{"gene":"DIRAS1","run_date":"2026-06-09T23:54:42","timeline":{"discoveries":[{"year":2018,"finding":"DIRAS1 re-expression induces autophagy-mediated cancer cell death by inhibiting AKT1-MTOR and RAS-MAPK signaling pathways and modulating nuclear localization of autophagy-related transcription factors FOXO3/FOXO3A and TFEB in ovarian cancer cells.","method":"Overexpression in human and murine ovarian cancer cells; pathway analysis by western blot; nuclear localization assays for FOXO3 and TFEB","journal":"Autophagy","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean overexpression with defined phenotypic readouts and multiple pathway endpoints in a single lab study","pmids":["29368982"],"is_preprint":false},{"year":2016,"finding":"DiRas1 binds SmgGDS (a noncanonical guanine nucleotide exchange factor) and acts as a dominant-negative-like GTPase, inhibiting SmgGDS binding to oncogenic GTPases K-Ras4B, RhoA, and Rap1A. SmgGDS does not mediate GDP/GTP exchange on DiRas1. DiRas1 inhibits RhoA- and SmgGDS-mediated NF-κB transcriptional activity.","method":"Co-immunoprecipitation, in silico docking, GDP/GTP exchange assay, competitive binding assays, NF-κB transcriptional reporter assays in HEK293T and cancer cell lines","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1–2 / Moderate — multiple orthogonal methods (Co-IP, in vitro exchange assay, competitive binding, transcriptional reporter) in a single focused study","pmids":["26814130"],"is_preprint":false},{"year":2015,"finding":"Zebrafish diras1 promotes neurite outgrowth via a Rac1-dependent pathway: diras1a/b overexpression elevates Rac1 protein levels and activity (GST pull-down), downregulates RhoA, and requires an intact C-terminus. Knockdown of diras1a/b reduces axon guidance and causes loss of trigeminal ganglion neurons; co-injection of mouse diras1 mRNA or constitutively active Rac1 rescues this phenotype. The pathway involves Pak1, CDK5, and Arp2/3.","method":"Overexpression and morpholino knockdown in zebrafish; GST pull-down for Rac1 activity; mRNA rescue; pharmacological inhibition of Rac1, Pak1, CDK5, and Arp2/3 in Neuro-2a cells","journal":"Molecular neurobiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic epistasis (morpholino + mRNA rescue), biochemical activity assay (GST pull-down), and multiple inhibitor experiments in one study; zebrafish ortholog","pmids":["26635085"],"is_preprint":false},{"year":2022,"finding":"DIRAS1 localizes to the nucleus of osteosarcoma cells and suppresses ERK phosphorylation (p-ERK) without affecting p-AKT. DIRAS1 expression is suppressed by METTL3 and METTL14 (m6A writers), and the inhibitory effect of DIRAS1 overexpression on malignant behaviors and ERK inactivation is reversed by METTL3/METTL14 co-treatment.","method":"Immunofluorescence for subcellular localization; siRNA knockdown and overexpression; western blot for p-ERK and p-AKT; ELISA and dot blot for m6A methylation; rescue assays with METTL3/METTL14","journal":"Tissue & cell","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — direct localization experiment plus rescue/epistasis assays linking METTL3/14 to DIRAS1 expression and downstream ERK signaling; single lab, multiple orthogonal methods","pmids":["35413492"],"is_preprint":false},{"year":2024,"finding":"DIRAS1 mRNA stability and protein translation efficiency in cervical cancer cells are regulated by m6A modification: METTL3 and METTL14 (writers) promote DIRAS1 protein expression, while FTO and ALKBH5 (erasers) reduce it. FTO inhibition (FB23-2) down-regulates DIRAS1 mRNA but up-regulates DIRAS1 protein levels.","method":"siRNA knockdown of m6A writers/erasers (METTL3, METTL14, FTO, ALKBH5); pharmacological inhibitors (5-Azacytidine, SAHA, FB23-2); western blot and qPCR for DIRAS1 protein and mRNA","journal":"Cancer biology & therapy","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — multiple m6A writer/eraser perturbations with orthogonal mRNA and protein readouts; single lab","pmids":["38372700"],"is_preprint":false},{"year":2021,"finding":"Overexpression of DIRAS1 in glioblastoma cells increases sensitivity to lomustine (alkylating chemotherapy) and involves a p53-dependent DNA damage response. DIRAS1 promoter is silenced by hypermethylation and histone