{"gene":"BPIFB1","run_date":"2026-06-09T22:02:45","timeline":{"discoveries":[{"year":2013,"finding":"BPIFB1 (LPLUNC1) inhibits IL-6-induced NPC cell proliferation by suppressing JAK2/STAT3 activation; overexpression decreased cyclin D1, Bcl-2, and JAK2/STAT3 phosphorylation while increasing Bax and p21, and also suppressed LPS-induced IL-6, IL-8, TNF-α, and IL-1β expression in vitro.","method":"Stable transfection overexpression in NPC cell lines, western blotting, in vivo tumor implantation model, THP-1 macrophage co-treatment assay","journal":"Oncogene","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean overexpression with defined cellular phenotype and pathway readout, in vitro and in vivo, single lab","pmids":["23708661"],"is_preprint":false},{"year":2013,"finding":"BPIFB1 (LPLUNC1) inhibits NPC cell growth by downregulating MEK1, phospho-ERK1/2, phospho-JNK1/2, c-Myc, and c-Jun, reducing AP-1 transcriptional activity, and inhibiting cyclin D1, CDK4, and phospho-Rb, thereby delaying G1-to-S phase transition.","method":"Stable transfection overexpression, cDNA microarray, western blotting, in vitro proliferation and cell cycle assays, in vivo tumor formation","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (microarray + western blot + cell cycle + in vivo), single lab","pmids":["23650533"],"is_preprint":false},{"year":2017,"finding":"BPIFB1 inhibits NPC cell migration, invasion, and lung metastasis by interacting with vitronectin (VTN) and vimentin (VIM); it reduces VTN expression and VTN-integrin αV complex formation, thereby suppressing FAK/Src/ERK signalling and inhibiting VTN- or VIM-induced epithelial-mesenchymal transition.","method":"Co-immunoprecipitation coupled with mass spectrometry, western blotting, immunofluorescence, immunohistochemistry, in vitro migration/invasion assays, in vivo lung metastasis model","journal":"British journal of cancer","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP/MS identification of interacting partners combined with functional pathway readout, in vitro and in vivo validation","pmids":["29123267"],"is_preprint":false},{"year":2018,"finding":"BPIFB1 inhibits VTN-mediated radioresistance in NPC cells; VTN promotes G2/M arrest, DNA repair, ATM-Chk2 and ATR-Chk1 pathway activation, and anti-apoptotic effects after ionizing radiation, while BPIFB1 suppresses these VTN-dependent pro-survival responses to sensitize NPC cells to radiation.","method":"Colony formation assay, cell survival assay, overexpression and knockdown experiments, western blotting for DNA damage checkpoint proteins","journal":"Cell death & disease","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional rescue/pathway experiments with defined molecular readouts, single lab, multiple complementary assays","pmids":["29568064"],"is_preprint":false},{"year":2019,"finding":"BPIFB1 (LPLUNC1) stabilizes PHB1 protein by competitively impairing PHB1 binding to E3 ubiquitin ligase TRIM21 (due to stronger BPIFB1-PHB1 affinity), thereby preventing TRIM21-mediated PHB1 ubiquitination and degradation; stabilized PHB1 then inhibits NF-κB activity, and PHB1 depletion reverses the anti-tumour effects of BPIFB1.","method":"Co-immunoprecipitation, ubiquitination assay, siRNA knockdown, western blotting, NF-κB reporter assay","journal":"Oncogene","confidence":"High","confidence_rationale":"Tier 1-2 / Moderate — mechanistic dissection of ubiquitination pathway with co-IP, ubiquitination assay, and epistasis rescue, single lab but multiple orthogonal methods","pmids":["30886235"],"is_preprint":false},{"year":2011,"finding":"BPIFB1 (LPLUNC1) attenuates proinflammatory innate immune responses to V. cholerae and E. coli LPS in a TLR4-dependent, dose-dependent manner; it does not affect TLR2-mediated responses. The protein is expressed in Paneth cells in the duodenum.","method":"In vitro LPS stimulation assays, TLR4-dependent signalling readout, immunostaining of duodenal biopsies from cholera patients","journal":"The Journal of infectious diseases","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional assay with TLR pathway specificity control and tissue localization, single lab","pmids":["21900486"],"is_preprint":false},{"year":2013,"finding":"BPIFB1 reduces inflammatory responses to P. aeruginosa LPS in RAW264.7 macrophages by decreasing CD14, TLR4, and MyD88 expression, and inhibiting TRAF6/NF-κB activity and ERK1/2, p38, and Akt1 phosphorylation, as demonstrated by siRNA knockdown and specific kinase inhibitors.","method":"ELISA, western blotting, siRNA knockdown of MyD88/TRAF6/NF-κB, kinase inhibitor treatment, LPS stimulation assay","journal":"Xi bao yu fen zi mian yi xue za zhi (Chinese journal of cellular and molecular immunology)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — pathway dissection using siRNA and inhibitors with multiple molecular readouts, single lab","pmids":["23746244"],"is_preprint":false},{"year":2010,"finding":"BPIFB1 (LPLUNC1) is a secreted, glycosylated protein produced by goblet cells of the airway epithelium and nasal passages, and by submucosal glands; it is present in bronchoalveolar lavage fluid as two glycosylated isoforms, and primary airway epithelial cells secrete identical isoforms during mucociliary differentiation.","method":"Affinity-purified antibody immunolocalization, western blotting of BAL and cell culture secretions, primary human airway epithelial cell cultures","journal":"Histochemistry and cell biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct localization with functional-context secretion characterization, multiple tissue/cell types, single lab","pmids":["20237794"],"is_preprint":false},{"year":2021,"finding":"BPIFB1 inhibits vasculogenic mimicry in NPC by reducing GLUT1 transcription via downregulation of the JNK/AP1 signalling pathway; reduced glycolysis lowers histone H3K27 acetylation levels, which decreases expression of vasculogenic mimicry-related genes VEGFA, VE-cadherin, and MMP2.","method":"Overexpression studies, glycolysis assays, histone acetylation profiling, gene expression analysis, western blotting, vasculogenic mimicry tube-formation assay","journal":"Oncogene","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multi-step pathway established in