{"type": "root", "children": [{"type": "t", "text": "<head>\n <meta charset=\"UTF-8\">\n <title>Summary of LINC01021 Function</title>\n </head>\n \n "}, {"type": "p", "children": [{"type": "t", "text": "\n LINC01021, also known as PURPL, has emerged as a multifunctional long non‐coding RNA implicated in both tumor suppression and tumor progression, depending on the cellular context. In colorectal cancer cells, LINC01021 is directly induced by p53 and is an integral part of an auto‐regulatory feedback circuit that modulates basal p53 levels. In one study, ectopic expression of LINC01021 reduced cell proliferation in the SW480 colorectal cancer cell line, suggesting its role in fine‐tuning the p53 response, whereas depletion of LINC01021 (PURPL) led to elevated basal p53 levels and consequent growth defects, highlighting its function in maintaining p53 homeostasis."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": "\n "}]}, {"type": "t", "text": "\n "}, {"type": "p", "children": [{"type": "t", "text": "\n In contrast, in gastric cancer, LINC01021 is found to be upregulated. Functional studies reveal that high LINC01021 expression promotes malignant behaviors – including enhanced migration, invasion, and angiogenesis – by modulating key signaling pathways. Mechanistically, LINC01021 regulates the expression of KISS1 through a pathway governed by CDK2-mediated phosphorylation of the transcription factor CDX2. Inhibition of LINC01021 in this context suppresses tumorigenesis, underscoring its oncogenic role in gastric cancer progression."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "3"}]}, {"type": "t", "text": "\n "}]}, {"type": "t", "text": "\n "}, {"type": "p", "children": [{"type": "t", "text": "\n Furthermore, genetic studies have identified loci near LINC01021 that are associated with abdominal aortic aneurysm, pointing to possible roles in vascular disease pathogenesis and suggesting that the impact of LINC01021 may extend beyond cancer."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "4"}]}, {"type": "t", "text": "\n "}]}, {"type": "t", "text": "\n "}, {"type": "p", "children": [{"type": "t", "text": "\n In summary, LINC01021 functions as a p53-responsive lncRNA that contributes to the regulation of cell proliferation via an auto-regulatory loop in colorectal cancer, while in gastric cancer it acts as an oncogenic driver by facilitating malignant cell behaviors. Its association with vascular anomalies further broadens the significance of this lncRNA in human disease.\n "}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Sabine Hünten, Markus Kaller, Friedel Drepper, et al. "}, {"type": "b", "children": [{"type": "t", "text": "p53-Regulated Networks of Protein, mRNA, miRNA, and lncRNA Expression Revealed by Integrated Pulsed Stable Isotope Labeling With Amino Acids in Cell Culture (pSILAC) and Next Generation Sequencing (NGS) Analyses."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Mol Cell Proteomics (2015)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1074/mcp.M115.050237"}], "href": "https://doi.org/10.1074/mcp.M115.050237"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "26183718"}], "href": "https://pubmed.ncbi.nlm.nih.gov/26183718"}]}, {"type": "r", "ref": 2, "children": [{"type": "t", "text": "Xiao Ling Li, Murugan Subramanian, Matthew F Jones, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Long Noncoding RNA PURPL Suppresses Basal p53 Levels and Promotes Tumorigenicity in Colorectal Cancer."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Cell Rep (2017)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1016/j.celrep.2017.08.041"}], "href": "https://doi.org/10.1016/j.celrep.2017.08.041"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "28877474"}], "href": "https://pubmed.ncbi.nlm.nih.gov/28877474"}]}, {"type": "r", "ref": 3, "children": [{"type": "t", "text": "Yu Wang, Rongke Jiang, Qiang Wang, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Silencing LINC01021 inhibits gastric cancer through upregulation of KISS1 expression by blocking CDK2-dependent phosphorylation of CDX2."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Mol Ther Nucleic Acids (2021)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1016/j.omtn.2021.01.025"}], "href": "https://doi.org/10.1016/j.omtn.2021.01.025"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "34026327"}], "href": "https://pubmed.ncbi.nlm.nih.gov/34026327"}]}, {"type": "r", "ref": 4, "children": [{"type": "t", "text": "Tamara Ashvetiya, Sherry X Fan, Yi-Ju Chen, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Identification of novel genetic susceptibility loci for thoracic and abdominal aortic aneurysms via genome-wide association study using the UK Biobank Cohort."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "PLoS One (2021)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1371/journal.pone.0247287"}], "href": "https://doi.org/10.1371/journal.pone.0247287"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "34469433"}], "href": "https://pubmed.ncbi.nlm.nih.gov/34469433"}]}]}]}