Photodynamic Therapy / ROS Cancer Research Results

PDT, Photodynamic Therapy: Click to Expand ⟱
Features: Therapy
Photodynamic therapy is a form of phototherapy involving light and a photosensitizing chemical substance used in conjunction with molecular oxygen to elicit cell death.
Photodynamic therapy (PDT) is a 3-component cytotoxic platform: photosensitizer + light (matched wavelength) + oxygen. Light excites the photosensitizer, which then generates reactive oxygen species (ROS)—often dominated by singlet oxygen (¹O₂)—causing localized oxidative damage to tumor cells, tumor vasculature, and sometimes triggering immunogenic cell death (ICD).
Key constraints are light penetration depth and tumor hypoxia (and PDT itself can transiently consume oxygen).


Photodynamic Therapy (PDT) — Cancer-Oriented Time-Scale Flagged Pathway Table
Rank Pathway / Axis Cancer / Tumor Context Normal Tissue Context TSF Primary Effect Notes / Interpretation
1 Type II photochemistry: singlet oxygen (¹O₂) generation ¹O₂ ↑↑ locally; oxidative damage ↑ Localized injury only where PS+light overlap P Core cytotoxic mechanism PDT typically relies heavily on Type II energy transfer producing singlet oxygen as a primary cytotoxic agent (oxygen-dependent).
2 Type I photochemistry: radical ROS (O2•−, •OH, etc.) Radical ROS ↑ (context; PS-dependent) Localized oxidative injury (exposure-limited) P ROS amplification Type I electron-transfer pathways can contribute, especially for some PS designs and oxygen-limited niches.
3 Direct tumor cell kill (membrane/protein/DNA oxidation) Apoptosis/necrosis/other death programs ↑ (context) Collateral damage limited by targeting + light field R, G Local tumor cytotoxicity Oxidative injury can trigger multiple death modes; outcome depends on dose, PS localization (membrane/mitochondria/lysosome), and oxygen.
4 Vascular shutdown (tumor vasculature damage) Perfusion ↓; secondary hypoxia/ischemia ↑ Local vascular injury possible R Indirect tumor starvation PDT can damage tumor-associated vessels, restricting nutrient/oxygen supply and contributing to delayed tumor kill.
5 Oxygen dependence / hypoxia limitation Efficacy ↓ in hypoxic tumors; PDT consumes O2 during reaction P, R Core constraint Tumor hypoxia is a major barrier; PDT can transiently reduce local oxygen levels during illumination.
6 Immune activation / immunogenic cell death (ICD) DAMP release ↑; anti-tumor immunity ↑ (protocol/PS-dependent) Inflammatory signaling ↑ locally G Systemic immune leverage PDT can trigger ICD and stimulate adaptive immune responses, but this is highly dependent on photosensitizer and protocol.
7 Inflammation & cytokine wave (acute) Local cytokines ↑; immune cell recruitment ↑ Local inflammation ↑ R, G Microenvironment remodeling Post-PDT inflammation can support tumor clearance or, if suboptimal, contribute to repair/regrowth; protocol matters.
8 Combination leverage (radiation/chemo/immunotherapy) Sensitization ↑ (context-dependent) G Adjunct synergy PDT is often paired with other modalities; strongest logic is local tumor kill + immune priming + improved control of residual disease.
9 Light penetration depth constraint Deep tumors harder to treat (limited light reach) Translation constraint Most activation light has limited tissue penetration; strategies include fiber optics, endoscopic delivery, or NIR-shifted PS designs.
10 Photosensitizer PK & phototoxicity risk PS accumulation affects selectivity Skin/eye photosensitivity risk (agent-dependent) R, G Clinical constraint Systemic photosensitizers can cause prolonged photosensitivity; topical/ALA-based approaches reduce systemic exposure in some uses.

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

  • P: 0–30 min (photoactivation + ROS burst)
  • R: 30 min–3 hr (vascular effects, acute stress signaling)
  • G: >3 hr (cell-death completion, immune recruitment, ICD outcomes)


