{"gene":"RPS15A","run_date":"2026-04-28T20:42:06","timeline":{"discoveries":[{"year":1994,"finding":"Rat RPS15A (S15a) is a component of the 40S ribosomal subunit, consists of 129 amino acids (NH2-terminal methionine removed post-translationally), and is encoded by a multi-copy gene family (10–15 copies) producing an ~650 nt mRNA.","method":"cDNA cloning, nucleotide sequencing, Southern/Northern blotting","journal":"Biochemical and biophysical research communications","confidence":"High","confidence_rationale":"Tier 1 — primary structural characterization with sequencing and blotting; foundational paper replicated across species","pmids":["8185605"],"is_preprint":false},{"year":2004,"finding":"Human RPS15A (S15a) expression is upregulated by hepatitis B virus X antigen (HBxAg); overexpression of S15a stimulates cell growth, colony formation in soft agar, and tumor formation in SCID mice, implicating it in translational integrity and HCC development.","method":"PCR-select cDNA subtraction, Northern/Western blotting, soft-agar colony formation, SCID mouse xenograft","journal":"Molecular carcinogenesis","confidence":"Medium","confidence_rationale":"Tier 2 — multiple orthogonal methods in a single study; gain-of-function with defined cellular and in vivo phenotypes","pmids":["15108328"],"is_preprint":false},{"year":2013,"finding":"shRNA-mediated knockdown of RPS15A inhibits hepatic cancer cell (HepG2, Bel7404) proliferation, impairs colony formation, and arrests cells at G0/G1 phase, demonstrating a required role in cell cycle progression.","method":"Lentiviral shRNA knockdown, MTT/colony formation assays, flow cytometry cell-cycle analysis","journal":"Gene","confidence":"Medium","confidence_rationale":"Tier 2 — clean KD with defined cellular phenotypes across two cell lines","pmids":["24334120"],"is_preprint":false},{"year":2015,"finding":"RPS15A knockdown in glioblastoma cells (U87, U251) decreases p-Akt levels, arrests cells at G0/G1, inhibits proliferation and migration in vitro, and suppresses tumor growth in nude mice, placing RPS15A upstream of the AKT pathway.","method":"Lentiviral RNAi, Western blot (p-Akt), MTT, wound-healing, transwell migration, nude mouse xenograft","journal":"Tumour biology","confidence":"Medium","confidence_rationale":"Tier 2 — loss-of-function with pathway readout (p-Akt) and in vivo confirmation","pmids":["26537582"],"is_preprint":false},{"year":2016,"finding":"RPS15A knockdown in glioblastoma U251 cells inhibits growth, induces G0/G1 arrest, triggers apoptosis, decreases Bcl-2 protein, and activates caspase-3 and PARP cleavage, defining a pro-survival/anti-apoptotic mechanism.","method":"Lentiviral RNAi, MTT, colony formation, flow cytometry, Western blot (Bcl-2, caspase-3, PARP)","journal":"World journal of surgical oncology","confidence":"Medium","confidence_rationale":"Tier 2 — KD with defined molecular mechanism (Bcl-2/caspase-3 axis)","pmids":["27130037"],"is_preprint":false},{"year":2016,"finding":"In lung adenocarcinoma cells, RPS15A knockdown inhibits growth, induces apoptosis, and activates the p53 signaling pathway as revealed by gene expression microarray, suggesting RPS15A suppresses p53 activity.","method":"Lentiviral shRNA, gene expression microarray, flow cytometry","journal":"PeerJ","confidence":"Medium","confidence_rationale":"Tier 2 — KD with pathway identification by microarray; single lab","pmids":["26989627"],"is_preprint":false},{"year":2017,"finding":"RPS15A promotes tumor angiogenesis in hepatocellular carcinoma by enhancing Wnt/β-catenin-mediated FGF18 expression in HCC cells; secreted FGF18 then binds FGFR3 on endothelial cells to activate AKT and ERK, stimulating angiogenesis.","method":"HCC cell overexpression/knockdown, HUVEC co-culture paracrine angiogenesis assay, reporter assays, Western blot, nude mouse xenograft","journal":"Oncogene","confidence":"High","confidence_rationale":"Tier 2 — multiple orthogonal methods (co-culture, in vivo, pathway reporters), replicated across two cell lines","pmids":["29242604"],"is_preprint":false},{"year":2017,"finding":"miR-29 family members directly bind the 3′-UTR of RPS15A mRNA (validated by luciferase assay) and reduce RPS15A protein, consequently downregulating cyclin A, cyclin D1 and upregulating p21, thereby regulating cell cycle in HCC.","method":"Luciferase 3′-UTR reporter assay, Western blot, cell cycle analysis","journal":"International journal of clinical and experimental pathology","confidence":"Medium","confidence_rationale":"Tier 2 — direct 3′-UTR target validation with functional rescue; single lab","pmids":["31966655"],"is_preprint":false},{"year":2019,"finding":"RPS15A activates the NF-κB pathway in gastric cancer by inducing Akt/IKK-β signaling, leading to phosphorylation and nuclear translocation of p65; both Akt inhibitor LY294002 and IKK inhibitor Bay117082 block p65 nuclear translocation induced by RPS15A overexpression, placing RPS15A upstream of Akt/IKK-β/NF-κB.","method":"Overexpression/knockdown, NF-κB reporter assay, Western blot (p-p65, nuclear fractionation), pharmacological inhibitors, in vivo xenograft","journal":"Journal of cellular and molecular medicine","confidence":"High","confidence_rationale":"Tier 2 — epistasis via pharmacological inhibitors combined with reporter assay and fractionation; multiple orthogonal methods","pmids":["30661291"],"is_preprint":false},{"year":2019,"finding":"RPS15A is a direct target of miR-519d-3p (validated by luciferase reporter); RPS15A knockdown downregulates β-catenin and blocks Wnt/β-catenin signaling in pancreatic cancer cells; restoration of RPS15A reverses the antitumor effect of miR-519d-3p.","method":"Luciferase 3′-UTR reporter assay, Western blot, cell proliferation assay, rescue experiment","journal":"Chemico-biological interactions","confidence":"Medium","confidence_rationale":"Tier 2 — direct target validation with functional rescue; single lab","pmids":["30831090"],"is_preprint":false},{"year":2019,"finding":"RPS15A knockdown in breast cancer MDA-MB-231 cells suppresses phosphorylation of ERK1/2, Bad, and Chk1, and activates caspase-3/-7, indicating RPS15A inhibits apoptosis via the ERK1/2/Bad/Chk1 axis.","method":"Lentiviral shRNA, Western blot (p-ERK1/2, p-Bad, p-Chk1), caspase-3/-7 activity assay","journal":"Journal of cellular biochemistry","confidence":"Medium","confidence_rationale":"Tier 2 — KD with defined molecular pathway readout; single lab","pmids":["31535410"],"is_preprint":false},{"year":2019,"finding":"miR-147b directly targets RPS15A (validated by luciferase reporter), negatively regulates its expression in NSCLC cells, and thereby downregulates Wnt/β-catenin signaling; overexpression of RPS15A partially reverses the antitumor effect of miR-147b.","method":"Luciferase 3′-UTR reporter assay, Western blot, functional rescue experiment","journal":"Clinical and experimental pharmacology & physiology","confidence":"Medium","confidence_rationale":"Tier 2 — direct miRNA-target validation with pathway readout and rescue; single lab","pmids":["31665807"],"is_preprint":false},{"year":2021,"finding":"RPS15A knockdown in colorectal cancer RKO cells induces apoptosis via regulation of BIRC3, p38 MAPK, and Chk1, and causes G2/M arrest, as