{"gene":"PRKAR2B","run_date":"2026-06-10T06:43:35","timeline":{"discoveries":[{"year":2018,"finding":"PRKAR2B promotes prostate cancer cell invasion and metastasis by activating Wnt/β-catenin signaling, which in turn induces epithelial-mesenchymal transition (EMT), evidenced by decreased E-cadherin and increased Vimentin, N-cadherin, and Fibronectin; inhibition of Wnt/β-catenin attenuated PRKAR2B-induced EMT and invasion.","method":"Loss-of-function (knockdown) and gain-of-function (overexpression) in CRPC cell lines; in vivo metastasis assay; Western blotting for EMT markers; Wnt/β-catenin pathway inhibition rescue experiment","journal":"Journal of cellular biochemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal gain/loss-of-function with defined molecular readouts and pathway rescue, single lab","pmids":["29761841"],"is_preprint":false},{"year":2020,"finding":"PRKAR2B enhances aerobic glycolysis (Warburg effect) in prostate cancer by upregulating HIF-1α; conversely, HIF-1α transcriptionally induces PRKAR2B expression, forming a positive feedback loop. Glycolytic inhibition or HIF-1α silencing abolished PRKAR2B-mediated tumor growth.","method":"Loss-of-function and gain-of-function studies; glucose consumption, lactate production, and extracellular acidification rate assays; luciferase reporter assay; chromatin immunoprecipitation (ChIP); siRNA silencing of HIF-1α; glycolytic inhibitor 2-DG treatment","journal":"Cell proliferation","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (ChIP, reporter assay, metabolic assays, genetic rescue) in a single lab","pmids":["33025691"],"is_preprint":false},{"year":2020,"finding":"PRKAR2B expression in prostate cancer is regulated post-transcriptionally by miR-200b-3p and miR-200c-3p (which directly repress it) and transcriptionally by the transcription factor XBP1 (which induces it); knockdown of miR-200b-3p/200c-3p or XBP1 effects on proliferation and apoptosis were rescued by PRKAR2B overexpression, placing PRKAR2B downstream of both regulators.","method":"miRNA overexpression and knockdown; XBP1 knockdown; rescue experiments with PRKAR2B overexpression; luciferase reporter assay (implied from context); qPCR and Western blotting","journal":"Biomedicine & pharmacotherapy","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — epistatic rescue experiments establish pathway order; single lab with multiple methods","pmids":["31986411"],"is_preprint":false},{"year":2018,"finding":"FOXG1 regulates PRKAR2B expression both transcriptionally and post-transcriptionally via the miR-200 family; FOXG1 affects biogenesis of miR-200b/a/429 by interacting with DDX5/p68, which recruits FOXG1 to the DROSHA microprocessor complex. PRKAR2B was identified as a miR-200 target in neural cells, and elevated PRKAR2B inhibits postsynaptic PKA activity.","method":"Genome-wide small RNA sequencing; quantitative proteomics; RNA-Seq of Foxg1cre/+ hippocampi; N2a cells overexpressing miR-200 family; Co-IP/association of FOXG1 with DDX5 and DROSHA","journal":"Molecular neurobiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal genomic and proteomic methods establishing pathway; single lab","pmids":["30539330"],"is_preprint":false},{"year":2014,"finding":"Depletion of PRKAR2B in adrenocortical H295R cells is compensated by upregulation of PRKAR1A protein (but not vice versa). PRKAR2B depletion activates PKA and MEK/ERK pathways, impairs IκB leading to NF-κB activation, promotes Bcl-xL expression and apoptosis resistance, and specifically drives accumulation of cyclins A, B, cdk1, cdc2, and p21Cip (distinct from PRKAR1A depletion which accumulates cyclin D1 and p27kip).","method":"siRNA-mediated knockdown; Western blotting for signaling pathway components, cyclins, and apoptotic markers; cell cycle analysis","journal":"Hormone and metabolic research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean KO/KD with defined signaling and cell-cycle readouts; single lab, single method type","pmids":["25268545"],"is_preprint":false},{"year":2017,"finding":"PRKAR2B promotes CRPC cell proliferation and invasion and inhibits apoptosis; transcriptome analysis following PRKAR2B knockdown revealed that it accelerates the cell cycle by modulating cell cycle genes including CCNB1, MCM2, PLK1, and AURKB.","method":"Knockdown (loss-of-function); whole genome transcriptome and GO enrichment analysis; functional assays for proliferation, invasion, apoptosis","journal":"Oncotarget","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — genome-wide transcriptome plus functional assays but single lab and transcriptome-level