{"gene":"SPECC1","run_date":"2026-06-10T07:46:39","timeline":{"discoveries":[{"year":2004,"finding":"HCMOGT-1 (SPECC1) was identified as a novel fusion partner to PDGFRB in juvenile myelomonocytic leukemia via t(5;17)(q33;p11.2) translocation. The breakpoint in PDGFRB occurred at the same site as all previously reported PDGFRB translocations, resulting in a constitutively activated PDGFRB/HCMOGT-1 fusion kinase.","method":"Molecular cloning of translocation breakpoint via 5'-RACE, confirmed by FISH and RT-PCR","journal":"Cancer research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct molecular cloning with two orthogonal confirmation methods (FISH + RT-PCR), single lab","pmids":["15087372"],"is_preprint":false},{"year":2008,"finding":"SPECC1 protein isoforms NSP 5a3a and NSP 5a3b interact with nucleolar phosphoprotein B23 (NPM1). siRNA silencing of HCMOGT-1 combined with proteomic analysis confirmed this interaction. siRNA silencing of HCMOGT-1 and NPM1 implicated NSP 5a3a and 5a3b in cell proliferation and apoptosis regulation. Sequence analysis identified SMC/SbcC ATPase motif similarity and a calponin homology (CH) domain in the 3B isoforms.","method":"siRNA silencing of HCMOGT-1, proteomic analysis, FACS analysis; sequence/domain analysis","journal":"Cell cycle (Georgetown, Tex.)","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — proteomic interaction data plus FACS functional readout, two orthogonal methods, single lab","pmids":["18763323"],"is_preprint":false},{"year":2010,"finding":"The SPECC1 isoform NSP 5a3a physically interacts with nucleolar protein B23 and with ribonuclear protein hnRNP-L, implicating SPECC1 in ribosome biogenesis and rRNA processing. Additionally, hnRNP-L was identified as a potential regulator of NSP 5a3a expression via siRNA silencing. A differential cooperation between NSP 5a3a, B23, and hnRNP-L was observed comparing normal and cancer breast cell models.","method":"Co-immunoprecipitation/pulldown (confirmed interaction with B23 and hnRNP-L), siRNA silencing of NSP 5a3a and hnRNP-L, differential expression analysis in normal vs. cancer breast cell lines","journal":"Cell cycle (Georgetown, Tex.)","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — reciprocal interaction confirmed by pulldown and RIP-like assays, siRNA functional follow-up, single lab with multiple orthogonal methods","pmids":["20237420"],"is_preprint":false},{"year":2010,"finding":"Overexpression of NSP 5a3a (SPECC1 isoform) in head and neck carcinoma cell lines (HN30, FaDu) and control WI38 cells induced significant apoptosis (~10-13 fold increase). The apoptotic mechanism was identified as p73-dependent and independent of p53 and caspase-3 activity.","method":"Overexpression transfection in cancer cell lines, apoptosis quantification, molecular pathway analysis (p73, p53, caspase-3)","journal":"Oncotarget","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, single overexpression experiment with pathway marker analysis but no genetic rescue or reconstitution","pmids":["21311098"],"is_preprint":false},{"year":2012,"finding":"A gene-trap mouse mutant of specc1/cytospinB showed a profound and specific delay in avoidance learning compared to control strains, establishing a functional role for SPECC1 in this aspect of cognition.","method":"Gene-trap mouse mutant phenotyping using automated home-cage behavioral assay (PhenoTyper) with aversive stimulus paradigm","journal":"Genes, brain, and behavior","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — clean loss-of-function (gene-trap) with defined behavioral phenotype, single lab, single method","pmids":["22846151"],"is_preprint":false},{"year":2021,"finding":"Specc1 expression increases markedly from the morula stage onward in mouse preimplantation development, with preferential localization in trophectoderm cells. siRNA-mediated knockdown of both maternal and zygotic Specc1 transcripts did not affect development through the morula stage but significantly reduced blastocyst formation and increased tight junction permeability (assessed by FITC uptake), indicating a role for Specc1 in tight junction complex formation during