Jovana Jovankić1, Sanja Goč2, Aleksandra Nikezić1, Olgica Nedić3, Jovana Stevanović3, Miloš Brkušanin4 and Zorana Dobrijevic3*
1Faculty of Science, University of Kragujevac
2University of Belgrade, Institute for the Application of Nuclear Energy, INEP
3Institute for the Application of Nuclear Energy
4University of Belgrade – Faculty of Biology
zorana.dobrijevic [at] inep.co.rs
Abstract
Downregulation of tumor-suppressive microRNAs in breast cancer (BC) triggers molecular disturbances underlying cancer initiation, disease progression and metastasis. However, key microRNAs players acting as vital breaks on BC aggressiveness, with crucial regulatory roles in cell migration, epithelial-mesenchymal transition (EMT), invasion, and metas-tasis, remain underinvestigated. Our goal was to uncover candidate tumor-suppresive microRNAs associated with metastatic potential of BC via an in silico approach, which combined data from microRNA profiling studies on cell lines relevant to BC invasiveness, as well as on primary vs. metastatic BC. A minimal set of candidate microRNAs was determined from the intersection of downregulated sets from multiple eligible studies, confirmed by qPCR, assessed for potential clinical relevance in BC and functionally characterized. Predicted and experimentally valdated targets of these microRNAs were identified (MiRTargetLink) and subjected to gene ontology (GO), KEGG pathway, and cancer hallmark enrichment analysis. A microRNA-mRNA interaction network was constructed (MiRNet), and mRNA profiling data was integrated, in order to enable the identification of hub genes and upregulated microRNA targets mediating BC EMT, invasion, and metastasis. Three microRNAs emerged as plausible BC metastasis-related candidates: miR-141-3p, miR-200c-3p, and miR-205-5p. The downregulation of these microRNAs in cell lines with higher invasiveness was confirmed by qPCR, while an association with negative clinical features was also noted. Both members of miR-200 family demonstrated a correlation with the expression of key regulators of EMT in BC tissues. Hub genes from DE-microRNA-mRNA network showed enrichment in pathway and GO terms related to malignant phenotype, while “tissue invasion and metastasis” was one of the top enriched cancer hallmarks. These results support the hypothesized functional relevance of analyzed microRNAs in BC.
Keywords: microRNAs, invasion, EMT, metastasis, BRCA
Acknowledgement: This research was supported by the Ministry of Science, Technological Development and Innovation of the Republic of Serbia (Agreement nos. 451-03-33/2026-03/200019 and 451-03-33/2026-03/200122) and aligns with United Nations Sustainable Development Goal 3 (Good Health and Wellbeing) of the 2030 Agenda.