mechanism only","pmids":["28008150"],"is_preprint":false},{"year":2018,"finding":"PRKAR2B is required for oocyte maturation: RNAi-mediated knockdown of Prkar2b in mouse oocytes caused arrest at metaphase I, abnormal spindle formation, and chromosome aggregation. Knockdown also reduced expression of other PKA family members (except Prkaca) and the majority of pentose phosphate pathway (PPP) factors.","method":"RNAi microinjection into mouse oocytes; immunofluorescence for spindle/chromosome morphology; time-lapse video microscopy; qRT-PCR for PKA family and PPP gene expression","journal":"Cellular physiology and biochemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct loss-of-function with specific cellular and molecular phenotype readouts; single lab","pmids":["29518769"],"is_preprint":false},{"year":2023,"finding":"In Theileria annulata-infected bovine leukocytes and Plasmodium falciparum-infected red blood cells, infection-induced upregulation of miR-34c-3p represses PRKAR2B expression, leading to increased PKA activity independent of cAMP fluxes; this mechanism enhances the disseminating tumor-like phenotype of T. annulata-transformed macrophages.","method":"miR-34c-3p target identification (PRKAR2B as target gene); miRNA overexpression; PRKAR2B mRNA and protein level measurement; PKA activity assay; infection model experiments","journal":"mSphere","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional miRNA–target relationship with PKA activity readout in two infection models; single lab","pmids":["36847534"],"is_preprint":false},{"year":2026,"finding":"In pancreatic ductal adenocarcinoma, downregulation of transcription factor HHEX represses PRKAR2B expression, relieving inhibition of PKA catalytic activity; activated PKA then enhances glycolysis via upregulation of hexokinase 2 (HK2). A high-glucose microenvironment promotes cAMP production to further activate PKA, and glycolysis inhibition blocked metastasis in vivo.","method":"HHEX knockdown; PRKAR2B expression analysis; PKA activity assay; HK2 expression and glycolysis assays; in vivo high-glucose synergy and glycolysis inhibition experiments","journal":"iScience","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — mechanistic chain established with multiple functional readouts; single lab, single study","pmids":["41704777"],"is_preprint":false}],"current_model":"PRKAR2B, the type II-beta regulatory subunit of PKA, inhibits PKA catalytic activity when expressed; its downregulation (by miR-34c-3p, miR-200 family, or transcriptional repression via HHEX loss) de-represses PKA, and in cancer contexts PRKAR2B paradoxically promotes oncogenesis by activating Wnt/β-catenin-driven EMT, upregulating HIF-1α to drive the Warburg effect, and modulating cell cycle regulators (CCNB1, PLK1, AURKB) and glycolytic enzymes (HK2), while in normal physiology it is required for oocyte spindle formation and is controlled transcriptionally by FOXG1/XBP1 and post-transcriptionally by the miR-200 family."},"narrative":{"mechanistic_narrative":"PRKAR2B is the type II-beta regulatory subunit of protein kinase A (PKA) and functions as an inhibitory constraint on PKA catalytic activity, with its loss de-repressing PKA and downstream signaling [PMID:25268545, PMID:36847534, PMID:41704777]. In adrenocortical cells, PRKAR2B depletion activates PKA and MEK/ERK, drives NF-κB activation through impaired IκB, promotes Bcl-xL-mediated apoptosis resistance, and specifically accumulates cyclins A and B, cdk1/cdc2, and p21Cip, a profile distinct from that of the type I-alpha subunit PRKAR1A whose loss it can compensate for [PMID:25268545]. Paradoxically, in prostate cancer PRKAR2B acts as a driver of malignancy: it activates Wnt/β-catenin signaling to induce epithelial-mesenchymal transition and invasion [PMID:29761841], enhances aerobic glycolysis through a HIF-1α positive-feedback loop [PMID:33025691], and accelerates the cell cycle by modulating CCNB1, MCM2, PLK1, and AURKB [PMID:28008150]. PRKAR2B levels are set post-transcriptionally by the miR-200 family (miR-200b-3p/200c-3p) and miR-34c-3p and transcriptionally by XBP1, FOXG1, HHEX, and HIF-1α, integrating these regulators into control of PKA-dependent proliferation, glycolysis, and metastasis [PMID:33025691, PMID:31986411, PMID:30539330, PMID:36847534, PMID:41704777]. Beyond cancer, PRKAR2B is required for mouse oocyte maturation, where its knockdown causes metaphase I arrest, abnormal spindle formation, and chromosome aggregation [PMID:29518769].","teleology":[{"year":2014,"claim":"Established that PRKAR2B restrains PKA