morula-to-blastocyst transition.","method":"siRNA injection into 1-cell zygotes, qRT-PCR, immunocytochemistry for localization, FITC uptake assay for tight junction permeability","journal":"Gene expression patterns : GEP","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean loss-of-function (siRNA knockdown) with defined functional readout (tight junction permeability) and localization data, single lab, multiple orthogonal methods","pmids":["34166821"],"is_preprint":false}],"current_model":"SPECC1 (also known as HCMOGT-1/NSP/CYTSB) is a coiled-coil and calponin homology domain-containing structural protein that physically interacts with nucleolar protein B23/NPM1 and hnRNP-L to participate in ribosome biogenesis and rRNA processing; it can act as an oncogenic fusion partner (PDGFRB-HCMOGT-1) through chromosomal translocation, plays a role in blastocyst formation by supporting tight junction integrity in trophectoderm cells, and is required for normal avoidance learning behavior in mice, with overexpression inducing apoptosis via a p73-dependent, p53/caspase-3-independent mechanism in certain cancer cell lines."},"narrative":{"mechanistic_narrative":"SPECC1 (HCMOGT-1/NSP) is a coiled-coil and calponin homology domain-containing protein implicated in nucleolar RNA metabolism, cell-fate regulation, and epithelial junction integrity [PMID:18763323, PMID:20237420, PMID:34166821]. Its isoforms NSP 5a3a and NSP 5a3b physically associate with the nucleolar phosphoprotein B23/NPM1, and NSP 5a3a additionally binds the ribonuclear protein hnRNP-L, linking SPECC1 to ribosome biogenesis and rRNA processing, with this cooperation differing between normal and cancer breast cell models [PMID:18763323, PMID:20237420]. Consistent with a role in proliferation/apoptosis control, overexpression of NSP 5a3a triggers apoptosis through a p73-dependent, p53- and caspase-3-independent pathway in head and neck carcinoma cells [PMID:21311098]. Beyond its nucleolar interactions, SPECC1 supports the morula-to-blastocyst transition by maintaining tight junction integrity in trophectoderm cells [PMID:34166821] and is required for normal avoidance learning in mice [PMID:22846151]. SPECC1 is also recurrently captured as an oncogenic fusion partner: a t(5;17) translocation fuses HCMOGT-1 to PDGFRB, generating a constitutively active fusion kinase in juvenile myelomonocytic leukemia [PMID:15087372]. The biochemical activity of the calponin homology and SMC/SbcC ATPase-like motifs has not been functionally characterized in the available corpus.","teleology":[{"year":2004,"claim":"Established SPECC1's first disease link by showing it serves as a chromosomal translocation partner that activates an oncogenic kinase.","evidence":"Molecular cloning of the t(5;17) breakpoint by 5'-RACE with FISH and RT-PCR confirmation in juvenile myelomonocytic leukemia","pmids":["15087372"],"confidence":"Medium","gaps":["Does not define the normal function of full-length SPECC1","Mechanism of fusion-kinase transformation downstream of PDGFRB not addressed"]},{"year":2008,"claim":"Answered where SPECC1 isoforms act biochemically by demonstrating interaction with the nucleolar protein B23/NPM1 and linking the protein to proliferation and apoptosis.","evidence":"siRNA silencing of HCMOGT-1 plus proteomic and FACS analysis; domain analysis identifying SMC/SbcC ATPase and calponin homology motifs","pmids":["18763323"],"confidence":"Medium","gaps":["Functional consequence of B23 binding not resolved","Activity of identified ATPase/CH domains untested"]},{"year":2010,"claim":"Extended the nucleolar role by adding hnRNP-L as a partner and a regulator of NSP 5a3a, placing SPECC1 in ribosome biogenesis/rRNA processing.","evidence":"Co-IP/pulldown of NSP 5a3a with B23 and hnRNP-L, siRNA silencing, and differential expression analysis in normal vs cancer breast cells","pmids":["20237420"],"confidence":"Medium","gaps":["Direct involvement in specific rRNA processing steps not demonstrated","Basis of normal-vs-cancer differential cooperation unknown"]},{"year":2010,"claim":"Tested the functional output of SPECC1 by showing overexpression drives apoptosis through a