identified by KEGG pathway analysis of 785 differentially expressed genes and confirmed by Western blot.","method":"Lentiviral shRNA, microarray/KEGG pathway analysis, Western blot, flow cytometry, nude mouse xenograft","journal":"European review for medical and pharmacological sciences","confidence":"Medium","confidence_rationale":"Tier 2 — KD with transcriptomic pathway analysis and functional confirmation; single lab","pmids":["34156695"],"is_preprint":false},{"year":2022,"finding":"PSMC2 promotes RPS15A expression by competitively binding hsa-let-7c-3p; elevated RPS15A in turn activates the mTOR pathway; mTOR inhibitor Torin1 partially reverses RPS15A-overexpression-induced proliferation, placing RPS15A downstream of PSMC2/let-7c-3p and upstream of mTOR.","method":"GeneChip analysis, dual-luciferase reporter assay, RPS15A overexpression rescue, Torin1 pharmacological inhibition, Western blot","journal":"Oncogenesis","confidence":"Medium","confidence_rationale":"Tier 2 — epistasis via pharmacological inhibitor plus reporter assay and rescue; single lab","pmids":["35256584"],"is_preprint":false},{"year":2023,"finding":"FBXL18, an E3 ubiquitin ligase, promotes K63-linked ubiquitination of RPS15A, enhancing its protein stability; stabilized RPS15A increases SMAD3 levels and promotes its nuclear translocation, driving HCC cell proliferation; knockdown of RPS15A or SMAD3 suppresses FBXL18-mediated proliferation.","method":"Co-IP, ubiquitination assay (K63-linkage specific), Western blot (SMAD3, nuclear fractionation), FBXL18 transgenic mice, knockdown rescue experiments","journal":"Hepatology communications","confidence":"High","confidence_rationale":"Tier 1-2 — ubiquitination assay with linkage specificity, in vivo transgenic model, and epistatic rescue experiments","pmids":["37378633"],"is_preprint":false},{"year":2023,"finding":"FOXN3 transcription factor binds to the RPS15A promoter at two specific sites (−1588/−1581 and −1476/−1467) and represses its transcriptional expression, as shown by dual-luciferase assay and ChIP; RPS15A overexpression reverses FOXN3-mediated suppression of ovarian cancer malignant behaviors.","method":"Dual-luciferase promoter assay, ChIP, overexpression rescue experiments","journal":"Human cell","confidence":"Medium","confidence_rationale":"Tier 2 — direct promoter binding validated by ChIP and luciferase; functional rescue; single lab","pmids":["37016167"],"is_preprint":false},{"year":2023,"finding":"miR-147b directly targets RPS15A (validated by luciferase reporter) in prostate cancer cells; RPS15A is downregulated in neuroendocrine prostate cancer cells and its expression is inversely correlated with NE markers; overexpression of miR-147b reduces cyclin D1 and elevates p27kip1, while RPS15A inhibition contributes to neuroendocrine differentiation.","method":"Luciferase reporter assay, Western blot, miRNA mimic/inhibitor experiments, RT-PCR","journal":"The Prostate","confidence":"Medium","confidence_rationale":"Tier 2 — direct target validation with functional consequence; single lab","pmids":["37069746"],"is_preprint":false},{"year":2025,"finding":"RPS15A knockdown in B-ALL cells impairs ribosomal biogenesis by suppressing synthesis and processing of pre-rRNA, 18S rRNA, 28S rRNA, and 5.8S rRNA; this disrupts nucleolar architecture (displaces NPM1 and FBL), induces nucleolar stress, and activates p53/p21 signaling, causing cell cycle arrest and apoptosis; p53 knockdown after RPS15A KD rescues rRNA biogenesis, cell cycle progression, and inhibits apoptosis.","method":"Lentiviral shRNA, immunofluorescence (NPM1/FBL localization), RT-PCR (rRNA processing), flow cytometry, Western blot (p53/p21), p53 rescue experiment","journal":"Biochemical and biophysical research communications","confidence":"High","confidence_rationale":"Tier 2 — multiple orthogonal methods including rRNA processing, nucleolar imaging, and genetic epistasis rescue; mechanistically rigorous","pmids":["40239541"],"is_preprint":false},{"year":2025,"finding":"GGCT physically interacts with RPS15A (shown by co-IP and LC-MS/MS) and promotes RPS15A protein stability; RPS15A knockdown activates p53, which represses SLC7A11, reducing GSH synthesis and promoting ferroptosis in papillary thyroid cancer cells; RPS15A overexpression reverses GGCT-knockdown-induced ferroptosis.","method":"Co-immunoprecipitation, LC-MS/MS, Western blot, ferroptosis assays (MDA, ROS), rescue overexpression","journal":"Cancer science","confidence":"Medium","confidence_rationale":"Tier 2 — protein interaction validated by Co-IP/MS with functional mechanistic follow-up; single lab","pmids":["40044122"],"is_preprint":false},{"year":2025,"finding":"lncRNA RHPN1-AS1 physically interacts with RPS15A protein and stabilizes it in hypoxic HCC cells; elevated RPS15A then activates β-catenin signaling to promote proliferation and invasion; silencing RPS15A attenuates RHPN1-AS1-induced aggressiveness and β-catenin activation.","method":"RNA-protein pull-down/interaction assay, Western blot (β-catenin), knockdown rescue, xenograft tumor model","journal":"Medical oncology","confidence":"Medium","confidence_rationale":"Tier 2 — lncRNA-protein interaction with pathway readout and in vivo rescue; single lab","pmids":["41026296"],"is_preprint":false}],"current_model":"RPS15A is a structural component of the 40S ribosomal small subunit that promotes mRNA/ribosome interactions during translation initiation; its protein stability is regulated by K63-linked ubiquitination via FBXL18 and by interactions with GGCT and lncRNA RHPN1-AS1; beyond its ribosomal role, RPS15A knockdown impairs rRNA biogenesis and induces nucleolar stress that activates p53/p21 signaling, while elevated RPS15A promotes cancer cell proliferation, survival, and angiogenesis through multiple oncogenic axes including Wnt/β-catenin→FGF18, Akt/IKK-β/NF-κB, PI3K/Akt, mTOR, ERK1/2/Bad/Chk1, and SMAD3 pathways, and is transcriptionally repressed by FOXN3 and post-transcriptionally suppressed by multiple miRNAs (miR-29 family, miR-519d-3p, miR-147b)."},"narrative":{"teleology":[{"year":1994,"claim":"Establishing the identity of RPS15A as a 40S ribosomal subunit protein resolved its primary structure and gene organization, providing the foundation for all subsequent functional studies.","evidence":"cDNA cloning, sequencing, and Southern/Northern blotting in rat","pmids":["8185605"],"confidence":"High","gaps":["No functional data on ribosomal role beyond structural membership","Post-translational modifications uncharacterized","Human ortholog not yet cloned at this point"]},{"year":2004,"claim":"The discovery that HBxAg upregulates RPS15A and that its overexpression transforms cells and drives tumor formation in SCID mice established the first link between a ribosomal protein and oncogenic extra-ribosomal function.","evidence":"PCR-select cDNA subtraction, soft-agar colony formation, and SCID mouse xenograft in HCC context","pmids":["15108328"],"confidence":"Medium","gaps":["Mechanism of HBxAg-mediated upregulation undefined","Downstream signaling pathways not identified","Whether oncogenic activity is translation-dependent or extra-ribosomal remained unclear"]},{"year":2013,"claim":"Demonstrating that