modifications (heterochromatinization); treatment with 5-azacytidine or HDAC inhibitors restores DIRAS1 expression.","method":"Overexpression in glioblastoma cell lines; cytotoxicity assays; DNA damage marker analysis; methylation-specific PCR; HDAC inhibitor and 5-azacytidine treatment","journal":"Cancers","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — functional overexpression with chemosensitivity phenotype and DNA damage markers; epigenetic regulation confirmed by pharmacological reactivation","pmids":["34680261"],"is_preprint":false},{"year":2025,"finding":"DIRAS1 drives oxaliplatin resistance in colorectal cancer by upregulating PHB1 (Prohibitin 1), which maintains mitochondrial stability. Silencing DIRAS1 reduces OXA IC50 and increases tumor sensitivity in vivo; PHB1 was identified as a downstream effector by transcriptomic sequencing.","method":"Stable knockdown/overexpression via lentiviral systems; MTT and cytotoxicity assays; transcriptomic sequencing; in vivo xenograft; immunohistochemistry","journal":"Biology","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — single lab, transcriptomic identification of PHB1 plus functional validation in vitro and in vivo, but mechanism linking DIRAS1 to PHB1 is not fully resolved at molecular level","pmids":["40723377"],"is_preprint":false},{"year":2021,"finding":"miR-552-3p directly targets and suppresses DIRAS1 mRNA; LINC00261 sponges miR-552-3p to relieve this suppression and up-regulate DIRAS1 transcription, thereby reducing radioresistance in esophageal cancer cells.","method":"Luciferase reporter binding assays for miR-552-3p/DIRAS1 interaction; overexpression and silencing of LINC00261, miR-552-3p, and DIRAS1; colony formation, apoptosis, and γ-H2AX assays; xenograft model","journal":"Cancer management and research","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab; the mechanistic finding concerns regulation OF DIRAS1 via ceRNA network; direct mechanistic insight into DIRAS1 protein function is minimal here","pmids":["34803403"],"is_preprint":false}],"current_model":"DIRAS1 is a tumor-suppressive small GTPase that suppresses oncogenic signaling (AKT-MTOR, RAS-MAPK, ERK, NF-κB) and induces autophagy-mediated cell death; it binds SmgGDS as a dominant-negative-like competitor to block activation of oncogenic GTPases (K-Ras4B, RhoA, Rap1A), and in neurons promotes neurite outgrowth via Rac1/Pak1/CDK5/Arp2/3 activation; its expression is epigenetically silenced by promoter methylation, histone deacetylation, and m6A modification (written by METTL3/METTL14, erased by FTO/ALKBH5), and in certain contexts it can drive chemoresistance through a DIRAS1-PHB1 mitochondrial stability axis."},"narrative":{"mechanistic_narrative":"DIRAS1 is a small GTPase that acts as a tumor suppressor by restraining oncogenic signaling and promoting autophagy-mediated cancer cell death [PMID:29368982, PMID:26814130]. Mechanistically, it binds SmgGDS, a noncanonical guanine nucleotide exchange factor, but is not itself a substrate for SmgGDS-mediated GDP/GTP exchange; instead it functions as a dominant-negative-like competitor that blocks SmgGDS engagement of the oncogenic GTPases K-Ras4B, RhoA, and Rap1A and thereby suppresses RhoA- and SmgGDS-driven NF-κB transcriptional activity [PMID:26814130]. Downstream, re-expressed DIRAS1 inhibits AKT1-MTOR and RAS-MAPK signaling and drives nuclear accumulation of the autophagy transcription factors FOXO3 and TFEB to induce autophagic cell death [PMID:29368982], and in osteosarcoma it suppresses ERK phosphorylation selectively without affecting AKT [PMID:35413492]. In the nervous system, DIRAS1 promotes neurite outgrowth and axon guidance through a Rac1-dependent pathway requiring an intact C-terminus, elevating Rac1 activity while downregulating RhoA and acting via Pak1, CDK5, and Arp2/3 [PMID:26635085]. DIRAS1 expression is silenced by layered epigenetic control — promoter hypermethylation and histone deacetylation [PMID:34680261] and m6A modification written by METTL3/METTL14 and erased by FTO/ALKBH5 that tunes mRNA stability and translation efficiency [PMID:35413492, PMID:38372700] — and its restoration sensitizes glioblastoma cells to lomustine through a p53-dependent DNA damage response [PMID:34680261]. In