Auranofin / Casp9 Cancer Research Results

AF, Auranofin: Click to Expand ⟱
Features:

Auranofin — an orally administered gold(I) coordination complex (gold–phosphine–thiolate “thiosugar” drug) originally approved as a disease-modifying antirheumatic drug (DMARD) for rheumatoid arthritis and widely studied for repurposing as a redox-targeted anticancer and anti-infective agent. It is a small-molecule metallodrug whose pharmacology is typically tracked via blood/plasma gold concentrations because intact auranofin is rapidly transformed and not reliably detected in blood. Standard abbreviation(s): AF (auranofin); primary target shorthand: TrxR/TxNRD (thioredoxin reductase).

Primary mechanisms (ranked):

  1. Thioredoxin reductase (TXNRD1/TXNRD2; TrxR) inhibition by gold(I) → thioredoxin system suppression and loss of redox-buffering capacity
  2. ROS and redox stress escalation (secondary to TrxR blockade; often NAC-reversible in models) → apoptosis and other regulated death programs
  3. Mitochondrial dysfunction (Δψm collapse, bioenergetic stress) coupled to redox imbalance
  4. Proteostasis stress (ER stress/UPR; proteasome involvement in selected contexts) → non-apoptotic death phenotypes (model-dependent)
  5. Ferroptosis contribution in subsets of models (lipid peroxidation–dependent; context-dependent)
  6. Radiosensitization / chemosensitization via impaired antioxidant recovery and enhanced oxidative injury (context-dependent)
  7. Stress-response transcription (e.g., NRF2 activation as an adaptive resistance program in some settings; protective in normal cells)

Bioavailability / PK relevance: Oral absorption is incomplete; clinical PK is commonly described as ~25% of the gold content absorbed. Gold is highly protein-bound and exhibits prolonged retention/long terminal half-life, so effective exposure depends strongly on dose and dosing duration. Because “gold levels” are the main measurable surrogate, cross-study comparisons should specify matrix (whole blood vs plasma) and timing (steady-state vs short course).

In-vitro vs systemic exposure relevance: Many oncology cell studies use ~0.5–5 µM AF. Human short-course data at 6 mg/day for 7 days report plasma gold on the order of ~0.1–0.3 µg/mL (roughly sub-µM to ~1–1.5 µM range when expressed as gold equivalents), meaning lower in-vitro ranges can overlap clinically observed exposure surrogates, while higher µM regimens may exceed typical oral exposures unless higher doses/longer courses or formulation changes are used.

Clinical evidence status: Approved for rheumatoid arthritis (historical DMARD use) but oncology use remains investigational. Multiple early-phase repurposing trials exist across hematologic and solid tumors; several completed studies have limited publicly posted outcomes, and there is no established standard-of-care anticancer indication.


Pathways:
1.Thioredoxin Reductase (TrxR) Inhibition.
- Most widely recognized for potently inhibiting TrxR.
2.Induction of Reactive Oxygen Species (ROS) and Oxidative Stress.
3.MMP depolarization, release of cytochrome c
4.Endoplasmic Reticulum (ER) Stress and Unfolded Protein Response (UPR)
5.Inhibition of Pro-survival Pathways (e.g., NF-κB Signaling)

-ic50 for cancer typically 1-3uM, normal cell 5-10uM or higher.
-Several studies animal testing antitumor efficacy have used doses in the region of 5–8 mg/kg via intraperitoneal injection or oral administration.

-Auranofin’s anticancer activity is often linked to its inhibition of thioredoxin reductase, leading to increased oxidative stress.

Mechanistic axes for Auranofin (Cancer vs Normal)