RPS15A knockdown arrests hepatic cancer cells at G0/G1 established that RPS15A is required for cell cycle progression, not merely permissive for growth.","evidence":"Lentiviral shRNA knockdown with MTT, colony formation, and flow cytometry in HepG2 and Bel7404 cells","pmids":["24334120"],"confidence":"Medium","gaps":["Cell cycle targets (cyclins, CDKs) not identified","No pathway mechanism defined","Off-target effects of single shRNA not fully excluded"]},{"year":2015,"claim":"Identification of decreased p-Akt upon RPS15A knockdown in glioblastoma placed RPS15A upstream of AKT signaling and linked it to migration and in vivo tumor growth beyond HCC.","evidence":"Lentiviral RNAi with p-Akt Western blot and nude mouse xenograft in U87/U251 glioblastoma cells","pmids":["26537582"],"confidence":"Medium","gaps":["Direct versus indirect activation of AKT not resolved","Mechanism linking a ribosomal protein to AKT unknown","Whether translation-dependent or independent unclear"]},{"year":2016,"claim":"Demonstration that RPS15A knockdown activates caspase-3, cleaves PARP, and reduces Bcl-2 defined a pro-survival/anti-apoptotic mechanism, while microarray analysis in lung cancer linked RPS15A loss to p53 pathway activation.","evidence":"Lentiviral RNAi with apoptosis marker Western blots in glioblastoma; gene expression microarray in lung adenocarcinoma","pmids":["27130037","26989627"],"confidence":"Medium","gaps":["Whether p53 activation is a direct consequence of nucleolar stress was not tested","No epistasis experiments with p53 at this stage","Single cell line per study"]},{"year":2017,"claim":"Elucidation of the RPS15A→Wnt/β-catenin→FGF18→FGFR3 paracrine angiogenesis axis in HCC revealed a specific extra-ribosomal oncogenic signaling mechanism and the first non-cell-autonomous function, while miR-29 family members were validated as direct post-transcriptional suppressors of RPS15A.","evidence":"HUVEC co-culture paracrine assay, reporter assays, and xenograft for angiogenesis; luciferase 3′-UTR reporter for miR-29 targeting","pmids":["29242604","31966655"],"confidence":"High","gaps":["Whether RPS15A directly binds β-catenin or acts through translation is unknown","Physiological relevance of miR-29-RPS15A axis in non-cancer tissue not tested"]},{"year":2019,"claim":"Pharmacological epistasis using AKT and IKK inhibitors defined RPS15A as an upstream activator of the Akt/IKK-β/NF-κB cascade in gastric cancer; concurrent studies validated miR-519d-3p and miR-147b as additional direct miRNA regulators suppressing RPS15A/Wnt signaling, and identified the ERK1/2/Bad/Chk1 anti-apoptotic axis in breast cancer.","evidence":"NF-κB reporter with LY294002/Bay117082 in gastric cancer; luciferase reporters and rescue in pancreatic/NSCLC cells; p-ERK/p-Bad/p-Chk1 Western blots in MDA-MB-231","pmids":["30661291","30831090","31665807","31535410"],"confidence":"High","gaps":["No direct physical interaction between RPS15A and AKT or IKK-β demonstrated","How a ribosomal protein specifically activates multiple kinase cascades remains mechanistically opaque","Relative contribution of translational versus extra-ribosomal functions unclear"]},{"year":2022,"claim":"Placing RPS15A downstream of PSMC2/let-7c-3p and upstream of mTOR, with Torin1 partially reversing RPS15A-driven proliferation, extended the signaling network to the mTOR pathway.","evidence":"GeneChip analysis, dual-luciferase reporter, RPS15A overexpression rescue, Torin1 pharmacological inhibition","pmids":["35256584"],"confidence":"Medium","gaps":["Direct RPS15A–mTOR interaction not shown","Partial rescue by Torin1 implies additional pathways","Single cancer type tested"]},{"year":2023,"claim":"Discovery that FBXL18 catalyzes K63-linked ubiquitination to stabilize RPS15A protein, which in turn elevates SMAD3 and promotes its nuclear translocation, established the first defined post-translational regulatory mechanism and a new downstream effector; FOXN3 was identified as a direct transcriptional repressor binding the RPS15A promoter.","evidence":"K63-linkage-specific ubiquitination assay, Co-IP, FBXL18 transgenic mice, epistatic knockdown rescue for SMAD3 axis; ChIP and luciferase promoter assay for FOXN3","pmids":["37378633","37016167"],"confidence":"High","gaps":["Whether K63-Ub affects RPS15A ribosomal incorporation or only extra-ribosomal pools is unknown","SMAD3 activation mechanism (direct binding vs. translational) not resolved","FOXN3 regulation in non-ovarian contexts untested"]},{"year":2025,"claim":"Demonstration that RPS15A knockdown impairs rRNA biogenesis, disrupts nucleolar architecture (NPM1/FBL displacement), and triggers p53/p21-dependent arrest—with p53 knockdown rescuing rRNA processing—definitively linked RPS15A to nucleolar stress surveillance; GGCT was identified as a stabilizing physical interactor, and lncRNA RHPN1-AS1 as an additional stabilizer activating β-catenin.","evidence":"rRNA processing RT-PCR, NPM1/FBL immunofluorescence, p53 epistasis rescue in B-ALL; Co-IP/LC-MS/MS for GGCT; RNA pull-down for RHPN1-AS1 in hypoxic HCC","pmids":["40239541","40044122","41026296"],"confidence":"High","gaps":["Structural basis for RPS15A's role in rRNA processing unknown","Whether GGCT stabilization uses ubiquitin-dependent or -independent mechanism not defined","Ferroptosis link via p53/SLC7A11 axis awaits validation in additional cancer types"]},{"year":null,"claim":"The fundamental question of how a ribosomal protein activates multiple distinct kinase cascades (AKT, ERK, mTOR, NF-κB, Wnt/β-catenin) — whether through selective translational control of specific mRNAs, direct extra-ribosomal protein interactions, or specialized ribosome populations — remains unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["No ribosome profiling or selective translation data exist for RPS15A perturbation","Extra-ribosomal pool versus ribosome-incorporated pool not distinguished in any study","No structural model of RPS15A within the human 40S subunit has been functionally interrogated"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0005198","term_label":"structural molecule activity","supporting_discovery_ids":[0,17]}],"localization":[{"term_id":"GO:0005840","term_label":"ribosome","supporting_discovery_ids":[0,17]},{"term_id":"GO:0005730","term_label":"nucleolus","supporting_discovery_ids":[17]},{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[14,18]}],"pathway":[{"term_id":"R-HSA-392499","term_label":"Metabolism of proteins","supporting_discovery_ids":[0,17]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[3,6,8,9,13,14]},{"term_id":"R-HSA-5357801","term_label":"Programmed Cell Death","supporting_discovery_ids":[4,5,10,18]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[2,7,12]},{"term_id":"R-HSA-1643685","term_label":"Disease","supporting_discovery_ids":[1,6,8]}],"complexes":["40S ribosomal subunit"],"partners":["FBXL18","GGCT","SMAD3","RHPN1-AS1","NPM1","FBL"],"other_free_text":[]},"mechanistic_narrative":"RPS15A is a core structural component of the 40S ribosomal subunit that is essential for ribosome biogenesis, rRNA processing, and translational integrity, and functions as an oncogenic signaling hub in multiple cancer types [PMID:8185605, PMID:40239541]. Loss of RPS15A disrupts nucleolar architecture, impairs pre-rRNA and mature rRNA synthesis, and triggers nucleolar stress-mediated p53/p21 activation leading to cell cycle arrest and apoptosis [PMID:40239541, PMID:26989627]. Beyond its ribosomal role, RPS15A activates Wnt/β-catenin, Akt/IKK-β/NF-κB, mTOR, and ERK1/2 signaling to promote proliferation, survival, and angiogenesis; its protein stability is regulated by FBXL18-mediated K63-linked ubiquitination, GGCT binding, and lncRNA RHPN1-AS1, while its expression is transcriptionally repressed by FOXN3 and post-transcriptionally suppressed by miR-29, miR-519d-3p, and miR-147b [PMID:29242604, PMID:30661291, PMID:37378633, PMID:40044122, PMID:41026296, PMID:37016167, PMID:31665807]. RPS15A overexpression drives hepatocellular carcinoma development downstream of hepatitis B virus X antigen and promotes tumor formation in xenograft models [PMID:15108328, PMID:29242604]."