{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\nLong noncoding RNA PURPL has emerged as an oncogenic regulator in multiple cancer types. In liver cancer, PURPL is significantly overexpressed compared with adjacent normal tissues and is linked to advanced tumor features such as poor differentiation and larger tumor size. Functional experiments demonstrated that silencing PURPL reduces liver cancer cell proliferation, blocks cell cycle progression, and induces apoptosis by negatively regulating p53 expression, thereby facilitating tumorigenesis."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": "In gastric cancer, PURPL is also markedly upregulated, and its high expression correlates with aggressive disease phenotypes. Detailed mechanistic studies have revealed that PURPL exerts its oncogenic effects by interacting with and downregulating miR-137. This interaction leads to increased expression of the transcription factor ZBTB7A, which in turn activates the PI3K-AKT-NF-κB signaling axis. The downstream consequence is an enhancement of colony formation, migration, and invasion alongside a reduction in apoptosis, cumulatively promoting malignant progression."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "2"}]}, {"type": "t", "text": "Collectively, these findings position PURPL as a critical lncRNA that drives tumor progression in both liver and gastric cancers via distinct molecular mechanisms—including p53 suppression and modulation of the miR-137-ZBTB7A-PI3K-AKT-NF-κB axis. This evidence underscores the potential of PURPL to serve as both a diagnostic biomarker and a therapeutic target in oncology."}, {"type": "fg", "children": [{"type": "fg_fs", "start_ref": "1", "end_ref": "3"}]}, {"type": "t", "text": ""}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Xueyan Fu, Yawei Wang, Gang Wu, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Long noncoding RNA PURPL promotes cell proliferation in liver cancer by regulating p53."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Mol Med Rep (2019)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.3892/mmr.2019.10159"}], "href": "https://doi.org/10.3892/mmr.2019.10159"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "31059022"}], "href": "https://pubmed.ncbi.nlm.nih.gov/31059022"}]}, {"type": "r", "ref": 2, "children": [{"type": "t", "text": "Heresh Moridi, Jamshid Karimi, Heidar Tavilani, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Overexpression of PURPL and downregulation of NONHSAT062994 as potential biomarkers in gastric cancer."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Life Sci (2019)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1016/j.lfs.2019.116904"}], "href": "https://doi.org/10.1016/j.lfs.2019.116904"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "31606380"}], "href": "https://pubmed.ncbi.nlm.nih.gov/31606380"}]}, {"type": "r", "ref": 3, "children": [{"type": "t", "text": "Zhonghua Cheng, Jing Hong, Nan Tang, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Long non-coding RNA p53 upregulated regulator of p53 levels (PURPL) promotes the development of gastric cancer."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Bioengineered (2022)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1080/21655979.2021.2017588"}], "href": "https://doi.org/10.1080/21655979.2021.2017588"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "35012438"}], "href": "https://pubmed.ncbi.nlm.nih.gov/35012438"}]}]}]}