Metformin / HO-1 Cancer Research Results

MET, Metformin: Click to Expand ⟱
Features: oral antidiabetic agent,
Metformin is a pleiotropic drug: attributed to its action on AMPK
Metformin is a biguanide drug used primarily for type 2 diabetes. Mechanistically, it is best described as a bioenergetic modulator: partial inhibition of mitochondrial respiration can raise AMP/ADP, engage AMPK, and suppress mTORC1 signaling; systemically it reduces hepatic gluconeogenesis and can lower insulin/IGF-1 growth signaling. In oncology, observational studies suggested improved outcomes in some settings, but randomized trial data are mixed (e.g., large adjuvant breast cancer data did not show broad benefit overall). Long-term use can be associated with vitamin B12 deficiency, and prescribing requires attention to renal function due to rare lactic acidosis risk in predisposed states.
Metformin directly(partially) inhibits Complex I of the electron transport chain (ETC) in mitochondria. This inhibition decreases mitochondrial ATP production and forces cells to rely more on glycolysis for energy.
Cancer cells, especially those with high energy demands, may be particularly sensitive to a drop in ATP levels. The inhibition of Complex I also increases the AMP/ATP ratio, setting the stage for the activation of downstream energy stress pathways.
AMPK activation results in the inhibition of the mammalian target of rapamycin (mTOR) pathway, a central regulator of protein synthesis and cellular growth. mTOR inhibition reduces cell proliferation and limits tissue growth, which can slow tumor progression.

Metformin reduces circulating insulin levels, which in turn can decrease the activation of the insulin and insulin-like growth factor-1 (IGF-1) receptor pathways.

ETC Inhibitors: Drugs that directly inhibit specific ETC complexes (e.g., Complex I inhibitors like metformin or phenformin) can increase electron leakage and ROS production.(dose- and context-dependent, and not consistent)

-known as mild OXPHOS inhibitor(Complex I modulator)

Rank Pathway / Axis Cancer / Tumor Context Normal Tissue Context TSF Primary Effect Notes / Interpretation
1 Mitochondrial Complex I (OXPHOS) inhibition Energetic stress ↑; proliferation pressure ↓ (context) Hepatic energy shift; gluconeogenesis ↓ P, R Bioenergetic modulation Metformin partially inhibits mitochondrial Complex I (OXPHOS), increasing AMP/ADP ratio and triggering downstream AMPK activation. ROS changes are dose- and context-dependent.
2 AMPK activation (LKB1/AMPK axis) Growth programs ↓ (context-dependent) Metabolic homeostasis ↑ R Energy-sensor activation AMPK activation is frequently invoked downstream of respiratory inhibition, though some hepatic effects can be AMPK-independent.
3 mTORC1 inhibition (via AMPK→TSC2/Raptor; also AMPK-independent routes reported) Protein synthesis / growth signaling ↓ (reported) Reduced anabolic signaling in liver (context) R, G Anti-anabolic signaling Mechanistically supported: AMPK regulation of TSC2 and Raptor contributes to metformin-mediated mTORC1 inhibition; AMPK-independent mTORC1 inhibition has also been described.
4 Hepatic gluconeogenesis suppression Indirect tumor support via insulin/IGF-1 lowering (systemic) Liver glucose production ↓ (core clinical effect) R, G Systemic metabolic effect Metformin reduces hepatic glucose output through multiple mechanisms (energy state shifts, cAMP pathways, and other proposed nodes).
5 Insulin / IGF-1 axis (systemic growth signaling) Mitogenic tone ↓ (context; strongest in hyperinsulinemic settings) Insulin sensitivity ↑; insulin levels ↓ (context) G Systemic growth-factor modulation Many “anti-cancer” hypotheses depend on lowering insulin/IGF-1 signaling rather than direct tumor cytotoxicity.
6 Cell-cycle & apoptosis (secondary, model-dependent) Proliferation ↓; apoptosis ↑ (reported in some models) ↔ G Conditional cytostasis Often downstream of mTORC1 suppression/energy stress; not a universal direct cytotoxin signature.
7 Inflammation signaling (NF-κB and related programs) Inflammatory pro-survival transcription ↓ (reported) Anti-inflammatory trends in metabolic disease contexts R, G Inflammation modulation Frequently reported as downstream of improved metabolic/oxidative stress tone; avoid presenting as a primary direct target.
8 Autophagy / stress adaptation Autophagy ↑ or ↓ depending on context; can affect therapy response ↔ G Adaptive stress response Autophagy findings are heterogeneous across tumor models and combinations.
9 Clinical oncology evidence (adjunct use) Observational signals exist; randomized data are mixed — — Translation constraint Epidemiology/meta-analyses suggested potential benefit in some cancers, but large randomized trials (e.g., adjuvant breast cancer MA.32) did not show broad benefit across the overall population.
10 Safety / monitoring constraints (B12, lactic acidosis risk in predisposed states) — Vitamin B12 deficiency risk with long-term use; rare lactic acidosis risk increases with renal impairment and other conditions — Clinical risk management Long-term B12 monitoring is commonly advised; prescribing requires renal function assessment due to lactic acidosis risk in predisposed settings.

