G2/M Checkpoint Modulation: Insights from miRNA Profiles in FAM and Breast Cancer

The aim of this research is to understand the role of microRNA in cell cycle regulation especially on G2M Checkpoint from Luminal A samples Indonesian population. The profile results are used as biomarkers and therapeutic targets for breast cancer. For this reason, analysis was carried out on the comparison of miRNA expression between Luminal A and Fibroadenoma  mamae (FAM) using Nanostring nCounter.

In this study, 5 (Formalin-Fixed Paraffin-Embedded) FFPE Luminal A tissues and 4 FFPE FAM samples were used. RNA was isolated from cancer tissue samples. Differential expression analysis of miRNA was conducted using Nanostring nCounter technology, subsequently followed by the expression analysis between FAM and Luminal A using nSolver softwere. Elevated expression levels of miRNAs were subjected to pathway and gene regulation analysis using KEGG and GSEA MsigDB databases. Data visualization was performed utilizing Cytoscape, NetworkAnalyst, and SRplot tools.

Based on 792 miRNAs detected on Nanostring nCounter, it was found that 60 miRNAs were upregulated and 6 miRNAs were downregulated. The 15 upregulated miRNAs analyzed show their role in the G2M Checkpoint through several pathways. The five miRNAs that significantly regulate the G2M Checkpoint are hsa-miR-196b-5p, hsa-miR-218-5p, hsa-miR-7-5p, hsa-miR-19a-5p, and hsa-miR-18a-5p Where each of these miRNAs regulates the CDKN1B gene.

Significant differences in the expression of multiple miRNAs between Luminal A and FAM samples were observed. Furthermore, several of these miRNAs were found to modulate the G2M Checkpoint in Luminal A cancer by suppressing tumor suppressor genes.