Common Clinical Photosensitizers for Cancer PDT
Photosensitizer Class Activation Wavelength (nm) Penetration Depth* Photosensitivity Duration Typical Clinical Use Notes
5-ALA (→ Protoporphyrin IX) Endogenous porphyrin precursor ~630–635 nm Shallow–Moderate (~2–5 mm) Short (24–48 hrs; topical shorter) Skin cancers, actinic keratosis, bladder, glioma visualization Prodrug converted intracellularly to PpIX; good tumor selectivity; minimal prolonged systemic photosensitivity.
Porfimer sodium (Photofrin®) First-generation porphyrin ~630 nm Moderate (~5–10 mm) Long (4–6 weeks) Esophageal, lung, bladder cancers Prolonged skin photosensitivity is a major limitation.
Temoporfin (Foscan®) Chlorin ~652 nm Moderate (~5–10 mm) 2–3 weeks Head & neck cancers Higher potency than Photofrin; improved absorption spectrum.
Verteporfin (Visudyne®) Benzoporphyrin derivative ~689 nm Moderate–Deeper (~5–10+ mm) Short (few days) Primarily ophthalmology; investigated in oncology Better red/NIR absorption; shorter photosensitivity window.
Talcaporfin sodium (Laserphyrin®) Chlorin derivative ~664 nm Moderate (~5–10 mm) Short (~1–2 weeks) Lung, brain tumors (Japan) Improved safety vs first-generation porphyrins.
Methylene Blue Phenothiazine dye ~660–670 nm Shallow–Moderate Short Experimental oncology; antimicrobial PDT Strong Type I ROS contribution; also has redox cycling effects without light.
Hypericin Natural anthraquinone ~590–600 nm Shallow Variable Investigational High singlet oxygen yield; hydrophobic; not widely used clinically.

*Penetration depth depends on wavelength, tissue optical properties, and light delivery method. Red/NIR light (~650–700 nm) penetrates deeper than blue/green light.



ROS, Reactive Oxygen Species: Click to Expand ⟱
Source: HalifaxProj (inhibit)
Type:
Reactive oxygen species (ROS) are highly reactive molecules that contain oxygen and can lead to oxidative stress in cells. They play a dual role in cancer biology, acting as both promoters and suppressors of cancer.
ROS can cause oxidative damage to DNA, leading to mutations that may contribute to cancer initiation and progression. So normally you want to inhibit ROS to prevent cell mutations.
However excessive ROS can induce apoptosis (programmed cell death) in cancer cells, potentially limiting tumor growth. Chemotherapy typically raises ROS.
-mitochondria is the main source of reactive oxygen species (ROS) (and the ETC is heavily related)

"Reactive oxygen species (ROS) are two electron reduction products of oxygen, including superoxide anion, hydrogen peroxide, hydroxyl radical, lipid peroxides, protein peroxides and peroxides formed in nucleic acids 1. They are maintained in a dynamic balance by a series of reduction-oxidation (redox) reactions in biological systems and act as signaling molecules to drive cellular regulatory pathways."
"During different stages of cancer formation, abnormal ROS levels play paradoxical roles in cell growth and death 8. A physiological concentration of ROS that maintained in equilibrium is necessary for normal cell survival. Ectopic ROS accumulation promotes cell proliferation and consequently induces malignant transformation of normal cells by initiating pathological conversion of physiological signaling networks. Excessive ROS levels lead to cell death by damaging cellular components, including proteins, lipid bilayers, and chromosomes. Therefore, both scavenging abnormally elevated ROS to prevent early neoplasia and facilitating ROS production to specifically kill cancer cells are promising anticancer therapeutic strategies, in spite of their contradictoriness and complexity."
"ROS are the collection of derivatives of molecular oxygen that occur in biology, which can be categorized into two types, free radicals and non-radical species. The non-radical species are hydrogen peroxide (H 2O 2 ), organic hydroperoxides (ROOH), singlet molecular oxygen ( 1 O 2 ), electronically excited carbonyl, ozone (O3 ), hypochlorous acid (HOCl, and hypobromous acid HOBr). Free radical species are super-oxide anion radical (O 2•−), hydroxyl radical (•OH), peroxyl radical (ROO•) and alkoxyl radical (RO•) [130]. Any imbalance of ROS can lead to adverse effects. H2 O 2 and O 2 •− are the main redox signalling agents. The cellular concentration of H2 O 2 is about 10−8 M, which is almost a thousand times more than that of O2 •−".
"Radicals are molecules with an odd number of electrons in the outer shell [393,394]. A pair of radicals can be formed by breaking a chemical bond or electron transfer between two molecules."