single lab with several complementary functional and molecular assays","pmids":["34725462"],"is_preprint":false},{"year":2022,"finding":"BPIFB1 (LPLUNC1) reduces glycolysis and increases oxidative phosphorylation in NPC cells via the PHB1-p53/c-Myc axis; BPIFB1 overexpression promotes phosphorylated PHB1 nuclear translocation through 14-3-3σ, increases p53, and decreases c-Myc expression.","method":"Overexpression and knockdown, western blotting, metabolic assays (glycolysis vs. OXPHOS), nuclear fractionation, all-trans retinoic acid (ATRA) treatment","journal":"Cancer science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — mechanistic pathway with multiple molecular readouts and pharmacological validation, single lab","pmids":["36382614"],"is_preprint":false},{"year":2017,"finding":"Bpifb1 knockout mice exhibit higher MUC5B airway mucin protein levels, and Bpifb1 mRNA and protein are upregulated in parallel with MUC5B after allergen challenge, identifying BPIFB1 as a novel trans-acting regulator of MUC5B.","method":"Genetic QTL mapping in Collaborative Cross mice, Bpifb1 knockout mouse model, allergen challenge, gene and protein expression analysis","journal":"Genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic KO with defined molecular phenotype, supported by QTL mapping, single lab","pmids":["28851744"],"is_preprint":false},{"year":2023,"finding":"BPIFB1 loss in mice reduces mucociliary clearance (MCC) in vivo independently of defects in epithelial ion transport or ciliary beat frequency; loss of BPIFB1 alters biophysical and biochemical properties of mucus. BPIFB1 co-localizes with MUC5B in secretory granules in mice and in the secreted mucus protein mesh in human airway epithelial cultures.","method":"Bpifb1 knockout mouse model, in vivo MCC measurement, mucus biophysical/biochemical characterization, colocalization by immunofluorescence in mouse tissue and human airway cultures","journal":"American journal of physiology. Lung cellular and molecular physiology","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic KO with specific in vivo functional phenotype, orthogonal mechanistic exclusions (ion transport, CBF), and colocalization in two species","pmids":["37847709"],"is_preprint":false},{"year":2022,"finding":"BPIFB1 acts as a downstream target of alveolar type 2 cell-specific PER2 circadian signalling; intense light-elicited ATII-PER2 upregulates BPIFB1, which mediates lung-protective and anti-inflammatory effects during Pseudomonas aeruginosa-induced acute lung injury.","method":"Cell-type-specific Per2 knockout mice (ATII, endothelial, myeloid), P. aeruginosa ALI model, genome-wide mRNA array, nobiletin (PER2 enhancer) pharmacological recapitulation","journal":"American journal of physiology. Lung cellular and molecular physiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic epistasis in cell-type-specific KO with genome-wide target identification and pharmacological validation, single lab","pmids":["35272486"],"is_preprint":false},{"year":2024,"finding":"BPIFB1 suppresses PD-L1 expression in NPC cells by repressing STAT1, an upstream activator of PD-L1; BPIFB1 overexpression inhibits CD8+ T cell apoptosis. EBV-encoded miR-BART4 directly targets and inhibits BPIFB1, establishing an EBV-miR-BART4/BPIFB1/STAT1/PD-L1 immune-escape axis.","method":"Overexpression/knockdown, qRT-PCR, western blot, flow cytometry (CD8+ T cell apoptosis), chromatin immunoprecipitation (ChIP), luciferase reporter assay","journal":"Biochemical genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — mechanistic pathway with ChIP, luciferase, and functional immune readout, multiple orthogonal methods, single lab","pmids":["38467887"],"is_preprint":false},{"year":2023,"finding":"BPIFB1 promotes metastasis of hormone receptor-positive breast cancer by stimulating M2-like polarization of macrophages; demonstrated using breast cancer cell/THP-1 macrophage co-culture, Transwell invasion assays, and animal experiments.","method":"BC/THP-1 macrophage co-culture system, qPCR, Transwell assay, animal experiments","journal":"Cancer science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional co-culture and in vivo experiments with defined immune phenotype, single lab","pmids":["37702269"],"is_preprint":false},{"year":2019,"finding":"BPIFB1 overexpression induces apoptosis and DNA damage and arrests the cell cycle at G0/G1 in NPC cells via the MEK/ERK signalling pathway; MEK inhibitor U0126 reversed the proliferative effects of BPIFB1 silencing, confirming pathway dependency.","method":"Overexpression and siRNA knockdown, colony formation, cell cycle analysis, western blotting, MEK inhibitor (U0126) rescue experiment","journal":"International journal of clinical and experimental pathology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — pharmacological rescue with inhibitor confirms pathway, multiple assays, single lab","pmids":["31933752"],"is_preprint":false},{"year":2017,"finding":"BPIFB1 protein is localized in secretory granules of parotid gland acinar cells in NOD mice and is secreted into saliva, where it carries N-linked glycans reactive with Aleuria aurantia lectin, appearing as two spots of slightly different pI and molecular weight.","method":"Immunoblotting of subcellular fractions, immunohistochemistry, lectin blotting, saliva western blot","journal":"Odontology","confidence":"Low","confidence_rationale":"Tier 3 / Weak — subcellular fractionation localization in a single animal model without functional consequence established","pmids":["28748269"],"is_preprint":false}],"current_model":"BPIFB1 is a secreted, glycosylated goblet-cell protein of the upper airway that functions as an innate immune modulator and tumor suppressor: it dampens TLR4/LPS-driven inflammation (via CD14/TLR4/MyD88/NF-κB and MAPK pathways), inhibits NPC cell growth and metastasis by interacting with VTN and VIM to suppress FAK/Src/ERK and EMT, stabilizes PHB1 by blocking TRIM21-mediated ubiquitination to restrain NF-κB, reduces glycolysis through a PHB1-p53/c-Myc axis, inhibits vasculogenic mimicry via JNK/AP1-GLUT1-H3K27ac, suppresses PD-L1 through STAT1 repression, and is required for normal mucociliary clearance through co-assembly with MUC5B in secretory granules."