defined p73-dependent pathway.","evidence":"Overexpression of NSP 5a3a in HN30, FaDu and WI38 cells with apoptosis quantification and p73/p53/caspase-3 pathway analysis","pmids":["21311098"],"confidence":"Low","gaps":["No genetic rescue or reconstitution to confirm specificity","How NSP 5a3a engages the p73 axis is unknown"]},{"year":2012,"claim":"Revealed an in vivo physiological role by linking SPECC1 loss to a specific cognitive deficit.","evidence":"Gene-trap mouse mutant phenotyped in an automated home-cage avoidance learning assay","pmids":["22846151"],"confidence":"Medium","gaps":["Molecular/cellular basis of the learning defect not defined","Neuronal localization or partners not identified"]},{"year":2021,"claim":"Identified a developmental role by showing SPECC1 maintains trophectoderm tight junctions during the morula-to-blastocyst transition.","evidence":"siRNA knockdown of maternal and zygotic transcripts in zygotes with qRT-PCR, immunocytochemistry, and FITC tight-junction permeability assay","pmids":["34166821"],"confidence":"Medium","gaps":["Molecular link between SPECC1 and tight junction components not defined","Whether this role relates to the nucleolar interactions is unknown"]},{"year":null,"claim":"The biochemical activity of SPECC1's calponin homology and SMC/SbcC ATPase-like motifs, and how its nucleolar, developmental, and behavioral roles mechanistically connect, remain unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["No demonstrated enzymatic or cytoskeletal-binding activity","No structural model","No unifying mechanism across tissues"]}],"mechanism_profile":{"molecular_activity":[],"localization":[{"term_id":"GO:0005730","term_label":"nucleolus","supporting_discovery_ids":[1,2]}],"pathway":[],"complexes":[],"partners":["NPM1","HNRNPL","PDGFRB"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q5M775","full_name":"Cytospin-B","aliases":["Nuclear structure protein 5","NSP5","Sperm antigen HCMOGT-1","Sperm antigen with calponin homology and coiled-coil domains 1"],"length_aa":1068,"mass_kda":118.6,"function":"","subcellular_location":"Membrane","url":"https://www.uniprot.org/uniprotkb/Q5M775/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/SPECC1","classification":"Not Classified","n_dependent_lines":1,"n_total_lines":1208,"dependency_fraction":0.0008278145695364238},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"CALD1","stoichiometry":0.2},{"gene":"CALM3","stoichiometry":0.2},{"gene":"CAPZB","stoichiometry":0.2},{"gene":"CTTN","stoichiometry":0.2},{"gene":"MYH10","stoichiometry":0.2},{"gene":"PPP2CA","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/SPECC1","total_profiled":1310},"omim":[{"mim_id":"614140","title":"SPERM ANTIGEN WITH CALPONIN HOMOLOGY AND COILED-COIL DOMAINS 1-LIKE; SPECC1L","url":"https://www.omim.org/entry/614140"},{"mim_id":"608793","title":"SPERM ANTIGEN WITH CALPONIN HOMOLOGY AND COILED-COIL DOMAINS 1; SPECC1","url":"https://www.omim.org/entry/608793"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Nucleoplasm","reliability":"Supported"},{"location":"Vesicles","reliability":"Supported"},{"location":"Nucleoli fibrillar center","reliability":"Additional"},{"location":"Cytosol","reliability":"Additional"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in all","driving_tissues":[{"tissue":"brain","ntpm":42.9}],"url":"https://www.proteinatlas.org/search/SPECC1"},"hgnc":{"alias_symbol":["HCMOGT-1","FLJ36955","NSP"],"prev_symbol":["CYTSB"]},"alphafold":{"accession":"Q5M775","domains":[{"cath_id":"1.10.418.10","chopping":"957-1066","consensus_level":"high","plddt":90.4548,"start":957,"end":1066}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q5M775","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q5M775-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q5M775-F1-predicted_aligned_error_v6.png","plddt_mean":66.62},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=SPECC1","jax_strain_url":"https://www.jax.org/strain/search?query=SPECC1"},"sequence":{"accession":"Q5M775","fasta_url":"https://rest.uniprot.org/uniprotkb/Q5M775.