a context-dependent reversal, DIRAS1 can also promote oxaliplatin resistance in colorectal cancer by upregulating PHB1 to maintain mitochondrial stability [PMID:40723377].","teleology":[{"year":2015,"claim":"Established that DIRAS1 has a developmental signaling function in neurons, acting upstream of the Rac1/RhoA balance to drive neurite outgrowth, rather than being a purely tumor-associated gene.","evidence":"Overexpression and morpholino knockdown with mRNA rescue in zebrafish plus GST pull-down for Rac1 activity and pharmacological inhibition in Neuro-2a cells","pmids":["26635085"],"confidence":"Medium","gaps":["Direct biochemical mechanism by which DIRAS1 elevates Rac1 activity is not resolved","Findings rest on a zebrafish ortholog and a neuronal cell line, not human neurons","Whether the same Rac1 axis operates in non-neuronal contexts is untested"]},{"year":2016,"claim":"Defined the core molecular mechanism: DIRAS1 is not an exchange substrate but a competitive inhibitor that sequesters SmgGDS away from oncogenic GTPases, explaining how it can dampen RhoA/NF-κB output.","evidence":"Co-immunoprecipitation, in silico docking, GDP/GTP exchange assay, competitive binding, and NF-κB reporter assays in HEK293T and cancer cell lines","pmids":["26814130"],"confidence":"High","gaps":["Structural basis of the DIRAS1-SmgGDS interface not determined experimentally","Nucleotide-loading state of DIRAS1 in cells and its upstream regulators unknown","Endogenous (non-overexpression) competition with K-Ras4B/RhoA/Rap1A not quantified"]},{"year":2018,"claim":"Connected DIRAS1 re-expression to a defined tumor-suppressive output, showing it inhibits AKT-MTOR and RAS-MAPK signaling and engages an autophagy transcriptional program (FOXO3, TFEB) to kill cancer cells.","evidence":"Overexpression in human and murine ovarian cancer cells with western blot pathway analysis and FOXO3/TFEB nuclear localization assays","pmids":["29368982"],"confidence":"Medium","gaps":["Whether autophagy induction is causal for cell death versus correlative is not dissected","Link between SmgGDS competition and AKT-MTOR/FOXO3/TFEB modulation not established","Single tumor type tested"]},{"year":2021,"claim":"Showed that DIRAS1 is epigenetically silenced in tumors and that its restoration improves therapeutic response, framing it as a druggable suppressor.","evidence":"Glioblastoma overexpression with lomustine cytotoxicity and DNA damage assays; methylation-specific PCR; 5-azacytidine and HDAC inhibitor reactivation; and an esophageal LINC00261/miR-552-3p/DIRAS1 ceRNA radioresistance study","pmids":["34680261","34803403"],"confidence":"Medium","gaps":["How DIRAS1 mechanistically promotes the p53-dependent DNA damage response is unresolved","ceRNA regulation provides regulation OF DIRAS1, not insight into DIRAS1 protein function","Reactivation drugs are not DIRAS1-specific"]},{"year":2024,"claim":"Refined the regulatory layer by establishing m6A control of DIRAS1, with METTL3/METTL14 writers and FTO/ALKBH5 erasers setting mRNA stability and translation efficiency, and linked this to downstream ERK suppression.","evidence":"siRNA knockdown of m6A writers/erasers, pharmacological inhibitors, immunofluorescence localization, and western blot/qPCR for DIRAS1 and p-ERK in osteosarcoma and cervical cancer cells","pmids":["35413492","38372700"],"confidence":"Medium","gaps":["Direct m6A sites on DIRAS1 transcript not mapped","Discordant mRNA-versus-protein effects of FTO inhibition not mechanistically explained","Reader proteins coupling m6A marks to DIRAS1 fate unidentified"]},{"year":2025,"claim":"Demonstrated a context-dependent oncogenic role, where DIRAS1 upregulates PHB1 to stabilize mitochondria and confer oxaliplatin resistance, complicating the uniform tumor-suppressor model.","evidence":"Lentiviral knockdown/overexpression, cytotoxicity assays, transcriptomic sequencing, and in vivo xenografts with IHC in colorectal cancer","pmids":["40723377"],"confidence":"Medium","gaps":["Molecular link between DIRAS1 and PHB1 upregulation not resolved","Reconciliation with tumor-suppressive roles in other cancers untested","Whether GTPase activity or SmgGDS axis is involved in PHB1 regulation unknown"]},{"year":null,"claim":"How DIRAS1's