5-fluorouracil / Cyt‑c Cancer Research Results

5-FU, 5-fluorouracil: Click to Expand ⟱
Features:
5-FU is a chemotherapy medication used to treat various types of cancer, including colorectal, breast, stomach, and pancreatic cancer. It belongs to a class of drugs known as antimetabolites, which work by interfering with the growth and replication of cancer cells.
Mechanisms:
- functionally irreversibly inhibits Thymidylate Synthase (TS), thereby depleting the deoxythymidine monophosphate (dTMP) pool required for DNA synthesis. The resulting “thymineless death” prevents DNA replication and repair, particularly affecting rapidly proliferating tumor cells.

5-FU is a cornerstone in chemotherapy with a dual mechanism of action—primarily inhibiting thymidylate synthase (leading to disruption of DNA synthesis) and interfering with RNA processing by misincorporation. Its metabolism via activation (OPRT) and degradation (DPD) plays a crucial role in both its effectiveness and toxicity. Clinically, 5-FU is extensively used in treating a variety of cancers, most notably colorectal cancer, and remains a mainstay in multi-agent chemotherapeutic regimens due to its proven efficacy across diverse cancer types.

5-FU is one of the most common chemotherapeutic agents worldwide, particularly noted in gastrointestinal (GI) cancers.

Rank Pathway / Axis Cancer / Tumor Context Normal Tissue Context TSF Primary Effect Notes / Interpretation
1 Thymidylate synthase (TS) inhibition → dTMP depletion dTMP ↓ → DNA synthesis ↓ → replication stress ↑ Also affects normal proliferating tissues (marrow, GI mucosa) P, R Core cytotoxic mechanism 5-FU is converted to FdUMP, which forms a ternary complex with TS and folate, blocking thymidylate production (“thymineless death”).
2 RNA misincorporation (FUTP incorporation) RNA processing/translation defects ↑ Contributes to mucositis and systemic toxicity P, R Transcription/translation disruption RNA effects are a major contributor to cytotoxicity, particularly with bolus dosing.
3 DNA misincorporation (FdUTP incorporation) DNA damage signaling ↑; apoptosis ↑ (context) DDR activation in normal tissues contributes to toxicity R, G Genome instability Misincorporation triggers mismatch repair and DNA damage responses.
4 S-phase specificity (cell-cycle dependence) Greater killing in actively cycling/S-phase cells Bone marrow & GI epithelium vulnerability ↑ R, G Cell-cycle–linked cytotoxicity Antimetabolite activity is strongest in proliferating cells.
5 Folate modulation (leucovorin synergy) TS inhibition ↑ when combined with leucovorin — R Mechanism amplification Leucovorin stabilizes the FdUMP–TS–folate complex, enhancing cytotoxicity.
6 Myelosuppression — Neutropenia/anemia risk ↑ R, G Dose-limiting toxicity Expected on-target effect in rapidly dividing marrow progenitors.
7 Gastrointestinal toxicity (mucositis/diarrhea) — GI epithelial injury ↑ R, G Dose-limiting toxicity Reflects RNA/DNA effects in rapidly renewing GI mucosa.
8 Cardiotoxicity (vasospasm; rare cardiomyopathy) — Chest pain/ischemia risk ↑ (rare but important) R Serious adverse effect Coronary vasospasm is the most recognized mechanism; monitoring required in symptomatic patients.
9 DPD metabolism (DPYD enzyme) Severe toxicity risk ↑ if DPD deficient — — Pharmacogenetic constraint Dihydropyrimidine dehydrogenase (DPD) metabolizes 5-FU; deficiency can cause life-threatening toxicity. Pre-treatment DPYD testing is increasingly recommended.
10 Infusion vs bolus pharmacodynamics Continuous infusion → more TS-driven DNA effect Bolus → more RNA-mediated toxicity P, R, G Dosing-dependent mechanism balance Administration schedule alters relative DNA vs RNA contribution and toxicity profile.