},"narrative":{"mechanistic_narrative":"BPIFB1 (LPLUNC1) is a secreted, glycosylated protein of upper-airway goblet cells and submucosal glands that serves dual roles as an innate-immune modulator of the mucosal surface and as a tumor suppressor in nasopharyngeal carcinoma (NPC) [PMID:20237794, PMID:29123267]. In the airway it co-assembles with the gel-forming mucin MUC5B in secretory granules and in the secreted mucus mesh, acting as a trans-regulator of MUC5B levels and as a determinant of mucus biophysical/biochemical properties required for normal mucociliary clearance independently of ciliary beat frequency or epithelial ion transport [PMID:28851744, PMID:37847709]. It dampens LPS-driven proinflammatory signalling in a TLR4-dependent manner, downregulating CD14/TLR4/MyD88 and TRAF6/NF-κB activity along with ERK, p38, and Akt phosphorylation [PMID:21900486, PMID:23746244]. In NPC, BPIFB1 restrains proliferation and survival by suppressing MEK/ERK and JAK2/STAT3 signalling, lowering cyclin D1/CDK4 and AP-1 activity to block the G1–S transition [PMID:23708661, PMID:23650533, PMID:31933752]. It inhibits migration, invasion, metastasis, and radioresistance through physical interaction with vitronectin (VTN) and vimentin (VIM), reducing VTN–integrin αV complexes and downstream FAK/Src/ERK signalling and EMT [PMID:29123267, PMID:29568064]. Mechanistically, BPIFB1 stabilizes PHB1 by outcompeting the E3 ligase TRIM21 to block PHB1 ubiquitination, thereby restraining NF-κB and, via a PHB1–p53/c-Myc axis, shifting metabolism away from glycolysis toward oxidative phosphorylation [PMID:30886235, PMID:36382614]. It further suppresses vasculogenic mimicry through a JNK/AP1–GLUT1–H3K27ac axis [PMID:34725462] and limits immune escape by repressing STAT1-driven PD-L1, an axis targeted by EBV miR-BART4 [PMID:38467887].","teleology":[{"year":2010,"claim":"Established BPIFB1 as a secreted glycoprotein product of airway goblet cells, defining the cellular source and processed isoforms that anchor all later functional work.","evidence":"Antibody immunolocalization and western blotting of BAL fluid and primary airway epithelial secretions","pmids":["20237794"],"confidence":"Medium","gaps":["Function of the secreted protein not addressed","Role of glycosylation isoforms undefined"]},{"year":2011,"claim":"Showed BPIFB1 attenuates LPS-induced innate immune responses specifically through TLR4 and not TLR2, establishing it as a pathway-selective anti-inflammatory mucosal factor.","evidence":"In vitro LPS stimulation with TLR pathway controls; duodenal Paneth-cell immunostaining","pmids":["21900486"],"confidence":"Medium","gaps":["Direct LPS/TLR4 binding not demonstrated","Mechanism of TLR4 selectivity unresolved"]},{"year":2013,"claim":"Defined the intracellular signalling consequences of BPIFB1 anti-inflammatory action and its tumor-suppressive proliferation control, linking it to CD14/TLR4/MyD88/TRAF6/NF-κB, MEK/ERK, JNK, AP-1, and JAK2/STAT3 nodes.","evidence":"siRNA knockdown and kinase inhibitors in macrophages; overexpression with microarray, western blot, cell cycle, and in vivo tumor assays in NPC cells","pmids":["23746244","23650533","23708661"],"confidence":"Medium","gaps":["Direct molecular target upstream of these pathways not identified","Connection between immune and tumor-suppressive functions unclear"]},{"year":2017,"claim":"Connected BPIFB1 to mucin biology and metastasis: it regulates MUC5B levels in vivo and physically engages VTN/VIM to suppress FAK/Src/ERK signalling and EMT-driven invasion.","evidence":"Bpifb1 knockout mice with allergen challenge and QTL mapping; reciprocal Co-IP/MS, IHC, and in vivo lung metastasis model","pmids":["28851744","29123267"],"confidence":"Medium","gaps":["Domain mediating VTN/VIM interaction not mapped","Whether airway and tumor-suppressive functions use the same binding mode unknown"]},{"year":2018,"claim":"Extended the VTN axis to radioresistance, showing BPIFB1 reverses VTN-driven DNA-damage checkpoint activation and pro-survival signalling to radiosensitize NPC cells.","evidence":"Colony formation and survival assays with overexpression/knockdown and checkpoint protein western blots after irradiation","pmids":["29568064"],"confidence":"Medium","gaps":["Direct effect on DNA repair machinery not distinguished from VTN-mediated indirect effect"]},{"year":2019,"claim":"Identified the central biochemical mechanism: BPIFB1 stabilizes PHB1 by competitively blocking TRIM21-mediated ubiquitination, providing a defined molecular route to NF-κB restraint and anti-tumour activity.","evidence":"Co-IP, in vitro ubiquitination assay, siRNA epistasis rescue, and NF-κB reporter assays","pmids":["30886235"],"confidence":"High","gaps":["Structural basis of preferential BPIFB1-PHB1 affinity not solved","Whether secreted BPIFB1 or an intracellular pool mediates PHB1 binding unresolved"]},{"year":2021,"claim":"Linked BPIFB1 to metabolic and angiogenic reprogramming by showing it suppresses vasculogenic mimicry through a JNK/AP1-GLUT1-H3K27ac cascade.","evidence":"Overexpression, glycolysis and histone acetylation profiling, and tube-formation assays in NPC","pmids":["34725462"],"confidence":"Medium","gaps":["Direct GLUT1 promoter regulation by AP1 not shown by ChIP in this context"]},{"year":2022,"claim":"Resolved the metabolic mechanism and placed BPIFB1 within circadian lung defense: it drives PHB1 nuclear translocation via 14-3-3σ to shift cells toward OXPHOS through a p53/c-Myc axis, and acts downstream of ATII-PER2 to protect against acute lung injury.","evidence":"Metabolic assays, nuclear fractionation, ATRA treatment; cell-type-specific Per2 knockout mice with P. aeruginosa ALI and pharmacological recapitulation","pmids":["36382614","35272486"],"confidence":"Medium","gaps":["Mechanism of PER2-driven BPIFB1 transcription not defined","Whether metabolic and immune protective functions are coupled unknown"]},{"year":2023,"claim":"Established that BPIFB1 is required for mucociliary clearance through MUC5B co-assembly and mucus property control, while revealing a context-dependent pro-metastatic role in breast cancer via M2 macrophage polarization.","evidence":"Bpifb1 knockout mice with in vivo MCC and mucus characterization