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q5M775/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q5M775"}},"corpus_meta":[{"pmid":"15087372","id":"PMC_15087372","title":"HCMOGT-1 is a novel fusion partner to PDGFRB in juvenile myelomonocytic leukemia with t(5;17)(q33;p11.2).","date":"2004","source":"Cancer research","url":"https://pubmed.ncbi.nlm.nih.gov/15087372","citation_count":53,"is_preprint":false},{"pmid":"22846151","id":"PMC_22846151","title":"High-throughput phenotyping of avoidance learning in mice discriminates different genotypes and identifies a novel gene.","date":"2012","source":"Genes, brain, and behavior","url":"https://pubmed.ncbi.nlm.nih.gov/22846151","citation_count":47,"is_preprint":false},{"pmid":"30376358","id":"PMC_30376358","title":"Upregulation of Circular RNA VPS13C-has-circ-001567 Promotes Ovarian Cancer Cell Proliferation and Invasion.","date":"2018","source":"Cancer biotherapy & radiopharmaceuticals","url":"https://pubmed.ncbi.nlm.nih.gov/30376358","citation_count":40,"is_preprint":false},{"pmid":"34957935","id":"PMC_34957935","title":"Circ_0000745 promotes acute lymphoblastic leukemia progression through mediating miR-494-3p/NET1 axis.","date":"2022","source":"Hematology (Amsterdam, Netherlands)","url":"https://pubmed.ncbi.nlm.nih.gov/34957935","citation_count":36,"is_preprint":false},{"pmid":"31349968","id":"PMC_31349968","title":"Circ_SPECC1 enhances the inhibition of miR-526b on downstream KDM4A/YAP1 pathway to regulate the growth and invasion of gastric cancer cells.","date":"2019","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/31349968","citation_count":30,"is_preprint":false},{"pmid":"23299920","id":"PMC_23299920","title":"Genome-wide analysis shows association of epigenetic changes in regulators of Rab and Rho GTPases with spinal muscular atrophy severity.","date":"2013","source":"European journal of human genetics : EJHG","url":"https://pubmed.ncbi.nlm.nih.gov/23299920","citation_count":27,"is_preprint":false},{"pmid":"32627938","id":"PMC_32627938","title":"Circ-SPECC1 modulates TGFβ2 and autophagy under oxidative stress by sponging miR-33a to promote hepatocellular carcinoma tumorigenesis.","date":"2020","source":"Cancer medicine","url":"https://pubmed.ncbi.nlm.nih.gov/32627938","citation_count":26,"is_preprint":false},{"pmid":"33789425","id":"PMC_33789425","title":"Myocardial Infarction Induces Cardiac Fibroblast Transformation within Injured and Noninjured Regions of the Mouse Heart.","date":"2021","source":"Journal of proteome research","url":"https://pubmed.ncbi.nlm.nih.gov/33789425","citation_count":20,"is_preprint":false},{"pmid":"32344305","id":"PMC_32344305","title":"A data-driven hypothesis on the epigenetic dysregulation of host metabolism by SARS coronaviral infection: Potential implications for the SARS-CoV-2 modus operandi.","date":"2020","source":"Medical hypotheses","url":"https://pubmed.ncbi.nlm.nih.gov/32344305","citation_count":16,"is_preprint":false},{"pmid":"20237420","id":"PMC_20237420","title":"NSP 5a3a's link to nuclear-cyto proteins B23 and hnRNP-L between normal and aberrant breast cell lines.","date":"2010","source":"Cell cycle (Georgetown, Tex.)","url":"https://pubmed.ncbi.nlm.nih.gov/20237420","citation_count":14,"is_preprint":false},{"pmid":"39333871","id":"PMC_39333871","title":"A novel protein SPECC1-415aa encoded by N6-methyladenosine modified circSPECC1 regulates the sensitivity of glioblastoma to TMZ.","date":"2024","source":"Cellular & molecular biology letters","url":"https://pubmed.ncbi.nlm.nih.gov/39333871","citation_count":13,"is_preprint":false},{"pmid":"21311098","id":"PMC_21311098","title":"NSP 5a3a: a potential novel cancer target in head and neck carcinoma.","date":"2010","source":"Oncotarget","url":"https://pubmed.ncbi.nlm.nih.gov/21311098","citation_count":12,"is_preprint":false},{"pmid":"34796107","id":"PMC_34796107","title":"Multidimensional Mutational Profiling of the Indian HNSCC Sub-Population Provides IRAK1, a Novel Driver Gene and Potential Druggable Target.","date":"2021","source":"Frontiers in oncology","url":"https://pubmed.ncbi.nlm.nih.gov/34796107","citation_count":9,"is_preprint":false},{"pmid":"34166821","id":"PMC_34166821","title":"Expression patterns and