activity and shapes a specific signaling and cell-cycle output, distinguishing it functionally from the PRKAR1A regulatory subunit.","evidence":"siRNA knockdown in adrenocortical H295R cells with signaling, cyclin, and apoptosis readouts","pmids":["25268545"],"confidence":"Medium","gaps":["Single cell line and single method type","Direct biochemical inhibition of PKA holoenzyme not reconstituted","Mechanism of PRKAR1A compensatory upregulation unresolved"]},{"year":2017,"claim":"Defined PRKAR2B as a pro-proliferative, pro-invasive factor in castration-resistant prostate cancer acting through cell-cycle gene programs.","evidence":"Knockdown with whole-genome transcriptome/GO analysis and proliferation/invasion/apoptosis assays","pmids":["28008150"],"confidence":"Medium","gaps":["Mechanism is transcriptome-level correlation, not direct regulation of CCNB1/PLK1/AURKB","Single lab","How a PKA inhibitory subunit promotes proliferation not mechanistically reconciled"]},{"year":2018,"claim":"Connected PRKAR2B to a defined oncogenic pathway by showing it activates Wnt/β-catenin to drive EMT and metastasis.","evidence":"Reciprocal gain/loss-of-function in CRPC lines, in vivo metastasis assay, EMT marker blotting, and Wnt inhibition rescue","pmids":["29761841"],"confidence":"Medium","gaps":["Molecular link between PRKAR2B and Wnt/β-catenin not identified","Single lab","Whether effect requires PKA catalytic activity unknown"]},{"year":2018,"claim":"Established PRKAR2B as a physiological requirement for meiotic progression and spindle integrity in oocytes, outside any cancer context.","evidence":"RNAi microinjection in mouse oocytes with immunofluorescence, time-lapse imaging, and qRT-PCR","pmids":["29518769"],"confidence":"Medium","gaps":["Mechanistic link between PRKAR2B and spindle assembly unresolved","Effect on PPP gene expression correlative","Single lab"]},{"year":2018,"claim":"Identified an upstream regulatory axis in which FOXG1 controls PRKAR2B both transcriptionally and via miR-200 biogenesis, linking PRKAR2B to postsynaptic PKA tone.","evidence":"Small RNA-seq, proteomics, RNA-seq of Foxg1cre/+ hippocampi, N2a miR-200 overexpression, and FOXG1–DDX5–DROSHA Co-IP","pmids":["30539330"],"confidence":"Medium","gaps":["Direct miR-200 binding to PRKAR2B in neurons not fully demonstrated","Functional consequence of postsynaptic PKA inhibition not measured","Single lab"]},{"year":2020,"claim":"Showed PRKAR2B drives the Warburg effect through a HIF-1α positive-feedback loop, linking it to tumor metabolic reprogramming.","evidence":"Gain/loss-of-function, metabolic assays, luciferase reporter, ChIP, HIF-1α siRNA, and 2-DG treatment in prostate cancer","pmids":["33025691"],"confidence":"Medium","gaps":["How PRKAR2B raises HIF-1α not defined mechanistically","Single lab","Relationship to PKA catalytic activity unclear"]},{"year":2020,"claim":"Placed PRKAR2B downstream of miR-200b/c and XBP1, defining a regulatory hierarchy controlling its oncogenic output.","evidence":"miRNA and XBP1 knockdown/overexpression with PRKAR2B rescue, reporter assays, qPCR and Western blot","pmids":["31986411"],"confidence":"Medium","gaps":["XBP1 direct binding to PRKAR2B promoter not shown","Single lab","Interplay between transcriptional and post-transcriptional control not resolved"]},{"year":2023,"claim":"Demonstrated that pathogen-induced miR-34c-3p represses PRKAR2B to activate PKA independent of cAMP, extending PRKAR2B regulation to infection-driven transformation.","evidence":"miR-34c-3p target validation, miRNA overexpression, PKA activity assays in Theileria- and Plasmodium-infected cells","pmids":["36847534"],"confidence":"Medium","gaps":["Direct miR-34c-3p:PRKAR2B binding details limited","Single lab","Generality across infection models unestablished"]},{"year":2026,"claim":"Defined an HHEX–PRKAR2B–PKA–HK2 axis coupling glucose availability to PKA-driven glycolysis and metastasis in pancreatic cancer.","evidence":"HHEX knockdown, PKA activity and HK2/glycolysis assays, and in vivo high-glucose and glycolysis-inhibition experiments","pmids":["41704777"],"confidence":"Medium","gaps":["HHEX direct transcriptional control of PRKAR2B not fully mapped","Single study","Link between PKA activation and HK2 upregulation mechanistically incomplete"]},{"year":null,"claim":"It remains unresolved how a PKA-inhibitory regulatory subunit acts as an oncogenic driver across multiple cancers, and whether its tumor-promoting effects depend on PKA catalytic activity or on PKA-independent functions.