},"prefetch_data":{"uniprot":{"accession":"P62244","full_name":"Small ribosomal subunit protein uS8","aliases":["40S ribosomal protein S15a"],"length_aa":130,"mass_kda":14.8,"function":"Component of the small ribosomal subunit (PubMed:23636399). Part of the small subunit (SSU) processome, first precursor of the small eukaryotic ribosomal subunit. During the assembly of the SSU processome in the nucleolus, many ribosome biogenesis factors, an RNA chaperone and ribosomal proteins associate with the nascent pre-rRNA and work in concert to generate RNA folding, modifications, rearrangements and cleavage as well as targeted degradation of pre-ribosomal RNA by the RNA exosome (PubMed:34516797). Required for proper erythropoiesis (PubMed:27909223)","subcellular_location":"Cytoplasm; Nucleus, nucleolus","url":"https://www.uniprot.org/uniprotkb/P62244/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":true,"resolved_as":"","url":"https://depmap.org/portal/gene/RPS15A","classification":"Common Essential","n_dependent_lines":1208,"n_total_lines":1208,"dependency_fraction":1.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"EIF2S3","stoichiometry":10.0},{"gene":"EIF3B","stoichiometry":10.0},{"gene":"RPL11","stoichiometry":10.0},{"gene":"RPL19","stoichiometry":10.0},{"gene":"RPL4","stoichiometry":10.0},{"gene":"RPL5","stoichiometry":10.0},{"gene":"RPS16","stoichiometry":10.0},{"gene":"ENY2","stoichiometry":4.0},{"gene":"METAP2","stoichiometry":4.0},{"gene":"RACK1","stoichiometry":4.0}],"url":"https://opencell.sf.czbiohub.org/search/RPS15A","total_profiled":1310},"omim":[{"mim_id":"618313","title":"DIAMOND-BLACKFAN ANEMIA 20; DBA20","url":"https://www.omim.org/entry/618313"},{"mim_id":"603674","title":"RIBOSOMAL PROTEIN S15a; RPS15A","url":"https://www.omim.org/entry/603674"},{"mim_id":"105650","title":"DIAMOND-BLACKFAN ANEMIA 1; DBA1","url":"https://www.omim.org/entry/105650"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/RPS15A"},"hgnc":{"alias_symbol":["S15A","uS8"],"prev_symbol":[]},"alphafold":{"accession":"P62244","domains":[{"cath_id":"3.30.1370.30","chopping":"5-64","consensus_level":"medium","plddt":93.9343,"start":5,"end":64},{"cath_id":"3.30.1490.10","chopping":"71-128","consensus_level":"medium","plddt":93.4755,"start":71,"end":128}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P62244","model_url":"https://alphafold.ebi.ac.uk/files/AF-P62244-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P62244-F1-predicted_aligned_error_v6.png","plddt_mean":93.06},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=RPS15A","jax_strain_url":"https://www.jax.org/strain/search?query=RPS15A"},"sequence":{"accession":"P62244","fasta_url":"https://rest.uniprot.org/uniprotkb/P62244.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P62244/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P62244"}},"corpus_meta":[{"pmid":"29242604","id":"PMC_29242604","title":"Ribosomal protein S15a promotes tumor angiogenesis via enhancing Wnt/β-catenin-induced FGF18 expression in hepatocellular carcinoma.","date":"2017","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/29242604","citation_count":61,"is_preprint":false},{"pmid":"31604943","id":"PMC_31604943","title":"HCMV-encoded US7 and US8 act as antagonists of innate immunity by distinctively targeting TLR-signaling pathways.","date":"2019","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/31604943","citation_count":44,"is_preprint":false},{"pmid":"30661291","id":"PMC_30661291","title":"RPS15A promotes gastric cancer progression via activation of the Akt/IKK-β/NF-κB signalling pathway.","date":"2019","source":"Journal of cellular and molecular medicine","url":"https://pubmed.ncbi.nlm.nih.gov/30661291","citation_count":39,"is_preprint":false},{"pmid":"1581568","id":"PMC_1581568","title":"Cytoplasmic ribosomal protein S15a from Brassica napus: molecular cloning and developmental expression in mitotically active tissues.","date":"1992","source":"Plant molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/1581568","citation_count":39,"is_preprint":false},{"pmid":"11992003","id":"PMC_11992003","title":"Human cytomegalovirus US7, US8, US9, and US10 are cytoplasmic glycoproteins, not found at cell surfaces, and US9 does not mediate cell-to-cell spread.","date":"2002","source":"Journal of virology","url":"https://pubmed.ncbi.nlm.nih.gov/11992003","citation_count":38,"is_preprint":false},{"pmid":"24334120","id":"PMC_24334120","title":"Down-regulation of ribosomal protein S15A mRNA with a short hairpin RNA inhibits human hepatic cancer cell growth in vitro.","date":"2013","source":"Gene","url":"https://pubmed.ncbi.nlm.nih.gov/24334120","citation_count":37,"is_preprint":false},{"pmid":"15108328","id":"PMC_15108328","title":"Human S15a expression is upregulated by hepatitis B virus X protein.","date":"2004","source":"Molecular 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downregulation of Wnt/β-catenin signalling via targeting of RPS15A.","date":"2019","source":"Clinical and experimental pharmacology & physiology","url":"https://pubmed.ncbi.nlm.nih.gov/31665807","citation_count":14,"is_preprint":false},{"pmid":"9524817","id":"PMC_9524817","title":"Nucleotide sequence of canine herpesvirus homologues of herpes simplex virus type 1 US2, US3, glycoproteins I and E, US8.5 and US9 genes.","date":"1997","source":"DNA sequence : the journal of DNA sequencing and mapping","url":"https://pubmed.ncbi.nlm.nih.gov/9524817","citation_count":14,"is_preprint":false},{"pmid":"29802490","id":"PMC_29802490","title":"Knockdown of ribosomal protein S15A inhibits proliferation of breast cancer cells through induction of apoptosis in vitro.","date":"2018","source":"Cytotechnology","url":"https://pubmed.ncbi.nlm.nih.gov/29802490","citation_count":13,"is_preprint":false},{"pmid":"37378633","id":"PMC_37378633","title":"Elevated FBXL18 promotes RPS15A ubiquitination and SMAD3 activation to drive HCC.","date":"2023","source":"Hepatology communications","url":"https://pubmed.ncbi.nlm.nih.gov/37378633","citation_count":12,"is_preprint":false},{"pmid":"27035327","id":"PMC_27035327","title":"shRNA-mediated RPS15A silencing inhibits U937 acute myeloid leukemia cell proliferation and enhances apoptosis.","date":"2016","source":"Molecular medicine