nucleotide-loading state, SmgGDS competition, and subcellular localization are mechanistically coupled to its divergent tumor-suppressive versus chemoresistance outputs remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structural or biochemical model linking SmgGDS competition to downstream AKT-MTOR/ERK/autophagy effects","Determinants of context-dependent suppressor-versus-oncogene behavior unknown","Endogenous upstream activators/regulators of DIRAS1 GTPase cycle uncharacterized"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0003924","term_label":"GTPase activity","supporting_discovery_ids":[1,2]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[1]}],"localization":[{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[3]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[0,1,3]},{"term_id":"R-HSA-9612973","term_label":"Autophagy","supporting_discovery_ids":[0]},{"term_id":"R-HSA-1643685","term_label":"Disease","supporting_discovery_ids":[5,6]}],"complexes":[],"partners":["SMGGDS","PHB1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"O95057","full_name":"GTP-binding protein Di-Ras1","aliases":["Distinct subgroup of the Ras family member 1","Ras-related inhibitor of cell growth","Rig","Small GTP-binding tumor suppressor 1"],"length_aa":198,"mass_kda":22.3,"function":"Displays low GTPase activity and exists predominantly in the GTP-bound form","subcellular_location":"Cell membrane","url":"https://www.uniprot.org/uniprotkb/O95057/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/DIRAS1","classification":"Not Classified","n_dependent_lines":0,"n_total_lines":1208,"dependency_fraction":0.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/DIRAS1","total_profiled":1310},"omim":[{"mim_id":"607863","title":"DIRAS FAMILY, GTP-BINDING RAS-LIKE PROTEIN 2; DIRAS2","url":"https://www.omim.org/entry/607863"},{"mim_id":"607862","title":"DIRAS FAMILY, GTP-BINDING RAS-LIKE PROTEIN 1; DIRAS1","url":"https://www.omim.org/entry/607862"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Vesicles","reliability":"Approved"},{"location":"Plasma membrane","reliability":"Approved"},{"location":"Nucleoplasm","reliability":"Additional"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"brain","ntpm":90.2},{"tissue":"heart muscle","ntpm":98.9},{"tissue":"tongue","ntpm":48.4}],"url":"https://www.proteinatlas.org/search/DIRAS1"},"hgnc":{"alias_symbol":["Di-Ras1","GBTS1","RIG"],"prev_symbol":[]},"alphafold":{"accession":"O95057","domains":[{"cath_id":"3.40.50.300","chopping":"11-174","consensus_level":"high","plddt":94.9419,"start":11,"end":174}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/O95057","model_url":"https://alphafold.ebi.ac.uk/files/AF-O95057-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-O95057-F1-predicted_aligned_error_v6.png","plddt_mean":87.0},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=DIRAS1","jax_strain_url":"https://www.jax.org/strain/search?query=DIRAS1"},"sequence":{"accession":"O95057","fasta_url":"https://rest.uniprot.org/uniprotkb/O95057.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/O95057/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/O95057"}},"corpus_meta":[{"pmid":"29368982","id":"PMC_29368982","title":"RAS-related GTPases DIRAS1 and DIRAS2 induce autophagic cancer cell death and are required for autophagy in murine ovarian cancer cells.","date":"2018","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/29368982","citation_count":47,"is_preprint":false},{"pmid":"26814130","id":"PMC_26814130","title":"The Tumor-suppressive Small GTPase DiRas1 Binds the Noncanonical Guanine Nucleotide Exchange Factor SmgGDS and Antagonizes SmgGDS Interactions with Oncogenic Small GTPases.","date":"2016","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/26814130","citation_count":23,"is_preprint":false},{"pmid":"29556894","id":"PMC_29556894","title":"Sodium butyrate induces cell death by autophagy and reactivates a tumor suppressor gene DIRAS1 in renal cell carcinoma cell line UOK146.","date":"2018","source":"In vitro cellular & developmental biology. Animal","url":"https://pubmed.ncbi.nlm.nih.gov/29556894","citation_count":19,"is_preprint":false},{"pmid":"26635085","id":"PMC_26635085","title":"Zebrafish diras1 Promoted Neurite