{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\nRecent studies have underscored the value of circulating miRNAs as biomarkers in disease settings. In one investigation focused on chronic heart failure, researchers sought to identify cardiac‐related miRNAs that mirror the diseased state of failing hearts. Although the study (abstract 1:"}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": "did not elaborate in detail on the individual functions of miR‑4491, its inclusion among the circulating miRNAs highlights its potential as a candidate marker for cardiac pathology.\n"}]}, {"type": "t", "text": "\n"}, {"type": "p", "children": [{"type": "t", "text": "\nIn a separate study addressing non‑small cell lung cancer (NSCLC), miR‑4491 emerged as a tumor‐suppressor. Here, investigators demonstrated that the circular RNA circ‑BIRC6 is upregulated in NSCLC and acts as a molecular sponge, binding to and negatively regulating miR‑4491. This interaction compromises the tumor‐suppressive effects of miR‑4491, thereby promoting cancer cell proliferation, colony formation, migration, and invasion, while reducing apoptosis. Notably, depletion of circ‑BIRC6 led to suppression of the Wnt2B/β‑catenin pathway and tumor growth, emphasizing the role of miR‑4491 in modulating oncogenic signaling (abstract 2:."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "2"}]}, {"type": "t", "text": "\n"}]}, {"type": "t", "text": "\n"}, {"type": "p", "children": [{"type": "t", "text": "\nTogether, these findings suggest that miR‑4491 may serve dual roles in distinct disease contexts. In chronic heart failure, while its detailed mechanism remains to be further explored, miR‑4491 is potentially valuable as part of a circulating miRNA signature for cardiac dysfunction. In NSCLC, its tumor‐suppressive activity—subject to modulation by circ‑BIRC6—illustrates its functional importance in restraining oncogenic processes, thereby offering a promising target for therapeutic intervention."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": "\n"}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Huaping Li, Jiahui Fan, Zhongwei Yin, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Identification of cardiac-related circulating microRNA profile in human chronic heart failure."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Oncotarget (2016)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.18632/oncotarget.6631"}], "href": "https://doi.org/10.18632/oncotarget.6631"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "26683101"}], "href": "https://pubmed.ncbi.nlm.nih.gov/26683101"}]}, {"type": "r", "ref": 2, "children": [{"type": "t", "text": "Zhu Jin, Baoan Gao, Yuan Gong, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Depletion of circ-BIRC6, a circular RNA, suppresses non-small cell lung cancer progression by targeting miR-4491."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Biosci Trends (2021)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.5582/bst.2020.03310"}], "href": "https://doi.org/10.5582/bst.2020.03310"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "33177288"}], "href": "https://pubmed.ncbi.nlm.nih.gov/33177288"}]}]}]}