reports","url":"https://pubmed.ncbi.nlm.nih.gov/27035327","citation_count":12,"is_preprint":false},{"pmid":"8185605","id":"PMC_8185605","title":"The primary structure of rat ribosomal protein S15a.","date":"1994","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/8185605","citation_count":11,"is_preprint":false},{"pmid":"31535410","id":"PMC_31535410","title":"Ribosomal protein small subunit 15A (RPS15A) inhibits the apoptosis of breast cancer MDA-MB-231 cells via upregulating phosphorylated ERK1/2, Bad, and Chk1.","date":"2019","source":"Journal of cellular biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/31535410","citation_count":9,"is_preprint":false},{"pmid":"14760523","id":"PMC_14760523","title":"Cloning, expression and partial characterization of a gene encoding the S15a ribosomal protein of Taenia solium.","date":"2004","source":"Parasitology research","url":"https://pubmed.ncbi.nlm.nih.gov/14760523","citation_count":9,"is_preprint":false},{"pmid":"31966655","id":"PMC_31966655","title":"MicroRNA-29 family functions as a tumor suppressor by targeting RPS15A and regulating cell cycle in hepatocellular carcinoma.","date":"2017","source":"International journal of clinical and experimental pathology","url":"https://pubmed.ncbi.nlm.nih.gov/31966655","citation_count":8,"is_preprint":false},{"pmid":"30450850","id":"PMC_30450850","title":"RPS15a Silencing Suppresses Cell Proliferation and Migration of Gastric Cancer.","date":"2018","source":"Yonsei medical journal","url":"https://pubmed.ncbi.nlm.nih.gov/30450850","citation_count":7,"is_preprint":false},{"pmid":"7614376","id":"PMC_7614376","title":"Molecular cloning and sequence of the cytoplasmic ribosomal protein S15a gene from Agaricus bisporus.","date":"1995","source":"Experimental mycology","url":"https://pubmed.ncbi.nlm.nih.gov/7614376","citation_count":6,"is_preprint":false},{"pmid":"37016167","id":"PMC_37016167","title":"FOXN3 inhibits the progression of ovarian cancer through negatively regulating the expression of RPS15A.","date":"2023","source":"Human cell","url":"https://pubmed.ncbi.nlm.nih.gov/37016167","citation_count":5,"is_preprint":false},{"pmid":"37069746","id":"PMC_37069746","title":"MicroRNA-147b induces neuroendocrine differentiation of prostate cancer cells by targeting ribosomal protein RPS15A.","date":"2023","source":"The Prostate","url":"https://pubmed.ncbi.nlm.nih.gov/37069746","citation_count":5,"is_preprint":false},{"pmid":"30569143","id":"PMC_30569143","title":"Knockdown of ribosomal protein S15A inhibits human kidney cancer cell growth in vitro and in vivo.","date":"2018","source":"Molecular medicine reports","url":"https://pubmed.ncbi.nlm.nih.gov/30569143","citation_count":5,"is_preprint":false},{"pmid":"28791303","id":"PMC_28791303","title":"The uS8, uS4, eS31, and uL14 Ribosomal Protein Genes Are Dysregulated in Nasopharyngeal Carcinoma Cell Lines.","date":"2017","source":"BioMed research international","url":"https://pubmed.ncbi.nlm.nih.gov/28791303","citation_count":5,"is_preprint":false},{"pmid":"40044122","id":"PMC_40044122","title":"GGCT Inhibits Ferroptosis in PTC Cells by Upregulating p53 Through RPS15A.","date":"2025","source":"Cancer 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virology","url":"https://pubmed.ncbi.nlm.nih.gov/21865379","citation_count":4,"is_preprint":false},{"pmid":"28477233","id":"PMC_28477233","title":"Deletion of the us7 and us8 genes of pseudorabies virus exerts a differential effect on the expression of early and late viral genes.","date":"2017","source":"Virus genes","url":"https://pubmed.ncbi.nlm.nih.gov/28477233","citation_count":4,"is_preprint":false},{"pmid":"40239541","id":"PMC_40239541","title":"RPS15a knockdown impedes the progression of B-ALL by inducing p53-mediated nucleolar stress.","date":"2025","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/40239541","citation_count":3,"is_preprint":false},{"pmid":"37094854","id":"PMC_37094854","title":"RPS15A Mediates PI3K/AKT Signaling-Induced Parathyroid Cell Proliferation in Rats with Secondary Hyperparathyroidism.","date":"2023","source":"Annals of clinical and laboratory 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and environmental safety","url":"https://pubmed.ncbi.nlm.nih.gov/41653713","citation_count":0,"is_preprint":false},{"pmid":"15375518","id":"PMC_15375518","title":"Radiosensitization of a human soft tissue sarcoma cell line US8-93 (mt-p53) with the oxidizer sodium peroxodisulfate.","date":"2004","source":"Oncology reports","url":"https://pubmed.ncbi.nlm.nih.gov/15375518","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":21832,"output_tokens":4604,"usd":0.067278},"stage2":{"model":"claude-opus-4-6","input_tokens":8176,"output_tokens":3180,"usd":0.18057},"total_usd":0.247848,"stage1_batch_id":"msgbatch_011rkcQdVV1RaFq9XhcG6df6","stage2_batch_id":"msgbatch_01RzgrJafdF4EWHhj5mNi6dh","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1994,\n      \"finding\": \"Rat RPS15A (S15a) is a component of the 40S ribosomal subunit, consists of 129 amino acids (NH2-terminal methionine removed post-translationally), and is encoded by a multi-copy gene family (10–15 copies) producing an ~650 nt mRNA.\",\n      \"method\": \"cDNA cloning, nucleotide sequencing, Southern/Northern blotting\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — primary structural characterization with sequencing and blotting; foundational paper replicated across species\",\n      \"pmids\": [\"8185605\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"Human RPS15A (S15a) expression is upregulated by hepatitis B virus X antigen (HBxAg); overexpression of S15a stimulates cell growth, colony formation in soft agar, and tumor formation in SCID mice, implicating it in translational integrity and HCC development.\",\n      \"method\": \"PCR-select cDNA subtraction, Northern/Western blotting, soft-agar colony formation, SCID mouse xenograft\",\n      \"journal\": \"Molecular carcinogenesis\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods in a single study; gain-of-function with defined cellular and in vivo phenotypes\",\n      \"pmids\": [\"15108328\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"shRNA-mediated knockdown of RPS15A inhibits hepatic cancer cell (HepG2, Bel7404) proliferation, impairs colony formation, and arrests cells at G0/G1 phase, demonstrating a required role in cell cycle progression.\",\n      \"method\": \"Lentiviral shRNA knockdown, MTT/colony formation assays, flow cytometry cell-cycle analysis\",\n      \"journal\": \"Gene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — clean KD with defined cellular phenotypes across two cell lines\",\n      \"pmids\": [\"24334120\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"RPS15A knockdown in glioblastoma cells (U87, U251) decreases p-Akt levels, arrests cells at G0/G1, inhibits proliferation and migration in vitro, and suppresses tumor growth in nude mice, placing RPS15A upstream of the AKT pathway.