plus two-species colocalization; breast cancer/THP-1 co-culture and in vivo metastasis assays","pmids":["37847709","37702269"],"confidence":"High","gaps":["Molecular basis of BPIFB1-MUC5B co-assembly not defined","Reconciliation of tumor-suppressive (NPC) versus pro-metastatic (breast) roles unresolved"]},{"year":2024,"claim":"Connected BPIFB1 to tumor immune evasion by showing it represses STAT1-driven PD-L1 and is silenced by EBV miR-BART4, defining a viral immune-escape axis.","evidence":"Overexpression/knockdown, ChIP, luciferase reporter, and CD8+ T cell apoptosis flow cytometry","pmids":["38467887"],"confidence":"Medium","gaps":["Direct STAT1 binding mechanism by BPIFB1 not established","In vivo immune-escape consequences not tested"]},{"year":null,"claim":"How a single secreted glycoprotein mechanistically reconciles its extracellular mucosal/immune roles with intracellular partner interactions (PHB1, VTN, VIM, STAT1) remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structural model of BPIFB1 or its interaction interfaces","Subcellular trafficking that permits intracellular partner binding undefined","Determinants of opposing tumor-suppressive versus pro-metastatic outcomes unknown"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[4,5,6]},{"term_id":"GO:0005198","term_label":"structural molecule activity","supporting_discovery_ids":[11,10]}],"localization":[{"term_id":"GO:0005576","term_label":"extracellular region","supporting_discovery_ids":[7,16,11]},{"term_id":"GO:0031410","term_label":"cytoplasmic vesicle","supporting_discovery_ids":[11,16]}],"pathway":[{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[5,6,13]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[2,4,15]},{"term_id":"R-HSA-1643685","term_label":"Disease","supporting_discovery_ids":[0,2,13]}],"complexes":[],"partners":["VTN","VIM","PHB1","TRIM21","MUC5B"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q8TDL5","full_name":"BPI fold-containing family B member 1","aliases":["Long palate, lung and nasal epithelium carcinoma-associated protein 1","von Ebner minor salivary gland protein","VEMSGP"],"length_aa":484,"mass_kda":52.4,"function":"May play a role in innate immunity in mouth, nose and lungs. Binds bacterial lipopolysaccharide (LPS) and modulates the cellular responses to LPS","subcellular_location":"Secreted","url":"https://www.uniprot.org/uniprotkb/Q8TDL5/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/BPIFB1","classification":"Not Classified","n_dependent_lines":0,"n_total_lines":1208,"dependency_fraction":0.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/BPIFB1","total_profiled":1310},"omim":[{"mim_id":"621168","title":"BPI FOLD-CONTAINING PROTEIN, FAMILY B, MEMBER 1; BPIFB1","url":"https://www.omim.org/entry/621168"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Group enriched","tissue_distribution":"Detected in some","driving_tissues":[{"tissue":"cervix","ntpm":532.0},{"tissue":"salivary gland","ntpm":255.4},{"tissue":"stomach 1","ntpm":483.0}],"url":"https://www.proteinatlas.org/search/BPIFB1"},"hgnc":{"alias_symbol":["dJ1187J4.1","MGC14597","bA49G10.6","LPLUNC1","VEMSGP"],"prev_symbol":["C20orf114"]},"alphafold":{"accession":"Q8TDL5","domains":[{"cath_id":"3.15.10.10","chopping":"34-219","consensus_level":"medium","plddt":89.4567,"start":34,"end":219},{"cath_id":"3.15.20.10","chopping":"298-444","consensus_level":"medium","plddt":94.5129,"start":298,"end":444}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8TDL5","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q8TDL5-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q8TDL5-F1-predicted_aligned_error_v6.png","plddt_mean":87.81},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=BPIFB1","jax_strain_url":"https://www.jax.org/strain/search?query=BPIFB1"},"sequence":{"accession":"Q8TDL5","fasta_url":"https://rest.uniprot.org/uniprotkb/Q8TDL5.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q8TDL5/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8TDL5"}},"corpus_meta":[{"pmid":"23708661","id":"PMC_23708661","title":"LPLUNC1 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localisation of BPIFA1 (SPLUNC1) and BPIFB1 (LPLUNC1) in the nasal and oral cavities of mice.","date":"2012","source":"Cell and tissue research","url":"https://pubmed.ncbi.nlm.nih.gov/22986921","citation_count":29,"is_preprint":false},{"pmid":"25979078","id":"PMC_25979078","title":"Elevated sputum BPIFB1 levels in smokers with chronic obstructive pulmonary disease: a longitudinal study.","date":"2015","source":"American journal of physiology. Lung cellular and molecular physiology","url":"https://pubmed.ncbi.nlm.nih.gov/25979078","citation_count":29,"is_preprint":false},{"pmid":"29296079","id":"PMC_29296079","title":"Association of innate defense proteins BPIFA1 and BPIFB1 with disease severity in COPD.","date":"2017","source":"International journal of chronic obstructive pulmonary disease","url":"https://pubmed.ncbi.nlm.nih.gov/29296079","citation_count":29,"is_preprint":false},{"pmid":"25574903","id":"PMC_25574903","title":"Polymorphisms associated with expression of BPIFA1/BPIFB1 and lung disease severity in cystic fibrosis.","date":"2015","source":"American journal of respiratory cell and molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/25574903","citation_count":28,"is_preprint":false},{"pmid":"34725462","id":"PMC_34725462","title":"BPIFB1 inhibits vasculogenic mimicry via downregulation of GLUT1-mediated H3K27 acetylation in nasopharyngeal carcinoma.","date":"2021","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/34725462","citation_count":21,"is_preprint":false},{"pmid":"28851744","id":"PMC_28851744","title":"Identification of trans Protein QTL for Secreted Airway Mucins in Mice and a Causal Role for Bpifb1.","date":"2017","source":"Genetics","url":"https://pubmed.ncbi.nlm.nih.gov/28851744","citation_count":19,"is_preprint":false},{"pmid":"37702269","id":"PMC_37702269","title":"BPIFB1 promotes metastasis of hormone receptor-positive breast cancer via inducing macrophage M2-like polarization.","date":"2023","source":"Cancer science","url":"https://pubmed.ncbi.nlm.nih.gov/37702269","citation_count":13,"is_preprint":false},{"pmid":"35272486","id":"PMC_35272486","title":"Intense