Construct dysregulated miRNA-mRNA interaction networks to conjecture possible pathogenesis for Stomach adenocarcinomas.

BACKGROUND: Post-transcriptional regulation of mRNA induced by microRNA is known crucial in tumor occurrence, progression, and metastasis. This study aims at identifying significant miRNA-mRNA axes for stomach adenocarcinomas (STAD).

METHOD: RNA expression profiles were collected from The Cancer Genome Atlas (TCGA) and GEO database for screening differently expressed RNAs and miRNAs (DE-miRNAs/DE-mRNAs). Functional enrichment analysis was conducted with Hiplot and DAVID-mirPath. Connectivity MAP was applied in compounds prediction. MiRNA-mRNA axes were forecasted by TarBase and MiRTarBase. Real-time reverse transcription polymerase chain reaction (RT-qPCR) of stomach specimen verified these miRNA-mRNA pairs. Diagnosis efficacy of miRNA-mRNA interactions was measured by Receiver operation characteristic curve and Decision Curve Analysis. Clinical and survival analysis were also carried out. CIBERSORT and ESTIMATE was employed for immune microenvironment measurement.

RESULT: Totally 228 DE-mRNAs (105 upregulated and 123 downregulated) and 38 DE-miRNAs (22 upregulated and 16 downregulated) were considered significant. TarBase and MiRTarBase identified 18 miRNA-mRNA pairs, 12 of which were verified in RT-qPCR. The network of miR-301a-3p/ELL2 and miR-1-3p/ANXA2 were established and verified in external validation. The model containing all 4 signatures showed better diagnosis ability. Via interacting with M0 macrophage and resting mast cell, these miRNA-mRNA axes may influence tumor microenvironment.

CONCLUSION: This study established a miRNA-mRNA network via bioinformatic analysis and experiment validation for STAD.