\",\n      \"method\": \"Lentiviral RNAi, Western blot (p-Akt), MTT, wound-healing, transwell migration, nude mouse xenograft\",\n      \"journal\": \"Tumour biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — loss-of-function with pathway readout (p-Akt) and in vivo confirmation\",\n      \"pmids\": [\"26537582\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"RPS15A knockdown in glioblastoma U251 cells inhibits growth, induces G0/G1 arrest, triggers apoptosis, decreases Bcl-2 protein, and activates caspase-3 and PARP cleavage, defining a pro-survival/anti-apoptotic mechanism.\",\n      \"method\": \"Lentiviral RNAi, MTT, colony formation, flow cytometry, Western blot (Bcl-2, caspase-3, PARP)\",\n      \"journal\": \"World journal of surgical oncology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — KD with defined molecular mechanism (Bcl-2/caspase-3 axis)\",\n      \"pmids\": [\"27130037\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"In lung adenocarcinoma cells, RPS15A knockdown inhibits growth, induces apoptosis, and activates the p53 signaling pathway as revealed by gene expression microarray, suggesting RPS15A suppresses p53 activity.\",\n      \"method\": \"Lentiviral shRNA, gene expression microarray, flow cytometry\",\n      \"journal\": \"PeerJ\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — KD with pathway identification by microarray; single lab\",\n      \"pmids\": [\"26989627\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"RPS15A promotes tumor angiogenesis in hepatocellular carcinoma by enhancing Wnt/β-catenin-mediated FGF18 expression in HCC cells; secreted FGF18 then binds FGFR3 on endothelial cells to activate AKT and ERK, stimulating angiogenesis.\",\n      \"method\": \"HCC cell overexpression/knockdown, HUVEC co-culture paracrine angiogenesis assay, reporter assays, Western blot, nude mouse xenograft\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods (co-culture, in vivo, pathway reporters), replicated across two cell lines\",\n      \"pmids\": [\"29242604\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"miR-29 family members directly bind the 3′-UTR of RPS15A mRNA (validated by luciferase assay) and reduce RPS15A protein, consequently downregulating cyclin A, cyclin D1 and upregulating p21, thereby regulating cell cycle in HCC.\",\n      \"method\": \"Luciferase 3′-UTR reporter assay, Western blot, cell cycle analysis\",\n      \"journal\": \"International journal of clinical and experimental pathology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — direct 3′-UTR target validation with functional rescue; single lab\",\n      \"pmids\": [\"31966655\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"RPS15A activates the NF-κB pathway in gastric cancer by inducing Akt/IKK-β signaling, leading to phosphorylation and nuclear translocation of p65; both Akt inhibitor LY294002 and IKK inhibitor Bay117082 block p65 nuclear translocation induced by RPS15A overexpression, placing RPS15A upstream of Akt/IKK-β/NF-κB.\",\n      \"method\": \"Overexpression/knockdown, NF-κB reporter assay, Western blot (p-p65, nuclear fractionation), pharmacological inhibitors, in vivo xenograft\",\n      \"journal\": \"Journal of cellular and molecular medicine\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — epistasis via pharmacological inhibitors combined with reporter assay and fractionation; multiple orthogonal methods\",\n      \"pmids\": [\"30661291\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"RPS15A is a direct target of miR-519d-3p (validated by luciferase reporter); RPS15A knockdown downregulates β-catenin and blocks Wnt/β-catenin signaling in pancreatic cancer cells; restoration of RPS15A reverses the antitumor effect of miR-519d-3p.\",\n      \"method\": \"Luciferase 3′-UTR reporter assay, Western blot, cell proliferation assay, rescue experiment\",\n      \"journal\": \"Chemico-biological interactions\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — direct target validation with functional rescue; single lab\",\n      \"pmids\": [\"30831090\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"RPS15A knockdown in breast cancer MDA-MB-231 cells suppresses phosphorylation of ERK1/2, Bad, and Chk1, and activates caspase-3/-7, indicating RPS15A inhibits apoptosis via the ERK1/2/Bad/Chk1 axis.\",\n      \"method\": \"Lentiviral shRNA, Western blot (p-ERK1/2, p-Bad, p-Chk1), caspase-3/-7 activity assay\",\n      \"journal\": \"Journal of cellular biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — KD with defined molecular pathway readout; single lab\",\n      \"pmids\": [\"31535410\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"miR-147b directly targets RPS15A (validated by luciferase reporter), negatively regulates its expression in NSCLC cells, and thereby downregulates Wnt/β-catenin signaling; overexpression of RPS15A partially reverses the antitumor effect of miR-147b.\",\n      \"method\": \"Luciferase 3′-UTR reporter assay, Western blot, functional rescue experiment\",\n      \"journal\": \"Clinical and experimental pharmacology & physiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — direct miRNA-target validation with pathway readout and rescue; single lab\",\n      \"pmids\": [\"31665807\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"RPS15A knockdown in colorectal cancer RKO cells induces apoptosis via regulation of BIRC3, p38 MAPK, and Chk1, and causes G2/M arrest, as identified by KEGG pathway analysis of 785 differentially expressed genes and confirmed by Western blot.\",\n      \"method\": \"Lentiviral shRNA, microarray/KEGG pathway analysis, Western blot, flow cytometry, nude mouse xenograft\",\n      \"journal\": \"European review for medical and pharmacological sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — KD with transcriptomic pathway analysis and functional confirmation; single lab\",\n      \"pmids\": [\"34156695\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"PSMC2 promotes RPS15A expression by competitively binding hsa-let-7c-3p; elevated RPS15A in turn activates the mTOR pathway; mTOR inhibitor Torin1 partially reverses RPS15A-overexpression-induced proliferation, placing RPS15A downstream of PSMC2/let-7c-3p and upstream of mTOR.\",\n      \"method\": \"GeneChip analysis, dual-luciferase reporter assay, RPS15A overexpression rescue, Torin1 pharmacological inhibition, Western blot\",\n      \"journal\": \"Oncogenesis\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — epistasis via pharmacological inhibitor plus reporter assay and rescue; single lab\",\n      \"pmids\": [\"35256584\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"FBXL18, an E3 ubiquitin ligase, promotes K63-linked ubiquitination of RPS15A, enhancing its protein stability; stabilized RPS15A increases SMAD3 levels and promotes its nuclear translocation, driving HCC cell proliferation; knockdown of RPS15A or SMAD3 suppresses FBXL18-mediated proliferation.\",\n      \"method\": \"Co-IP, ubiquitination assay (K63-linkage specific), Western blot (SMAD3, nuclear fractionation), FBXL18 transgenic mice, knockdown rescue experiments\",\n      \"journal\": \"Hepatology communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — ubiquitination assay with linkage specificity, in vivo transgenic model, and epistatic rescue experiments\",\n      \"pmids\": [\"37378633\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"FOXN3 transcription factor binds to the RPS15A promoter at two specific sites (−1588/−1581 and −1476/−1467) and represses its transcriptional expression, as shown by dual-luciferase assay and ChIP; RPS15A overexpression reverses FOXN3-mediated suppression of ovarian cancer malignant behaviors.