Time-Scale Flag (TSF): P / R / G

  • P: 0–30 min (rapid bioenergetic effects)
  • R: 30 min–3 hr (acute signaling shifts: AMPK/mTOR)
  • G: >3 hr (gene-regulatory adaptation and phenotype outcomes)
HO-1, HMOX1: Click to Expand ⟱
Source:
Type:
(Also known as Hsp32 and HMOX1)
HO-1 is the common abbreviation for the protein (heme oxygenase‑1) produced by the HMOX1 gene.
HO-1 is an enzyme that plays a crucial role in various cellular processes, including the breakdown of heme, a toxic molecule. Research has shown that HO-1 is involved in the development and progression of cancer.
-widely regarded as having antioxidant and cytoprotective effects
-The overall activity of HO‑1 helps to reduce the pro‐oxidant load (by degrading free heme, a pro‑oxidant) and to generate molecules (like bilirubin) that can protect cells from oxidative damage

Studies have found that HO-1 is overexpressed in various types of cancer, including lung, breast, colon, and prostate cancer. The overexpression of HO-1 in cancer cells can contribute to their survival and proliferation by:
  Reducing oxidative stress and inflammation
  Promoting angiogenesis (the formation of new blood vessels)
  Inhibiting apoptosis (programmed cell death)
  Enhancing cell migration and invasion
When HO-1 is at a normal level, it mainly exerts an antioxidant effect, and when it is excessively elevated, it causes an accumulation of iron ions.

A proper cellular level of HMOX1 plays an antioxidative function to protect cells from ROS toxicity. However, its overexpression has pro-oxidant effects to induce ferroptosis of cells, which is dependent on intracellular iron accumulation and increased ROS content upon excessive activation of HMOX1.

-Curcumin   Activates the Nrf2 pathway leading to HO‑1 induction; known for its anti‑inflammatory and antioxidant effects.
-Resveratrol  Induces HO‑1 via activation of SIRT1/Nrf2 signaling; exhibits antioxidant and cardioprotective properties.
-Quercetin   Activates Nrf2 and related antioxidant pathways; contributes to anti‑oxidative and anti‑inflammatory responses.
-EGCG     Promotes HO‑1 expression through activation of the Nrf2/ARE pathway; also exhibits anti‑inflammatory and anticancer properties.
-Sulforaphane One of the most potent natural HO‑1 inducers; triggers Nrf2 nuclear translocation and upregulates a battery of phase II detoxifying enzymes.
-Luteolin    Induces HO‑1 via Nrf2 activation; may also exert anti‑inflammatory and neuroprotective effects in various cell models.
-Apigenin   Has been reported to induce HO‑1 expression partly via the MAPK and Nrf2 pathways; also known for anti‑inflammatory and anticancer activities.
Scientific Papers found: Click to Expand⟱
1204- MET,    Metformin induces ferroptosis through the Nrf2/HO-1 signaling in lung cancer
- in-vitro, Lung, A549 - in-vitro, Lung, H1299
MDA↑, ROS↑, Iron↑, GSH↓, T-SOD↓, Catalase↓, GPx4↓, xCT↓, NRF2↓, HO-1↓,

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 ⓘ

Catalase↓, 1,   GPx4↓, 1,   GSH↓, 1,   HO-1↓, 1,   Iron↑, 1,   MDA↑, 1,   NRF2↓, 1,   ROS↑, 1,   T-SOD↓, 1,   xCT↓, 1,  
Total Targets: 10

Pathway results for Effect on Normal Cells:


Total Targets: 0

Scientific Paper Hit Count for: HO-1, HMOX1
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#:11  Target#:597  State#:%  Dir#:1
  wNotes=0  sortOrder:rid,rpid

 

Home Page