Outgrowth in Neuro-2a Cells and Maintained Trigeminal Ganglion Neurons In Vivo via Rac1-Dependent Pathway.","date":"2015","source":"Molecular neurobiology","url":"https://pubmed.ncbi.nlm.nih.gov/26635085","citation_count":12,"is_preprint":false},{"pmid":"35413492","id":"PMC_35413492","title":"Analysis of the function and mechanism of DIRAS1 in osteosarcoma.","date":"2022","source":"Tissue & cell","url":"https://pubmed.ncbi.nlm.nih.gov/35413492","citation_count":11,"is_preprint":false},{"pmid":"38372700","id":"PMC_38372700","title":"M6A modification regulates tumor suppressor DIRAS1 expression in cervical cancer cells.","date":"2024","source":"Cancer biology & therapy","url":"https://pubmed.ncbi.nlm.nih.gov/38372700","citation_count":11,"is_preprint":false},{"pmid":"30161023","id":"PMC_30161023","title":"RNAa and Vector-Mediated Overexpression of DIRAS1 Suppresses Tumor Growth and Migration in Renal Cell Carcinoma.","date":"2018","source":"Molecular therapy. Nucleic acids","url":"https://pubmed.ncbi.nlm.nih.gov/30161023","citation_count":10,"is_preprint":false},{"pmid":"34680261","id":"PMC_34680261","title":"Frequent Epigenetic Inactivation of DIRAS-1 and DIRAS-2 Contributes to Chemo-Resistance in Gliomas.","date":"2021","source":"Cancers","url":"https://pubmed.ncbi.nlm.nih.gov/34680261","citation_count":8,"is_preprint":false},{"pmid":"34803403","id":"PMC_34803403","title":"LINC00261 Inhibits Esophageal Cancer Radioresistance by Down-Regulating microRNA-552-3p and Promoting DIRAS1.","date":"2021","source":"Cancer management and research","url":"https://pubmed.ncbi.nlm.nih.gov/34803403","citation_count":3,"is_preprint":false},{"pmid":"40723377","id":"PMC_40723377","title":"DIRAS1 Drives Oxaliplatin Resistance in Colorectal Cancer via PHB1-Mediated Mitochondrial Homeostasis.","date":"2025","source":"Biology","url":"https://pubmed.ncbi.nlm.nih.gov/40723377","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":7660,"output_tokens":2443,"usd":0.029812,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":9525,"output_tokens":3171,"usd":0.06345,"stage2_stop_reason":"end_turn"},"total_usd":0.093262,"stage1_batch_id":"msgbatch_01AsR7g8dGTEiEw9U83bJeWn","stage2_batch_id":"msgbatch_01YV5ZyxtFNUZEjxRcpd9jzb","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2018,\n      \"finding\": \"DIRAS1 re-expression induces autophagy-mediated cancer cell death by inhibiting AKT1-MTOR and RAS-MAPK signaling pathways and modulating nuclear localization of autophagy-related transcription factors FOXO3/FOXO3A and TFEB in ovarian cancer cells.\",\n      \"method\": \"Overexpression in human and murine ovarian cancer cells; pathway analysis by western blot; nuclear localization assays for FOXO3 and TFEB\",\n      \"journal\": \"Autophagy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean overexpression with defined phenotypic readouts and multiple pathway endpoints in a single lab study\",\n      \"pmids\": [\"29368982\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"DiRas1 binds SmgGDS (a noncanonical guanine nucleotide exchange factor) and acts as a dominant-negative-like GTPase, inhibiting SmgGDS binding to oncogenic GTPases K-Ras4B, RhoA, and Rap1A. SmgGDS does not mediate GDP/GTP exchange on DiRas1. DiRas1 inhibits RhoA- and SmgGDS-mediated NF-κB transcriptional activity.\",\n      \"method\": \"Co-immunoprecipitation, in silico docking, GDP/GTP exchange assay, competitive binding assays, NF-κB transcriptional reporter assays in HEK293T and cancer cell lines\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Moderate — multiple orthogonal methods (Co-IP, in vitro exchange assay, competitive binding, transcriptional reporter) in a single focused study\",\n      \"pmids\": [\"26814130\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Zebrafish diras1 promotes neurite outgrowth via a Rac1-dependent pathway: diras1a/b overexpression elevates Rac1 protein levels and activity (GST pull-down), downregulates RhoA, and requires an intact C-terminus. Knockdown of diras1a/b reduces axon guidance and causes loss of trigeminal ganglion neurons; co-injection of mouse diras1 mRNA or constitutively active Rac1 rescues this phenotype. The pathway involves Pak1, CDK5, and Arp2/3.