Rank Pathway / Axis Cancer Cells Normal Cells TSF Primary Effect Notes / Interpretation
1 TXNRD1 TXNRD2 Thioredoxin system ↓ (primary) ↓ (primary) P→R Collapse of thioredoxin redox buffering Core, proximal target of AF; downstream effects track with redox reserve and compensatory antioxidant capacity rather than tumor lineage alone.
2 ROS redox stress ↑ (often primary downstream) ↑ (dose-dependent) P→R Oxidative injury signaling and death pathway engagement Frequently reversible with thiol antioxidants (e.g., NAC) in models, supporting causality; magnitude depends on baseline redox fragility.
3 Mitochondria bioenergetics Δψm ↓, ATP stress ↑ (context-dependent) Δψm ↓ (dose-dependent) R Energetic crisis and intrinsic death susceptibility Often coupled to redox imbalance; can amplify apoptosis/regulated necrosis depending on cellular checkpoints.
4 Proteostasis ER stress UPR ↑ (model-dependent) ↔/↑ (high exposure only) R→G Protein-folding overload and non-apoptotic death phenotypes Some reports implicate proteasome participation and paraptosis-like outcomes; not universal across tumor types.
5 NRF2 antioxidant response ↑ (adaptive; resistance role) ↑ (cytoprotective) R→G Transcriptional compensation to redox stress NRF2 induction can blunt AF efficacy in tumors yet protect normal tissues; net effect is (context-dependent).
6 Ferroptosis lipid peroxidation ↑ (model-dependent) ↔/↑ (stress-prone contexts) R→G Regulated death component in subsets Most consistent when AF-driven redox stress converges on lipid ROS handling; requires model-specific validation.
7 Radiosensitization chemosensitization ↑ sensitivity (context-dependent) ↑ toxicity risk (context-dependent) R→G Impaired antioxidant recovery increases treatment injury Mechanistically coherent with TrxR blockade; best supported where oxidative damage markers and combination indices are shown.
8 Ca²⁺ stress coupling ↑/↔ (secondary) ↑/↔ (secondary) R Amplifies ER mitochondrial death signaling Usually downstream of redox + organelle perturbation; include when Ca²⁺-dependent apoptosis/ER stress is explicitly demonstrated.
9 Glycolysis ATP production ↓ (context-dependent) ↔/↓ (high exposure only) R Metabolic stress that can reduce proliferative fitness Reported in some models; may be secondary to mitochondrial/redox disruption rather than a primary binding target.
10 HIF-1α hypoxia programs ↔ (model-dependent) ↔ G Context marker rather than core axis Evaluate case-by-case; AF’s primary leverage is redox enzyme inhibition, with HIF effects emerging indirectly in some systems.
11 Clinical Translation Constraint ↔ ↔ — Exposure, tolerability, and selectivity limit window Oral absorption is incomplete and gold is long-retained/protein-bound; many oncology studies rely on µM in-vitro dosing that may exceed typical oral exposure surrogates. Oncology trials exist but anticancer efficacy is not established as standard-of-care.

TSF legend: P: 0–30 min | R: 30 min–3 hr | G: >3 hr
Casp9, Caspase-9: Click to Expand ⟱
Source:
Type:
Caspase-9 is the apoptotic initiator protease of the intrinsic or mitochondrial apoptotic pathway, which is activated at multi-protein activation platforms.
Caspases are divided into two groups: the initiator caspases (caspase-2, -8, -9 and -10), which are the first to be activated in response to a signal, and the executioner caspases (caspase-3, -6, and -7) that carry out the demolition phase of apoptosis.
Caspase-9:
Role: Initiator caspase in the intrinsic apoptotic pathway.
Cancers: Frequently studied in leukemia and solid tumors.
Prognosis: Reduced expression is often linked to chemoresistance and poor prognosis.
Scientific Papers found: Click to Expand⟱
1459- SFN,  AF,    Auranofin Enhances Sulforaphane-Mediated Apoptosis in Hepatocellular Carcinoma Hep3B Cells through Inactivation of the PI3K/Akt Signaling Pathway
- in-vitro, Liver, Hep3B - in-vitro, Liver, HepG2
eff↑, TumCCA↑, Apoptosis↑, MMP↓, BAX↑, cl‑PARP↑, Casp3↑, Casp8↑, Casp9↑, ROS↑, eff↓, PI3K↓, Akt↓, TrxR↓, BAX↑, Bcl-2∅,

Showing Research Papers: 1 to 1 of 1

* indicates research on normal cells as opposed to diseased cells
Total Research Paper Matches: 1

Pathway results for Effect on Cancer / Diseased Cells:


Redox & Oxidative Stress ⓘ

ROS↑, 1,   TrxR↓, 1,  

Mitochondria & Bioenergetics ⓘ

MMP↓, 1,  

Cell Death ⓘ

Akt↓, 1,   Apoptosis↑, 1,   BAX↑, 2,   Bcl-2∅, 1,   Casp3↑, 1,   Casp8↑, 1,   Casp9↑, 1,  

DNA Damage & Repair ⓘ

cl‑PARP↑, 1,  

Cell Cycle & Senescence ⓘ

TumCCA↑, 1,  

Proliferation, Differentiation & Cell State ⓘ

PI3K↓, 1,  

Drug Metabolism & Resistance ⓘ

eff↓, 1,   eff↑, 1,  
Total Targets: 15

Pathway results for Effect on Normal Cells:


Total Targets: 0

Scientific Paper Hit Count for: Casp9, Caspase-9
Query results interpretion may depend on "conditions" listed in the research papers.
Such Conditions may include : 
  -low or high Dose
  -format for product, such as nano of lipid formations
  -different cell line effects
  -synergies with other products 
  -if effect was for normal or cancerous cells

Filter Conditions: Pro/AntiFlg:%  IllCat:%  CanType:%  Cells:%  prod#:273  Target#:45  State#:%  Dir#:%
  wNotes=0  sortOrder:rid,rpid

 

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