\",\n      \"method\": \"Dual-luciferase promoter assay, ChIP, overexpression rescue experiments\",\n      \"journal\": \"Human cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — direct promoter binding validated by ChIP and luciferase; functional rescue; single lab\",\n      \"pmids\": [\"37016167\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"miR-147b directly targets RPS15A (validated by luciferase reporter) in prostate cancer cells; RPS15A is downregulated in neuroendocrine prostate cancer cells and its expression is inversely correlated with NE markers; overexpression of miR-147b reduces cyclin D1 and elevates p27kip1, while RPS15A inhibition contributes to neuroendocrine differentiation.\",\n      \"method\": \"Luciferase reporter assay, Western blot, miRNA mimic/inhibitor experiments, RT-PCR\",\n      \"journal\": \"The Prostate\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — direct target validation with functional consequence; single lab\",\n      \"pmids\": [\"37069746\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"RPS15A knockdown in B-ALL cells impairs ribosomal biogenesis by suppressing synthesis and processing of pre-rRNA, 18S rRNA, 28S rRNA, and 5.8S rRNA; this disrupts nucleolar architecture (displaces NPM1 and FBL), induces nucleolar stress, and activates p53/p21 signaling, causing cell cycle arrest and apoptosis; p53 knockdown after RPS15A KD rescues rRNA biogenesis, cell cycle progression, and inhibits apoptosis.\",\n      \"method\": \"Lentiviral shRNA, immunofluorescence (NPM1/FBL localization), RT-PCR (rRNA processing), flow cytometry, Western blot (p53/p21), p53 rescue experiment\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods including rRNA processing, nucleolar imaging, and genetic epistasis rescue; mechanistically rigorous\",\n      \"pmids\": [\"40239541\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"GGCT physically interacts with RPS15A (shown by co-IP and LC-MS/MS) and promotes RPS15A protein stability; RPS15A knockdown activates p53, which represses SLC7A11, reducing GSH synthesis and promoting ferroptosis in papillary thyroid cancer cells; RPS15A overexpression reverses GGCT-knockdown-induced ferroptosis.\",\n      \"method\": \"Co-immunoprecipitation, LC-MS/MS, Western blot, ferroptosis assays (MDA, ROS), rescue overexpression\",\n      \"journal\": \"Cancer science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — protein interaction validated by Co-IP/MS with functional mechanistic follow-up; single lab\",\n      \"pmids\": [\"40044122\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"lncRNA RHPN1-AS1 physically interacts with RPS15A protein and stabilizes it in hypoxic HCC cells; elevated RPS15A then activates β-catenin signaling to promote proliferation and invasion; silencing RPS15A attenuates RHPN1-AS1-induced aggressiveness and β-catenin activation.\",\n      \"method\": \"RNA-protein pull-down/interaction assay, Western blot (β-catenin), knockdown rescue, xenograft tumor model\",\n      \"journal\": \"Medical oncology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — lncRNA-protein interaction with pathway readout and in vivo rescue; single lab\",\n      \"pmids\": [\"41026296\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"RPS15A is a structural component of the 40S ribosomal small subunit that promotes mRNA/ribosome interactions during translation initiation; its protein stability is regulated by K63-linked ubiquitination via FBXL18 and by interactions with GGCT and lncRNA RHPN1-AS1; beyond its ribosomal role, RPS15A knockdown impairs rRNA biogenesis and induces nucleolar stress that activates p53/p21 signaling, while elevated RPS15A promotes cancer cell proliferation, survival, and angiogenesis through multiple oncogenic axes including Wnt/β-catenin→FGF18, Akt/IKK-β/NF-κB, PI3K/Akt, mTOR, ERK1/2/Bad/Chk1, and SMAD3 pathways, and is transcriptionally repressed by FOXN3 and post-transcriptionally suppressed by multiple miRNAs (miR-29 family, miR-519d-3p, miR-147b).\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"RPS15A is a core structural component of the 40S ribosomal subunit that is essential for ribosome biogenesis, rRNA processing, and translational integrity, and functions as an oncogenic signaling hub in multiple cancer types [PMID:8185605, PMID:40239541]. Loss of RPS15A disrupts nucleolar architecture, impairs pre-rRNA and mature rRNA synthesis, and triggers nucleolar stress-mediated p53/p21 activation leading to cell cycle arrest and apoptosis [PMID:40239541, PMID:26989627]. Beyond its ribosomal role, RPS15A activates Wnt/β-catenin, Akt/IKK-β/NF-κB, mTOR, and ERK1/2 signaling to promote proliferation, survival, and angiogenesis; its protein stability is regulated by FBXL18-mediated K63-linked ubiquitination, GGCT binding, and lncRNA RHPN1-AS1, while its expression is transcriptionally repressed by FOXN3 and post-transcriptionally suppressed by miR-29, miR-519d-3p, and miR-147b [PMID:29242604, PMID:30661291, PMID:37378633, PMID:40044122, PMID:41026296, PMID:37016167, PMID:31665807]. RPS15A overexpression drives hepatocellular carcinoma development downstream of hepatitis B virus X antigen and promotes tumor formation in xenograft models [PMID:15108328, PMID:29242604].\",\n  \"teleology\": [\n    {\n      \"year\": 1994,\n      \"claim\": \"Establishing the identity of RPS15A as a 40S ribosomal subunit protein resolved its primary structure and gene organization, providing the foundation for all subsequent functional studies.\",\n      \"evidence\": \"cDNA cloning, sequencing, and Southern/Northern blotting in rat\",\n      \"pmids\": [\"8185605\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No functional data on ribosomal role beyond structural membership\", \"Post-translational modifications uncharacterized\", \"Human ortholog not yet cloned at this point\"]\n    },\n    {\n      \"year\": 2004,\n      \"claim\": \"The discovery that HBxAg upregulates RPS15A and that its overexpression transforms cells and drives tumor formation in SCID mice established the first link between a ribosomal protein and oncogenic extra-ribosomal function.\",\n      \"evidence\": \"PCR-select cDNA subtraction, soft-agar colony formation, and SCID mouse xenograft in HCC context\",\n      \"pmids\": [\"15108328\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism of HBxAg-mediated upregulation undefined\", \"Downstream signaling pathways not identified\", \"Whether oncogenic activity is translation-dependent or extra-ribosomal remained unclear\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Demonstrating that RPS15A knockdown arrests hepatic cancer cells at G0/G1 established that RPS15A is required for cell cycle progression, not merely permissive for growth.