PI3K/Akt/mTOR · target hub

FOXO3

Forkhead box protein O3 (FOXO3)

FOXO3 is a PDK1–Akt axis or canonical effector on the PI3K/Akt/mTOR axis. Transcriptional activator that recognizes and binds to the DNA sequence 5'-[AG]TAAA[TC]A-3' and regulates different processes, such as apoptosis and autophagy (PubMed:10102273, PubMed:16751106, PubMed:21329882, PubMed:30513302). Acts as a positive regulator of autophagy in skelet… It is indexed under "Canonical Akt substrates & effectors (selected)" on our pathway page for antibodies, inhibitors, and assay guidance.

Back to pathway overviewSearch: FOXO3UniProt (O43524)

Research notes

  • Combine with other genes in the same hub block via genetics or pharmacology to test non-redundant roles of FOXO3.
  • Annotate PIK3CA/PTEN and upstream RTK–Ras context when reading p-AKT, mTORC1/2, or lipid outputs.
  • Verify antibody clone, phospho-site, and stimulation; include KD/KO or inhibitor controls.

On the pathway hub (sections)

Genetic lesions & expression context (quick reference)

Type / exampleDomain / context (brief)
Expression contextTissue/cell-type–dependent expression
Rare variantsSporadic variants—require functional validation
Pathway couplingCo-occurs with neighboring nodes on the hub

Naming and prevalence vary by cohort and assay—annotate clinically with COSMIC, ClinVar, OncoKB, and datasheets; research context only.

Assay readouts for FOXO3

  • Kinase activity: IP–kinase or commercial assays for FOXO3 where applicable.
  • Phosphorylation: Akt Thr308/Ser473 or substrate-site antibodies—pair totals.
  • Substrate outputs: FOXO/GSK3/BAD phospho-status or localization shifts.
  • Context: PIK3CA/PTEN status; insulin/growth-factor stimulation.

FOXO3 experimental notes

Examples below reflect common literature and public resources (e.g., CCLE, DepMap)—validate genotypes, expression, and passage in your own stocks before committing assays.

[1] Cell lines commonly used for FOXO3 studies (examples)

  • Tool lines: HEK293T, MCF-7, HepG2, LNCaP, NIH-3T3—screen by FOXO3 expression and pathway context (CCLE/DepMap).
  • Combine with neighbors (FOXO1, FOXO4, GSK3A, GSK3B) via KD/pharmacology to test non-redundancy.
  • Overexpression/rescue in HEK293T supports mechanism and IP workflows.
  • Isogenic/CRISPR models separate pathway dependency from bypass survival.

[2] Cell samples for FOXO3 Western blot

  • Whole-cell lysates—optimize RIPA/NP-40 per antibody; phosphatase inhibitors for phospho blots.
  • Stimulation: serum starvation ± insulin/EGF or amino-acid withdrawal/refeed as relevant.
  • Controls: siRNA/shRNA, CRISPR KO, or inhibitors to validate band specificity.
  • Loading: BCA normalization; subcellular fractionation when needed.

[3] Tissue samples for FOXO3 Western blot

  • Matched tumor/adjacent frozen tissues after pathology review.
  • Mouse GEMM or xenografts—mind species antibody cross-reactivity.
  • Primary cells/PDCs when ethically approved.
  • FFPE needs specialized extraction; frozen tissue preferred for phospho work.

[4] Cell samples for FOXO3 immunoprecipitation

  • Tagged overexpression: HEK293T FLAG/HA-FOXO3 for complex capture.
  • Endogenous IP: high-expression lines; often ≥1–5×10⁶ cells per IP.
  • Stimulation: ligand or nutrient treatments enrich interactions—pilot time courses.
  • Controls: isotype IgG, empty vector, KD/KO negatives.

Human tissues and primary cells require ethics/IRB approval; tumors are heterogeneous—record histotype, site, and preservation conditions.

Bypass & related pathways

Models & genetics note

Overexpression vs endogenous FOXO3 can differ in dosage, splicing, and compartmentation—in organoids/PDX, record passage, matrix, and drug history.

Quick search presets

FOXO3FOXO3 antibodyPI3K inhibitormTOR inhibitor

FOXO3-related antibodies (keyword-biased)

Adds FOXO3 keyword bias atop the PI3K/Akt/mTOR antibody pool—if sparse, use presets above or global search.

Neighboring targets (same hub)

FOXO1FOXO4GSK3AGSK3BBADCASP9MDM2XIAP

External databases & resources

FAQ

This content supports research reagents and pathway education—not medical advice. Annotate mutations, drug indications, and protocols with authoritative databases, datasheets, and institutional oversight.

Last reviewed: 2026-05-18

Related on this site

See the PI3K/Akt/mTOR hub for neighboring nodes and assay guidance—cross-check MAPK, RTK, metabolism, and autophagy pages as needed.

PI3K/Akt/mTOR·MAPK/ERK·Receptor tyrosine kinase·Metabolism