biological function of Specc1 during mouse preimplantation development.","date":"2021","source":"Gene expression patterns : GEP","url":"https://pubmed.ncbi.nlm.nih.gov/34166821","citation_count":7,"is_preprint":false},{"pmid":"18763323","id":"PMC_18763323","title":"Possible functional role of NSPs in cancer.","date":"2008","source":"Cell cycle (Georgetown, Tex.)","url":"https://pubmed.ncbi.nlm.nih.gov/18763323","citation_count":7,"is_preprint":false},{"pmid":"39831223","id":"PMC_39831223","title":"Circular RNA SPECC1 promoted tumorigenesis and osimertinib resistance in lung adenocarcinoma via a circular RNA-microRNA network.","date":"2024","source":"Journal of thoracic disease","url":"https://pubmed.ncbi.nlm.nih.gov/39831223","citation_count":6,"is_preprint":false},{"pmid":"30854786","id":"PMC_30854786","title":"Cancer-testis antigens in canine histiocytic sarcoma and other malignancies.","date":"2019","source":"Veterinary and comparative oncology","url":"https://pubmed.ncbi.nlm.nih.gov/30854786","citation_count":6,"is_preprint":false},{"pmid":"35806237","id":"PMC_35806237","title":"Heat Shock Alters the Proteomic Profile of Equine Mesenchymal Stem Cells.","date":"2022","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/35806237","citation_count":4,"is_preprint":false},{"pmid":"40082884","id":"PMC_40082884","title":"Exploring the potential mechanisms of sorafenib resistance in hepatocellular carcinoma cell lines based on RNA sequencing.","date":"2025","source":"Cancer cell international","url":"https://pubmed.ncbi.nlm.nih.gov/40082884","citation_count":4,"is_preprint":false},{"pmid":"39397181","id":"PMC_39397181","title":"SPECC1 as a pan-cancer biomarker: unraveling its role in drug sensitivity and resistance mechanisms.","date":"2024","source":"Discover oncology","url":"https://pubmed.ncbi.nlm.nih.gov/39397181","citation_count":3,"is_preprint":false},{"pmid":"35222516","id":"PMC_35222516","title":"Comprehensive Genomic and Epigenomic Analyses on Transcriptomic Regulation in Stomach Adenocarcinoma.","date":"2022","source":"Frontiers in genetics","url":"https://pubmed.ncbi.nlm.nih.gov/35222516","citation_count":3,"is_preprint":false},{"pmid":"38341369","id":"PMC_38341369","title":"Interference of the Circular RNA Sperm Antigen With Calponin Homology and Coiled-Coil Domains 1 Suppresses Growth and Promotes Apoptosis of Breast Cancer Cells Partially Through Targeting miR-1236-3p/Chromobox 8 Pathway.","date":"2023","source":"Clinical breast cancer","url":"https://pubmed.ncbi.nlm.nih.gov/38341369","citation_count":3,"is_preprint":false},{"pmid":"30563523","id":"PMC_30563523","title":"A novel PAX5 rearrangement in TCF3-PBX1 acute lymphoblastic leukemia: a case report.","date":"2018","source":"BMC medical genomics","url":"https://pubmed.ncbi.nlm.nih.gov/30563523","citation_count":2,"is_preprint":false},{"pmid":"37020791","id":"PMC_37020791","title":"circSPECC1 Promotes Proliferation and Migration of LNCaP Prostate Cancer Cells by Affecting Their Epithelial-Mesenchymal Transition.","date":"2023","source":"Journal of immunology research","url":"https://pubmed.ncbi.nlm.nih.gov/37020791","citation_count":2,"is_preprint":false},{"pmid":"39210919","id":"PMC_39210919","title":"Prochloraz induced alterations in the expression of mRNA in the reproductive system of male offspring mice.","date":"2024","source":"PeerJ","url":"https://pubmed.ncbi.nlm.nih.gov/39210919","citation_count":1,"is_preprint":false},{"pmid":"40152114","id":"PMC_40152114","title":"Challenging diagnosis in pulmonary nut carcinoma: A report of two cases with different histopathologic and molecular features and a novel NUTM1::SPECC1 gene fusion.","date":"2025","source":"Histology and histopathology","url":"https://pubmed.ncbi.nlm.nih.gov/40152114","citation_count":0,"is_preprint":false},{"pmid":"41673661","id":"PMC_41673661","title":"Cell type resolved MR based on brain single cell eQTLs corroborated by single cell RNA sequencing uncovers neuroimmune and vascular programs in intracerebral hemorrhage.","date":"2026","source":"Journal of translational medicine","url":"https://pubmed.ncbi.nlm.nih.gov/41673661","citation_count":0,"is_preprint":false},{"pmid":"42097490","id":"PMC_42097490","title":"CircSPECC1 