\",\n      \"method\": \"Overexpression and morpholino knockdown in zebrafish; GST pull-down for Rac1 activity; mRNA rescue; pharmacological inhibition of Rac1, Pak1, CDK5, and Arp2/3 in Neuro-2a cells\",\n      \"journal\": \"Molecular neurobiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic epistasis (morpholino + mRNA rescue), biochemical activity assay (GST pull-down), and multiple inhibitor experiments in one study; zebrafish ortholog\",\n      \"pmids\": [\"26635085\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"DIRAS1 localizes to the nucleus of osteosarcoma cells and suppresses ERK phosphorylation (p-ERK) without affecting p-AKT. DIRAS1 expression is suppressed by METTL3 and METTL14 (m6A writers), and the inhibitory effect of DIRAS1 overexpression on malignant behaviors and ERK inactivation is reversed by METTL3/METTL14 co-treatment.\",\n      \"method\": \"Immunofluorescence for subcellular localization; siRNA knockdown and overexpression; western blot for p-ERK and p-AKT; ELISA and dot blot for m6A methylation; rescue assays with METTL3/METTL14\",\n      \"journal\": \"Tissue & cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — direct localization experiment plus rescue/epistasis assays linking METTL3/14 to DIRAS1 expression and downstream ERK signaling; single lab, multiple orthogonal methods\",\n      \"pmids\": [\"35413492\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"DIRAS1 mRNA stability and protein translation efficiency in cervical cancer cells are regulated by m6A modification: METTL3 and METTL14 (writers) promote DIRAS1 protein expression, while FTO and ALKBH5 (erasers) reduce it. FTO inhibition (FB23-2) down-regulates DIRAS1 mRNA but up-regulates DIRAS1 protein levels.\",\n      \"method\": \"siRNA knockdown of m6A writers/erasers (METTL3, METTL14, FTO, ALKBH5); pharmacological inhibitors (5-Azacytidine, SAHA, FB23-2); western blot and qPCR for DIRAS1 protein and mRNA\",\n      \"journal\": \"Cancer biology & therapy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — multiple m6A writer/eraser perturbations with orthogonal mRNA and protein readouts; single lab\",\n      \"pmids\": [\"38372700\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Overexpression of DIRAS1 in glioblastoma cells increases sensitivity to lomustine (alkylating chemotherapy) and involves a p53-dependent DNA damage response. DIRAS1 promoter is silenced by hypermethylation and histone modifications (heterochromatinization); treatment with 5-azacytidine or HDAC inhibitors restores DIRAS1 expression.\",\n      \"method\": \"Overexpression in glioblastoma cell lines; cytotoxicity assays; DNA damage marker analysis; methylation-specific PCR; HDAC inhibitor and 5-azacytidine treatment\",\n      \"journal\": \"Cancers\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — functional overexpression with chemosensitivity phenotype and DNA damage markers; epigenetic regulation confirmed by pharmacological reactivation\",\n      \"pmids\": [\"34680261\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"DIRAS1 drives oxaliplatin resistance in colorectal cancer by upregulating PHB1 (Prohibitin 1), which maintains mitochondrial stability. Silencing DIRAS1 reduces OXA IC50 and increases tumor sensitivity in vivo; PHB1 was identified as a downstream effector by transcriptomic sequencing.\",\n      \"method\": \"Stable knockdown/overexpression via lentiviral systems; MTT and cytotoxicity assays; transcriptomic sequencing; in vivo xenograft; immunohistochemistry\",\n      \"journal\": \"Biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — single lab, transcriptomic identification of PHB1 plus functional validation in vitro and in vivo, but mechanism linking DIRAS1 to PHB1 is not fully resolved at molecular level\",\n      \"pmids\": [\"40723377\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"miR-552-3p directly targets and suppresses DIRAS1 mRNA; LINC00261 sponges miR-552-3p to relieve this suppression and up-regulate DIRAS1 transcription, thereby reducing radioresistance in esophageal cancer cells.