Abstract:
Breast cancer remains one of the leading causes of cancer-related mortality among women worldwide. MicroRNAs (miRNAs), a class of small non-coding RNAs that regulate gene expression post-transcriptionally, have emerged as critical regulators in cancer development, progression, and therapeutic response. Aberrant expression of miRNAs can function either as oncogenes or tumor suppressors, influencing tumorigenesis through modulation of key signaling pathways.

We present here the ongoing research on microRNA profiles associated with Vietnamese breast cancer patients and explore the applications in risk prediction, diagnosis, and therapy:

1. Using next-generation sequencing (NGS) based on the Ion Torrent platform, we investigated candidate miRNA-related single nucleotide polymorphisms (miR-SNPs) in a pilot cohort of 50 breast cancer cases and 50 controls to evaluate their potential for genetic risk prediction through PRS model (polygenic Risk Score model). A panel of miR-SNPs had been found.
2. For diagnostic applications, the modified stemloop RT-qPCR assay had been choosen to improve in detection and measuring of the candidated miRNAs. Through that, we developed an open primer-design tool (PAprimer) that facilitates optimized stem-loop RT-qPCR primer generation and specificity validation. A set of miRNAs had been found as the potential maker for breast cancer diagnostic in Vietnamese. However, due to the similar sequence among miRNA, particular in the same family, the more efficient method is need to be developed.
3. We also explored the therapeutic potential of miRNA-based approaches. Using liposomemediated transfection (Lipofectamine RNAiMAX), miR-141-3p mimic delivery into MCF-7 breast cancer cells demonstrated increased expression of tumor suppressive pathways, reduced cell proliferation, and decreased migration. However, current lipid-based delivery systems present limitations, including variability and cytotoxicity.

These findings highlight the promise of miRNA-based biomarkers and therapeutics for breast cancer management in Vietnam, while emphasizing the need for improved miRNA detection technologies and more efficient delivery systems such as nanoparticle carriers, viral vectors, electroporation strategies, and endogenous miRNA activation approaches. Continued development of these platforms will facilitate the translation of miRNA research into precision oncology applications.