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structural or biochemical reconstitution of PRKAR2B-PKA holoenzyme in these contexts","Direct molecular link to Wnt/β-catenin and HIF-1α unknown","No in vivo genetic model distinguishing catalytic-dependent from independent roles"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[4,7,8]}],"localization":[],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[4,7,8]},{"term_id":"R-HSA-1430728","term_label":"Metabolism","supporting_discovery_ids":[1,8]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[4,5,6]}],"complexes":["PKA holoenzyme"],"partners":["PRKACA","PRKAR1A"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"P31323","full_name":"cAMP-dependent protein kinase type II-beta regulatory subunit","aliases":[],"length_aa":418,"mass_kda":46.3,"function":"Regulatory subunit of the cAMP-dependent protein kinases involved in cAMP signaling in cells. Type II regulatory chains mediate membrane association by binding to anchoring proteins, including the MAP2 kinase","subcellular_location":"Cytoplasm; Cell membrane","url":"https://www.uniprot.org/uniprotkb/P31323/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/PRKAR2B","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":[{"gene":"PRKACA","stoichiometry":4.0}],"url":"https://opencell.sf.czbiohub.org/search/PRKAR2B","total_profiled":1310},"omim":[{"mim_id":"615876","title":"RADIAL SPOKE HEAD 3; RSPH3","url":"https://www.omim.org/entry/615876"},{"mim_id":"609910","title":"CILIA- AND FLAGELLA-ASSOCIATED PROTEIN 91; CFAP91","url":"https://www.omim.org/entry/609910"},{"mim_id":"605824","title":"POPEYE DOMAIN-CONTAINING PROTEIN 3; POPDC3","url":"https://www.omim.org/entry/605824"},{"mim_id":"605823","title":"POPEYE DOMAIN-CONTAINING PROTEIN 2; POPDC2","url":"https://www.omim.org/entry/605823"},{"mim_id":"604694","title":"A-KINASE ANCHOR PROTEIN 10; AKAP10","url":"https://www.omim.org/entry/604694"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Golgi apparatus","reliability":"Approved"},{"location":"Centrosome","reliability":"Approved"},{"location":"Basal body","reliability":"Approved"},{"location":"Cytosol","reliability":"Approved"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"adipose tissue","ntpm":159.6}],"url":"https://www.proteinatlas.org/search/PRKAR2B"},"hgnc":{"alias_symbol":[],"prev_symbol":["PRKAR2"]},"alphafold":{"accession":"P31323","domains":[{"cath_id":"2.60.120.10","chopping":"138-253","consensus_level":"high","plddt":90.4461,"start":138,"end":253},{"cath_id":"2.60.120.10","chopping":"274-406","consensus_level":"high","plddt":86.7686,"start":274,"end":406}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P31323","model_url":"https://alphafold.ebi.ac.uk/files/AF-P31323-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P31323-F1-predicted_aligned_error_v6.png","plddt_mean":78.69},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=PRKAR2B","jax_strain_url":"https://www.jax.org/strain/search?query=PRKAR2B"},"sequence":{"accession":"P31323","fasta_url":"https://rest.uniprot.org/uniprotkb/P31323.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P31323/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P31323"}},"corpus_meta":[{"pmid":"33025691","id":"PMC_33025691","title":"PRKAR2B-HIF-1α loop promotes aerobic glycolysis and tumour growth in prostate cancer.","date":"2020","source":"Cell proliferation","url":"https://pubmed.ncbi.nlm.nih.gov/33025691","citation_count":47,"is_preprint":false},{"pmid":"29761841","id":"PMC_29761841","title":"PRKAR2B promotes prostate cancer metastasis by activating Wnt/β-catenin and inducing epithelial-mesenchymal transition.","date":"2018","source":"Journal of cellular biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/29761841","citation_count":31,"is_preprint":false},{"pmid":"31986411","id":"PMC_31986411","title":"Transcriptional regulation of PRKAR2B by miR-200b-3p/200c-3p and XBP1 in human prostate cancer.","date":"2020","source":"Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie","url":"https://pubmed.ncbi.nlm.nih.gov/31986411","citation_count":27,"is_preprint":false},{"pmid":"30539330","id":"PMC_30539330","title":"FOXG1 Regulates PRKAR2B Transcriptionally and Posttranscriptionally via miR200 in the Adult Hippocampus.","date":"2018","source":"Molecular neurobiology","url":"https://pubmed.ncbi.nlm.nih.gov/30539330","citation_count":21,"is_preprint":false},{"pmid":"25268545","id":"PMC_25268545","title":"Comparison of the effects of PRKAR1A and PRKAR2B depletion on signaling pathways, cell growth, and cell cycle control of adrenocortical cells.","date":"2014","source":"Hormone and metabolic research = Hormon- und