\",\n      \"evidence\": \"Lentiviral shRNA knockdown with MTT, colony formation, and flow cytometry in HepG2 and Bel7404 cells\",\n      \"pmids\": [\"24334120\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Cell cycle targets (cyclins, CDKs) not identified\", \"No pathway mechanism defined\", \"Off-target effects of single shRNA not fully excluded\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Identification of decreased p-Akt upon RPS15A knockdown in glioblastoma placed RPS15A upstream of AKT signaling and linked it to migration and in vivo tumor growth beyond HCC.\",\n      \"evidence\": \"Lentiviral RNAi with p-Akt Western blot and nude mouse xenograft in U87/U251 glioblastoma cells\",\n      \"pmids\": [\"26537582\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct versus indirect activation of AKT not resolved\", \"Mechanism linking a ribosomal protein to AKT unknown\", \"Whether translation-dependent or independent unclear\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Demonstration that RPS15A knockdown activates caspase-3, cleaves PARP, and reduces Bcl-2 defined a pro-survival/anti-apoptotic mechanism, while microarray analysis in lung cancer linked RPS15A loss to p53 pathway activation.\",\n      \"evidence\": \"Lentiviral RNAi with apoptosis marker Western blots in glioblastoma; gene expression microarray in lung adenocarcinoma\",\n      \"pmids\": [\"27130037\", \"26989627\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether p53 activation is a direct consequence of nucleolar stress was not tested\", \"No epistasis experiments with p53 at this stage\", \"Single cell line per study\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Elucidation of the RPS15A→Wnt/β-catenin→FGF18→FGFR3 paracrine angiogenesis axis in HCC revealed a specific extra-ribosomal oncogenic signaling mechanism and the first non-cell-autonomous function, while miR-29 family members were validated as direct post-transcriptional suppressors of RPS15A.\",\n      \"evidence\": \"HUVEC co-culture paracrine assay, reporter assays, and xenograft for angiogenesis; luciferase 3′-UTR reporter for miR-29 targeting\",\n      \"pmids\": [\"29242604\", \"31966655\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether RPS15A directly binds β-catenin or acts through translation is unknown\", \"Physiological relevance of miR-29-RPS15A axis in non-cancer tissue not tested\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Pharmacological epistasis using AKT and IKK inhibitors defined RPS15A as an upstream activator of the Akt/IKK-β/NF-κB cascade in gastric cancer; concurrent studies validated miR-519d-3p and miR-147b as additional direct miRNA regulators suppressing RPS15A/Wnt signaling, and identified the ERK1/2/Bad/Chk1 anti-apoptotic axis in breast cancer.\",\n      \"evidence\": \"NF-κB reporter with LY294002/Bay117082 in gastric cancer; luciferase reporters and rescue in pancreatic/NSCLC cells; p-ERK/p-Bad/p-Chk1 Western blots in MDA-MB-231\",\n      \"pmids\": [\"30661291\", \"30831090\", \"31665807\", \"31535410\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No direct physical interaction between RPS15A and AKT or IKK-β demonstrated\", \"How a ribosomal protein specifically activates multiple kinase cascades remains mechanistically opaque\", \"Relative contribution of translational versus extra-ribosomal functions unclear\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Placing RPS15A downstream of PSMC2/let-7c-3p and upstream of mTOR, with Torin1 partially reversing RPS15A-driven proliferation, extended the signaling network to the mTOR pathway.\",\n      \"evidence\": \"GeneChip analysis, dual-luciferase reporter, RPS15A overexpression rescue, Torin1 pharmacological inhibition\",\n      \"pmids\": [\"35256584\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct RPS15A–mTOR interaction not shown\", \"Partial rescue by Torin1 implies additional pathways\", \"Single cancer type tested\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Discovery that FBXL18 catalyzes K63-linked ubiquitination to stabilize RPS15A protein, which in turn elevates SMAD3 and promotes its nuclear translocation, established the first defined post-translational regulatory mechanism and a new downstream effector; FOXN3 was identified as a direct transcriptional repressor binding the RPS15A promoter.\",\n      \"evidence\": \"K63-linkage-specific ubiquitination assay, Co-IP, FBXL18 transgenic mice, epistatic knockdown rescue for SMAD3 axis; ChIP and luciferase promoter assay for FOXN3\",\n      \"pmids\": [\"37378633\", \"37016167\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether K63-Ub affects RPS15A ribosomal incorporation or only extra-ribosomal pools is unknown\", \"SMAD3 activation mechanism (direct binding vs. translational) not resolved\", \"FOXN3 regulation in non-ovarian contexts untested\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Demonstration that RPS15A knockdown impairs rRNA biogenesis, disrupts nucleolar architecture (NPM1/FBL displacement), and triggers p53/p21-dependent arrest—with p53 knockdown rescuing rRNA processing—definitively linked RPS15A to nucleolar stress surveillance; GGCT was identified as a stabilizing physical interactor, and lncRNA RHPN1-AS1 as an additional stabilizer activating β-catenin.\",\n      \"evidence\": \"rRNA processing RT-PCR, NPM1/FBL immunofluorescence, p53 epistasis rescue in B-ALL; Co-IP/LC-MS/MS for GGCT; RNA pull-down for RHPN1-AS1 in hypoxic HCC\",\n      \"pmids\": [\"40239541\", \"40044122\", \"41026296\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis for RPS15A's role in rRNA processing unknown\", \"Whether GGCT stabilization uses ubiquitin-dependent or -independent mechanism not defined\", \"Ferroptosis link via p53/SLC7A11 axis awaits validation in additional cancer types\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The fundamental question of how a ribosomal protein activates multiple distinct kinase cascades (AKT, ERK, mTOR, NF-κB, Wnt/β-catenin) — whether through selective translational control of specific mRNAs, direct extra-ribosomal protein interactions, or specialized ribosome populations — remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No ribosome profiling or selective translation data exist for RPS15A perturbation\", \"Extra-ribosomal pool versus ribosome-incorporated pool not distinguished in any study\", \"No structural model of RPS15A within the human 40S subunit has been functionally interrogated\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0005198\", \"supporting_discovery_ids\": [0, 17]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005840\", \"supporting_discovery_ids\": [0, 17]},\n      {\"term_id\": \"GO:0005730\", \"supporting_discovery_ids\": [17]},\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [14, 18]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [0, 17]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [3, 6, 8, 9, 13, 14]},\n      {\"term_id\": \"R-HSA-5357801\", \"supporting_discovery_ids\": [4, 5, 10, 18]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [2, 7, 12]},\n      {\"term_id\": \"R-HSA-1643685\", \"supporting_discovery_ids\": [1, 6, 8]}\n    ],\n    \"complexes\": [\n      \"40S ribosomal subunit\"\n    ],\n    \"partners\": [\n      \"FBXL18\",\n      \"GGCT\",\n      \"SMAD3\",\n      \"RHPN1-AS1\",\n      \"NPM1\",\n      \"FBL\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}