light-elicited alveolar type 2-specific circadian PER2 protects from bacterial lung injury via BPIFB1.","date":"2022","source":"American journal of physiology. Lung cellular and molecular physiology","url":"https://pubmed.ncbi.nlm.nih.gov/35272486","citation_count":11,"is_preprint":false},{"pmid":"36382614","id":"PMC_36382614","title":"LPLUNC1 reduces glycolysis in nasopharyngeal carcinoma cells through the PHB1-p53/c-Myc axis.","date":"2022","source":"Cancer science","url":"https://pubmed.ncbi.nlm.nih.gov/36382614","citation_count":9,"is_preprint":false},{"pmid":"31933752","id":"PMC_31933752","title":"Overexpression of BPIFB1 promotes apoptosis and inhibits proliferation via the MEK/ERK signal pathway in nasopharyngeal carcinoma.","date":"2019","source":"International journal of clinical and experimental pathology","url":"https://pubmed.ncbi.nlm.nih.gov/31933752","citation_count":8,"is_preprint":false},{"pmid":"37847709","id":"PMC_37847709","title":"BPIFB1 loss alters airway mucus properties and diminishes mucociliary clearance.","date":"2023","source":"American journal of physiology. Lung cellular and molecular physiology","url":"https://pubmed.ncbi.nlm.nih.gov/37847709","citation_count":7,"is_preprint":false},{"pmid":"26769076","id":"PMC_26769076","title":"Upregulation of Bpifb1 expression in the parotid glands of non-obese diabetic mice.","date":"2015","source":"Oral diseases","url":"https://pubmed.ncbi.nlm.nih.gov/26769076","citation_count":4,"is_preprint":false},{"pmid":"38467887","id":"PMC_38467887","title":"BPIFB1, Serving as a Downstream Effector of EBV-miR-BART4, Blocks Immune Escape of Nasopharyngeal Carcinoma via Inhibiting PD-L1 Expression.","date":"2024","source":"Biochemical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/38467887","citation_count":3,"is_preprint":false},{"pmid":"39552876","id":"PMC_39552876","title":"CLCA1 and BPIFB1 are potential novel biomarkers for asthma: an iTRAQ analysis.","date":"2024","source":"Journal of thoracic disease","url":"https://pubmed.ncbi.nlm.nih.gov/39552876","citation_count":2,"is_preprint":false},{"pmid":"28748269","id":"PMC_28748269","title":"Presence of BPIFB1 in saliva from non-obese diabetic mice.","date":"2017","source":"Odontology","url":"https://pubmed.ncbi.nlm.nih.gov/28748269","citation_count":1,"is_preprint":false},{"pmid":"23746244","id":"PMC_23746244","title":"[Role of BPIFB1 in regulating inflammatory response of RAW264.7 cells infected by P.aeruginosa].","date":"2013","source":"Xi bao yu fen zi mian yi xue za zhi = Chinese journal of cellular and molecular immunology","url":"https://pubmed.ncbi.nlm.nih.gov/23746244","citation_count":1,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":15565,"output_tokens":4348,"usd":0.055958,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":12236,"output_tokens":3784,"usd":0.07789,"stage2_stop_reason":"end_turn"},"total_usd":0.133848,"stage1_batch_id":"msgbatch_0179Z2pxRYBsXi2xADneafRw","stage2_batch_id":"msgbatch_01LaY9ZaVdgjWArcZo9eqQE5","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2013,\n      \"finding\": \"BPIFB1 (LPLUNC1) inhibits IL-6-induced NPC cell proliferation by suppressing JAK2/STAT3 activation; overexpression decreased cyclin D1, Bcl-2, and JAK2/STAT3 phosphorylation while increasing Bax and p21, and also suppressed LPS-induced IL-6, IL-8, TNF-α, and IL-1β expression in vitro.\",\n      \"method\": \"Stable transfection overexpression in NPC cell lines, western blotting, in vivo tumor implantation model, THP-1 macrophage co-treatment assay\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean overexpression with defined cellular phenotype and pathway readout, in vitro and in vivo, single lab\",\n      \"pmids\": [\"23708661\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"BPIFB1 (LPLUNC1) inhibits NPC cell growth by downregulating MEK1, phospho-ERK1/2, phospho-JNK1/2, c-Myc, and c-Jun, reducing AP-1 transcriptional activity, and inhibiting cyclin D1, CDK4, and phospho-Rb, thereby delaying G1-to-S phase transition.\",\n      \"method\": \"Stable transfection overexpression, cDNA microarray, western blotting, in vitro proliferation and cell cycle assays, in vivo tumor formation\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (microarray + western blot + cell cycle + in vivo), single lab\",\n      \"pmids\": [\"23650533\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"BPIFB1 inhibits NPC cell migration, invasion, and lung metastasis by interacting with vitronectin (VTN) and vimentin (VIM); it reduces VTN expression and VTN-integrin αV complex formation, thereby suppressing FAK/Src/ERK signalling and inhibiting VTN- or VIM-induced epithelial-mesenchymal transition.\",\n      \"method\": \"Co-immunoprecipitation coupled with mass spectrometry, western blotting, immunofluorescence, immunohistochemistry, in vitro migration/invasion assays, in vivo lung metastasis model\",\n      \"journal\": \"British journal of cancer\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP/MS identification of interacting partners combined with functional pathway readout, in vitro and in vivo validation\",\n      \"pmids\": [\"29123267\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"BPIFB1 inhibits VTN-mediated radioresistance in NPC cells; VTN promotes G2/M arrest, DNA repair, ATM-Chk2 and ATR-Chk1 pathway activation, and anti-apoptotic effects after ionizing radiation, while BPIFB1 suppresses these VTN-dependent pro-survival responses to sensitize NPC cells to radiation.\",\n      \"method\": \"Colony formation assay, cell survival assay, overexpression and knockdown experiments, western blotting for DNA damage checkpoint proteins\",\n      \"journal\": \"Cell death & disease\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional rescue/pathway experiments with defined molecular readouts, single lab, multiple complementary assays\",\n      \"pmids\": [\"29568064\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"BPIFB1 (LPLUNC1) stabilizes PHB1 protein by competitively impairing PHB1 binding to E3 ubiquitin ligase TRIM21 (due to stronger BPIFB1-PHB1 affinity), thereby preventing TRIM21-mediated PHB1 ubiquitination and degradation; stabilized PHB1 then inhibits NF-κB activity, and PHB1 depletion reverses the anti-tumour effects of BPIFB1.