attenuates sensitivity to PD-1 blockade through impaired antigen presentation in hepatocellular carcinoma.","date":"2026","source":"Cancer letters","url":"https://pubmed.ncbi.nlm.nih.gov/42097490","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":17355,"output_tokens":2065,"usd":0.04152,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":8535,"output_tokens":2153,"usd":0.04825,"stage2_stop_reason":"end_turn"},"total_usd":0.08977,"stage1_batch_id":"msgbatch_013LWZZT6MWaqB9qyTSeQBmU","stage2_batch_id":"msgbatch_0194ZzQaTGNpruoNJBbEMbt3","note":"batch pricing = 50% of standard"},"stage1_raw":"Looking through the abstracts, I need to distinguish papers about the canonical SPECC1 protein from papers about circular RNAs derived from the SPECC1 locus (circSPECC1, circ_0000745, etc.), which are non-protein locus products and should be excluded.\n\nPapers about the canonical SPECC1 protein (or its aliases HCMOGT-1, NSP isoforms, CYTSB/CytospinB):\n- [1] HCMOGT-1 fusion with PDGFRB in leukemia\n- [2] specc1/cytospinB mutant in avoidance learning\n- [10] NSP 5a3a interaction with B23 and hnRNP-L\n- [12] NSP 5a3a apoptosis mechanism\n- [14] Specc1 in preimplantation development\n- [15] NSP isoforms interaction with B23\n\nPapers about circSPECC1/circ_SPECC1 (non-protein circular RNA products) → EXCLUDE: [3,4,5,7,11,16,19,22,24,28]\n\nPapers that are pan-gene catalogs, expression studies, or have no direct mechanistic experiment on SPECC1 protein → EXCLUDE: [6,8,9,13,17,18,20,21,23,25,26,27]\n\n```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2004,\n      \"finding\": \"HCMOGT-1 (SPECC1) was identified as a novel fusion partner to PDGFRB in juvenile myelomonocytic leukemia via t(5;17)(q33;p11.2) translocation. The breakpoint in PDGFRB occurred at the same site as all previously reported PDGFRB translocations, resulting in a constitutively activated PDGFRB/HCMOGT-1 fusion kinase.\",\n      \"method\": \"Molecular cloning of translocation breakpoint via 5'-RACE, confirmed by FISH and RT-PCR\",\n      \"journal\": \"Cancer research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct molecular cloning with two orthogonal confirmation methods (FISH + RT-PCR), single lab\",\n      \"pmids\": [\"15087372\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"SPECC1 protein isoforms NSP 5a3a and NSP 5a3b interact with nucleolar phosphoprotein B23 (NPM1). siRNA silencing of HCMOGT-1 combined with proteomic analysis confirmed this interaction. siRNA silencing of HCMOGT-1 and NPM1 implicated NSP 5a3a and 5a3b in cell proliferation and apoptosis regulation. Sequence analysis identified SMC/SbcC ATPase motif similarity and a calponin homology (CH) domain in the 3B isoforms.\",\n      \"method\": \"siRNA silencing of HCMOGT-1, proteomic analysis, FACS analysis; sequence/domain analysis\",\n      \"journal\": \"Cell cycle (Georgetown, Tex.)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — proteomic interaction data plus FACS functional readout, two orthogonal methods, single lab\",\n      \"pmids\": [\"18763323\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"The SPECC1 isoform NSP 5a3a physically interacts with nucleolar protein B23 and with ribonuclear protein hnRNP-L, implicating SPECC1 in ribosome biogenesis and rRNA processing. Additionally, hnRNP-L was identified as a potential regulator of NSP 5a3a expression via siRNA silencing. A differential cooperation between NSP 5a3a, B23, and hnRNP-L was observed comparing normal and cancer breast cell models.\",\n      \"method\": \"Co-immunoprecipitation/pulldown (confirmed interaction with B23 and hnRNP-L), siRNA silencing of NSP 5a3a and hnRNP-L, differential expression analysis in normal vs. cancer breast cell lines\",\n      \"journal\": \"Cell cycle (Georgetown, Tex.)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — reciprocal interaction confirmed by pulldown and RIP-like assays, siRNA functional follow-up, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"20237420\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"Overexpression of NSP 5a3a (SPECC1 isoform) in head and neck carcinoma cell lines (HN30, FaDu) and control WI38 cells induced significant apoptosis (~10-13 fold increase). The apoptotic mechanism was identified as p73-dependent and independent of p53 and caspase-3 activity.