Stoffwechselforschung = Hormones et metabolisme","url":"https://pubmed.ncbi.nlm.nih.gov/25268545","citation_count":18,"is_preprint":false},{"pmid":"28008150","id":"PMC_28008150","title":"PRKAR2B plays an oncogenic role in the castration-resistant prostate cancer.","date":"2017","source":"Oncotarget","url":"https://pubmed.ncbi.nlm.nih.gov/28008150","citation_count":17,"is_preprint":false},{"pmid":"29518769","id":"PMC_29518769","title":"Knockdown of PRKAR2B Results in the Failure of Oocyte Maturation.","date":"2018","source":"Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/29518769","citation_count":16,"is_preprint":false},{"pmid":"36847534","id":"PMC_36847534","title":"miR-34c-3p Regulates Protein Kinase A Activity Independent of cAMP by Dicing prkar2b Transcripts in Theileria annulata-Infected Leukocytes.","date":"2023","source":"mSphere","url":"https://pubmed.ncbi.nlm.nih.gov/36847534","citation_count":9,"is_preprint":false},{"pmid":"24737441","id":"PMC_24737441","title":"Protein kinase cAMP-dependent regulatory type II beta (PRKAR2B) gene variants in antipsychotic-induced weight gain.","date":"2014","source":"Human psychopharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/24737441","citation_count":8,"is_preprint":false},{"pmid":"36817960","id":"PMC_36817960","title":"MAPKAPK2-centric transcriptome profiling reveals its major role in governing molecular crosstalk of IGFBP2, MUC4, and PRKAR2B during HNSCC pathogenesis.","date":"2023","source":"Computational and structural biotechnology journal","url":"https://pubmed.ncbi.nlm.nih.gov/36817960","citation_count":6,"is_preprint":false},{"pmid":"40589305","id":"PMC_40589305","title":"ceRNA Profiling Reveals circSAMD4A Promoted Porcine Adipocytes Differentiation via Targeting miR-127/PRKAR2B.","date":"2025","source":"Animal science journal = Nihon chikusan Gakkaiho","url":"https://pubmed.ncbi.nlm.nih.gov/40589305","citation_count":1,"is_preprint":false},{"pmid":"40571682","id":"PMC_40571682","title":"Glomerular mesangial derived extracellular vesicles deteriorate diabetic kidney disease via miR-3147/PRKAR2B axis.","date":"2025","source":"Renal failure","url":"https://pubmed.ncbi.nlm.nih.gov/40571682","citation_count":0,"is_preprint":false},{"pmid":"41704777","id":"PMC_41704777","title":"HHEX-PRKAR2B axis-mediated PKA activation drives glucose metabolism-dependent progression of pancreatic ductal adenocarcinoma.","date":"2026","source":"iScience","url":"https://pubmed.ncbi.nlm.nih.gov/41704777","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":8803,"output_tokens":2549,"usd":0.032322,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":9752,"output_tokens":3276,"usd":0.06533,"stage2_stop_reason":"end_turn"},"total_usd":0.097652,"stage1_batch_id":"msgbatch_01CNoDbkChHEkgrJnL7BwtGJ","stage2_batch_id":"msgbatch_016Y4x9E9Wg5VQDANj9quSQD","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2018,\n      \"finding\": \"PRKAR2B promotes prostate cancer cell invasion and metastasis by activating Wnt/β-catenin signaling, which in turn induces epithelial-mesenchymal transition (EMT), evidenced by decreased E-cadherin and increased Vimentin, N-cadherin, and Fibronectin; inhibition of Wnt/β-catenin attenuated PRKAR2B-induced EMT and invasion.\",\n      \"method\": \"Loss-of-function (knockdown) and gain-of-function (overexpression) in CRPC cell lines; in vivo metastasis assay; Western blotting for EMT markers; Wnt/β-catenin pathway inhibition rescue experiment\",\n      \"journal\": \"Journal of cellular biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal gain/loss-of-function with defined molecular readouts and pathway rescue, single lab\",\n      \"pmids\": [\"29761841\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"PRKAR2B enhances aerobic glycolysis (Warburg effect) in prostate cancer by upregulating HIF-1α; conversely, HIF-1α transcriptionally induces PRKAR2B expression, forming a positive feedback loop. Glycolytic inhibition or HIF-1α silencing abolished PRKAR2B-mediated tumor growth.\",\n      \"method\": \"Loss-of-function and gain-of-function studies; glucose consumption, lactate production, and extracellular acidification rate assays; luciferase reporter assay; chromatin immunoprecipitation (ChIP); siRNA silencing of HIF-1α; glycolytic inhibitor 2-DG treatment\",\n      \"journal\": \"Cell proliferation\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (ChIP, reporter assay, metabolic assays, genetic rescue) in a single lab\",\n      \"pmids\": [\"33025691\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"PRKAR2B expression in prostate cancer is regulated post-transcriptionally by miR-200b-3p and miR-200c-3p (which directly repress it) and transcriptionally by the transcription factor XBP1 (which induces it); knockdown of miR-200b-3p/200c-3p or XBP1 effects on proliferation and apoptosis were rescued by PRKAR2B overexpression, placing PRKAR2B downstream of both regulators.