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

  • P: 0–30 min (metabolic activation begins rapidly)
  • R: 30 min–3 hr (TS inhibition, RNA/DNA incorporation, DDR activation)
  • G: >3 hr (cell-cycle arrest, apoptosis, tissue-level toxicities)
Cyt‑c, cyt-c Release into Cytosol: Click to Expand ⟱
Source:
Type:
Cytochrome c
** The term "release of cytochrome c" ** an increase in level for the cytosol.
Small hemeprotein found loosely associated with the inner membrane of the mitochondrion where it plays a critical role in cellular respiration. Cytochrome c is highly water-soluble, unlike other cytochromes. It is capable of undergoing oxidation and reduction as its iron atom converts between the ferrous and ferric forms, but does not bind oxygen. It also plays a major role in cell apoptosis.

The term "release of cytochrome c" refers to a critical step in the process of programmed cell death, also known as apoptosis.
In its new location—the cytosol—cytochrome c participates in the apoptotic signaling pathway by helping to form the apoptosome, which activates caspases that execute cell death.
Cytochrome c is a small protein normally located in the mitochondrial intermembrane space. Its primary role in healthy cells is to participate in the electron transport chain, a process that helps produce energy (ATP) through oxidative phosphorylation.
Mitochondrial outer membrane permeability leads to the release of cytochrome c from the mitochondria into the cytosol.
The release of cytochrome c is a pivotal event in apoptosis where cytochrome c moves from the mitochondria to the cytosol, initiating a chain reaction that leads to programmed cell death.

On the one hand, cytochrome c can promote cancer cell survival and proliferation by regulating the activity of various signaling pathways, such as the PI3K/AKT pathway. This can lead to increased cell growth and resistance to apoptosis, which are hallmarks of cancer.
On the other hand, cytochrome c can also induce apoptosis in cancer cells by interacting with other proteins, such as Apaf-1 and caspase-9. This can lead to the activation of the intrinsic apoptotic pathway, which can result in the death of cancer cells.
Overexpressed in Breast, Lung, Colon, and Prostrate.
Underexpressed in Ovarian, and Pancreatic.
Scientific Papers found: Click to Expand⟱
4774- 5-FU,  TQ,  CoQ10,    Exploring potential additive effects of 5-fluorouracil, thymoquinone, and coenzyme Q10 triple therapy on colon cancer cells in relation to glycolysis and redox status modulation
- in-vitro, CRC, NA
AntiCan↑, TumCCA↑, Apoptosis↑, eff↑, Bcl-2↓, survivin↓, P21↑, p27↑, BAX↑, Cyt‑c↑, Casp3↑, PI3K↓, Akt↓, mTOR↓, Hif1a↓, PTEN↑, AMPKα↑, PDH↑, LDHA↓, antiOx↓, ROS↑, AntiCan↑,

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 ⓘ

antiOx↓, 1,   ROS↑, 1,  

Core Metabolism/Glycolysis ⓘ

LDHA↓, 1,   PDH↑, 1,  

Cell Death ⓘ

Akt↓, 1,   Apoptosis↑, 1,   BAX↑, 1,   Bcl-2↓, 1,   Casp3↑, 1,   Cyt‑c↑, 1,   p27↑, 1,   survivin↓, 1,  

Kinase & Signal Transduction ⓘ

AMPKα↑, 1,  

Cell Cycle & Senescence ⓘ

P21↑, 1,   TumCCA↑, 1,  

Proliferation, Differentiation & Cell State ⓘ

mTOR↓, 1,   PI3K↓, 1,   PTEN↑, 1,  

Angiogenesis & Vasculature ⓘ

Hif1a↓, 1,  

Drug Metabolism & Resistance ⓘ

eff↑, 1,  

Functional Outcomes ⓘ

AntiCan↑, 2,  
Total Targets: 21

Pathway results for Effect on Normal Cells:


Total Targets: 0

Scientific Paper Hit Count for: Cyt‑c, cyt-c Release into Cytosol
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#:191  Target#:77  State#:%  Dir#:2
  wNotes=0  sortOrder:rid,rpid

 

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