\",\n      \"method\": \"Co-immunoprecipitation, ubiquitination assay, siRNA knockdown, western blotting, NF-κB reporter assay\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — mechanistic dissection of ubiquitination pathway with co-IP, ubiquitination assay, and epistasis rescue, single lab but multiple orthogonal methods\",\n      \"pmids\": [\"30886235\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"BPIFB1 (LPLUNC1) attenuates proinflammatory innate immune responses to V. cholerae and E. coli LPS in a TLR4-dependent, dose-dependent manner; it does not affect TLR2-mediated responses. The protein is expressed in Paneth cells in the duodenum.\",\n      \"method\": \"In vitro LPS stimulation assays, TLR4-dependent signalling readout, immunostaining of duodenal biopsies from cholera patients\",\n      \"journal\": \"The Journal of infectious diseases\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional assay with TLR pathway specificity control and tissue localization, single lab\",\n      \"pmids\": [\"21900486\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"BPIFB1 reduces inflammatory responses to P. aeruginosa LPS in RAW264.7 macrophages by decreasing CD14, TLR4, and MyD88 expression, and inhibiting TRAF6/NF-κB activity and ERK1/2, p38, and Akt1 phosphorylation, as demonstrated by siRNA knockdown and specific kinase inhibitors.\",\n      \"method\": \"ELISA, western blotting, siRNA knockdown of MyD88/TRAF6/NF-κB, kinase inhibitor treatment, LPS stimulation assay\",\n      \"journal\": \"Xi bao yu fen zi mian yi xue za zhi (Chinese journal of cellular and molecular immunology)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — pathway dissection using siRNA and inhibitors with multiple molecular readouts, single lab\",\n      \"pmids\": [\"23746244\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"BPIFB1 (LPLUNC1) is a secreted, glycosylated protein produced by goblet cells of the airway epithelium and nasal passages, and by submucosal glands; it is present in bronchoalveolar lavage fluid as two glycosylated isoforms, and primary airway epithelial cells secrete identical isoforms during mucociliary differentiation.\",\n      \"method\": \"Affinity-purified antibody immunolocalization, western blotting of BAL and cell culture secretions, primary human airway epithelial cell cultures\",\n      \"journal\": \"Histochemistry and cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct localization with functional-context secretion characterization, multiple tissue/cell types, single lab\",\n      \"pmids\": [\"20237794\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"BPIFB1 inhibits vasculogenic mimicry in NPC by reducing GLUT1 transcription via downregulation of the JNK/AP1 signalling pathway; reduced glycolysis lowers histone H3K27 acetylation levels, which decreases expression of vasculogenic mimicry-related genes VEGFA, VE-cadherin, and MMP2.\",\n      \"method\": \"Overexpression studies, glycolysis assays, histone acetylation profiling, gene expression analysis, western blotting, vasculogenic mimicry tube-formation assay\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multi-step pathway established in single lab with several complementary functional and molecular assays\",\n      \"pmids\": [\"34725462\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"BPIFB1 (LPLUNC1) reduces glycolysis and increases oxidative phosphorylation in NPC cells via the PHB1-p53/c-Myc axis; BPIFB1 overexpression promotes phosphorylated PHB1 nuclear translocation through 14-3-3σ, increases p53, and decreases c-Myc expression.\",\n      \"method\": \"Overexpression and knockdown, western blotting, metabolic assays (glycolysis vs. OXPHOS), nuclear fractionation, all-trans retinoic acid (ATRA) treatment\",\n      \"journal\": \"Cancer science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mechanistic pathway with multiple molecular readouts and pharmacological validation, single lab\",\n      \"pmids\": [\"36382614\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Bpifb1 knockout mice exhibit higher MUC5B airway mucin protein levels, and Bpifb1 mRNA and protein are upregulated in parallel with MUC5B after allergen challenge, identifying BPIFB1 as a novel trans-acting regulator of MUC5B.\",\n      \"method\": \"Genetic QTL mapping in Collaborative Cross mice, Bpifb1 knockout mouse model, allergen challenge, gene and protein expression analysis\",\n      \"journal\": \"Genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic KO with defined molecular phenotype, supported by QTL mapping, single lab\",\n      \"pmids\": [\"28851744\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"BPIFB1 loss in mice reduces mucociliary clearance (MCC) in vivo independently of defects in epithelial ion transport or ciliary beat frequency; loss of BPIFB1 alters biophysical and biochemical properties of mucus. BPIFB1 co-localizes with MUC5B in secretory granules in mice and in the secreted mucus protein mesh in human airway epithelial cultures.\",\n      \"method\": \"Bpifb1 knockout mouse model, in vivo MCC measurement, mucus biophysical/biochemical characterization, colocalization by immunofluorescence in mouse tissue and human airway cultures\",\n      \"journal\": \"American journal of physiology. Lung cellular and molecular physiology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic KO with specific in vivo functional phenotype, orthogonal mechanistic exclusions (ion transport, CBF), and colocalization in two species\",\n      \"pmids\": [\"37847709\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"BPIFB1 acts as a downstream target of alveolar type 2 cell-specific PER2 circadian signalling; intense light-elicited ATII-PER2 upregulates BPIFB1, which mediates lung-protective and anti-inflammatory effects during Pseudomonas aeruginosa-induced acute lung injury.