\",\n      \"method\": \"miRNA overexpression and knockdown; XBP1 knockdown; rescue experiments with PRKAR2B overexpression; luciferase reporter assay (implied from context); qPCR and Western blotting\",\n      \"journal\": \"Biomedicine & pharmacotherapy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — epistatic rescue experiments establish pathway order; single lab with multiple methods\",\n      \"pmids\": [\"31986411\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"FOXG1 regulates PRKAR2B expression both transcriptionally and post-transcriptionally via the miR-200 family; FOXG1 affects biogenesis of miR-200b/a/429 by interacting with DDX5/p68, which recruits FOXG1 to the DROSHA microprocessor complex. PRKAR2B was identified as a miR-200 target in neural cells, and elevated PRKAR2B inhibits postsynaptic PKA activity.\",\n      \"method\": \"Genome-wide small RNA sequencing; quantitative proteomics; RNA-Seq of Foxg1cre/+ hippocampi; N2a cells overexpressing miR-200 family; Co-IP/association of FOXG1 with DDX5 and DROSHA\",\n      \"journal\": \"Molecular neurobiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal genomic and proteomic methods establishing pathway; single lab\",\n      \"pmids\": [\"30539330\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Depletion of PRKAR2B in adrenocortical H295R cells is compensated by upregulation of PRKAR1A protein (but not vice versa). PRKAR2B depletion activates PKA and MEK/ERK pathways, impairs IκB leading to NF-κB activation, promotes Bcl-xL expression and apoptosis resistance, and specifically drives accumulation of cyclins A, B, cdk1, cdc2, and p21Cip (distinct from PRKAR1A depletion which accumulates cyclin D1 and p27kip).\",\n      \"method\": \"siRNA-mediated knockdown; Western blotting for signaling pathway components, cyclins, and apoptotic markers; cell cycle analysis\",\n      \"journal\": \"Hormone and metabolic research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean KO/KD with defined signaling and cell-cycle readouts; single lab, single method type\",\n      \"pmids\": [\"25268545\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"PRKAR2B promotes CRPC cell proliferation and invasion and inhibits apoptosis; transcriptome analysis following PRKAR2B knockdown revealed that it accelerates the cell cycle by modulating cell cycle genes including CCNB1, MCM2, PLK1, and AURKB.\",\n      \"method\": \"Knockdown (loss-of-function); whole genome transcriptome and GO enrichment analysis; functional assays for proliferation, invasion, apoptosis\",\n      \"journal\": \"Oncotarget\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — genome-wide transcriptome plus functional assays but single lab and transcriptome-level mechanism only\",\n      \"pmids\": [\"28008150\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"PRKAR2B is required for oocyte maturation: RNAi-mediated knockdown of Prkar2b in mouse oocytes caused arrest at metaphase I, abnormal spindle formation, and chromosome aggregation. Knockdown also reduced expression of other PKA family members (except Prkaca) and the majority of pentose phosphate pathway (PPP) factors.\",\n      \"method\": \"RNAi microinjection into mouse oocytes; immunofluorescence for spindle/chromosome morphology; time-lapse video microscopy; qRT-PCR for PKA family and PPP gene expression\",\n      \"journal\": \"Cellular physiology and biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct loss-of-function with specific cellular and molecular phenotype readouts; single lab\",\n      \"pmids\": [\"29518769\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"In Theileria annulata-infected bovine leukocytes and Plasmodium falciparum-infected red blood cells, infection-induced upregulation of miR-34c-3p represses PRKAR2B expression, leading to increased PKA activity independent of cAMP fluxes; this mechanism enhances the disseminating tumor-like phenotype of T. annulata-transformed macrophages.