\",\n      \"method\": \"Luciferase reporter binding assays for miR-552-3p/DIRAS1 interaction; overexpression and silencing of LINC00261, miR-552-3p, and DIRAS1; colony formation, apoptosis, and γ-H2AX assays; xenograft model\",\n      \"journal\": \"Cancer management and research\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab; the mechanistic finding concerns regulation OF DIRAS1 via ceRNA network; direct mechanistic insight into DIRAS1 protein function is minimal here\",\n      \"pmids\": [\"34803403\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"DIRAS1 is a tumor-suppressive small GTPase that suppresses oncogenic signaling (AKT-MTOR, RAS-MAPK, ERK, NF-κB) and induces autophagy-mediated cell death; it binds SmgGDS as a dominant-negative-like competitor to block activation of oncogenic GTPases (K-Ras4B, RhoA, Rap1A), and in neurons promotes neurite outgrowth via Rac1/Pak1/CDK5/Arp2/3 activation; its expression is epigenetically silenced by promoter methylation, histone deacetylation, and m6A modification (written by METTL3/METTL14, erased by FTO/ALKBH5), and in certain contexts it can drive chemoresistance through a DIRAS1-PHB1 mitochondrial stability axis.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"DIRAS1 is a small GTPase that acts as a tumor suppressor by restraining oncogenic signaling and promoting autophagy-mediated cancer cell death [#0, #1]. Mechanistically, it binds SmgGDS, a noncanonical guanine nucleotide exchange factor, but is not itself a substrate for SmgGDS-mediated GDP/GTP exchange; instead it functions as a dominant-negative-like competitor that blocks SmgGDS engagement of the oncogenic GTPases K-Ras4B, RhoA, and Rap1A and thereby suppresses RhoA- and SmgGDS-driven NF-\\u03baB transcriptional activity [#1]. Downstream, re-expressed DIRAS1 inhibits AKT1-MTOR and RAS-MAPK signaling and drives nuclear accumulation of the autophagy transcription factors FOXO3 and TFEB to induce autophagic cell death [#0], and in osteosarcoma it suppresses ERK phosphorylation selectively without affecting AKT [#3]. In the nervous system, DIRAS1 promotes neurite outgrowth and axon guidance through a Rac1-dependent pathway requiring an intact C-terminus, elevating Rac1 activity while downregulating RhoA and acting via Pak1, CDK5, and Arp2/3 [#2]. DIRAS1 expression is silenced by layered epigenetic control \\u2014 promoter hypermethylation and histone deacetylation [#5] and m6A modification written by METTL3/METTL14 and erased by FTO/ALKBH5 that tunes mRNA stability and translation efficiency [#3, #4] \\u2014 and its restoration sensitizes glioblastoma cells to lomustine through a p53-dependent DNA damage response [#5]. In a context-dependent reversal, DIRAS1 can also promote oxaliplatin resistance in colorectal cancer by upregulating PHB1 to maintain mitochondrial stability [#6].\",\n  \"teleology\": [\n    {\n      \"year\": 2015,\n      \"claim\": \"Established that DIRAS1 has a developmental signaling function in neurons, acting upstream of the Rac1/RhoA balance to drive neurite outgrowth, rather than being a purely tumor-associated gene.\",\n      \"evidence\": \"Overexpression and morpholino knockdown with mRNA rescue in zebrafish plus GST pull-down for Rac1 activity and pharmacological inhibition in Neuro-2a cells\",\n      \"pmids\": [\"26635085\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Direct biochemical mechanism by which DIRAS1 elevates Rac1 activity is not resolved\",\n        \"Findings rest on a zebrafish ortholog and a neuronal cell line, not human neurons\",\n        \"Whether the same Rac1 axis operates in non-neuronal contexts is untested\"\n      ]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Defined the core molecular mechanism: DIRAS1 is not an exchange substrate but a competitive inhibitor that sequesters SmgGDS away from oncogenic GTPases, explaining how it can dampen RhoA/NF-\\u03baB output.\",\n      \"evidence\": \"Co-immunoprecipitation, in silico docking, GDP/GTP exchange assay, competitive binding, and NF-\\u03baB reporter assays in HEK293T and cancer cell lines\",\n      \"pmids\": [\"26814130\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Structural basis of the DIRAS1-SmgGDS interface not determined experimentally\",\n        \"Nucleotide-loading state of DIRAS1 in cells and its upstream regulators unknown\",\n        \"Endogenous (non-overexpression) competition with K-Ras4B/RhoA/Rap1A not quantified\"\n      ]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Connected DIRAS1 re-expression to a defined tumor-suppressive output, showing it inhibits AKT-MTOR and RAS-MAPK signaling and engages an autophagy transcriptional program (FOXO3, TFEB) to kill cancer cells.