsa-miR-495 were enriched in PAAD. Interestingly, we found hsa-miR-495 with a low expression having a poor overall survival and significantly different recurrence rate within 5 years.

Conclusion: Hsa-miR-495 and its target genes may serve as a prognostic and predictive marker in PAAD. Further research on the function of the hsa-miR-495 and its target genes in the KEGG pathway may provide references for treatment of PAAD.