Integrative Bioinformatics Analysis of hsa-miR-21 in Breast Cancer Reveals a Prognostic Hub-Gene Signature

Area of Science:

• Oncology
• Bioinformatics
• Molecular Biology

Background:

• Breast cancer (BC) is a leading cause of cancer mortality globally.
• hsa-miR-21 is an oncogenic microRNA implicated in tumorigenesis, but its regulatory network in BC is not fully understood.

Purpose of the Study:

• To characterize the molecular pathways and prognostic impact of hsa-miR-21 in breast cancer using an integrative bioinformatics approach.
• To identify key regulatory genes and pathways associated with hsa-miR-21 in BC.
• To evaluate the prognostic value of a network-based biomarker signature.

Main Methods:

• Integrated bioinformatics analysis using miRTarBase, STRING, Cytoscape, DAVID, and Kaplan-Meier Plotter.
• Construction of a high-confidence protein-protein interaction network of hsa-miR-21 targets.
• Functional enrichment analysis (Gene Ontology, KEGG pathways) and survival analysis in large BC cohorts (METABRIC, TCGA).

Main Results:

• Identified 12 hub genes central to apoptosis, proliferation, immune signaling, and transcriptional control.
• Discovered enrichment in cancer-related, immune, and metabolic pathways, indicating a pleiotropic role for miR-21.
• A composite hub-gene signature, unlike miR-21 alone, demonstrated significant prognostic value for overall survival in breast cancer.

Conclusions:

• Network-level analysis is crucial for understanding the clinical relevance of microRNAs like hsa-miR-21 in breast cancer.
• A novel hub-gene signature shows promise as a prognostic biomarker for breast cancer.
• This study provides a framework for dissecting miRNA regulatory networks and their clinical impact.