\",\n      \"method\": \"Cell-type-specific Per2 knockout mice (ATII, endothelial, myeloid), P. aeruginosa ALI model, genome-wide mRNA array, nobiletin (PER2 enhancer) pharmacological recapitulation\",\n      \"journal\": \"American journal of physiology. Lung cellular and molecular physiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic epistasis in cell-type-specific KO with genome-wide target identification and pharmacological validation, single lab\",\n      \"pmids\": [\"35272486\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"BPIFB1 suppresses PD-L1 expression in NPC cells by repressing STAT1, an upstream activator of PD-L1; BPIFB1 overexpression inhibits CD8+ T cell apoptosis. EBV-encoded miR-BART4 directly targets and inhibits BPIFB1, establishing an EBV-miR-BART4/BPIFB1/STAT1/PD-L1 immune-escape axis.\",\n      \"method\": \"Overexpression/knockdown, qRT-PCR, western blot, flow cytometry (CD8+ T cell apoptosis), chromatin immunoprecipitation (ChIP), luciferase reporter assay\",\n      \"journal\": \"Biochemical genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mechanistic pathway with ChIP, luciferase, and functional immune readout, multiple orthogonal methods, single lab\",\n      \"pmids\": [\"38467887\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"BPIFB1 promotes metastasis of hormone receptor-positive breast cancer by stimulating M2-like polarization of macrophages; demonstrated using breast cancer cell/THP-1 macrophage co-culture, Transwell invasion assays, and animal experiments.\",\n      \"method\": \"BC/THP-1 macrophage co-culture system, qPCR, Transwell assay, animal experiments\",\n      \"journal\": \"Cancer science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional co-culture and in vivo experiments with defined immune phenotype, single lab\",\n      \"pmids\": [\"37702269\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"BPIFB1 overexpression induces apoptosis and DNA damage and arrests the cell cycle at G0/G1 in NPC cells via the MEK/ERK signalling pathway; MEK inhibitor U0126 reversed the proliferative effects of BPIFB1 silencing, confirming pathway dependency.\",\n      \"method\": \"Overexpression and siRNA knockdown, colony formation, cell cycle analysis, western blotting, MEK inhibitor (U0126) rescue experiment\",\n      \"journal\": \"International journal of clinical and experimental pathology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — pharmacological rescue with inhibitor confirms pathway, multiple assays, single lab\",\n      \"pmids\": [\"31933752\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"BPIFB1 protein is localized in secretory granules of parotid gland acinar cells in NOD mice and is secreted into saliva, where it carries N-linked glycans reactive with Aleuria aurantia lectin, appearing as two spots of slightly different pI and molecular weight.\",\n      \"method\": \"Immunoblotting of subcellular fractions, immunohistochemistry, lectin blotting, saliva western blot\",\n      \"journal\": \"Odontology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — subcellular fractionation localization in a single animal model without functional consequence established\",\n      \"pmids\": [\"28748269\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"BPIFB1 is a secreted, glycosylated goblet-cell protein of the upper airway that functions as an innate immune modulator and tumor suppressor: it dampens TLR4/LPS-driven inflammation (via CD14/TLR4/MyD88/NF-κB and MAPK pathways), inhibits NPC cell growth and metastasis by interacting with VTN and VIM to suppress FAK/Src/ERK and EMT, stabilizes PHB1 by blocking TRIM21-mediated ubiquitination to restrain NF-κB, reduces glycolysis through a PHB1-p53/c-Myc axis, inhibits vasculogenic mimicry via JNK/AP1-GLUT1-H3K27ac, suppresses PD-L1 through STAT1 repression, and is required for normal mucociliary clearance through co-assembly with MUC5B in secretory granules.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"BPIFB1 (LPLUNC1) is a secreted, glycosylated protein of upper-airway goblet cells and submucosal glands that serves dual roles as an innate-immune modulator of the mucosal surface and as a tumor suppressor in nasopharyngeal carcinoma (NPC) [#7, #2]. In the airway it co-assembles with the gel-forming mucin MUC5B in secretory granules and in the secreted mucus mesh, acting as a trans-regulator of MUC5B levels and as a determinant of mucus biophysical/biochemical properties required for normal mucociliary clearance independently of ciliary beat frequency or epithelial ion transport [#10, #11]. It dampens LPS-driven proinflammatory signalling in a TLR4-dependent manner, downregulating CD14/TLR4/MyD88 and TRAF6/NF-\\u03baB activity along with ERK, p38, and Akt phosphorylation [#5, #6]. In NPC, BPIFB1 restrains proliferation and survival by suppressing MEK/ERK and JAK2/STAT3 signalling, lowering cyclin D1/CDK4 and AP-1 activity to block the G1\\u2013S transition [#0, #1, #15]. It inhibits migration, invasion, metastasis, and radioresistance through physical interaction with vitronectin (VTN) and vimentin (VIM), reducing VTN\\u2013integrin \\u03b1V complexes and downstream FAK/Src/ERK signalling and EMT [#2, #3]. Mechanistically, BPIFB1 stabilizes PHB1 by outcompeting the E3 ligase TRIM21 to block PHB1 ubiquitination, thereby restraining NF-\\u03baB and, via a PHB1\\u2013p53/c-Myc axis, shifting metabolism away from glycolysis toward oxidative phosphorylation [#4, #9]. It further suppresses vasculogenic mimicry through a JNK/AP1\\u2013GLUT1\\u2013H3K27ac axis [#8] and limits immune escape by repressing STAT1-driven PD-L1, an axis targeted by EBV miR-BART4 [#13].\",\n  \"teleology\": [\n    {\n      \"year\": 2010,\n      \"claim\": \"Established BPIFB1 as a secreted glycoprotein product of airway goblet cells, defining the cellular source and processed isoforms that anchor all later functional work.\",\n      \"evidence\": \"Antibody immunolocalization and western blotting of BAL fluid and primary airway epithelial secretions\",\n      \"pmids\": [\"20237794\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Function of the secreted protein not addressed\", \"Role of glycosylation isoforms undefined\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Showed BPIFB1 attenuates LPS-induced innate immune responses specifically through TLR4 and not TLR2, establishing it as a pathway-selective anti-inflammatory mucosal factor.