\",\n      \"evidence\": \"Overexpression in human and murine ovarian cancer cells with western blot pathway analysis and FOXO3/TFEB nuclear localization assays\",\n      \"pmids\": [\"29368982\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Whether autophagy induction is causal for cell death versus correlative is not dissected\",\n        \"Link between SmgGDS competition and AKT-MTOR/FOXO3/TFEB modulation not established\",\n        \"Single tumor type tested\"\n      ]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Showed that DIRAS1 is epigenetically silenced in tumors and that its restoration improves therapeutic response, framing it as a druggable suppressor.\",\n      \"evidence\": \"Glioblastoma overexpression with lomustine cytotoxicity and DNA damage assays; methylation-specific PCR; 5-azacytidine and HDAC inhibitor reactivation; and an esophageal LINC00261/miR-552-3p/DIRAS1 ceRNA radioresistance study\",\n      \"pmids\": [\"34680261\", \"34803403\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"How DIRAS1 mechanistically promotes the p53-dependent DNA damage response is unresolved\",\n        \"ceRNA regulation provides regulation OF DIRAS1, not insight into DIRAS1 protein function\",\n        \"Reactivation drugs are not DIRAS1-specific\"\n      ]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Refined the regulatory layer by establishing m6A control of DIRAS1, with METTL3/METTL14 writers and FTO/ALKBH5 erasers setting mRNA stability and translation efficiency, and linked this to downstream ERK suppression.\",\n      \"evidence\": \"siRNA knockdown of m6A writers/erasers, pharmacological inhibitors, immunofluorescence localization, and western blot/qPCR for DIRAS1 and p-ERK in osteosarcoma and cervical cancer cells\",\n      \"pmids\": [\"35413492\", \"38372700\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Direct m6A sites on DIRAS1 transcript not mapped\",\n        \"Discordant mRNA-versus-protein effects of FTO inhibition not mechanistically explained\",\n        \"Reader proteins coupling m6A marks to DIRAS1 fate unidentified\"\n      ]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Demonstrated a context-dependent oncogenic role, where DIRAS1 upregulates PHB1 to stabilize mitochondria and confer oxaliplatin resistance, complicating the uniform tumor-suppressor model.\",\n      \"evidence\": \"Lentiviral knockdown/overexpression, cytotoxicity assays, transcriptomic sequencing, and in vivo xenografts with IHC in colorectal cancer\",\n      \"pmids\": [\"40723377\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Molecular link between DIRAS1 and PHB1 upregulation not resolved\",\n        \"Reconciliation with tumor-suppressive roles in other cancers untested\",\n        \"Whether GTPase activity or SmgGDS axis is involved in PHB1 regulation unknown\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How DIRAS1's nucleotide-loading state, SmgGDS competition, and subcellular localization are mechanistically coupled to its divergent tumor-suppressive versus chemoresistance outputs remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"No structural or biochemical model linking SmgGDS competition to downstream AKT-MTOR/ERK/autophagy effects\",\n        \"Determinants of context-dependent suppressor-versus-oncogene behavior unknown\",\n        \"Endogenous upstream activators/regulators of DIRAS1 GTPase cycle uncharacterized\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0003924\", \"supporting_discovery_ids\": [1, 2]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [1]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [3]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [0, 1, 3]},\n      {\"term_id\": \"R-HSA-9612973\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"R-HSA-1643685\", \"supporting_discovery_ids\": [5, 6]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"SmgGDS\", \"PHB1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":4,"faith_total":6,"faith_pct":66.66666666666667}}