Tuluce, YasinKostekci, SedatKarakus, FuatKeles, Ahmet YasinTuncyurekli, Merve2025-05-102025-05-1020250301-48511573-497810.1007/s11033-025-10435-02-s2.0-105000280399https://doi.org/10.1007/s11033-025-10435-0https://hdl.handle.net/20.500.14720/12458Tuluce, Yasin/0000-0002-7312-5934BackgroundIn the present study, we investigated the immunotherapeutic and anticancer activities of microRNA-4477a (miR-4477a) as a PD-L1 inhibitor in breast cancer cells (MCF-7).MethodsTo this end, a series of analytical procedures were conducted, including bioinformatic analysis, RT-PCR analysis, PD-L1 ELISA, in vitro co-culture analysis, cytotoxicity assays, cell migration assays, and colony formation assays, with the objective of determining the anticancer activity of the compound in question.ResultsThe results demonstrated that miR-4477a can bind to three distinct regions of PD-L1 mRNA with high scores (94%, 88% and 80%), effectively targeting and suppressing the crucial regulatory pathways of cancer cells. In vitro studies demonstrated that a 25 nM dose of miR-4477a caused relatively high cytotoxicity in the MCF-7 cell line, suppressed PD-L1 gene expression, and decreased sPD-L1 protein levels, strongly inhibited cell migration, and significantly reduced colony formation. The in vitro co-culture analysis revealed that cancer cells were unable to evade the surveillance and cytotoxic activity of T cells (CD8+) due to the blockade of PD-L1 expression by miR-4477a.ConclusionsIn conclusion, miRNA-4477a has the capacity to regulate immune responses in breast cancer cells and may therefore be a promising candidate for use in cancer immunotherapy as a therapeutic agent.eninfo:eu-repo/semantics/closedAccessImmunotherapyBreast CancerImmune CheckpointPd-L1Mirna-4477AArticle521Q3Q340106025WOS:001447718800003