\",\n      \"method\": \"Overexpression transfection in cancer cell lines, apoptosis quantification, molecular pathway analysis (p73, p53, caspase-3)\",\n      \"journal\": \"Oncotarget\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, single overexpression experiment with pathway marker analysis but no genetic rescue or reconstitution\",\n      \"pmids\": [\"21311098\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"A gene-trap mouse mutant of specc1/cytospinB showed a profound and specific delay in avoidance learning compared to control strains, establishing a functional role for SPECC1 in this aspect of cognition.\",\n      \"method\": \"Gene-trap mouse mutant phenotyping using automated home-cage behavioral assay (PhenoTyper) with aversive stimulus paradigm\",\n      \"journal\": \"Genes, brain, and behavior\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — clean loss-of-function (gene-trap) with defined behavioral phenotype, single lab, single method\",\n      \"pmids\": [\"22846151\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Specc1 expression increases markedly from the morula stage onward in mouse preimplantation development, with preferential localization in trophectoderm cells. siRNA-mediated knockdown of both maternal and zygotic Specc1 transcripts did not affect development through the morula stage but significantly reduced blastocyst formation and increased tight junction permeability (assessed by FITC uptake), indicating a role for Specc1 in tight junction complex formation during morula-to-blastocyst transition.\",\n      \"method\": \"siRNA injection into 1-cell zygotes, qRT-PCR, immunocytochemistry for localization, FITC uptake assay for tight junction permeability\",\n      \"journal\": \"Gene expression patterns : GEP\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean loss-of-function (siRNA knockdown) with defined functional readout (tight junction permeability) and localization data, single lab, multiple orthogonal methods\",\n      \"pmids\": [\"34166821\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"SPECC1 (also known as HCMOGT-1/NSP/CYTSB) is a coiled-coil and calponin homology domain-containing structural protein that physically interacts with nucleolar protein B23/NPM1 and hnRNP-L to participate in ribosome biogenesis and rRNA processing; it can act as an oncogenic fusion partner (PDGFRB-HCMOGT-1) through chromosomal translocation, plays a role in blastocyst formation by supporting tight junction integrity in trophectoderm cells, and is required for normal avoidance learning behavior in mice, with overexpression inducing apoptosis via a p73-dependent, p53/caspase-3-independent mechanism in certain cancer cell lines.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"SPECC1 (HCMOGT-1/NSP) is a coiled-coil and calponin homology domain-containing protein implicated in nucleolar RNA metabolism, cell-fate regulation, and epithelial junction integrity [#1, #2, #5]. Its isoforms NSP 5a3a and NSP 5a3b physically associate with the nucleolar phosphoprotein B23/NPM1, and NSP 5a3a additionally binds the ribonuclear protein hnRNP-L, linking SPECC1 to ribosome biogenesis and rRNA processing, with this cooperation differing between normal and cancer breast cell models [#1, #2]. Consistent with a role in proliferation/apoptosis control, overexpression of NSP 5a3a triggers apoptosis through a p73-dependent, p53- and caspase-3-independent pathway in head and neck carcinoma cells [#3]. Beyond its nucleolar interactions, SPECC1 supports the morula-to-blastocyst transition by maintaining tight junction integrity in trophectoderm cells [#5] and is required for normal avoidance learning in mice [#4]. SPECC1 is also recurrently captured as an oncogenic fusion partner: a t(5;17) translocation fuses HCMOGT-1 to PDGFRB, generating a constitutively active fusion kinase in juvenile myelomonocytic leukemia [#0]. The biochemical activity of the calponin homology and SMC/SbcC ATPase-like motifs has not been functionally characterized in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 2004,\n      \"claim\": \"Established SPECC1's first disease link by showing it serves as a chromosomal translocation partner that activates an oncogenic kinase.