\",\n      \"method\": \"miR-34c-3p target identification (PRKAR2B as target gene); miRNA overexpression; PRKAR2B mRNA and protein level measurement; PKA activity assay; infection model experiments\",\n      \"journal\": \"mSphere\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional miRNA–target relationship with PKA activity readout in two infection models; single lab\",\n      \"pmids\": [\"36847534\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"In pancreatic ductal adenocarcinoma, downregulation of transcription factor HHEX represses PRKAR2B expression, relieving inhibition of PKA catalytic activity; activated PKA then enhances glycolysis via upregulation of hexokinase 2 (HK2). A high-glucose microenvironment promotes cAMP production to further activate PKA, and glycolysis inhibition blocked metastasis in vivo.\",\n      \"method\": \"HHEX knockdown; PRKAR2B expression analysis; PKA activity assay; HK2 expression and glycolysis assays; in vivo high-glucose synergy and glycolysis inhibition experiments\",\n      \"journal\": \"iScience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mechanistic chain established with multiple functional readouts; single lab, single study\",\n      \"pmids\": [\"41704777\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"PRKAR2B, the type II-beta regulatory subunit of PKA, inhibits PKA catalytic activity when expressed; its downregulation (by miR-34c-3p, miR-200 family, or transcriptional repression via HHEX loss) de-represses PKA, and in cancer contexts PRKAR2B paradoxically promotes oncogenesis by activating Wnt/β-catenin-driven EMT, upregulating HIF-1α to drive the Warburg effect, and modulating cell cycle regulators (CCNB1, PLK1, AURKB) and glycolytic enzymes (HK2), while in normal physiology it is required for oocyte spindle formation and is controlled transcriptionally by FOXG1/XBP1 and post-transcriptionally by the miR-200 family.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"PRKAR2B is the type II-beta regulatory subunit of protein kinase A (PKA) and functions as an inhibitory constraint on PKA catalytic activity, with its loss de-repressing PKA and downstream signaling [#4, #7, #8]. In adrenocortical cells, PRKAR2B depletion activates PKA and MEK/ERK, drives NF-\\u03baB activation through impaired I\\u03baB, promotes Bcl-xL-mediated apoptosis resistance, and specifically accumulates cyclins A and B, cdk1/cdc2, and p21Cip, a profile distinct from that of the type I-alpha subunit PRKAR1A whose loss it can compensate for [#4]. Paradoxically, in prostate cancer PRKAR2B acts as a driver of malignancy: it activates Wnt/\\u03b2-catenin signaling to induce epithelial-mesenchymal transition and invasion [#0], enhances aerobic glycolysis through a HIF-1\\u03b1 positive-feedback loop [#1], and accelerates the cell cycle by modulating CCNB1, MCM2, PLK1, and AURKB [#5]. PRKAR2B levels are set post-transcriptionally by the miR-200 family (miR-200b-3p/200c-3p) and miR-34c-3p and transcriptionally by XBP1, FOXG1, HHEX, and HIF-1\\u03b1, integrating these regulators into control of PKA-dependent proliferation, glycolysis, and metastasis [#1, #2, #3, #7, #8]. Beyond cancer, PRKAR2B is required for mouse oocyte maturation, where its knockdown causes metaphase I arrest, abnormal spindle formation, and chromosome aggregation [#6].\",\n  \"teleology\": [\n    {\n      \"year\": 2014,\n      \"claim\": \"Established that PRKAR2B restrains PKA activity and shapes a specific signaling and cell-cycle output, distinguishing it functionally from the PRKAR1A regulatory subunit.\",\n      \"evidence\": \"siRNA knockdown in adrenocortical H295R cells with signaling, cyclin, and apoptosis readouts\",\n      \"pmids\": [\"25268545\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single cell line and single method type\", \"Direct biochemical inhibition of PKA holoenzyme not reconstituted\", \"Mechanism of PRKAR1A compensatory upregulation unresolved\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Defined PRKAR2B as a pro-proliferative, pro-invasive factor in castration-resistant prostate cancer acting through cell-cycle gene programs.\",\n      \"evidence\": \"Knockdown with whole-genome transcriptome/GO analysis and proliferation/invasion/apoptosis assays\",\n      \"pmids\": [\"28008150\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism is transcriptome-level correlation, not direct regulation of CCNB1/PLK1/AURKB\", \"Single lab\", \"How a PKA inhibitory subunit promotes proliferation not mechanistically reconciled\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Connected PRKAR2B to a defined oncogenic pathway by showing it activates Wnt/\\u03b2-catenin to drive EMT and metastasis.