\",\n      \"evidence\": \"In vitro LPS stimulation with TLR pathway controls; duodenal Paneth-cell immunostaining\",\n      \"pmids\": [\"21900486\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct LPS/TLR4 binding not demonstrated\", \"Mechanism of TLR4 selectivity unresolved\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Defined the intracellular signalling consequences of BPIFB1 anti-inflammatory action and its tumor-suppressive proliferation control, linking it to CD14/TLR4/MyD88/TRAF6/NF-\\u03baB, MEK/ERK, JNK, AP-1, and JAK2/STAT3 nodes.\",\n      \"evidence\": \"siRNA knockdown and kinase inhibitors in macrophages; overexpression with microarray, western blot, cell cycle, and in vivo tumor assays in NPC cells\",\n      \"pmids\": [\"23746244\", \"23650533\", \"23708661\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct molecular target upstream of these pathways not identified\", \"Connection between immune and tumor-suppressive functions unclear\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Connected BPIFB1 to mucin biology and metastasis: it regulates MUC5B levels in vivo and physically engages VTN/VIM to suppress FAK/Src/ERK signalling and EMT-driven invasion.\",\n      \"evidence\": \"Bpifb1 knockout mice with allergen challenge and QTL mapping; reciprocal Co-IP/MS, IHC, and in vivo lung metastasis model\",\n      \"pmids\": [\"28851744\", \"29123267\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Domain mediating VTN/VIM interaction not mapped\", \"Whether airway and tumor-suppressive functions use the same binding mode unknown\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Extended the VTN axis to radioresistance, showing BPIFB1 reverses VTN-driven DNA-damage checkpoint activation and pro-survival signalling to radiosensitize NPC cells.\",\n      \"evidence\": \"Colony formation and survival assays with overexpression/knockdown and checkpoint protein western blots after irradiation\",\n      \"pmids\": [\"29568064\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct effect on DNA repair machinery not distinguished from VTN-mediated indirect effect\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Identified the central biochemical mechanism: BPIFB1 stabilizes PHB1 by competitively blocking TRIM21-mediated ubiquitination, providing a defined molecular route to NF-\\u03baB restraint and anti-tumour activity.\",\n      \"evidence\": \"Co-IP, in vitro ubiquitination assay, siRNA epistasis rescue, and NF-\\u03baB reporter assays\",\n      \"pmids\": [\"30886235\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of preferential BPIFB1-PHB1 affinity not solved\", \"Whether secreted BPIFB1 or an intracellular pool mediates PHB1 binding unresolved\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Linked BPIFB1 to metabolic and angiogenic reprogramming by showing it suppresses vasculogenic mimicry through a JNK/AP1-GLUT1-H3K27ac cascade.\",\n      \"evidence\": \"Overexpression, glycolysis and histone acetylation profiling, and tube-formation assays in NPC\",\n      \"pmids\": [\"34725462\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct GLUT1 promoter regulation by AP1 not shown by ChIP in this context\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Resolved the metabolic mechanism and placed BPIFB1 within circadian lung defense: it drives PHB1 nuclear translocation via 14-3-3\\u03c3 to shift cells toward OXPHOS through a p53/c-Myc axis, and acts downstream of ATII-PER2 to protect against acute lung injury.\",\n      \"evidence\": \"Metabolic assays, nuclear fractionation, ATRA treatment; cell-type-specific Per2 knockout mice with P. aeruginosa ALI and pharmacological recapitulation\",\n      \"pmids\": [\"36382614\", \"35272486\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism of PER2-driven BPIFB1 transcription not defined\", \"Whether metabolic and immune protective functions are coupled unknown\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Established that BPIFB1 is required for mucociliary clearance through MUC5B co-assembly and mucus property control, while revealing a context-dependent pro-metastatic role in breast cancer via M2 macrophage polarization.\",\n      \"evidence\": \"Bpifb1 knockout mice with in vivo MCC and mucus characterization plus two-species colocalization; breast cancer/THP-1 co-culture and in vivo metastasis assays\",\n      \"pmids\": [\"37847709\", \"37702269\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular basis of BPIFB1-MUC5B co-assembly not defined\", \"Reconciliation of tumor-suppressive (NPC) versus pro-metastatic (breast) roles unresolved\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Connected BPIFB1 to tumor immune evasion by showing it represses STAT1-driven PD-L1 and is silenced by EBV miR-BART4, defining a viral immune-escape axis.\",\n      \"evidence\": \"Overexpression/knockdown, ChIP, luciferase reporter, and CD8+ T cell apoptosis flow cytometry\",\n      \"pmids\": [\"38467887\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct STAT1 binding mechanism by BPIFB1 not established\", \"In vivo immune-escape consequences not tested\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How a single secreted glycoprotein mechanistically reconciles its extracellular mucosal/immune roles with intracellular partner interactions (PHB1, VTN, VIM, STAT1) remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structural model of BPIFB1 or its interaction interfaces\", \"Subcellular trafficking that permits intracellular partner binding undefined\", \"Determinants of opposing tumor-suppressive versus pro-metastatic outcomes unknown\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [4, 5, 6]},\n      {\"term_id\": \"GO:0005198\", \"supporting_discovery_ids\": [11, 10]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005576\", \"supporting_discovery_ids\": [7, 16, 11]},\n      {\"term_id\": \"GO:0031410\", \"supporting_discovery_ids\": [11, 16]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [5, 6, 13]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [2, 4, 15]},\n      {\"term_id\": \"R-HSA-1643685\", \"supporting_discovery_ids\": [0, 2, 13]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"VTN\", \"VIM\", \"PHB1\", \"TRIM21\", \"MUC5B\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":7,"faith_total":7,"faith_pct":100.0}}