\",\n      \"evidence\": \"Molecular cloning of the t(5;17) breakpoint by 5'-RACE with FISH and RT-PCR confirmation in juvenile myelomonocytic leukemia\",\n      \"pmids\": [\"15087372\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Does not define the normal function of full-length SPECC1\", \"Mechanism of fusion-kinase transformation downstream of PDGFRB not addressed\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Answered where SPECC1 isoforms act biochemically by demonstrating interaction with the nucleolar protein B23/NPM1 and linking the protein to proliferation and apoptosis.\",\n      \"evidence\": \"siRNA silencing of HCMOGT-1 plus proteomic and FACS analysis; domain analysis identifying SMC/SbcC ATPase and calponin homology motifs\",\n      \"pmids\": [\"18763323\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Functional consequence of B23 binding not resolved\", \"Activity of identified ATPase/CH domains untested\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Extended the nucleolar role by adding hnRNP-L as a partner and a regulator of NSP 5a3a, placing SPECC1 in ribosome biogenesis/rRNA processing.\",\n      \"evidence\": \"Co-IP/pulldown of NSP 5a3a with B23 and hnRNP-L, siRNA silencing, and differential expression analysis in normal vs cancer breast cells\",\n      \"pmids\": [\"20237420\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct involvement in specific rRNA processing steps not demonstrated\", \"Basis of normal-vs-cancer differential cooperation unknown\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Tested the functional output of SPECC1 by showing overexpression drives apoptosis through a defined p73-dependent pathway.\",\n      \"evidence\": \"Overexpression of NSP 5a3a in HN30, FaDu and WI38 cells with apoptosis quantification and p73/p53/caspase-3 pathway analysis\",\n      \"pmids\": [\"21311098\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No genetic rescue or reconstitution to confirm specificity\", \"How NSP 5a3a engages the p73 axis is unknown\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Revealed an in vivo physiological role by linking SPECC1 loss to a specific cognitive deficit.\",\n      \"evidence\": \"Gene-trap mouse mutant phenotyped in an automated home-cage avoidance learning assay\",\n      \"pmids\": [\"22846151\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Molecular/cellular basis of the learning defect not defined\", \"Neuronal localization or partners not identified\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Identified a developmental role by showing SPECC1 maintains trophectoderm tight junctions during the morula-to-blastocyst transition.\",\n      \"evidence\": \"siRNA knockdown of maternal and zygotic transcripts in zygotes with qRT-PCR, immunocytochemistry, and FITC tight-junction permeability assay\",\n      \"pmids\": [\"34166821\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Molecular link between SPECC1 and tight junction components not defined\", \"Whether this role relates to the nucleolar interactions is unknown\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The biochemical activity of SPECC1's calponin homology and SMC/SbcC ATPase-like motifs, and how its nucleolar, developmental, and behavioral roles mechanistically connect, remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No demonstrated enzymatic or cytoskeletal-binding activity\", \"No structural model\", \"No unifying mechanism across tissues\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [],\n    \"localization\": [\n      {\"term_id\": \"GO:0005730\", \"supporting_discovery_ids\": [1, 2]}\n    ],\n    \"pathway\": [],\n    \"complexes\": [],\n    \"partners\": [\"NPM1\", \"HNRNPL\", \"PDGFRB\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"faith_supported":5,"faith_total":5,"faith_pct":100.0}}