\",\n      \"evidence\": \"Reciprocal gain/loss-of-function in CRPC lines, in vivo metastasis assay, EMT marker blotting, and Wnt inhibition rescue\",\n      \"pmids\": [\"29761841\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Molecular link between PRKAR2B and Wnt/\\u03b2-catenin not identified\", \"Single lab\", \"Whether effect requires PKA catalytic activity unknown\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Established PRKAR2B as a physiological requirement for meiotic progression and spindle integrity in oocytes, outside any cancer context.\",\n      \"evidence\": \"RNAi microinjection in mouse oocytes with immunofluorescence, time-lapse imaging, and qRT-PCR\",\n      \"pmids\": [\"29518769\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanistic link between PRKAR2B and spindle assembly unresolved\", \"Effect on PPP gene expression correlative\", \"Single lab\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Identified an upstream regulatory axis in which FOXG1 controls PRKAR2B both transcriptionally and via miR-200 biogenesis, linking PRKAR2B to postsynaptic PKA tone.\",\n      \"evidence\": \"Small RNA-seq, proteomics, RNA-seq of Foxg1cre/+ hippocampi, N2a miR-200 overexpression, and FOXG1\\u2013DDX5\\u2013DROSHA Co-IP\",\n      \"pmids\": [\"30539330\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct miR-200 binding to PRKAR2B in neurons not fully demonstrated\", \"Functional consequence of postsynaptic PKA inhibition not measured\", \"Single lab\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Showed PRKAR2B drives the Warburg effect through a HIF-1\\u03b1 positive-feedback loop, linking it to tumor metabolic reprogramming.\",\n      \"evidence\": \"Gain/loss-of-function, metabolic assays, luciferase reporter, ChIP, HIF-1\\u03b1 siRNA, and 2-DG treatment in prostate cancer\",\n      \"pmids\": [\"33025691\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"How PRKAR2B raises HIF-1\\u03b1 not defined mechanistically\", \"Single lab\", \"Relationship to PKA catalytic activity unclear\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Placed PRKAR2B downstream of miR-200b/c and XBP1, defining a regulatory hierarchy controlling its oncogenic output.\",\n      \"evidence\": \"miRNA and XBP1 knockdown/overexpression with PRKAR2B rescue, reporter assays, qPCR and Western blot\",\n      \"pmids\": [\"31986411\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"XBP1 direct binding to PRKAR2B promoter not shown\", \"Single lab\", \"Interplay between transcriptional and post-transcriptional control not resolved\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Demonstrated that pathogen-induced miR-34c-3p represses PRKAR2B to activate PKA independent of cAMP, extending PRKAR2B regulation to infection-driven transformation.\",\n      \"evidence\": \"miR-34c-3p target validation, miRNA overexpression, PKA activity assays in Theileria- and Plasmodium-infected cells\",\n      \"pmids\": [\"36847534\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct miR-34c-3p:PRKAR2B binding details limited\", \"Single lab\", \"Generality across infection models unestablished\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Defined an HHEX\\u2013PRKAR2B\\u2013PKA\\u2013HK2 axis coupling glucose availability to PKA-driven glycolysis and metastasis in pancreatic cancer.\",\n      \"evidence\": \"HHEX knockdown, PKA activity and HK2/glycolysis assays, and in vivo high-glucose and glycolysis-inhibition experiments\",\n      \"pmids\": [\"41704777\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"HHEX direct transcriptional control of PRKAR2B not fully mapped\", \"Single study\", \"Link between PKA activation and HK2 upregulation mechanistically incomplete\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"It remains unresolved how a PKA-inhibitory regulatory subunit acts as an oncogenic driver across multiple cancers, and whether its tumor-promoting effects depend on PKA catalytic activity or on PKA-independent functions.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structural or biochemical reconstitution of PRKAR2B-PKA holoenzyme in these contexts\", \"Direct molecular link to Wnt/\\u03b2-catenin and HIF-1\\u03b1 unknown\", \"No in vivo genetic model distinguishing catalytic-dependent from independent roles\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [4, 7, 8]}\n    ],\n    \"localization\": [],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [4, 7, 8]},\n      {\"term_id\": \"R-HSA-1430728\", \"supporting_discovery_ids\": [1, 8]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [4, 5, 6]}\n    ],\n    \"complexes\": [\"PKA holoenzyme\"],\n    \"partners\": [\"PRKACA\", \"PRKAR1A\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}