{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\nBreast cancer resistance to chemotherapy is a major hurdle in effective treatment. In a recent study, a novel microRNA, miR-3609, was identified as a key modulator of breast cancer chemoresistance. The investigators found that miR-3609 expression was significantly lower in adriamycin‐resistant breast cancer cells compared to chemotherapy‐sensitive cells, an effect associated with a concomitant increase in PD-L1 expression. Mechanistic studies revealed that overexpression of miR-3609 suppressed the activity of a luciferase reporter linked to the PD-L1 3′UTR and that transfection with a miR-3609 mimic reduced PD-L1 protein levels in a dose-dependent manner."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": ""}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nMoreover, enforced expression of miR-3609 in resistant cells not only decreased PD-L1 levels but also enhanced the sensitivity of these cells to adriamycin. In vivo, mice injected with breast cancer cells stably overexpressing miR-3609 exhibited prolonged survival and a reduced number of tumors. Notably, the antitumor benefits of miR-3609 were abrogated by the depletion of CD8+ T cells, underscoring a critical role for the adaptive immune response in mediating these effects."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": ""}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nCollectively, these findings reveal that miR-3609 functions as a tumor suppressor in breast cancer by downregulating PD-L1 expression and thereby mitigating chemoresistance. The study further demonstrates that low levels of miR-3609, together with high PD-L1 expression, correlate with poor patient prognosis, suggesting that restoration of miR-3609 expression could be a promising strategy to enhance the efficacy of adriamycin chemotherapy."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": ""}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Duolu Li, Xinru Wang, Meng Yang, et al. "}, {"type": "b", "children": [{"type": "t", "text": "miR3609 sensitizes breast cancer cells to adriamycin by blocking the programmed death-ligand 1 immune checkpoint."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Exp Cell Res (2019)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1016/j.yexcr.2019.03.025"}], "href": "https://doi.org/10.1016/j.yexcr.2019.03.025"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "30904483"}], "href": "https://pubmed.ncbi.nlm.nih.gov/30904483"}]}]}]}