Recent investigations have documented that polyphenols with good antioxidant activity may exhibit pro-oxidant activity in the presence of copper ions, which can induce apoptosis in various cancer cell lines but not in normal cells. "We have shown that such cell growth inhibition by polyphenols in cancer cells is reversed by copper-specific sequestering agent neocuproine to a significant extent whereas iron and zinc chelators are relatively ineffective, thus confirming the role of endogenous copper in the cytotoxic action of polyphenols against cancer cells. Therefore, this mechanism of mobilization of endogenous copper." > Ions could be one of the important mechanisms for the cytotoxic action of plant polyphenols against cancer cells and is possibly a common mechanism for all plant polyphenols. In fact, similar results obtained with four different polyphenolic compounds in this study, namely apigenin, luteolin, EGCG, and resveratrol, strengthen this idea.
Interestingly, the normal breast epithelial MCF10A cells have earlier been shown to possess no detectable copper as opposed to breast cancer cells [24], which may explain their resistance to polyphenols apigenin- and luteolin-induced growth inhibition as observed here (Fig. 1). We have earlier proposed [25] that this preferential cytotoxicity of plant polyphenols toward cancer cells is explained by the observation made several years earlier, which showed that copper levels in cancer cells are significantly elevated in various malignancies. Thus, because of higher intracellular copper levels in cancer cells, it may be predicted that the cytotoxic concentrations of polyphenols required would be lower in these cells as compared to normal cells."

Majority of ROS are produced as a by-product of oxidative phosphorylation, high levels of ROS are detected in almost all cancers.
-It is well established that during ER stress, cytosolic calcium released from the ER is taken up by the mitochondrion to stimulate ROS overgeneration and the release of cytochrome c, both of which lead to apoptosis.

Note: Products that may raise ROS can be found using this database, by:
Filtering on the target of ROS, and selecting the Effect Direction of ↑

Targets to raise ROS (to kill cancer cells):
• NADPH oxidases (NOX): NOX enzymes are involved in the production of ROS.
    -Targeting NOX enzymes can increase ROS levels and induce cancer cell death.
    -eNOX2 inhibition leads to a high NADH/NAD⁺ ratio which can lead to increased ROS
• Mitochondrial complex I: Inhibiting can increase ROS production
• P53: Activating p53 can increase ROS levels(by inducing the expression of pro-oxidant genes)
Nrf2 inhibition: regulates the expression of antioxidant genes. Inhibiting Nrf2 can increase ROS levels
• Glutathione (GSH): an antioxidant. Depleting GSH can increase ROS levels
• Catalase: Catalase converts H2O2 into H2O+O. Inhibiting catalase can increase ROS levels
• SOD1: converts superoxide into hydrogen peroxide. Inhibiting SOD1 can increase ROS levels
• PI3K/AKT pathway: regulates cell survival and metabolism. Inhibiting can increase ROS levels
HIF-1α inhibition: regulates genes involved in metabolism and angiogenesis. Inhibiting HIF-1α can increase ROS
• Glycolysis: Inhibiting glycolysis can increase ROS levels • Fatty acid oxidation: Cancer cells often rely on fatty acid oxidation for energy production.
-Inhibiting fatty acid oxidation can increase ROS levels
• ER stress: Endoplasmic reticulum (ER) stress can increase ROS levels
• Autophagy: process by which cells recycle damaged organelles and proteins.
-Inhibiting autophagy can increase ROS levels and induce cancer cell death.
• KEAP1/Nrf2 pathway: regulates the expression of antioxidant genes.
    -Inhibiting KEAP1 or activating Nrf2 can increase ROS levels and induce cancer cell death.
• DJ-1: regulates the expression of antioxidant genes. Inhibiting DJ-1 can increase ROS levels
• PARK2: regulates the expression of antioxidant genes. Inhibiting PARK2 can increase ROS levels
SIRT1 inhibition:regulates the expression of antioxidant genes. Inhibiting SIRT1 can increase ROS levels
AMPK activation: regulates energy metabolism and can increase ROS levels when activated.
mTOR inhibition: regulates cell growth and metabolism. Inhibiting mTOR can increase ROS levels
HSP90 inhibition: regulates protein folding and can increase ROS levels when inhibited.
• Proteasome: degrades damaged proteins. Inhibiting the proteasome can increase ROS levels
Lipid peroxidation: a process by which lipids are oxidized, leading to the production of ROS.
    -Increasing lipid peroxidation can increase ROS levels
• Ferroptosis: form of cell death that is regulated by iron and lipid peroxidation.
    -Increasing ferroptosis can increase ROS levels
• Mitochondrial permeability transition pore (mPTP): regulates mitochondrial permeability.
    -Opening the mPTP can increase ROS levels
• BCL-2 family proteins: regulate apoptosis and can increase ROS levels when inhibited.
• Caspase-independent cell death: a form of cell death that is regulated by ROS.
    -Increasing caspase-independent cell death can increase ROS levels
• DNA damage response: regulates the repair of DNA damage. Increasing DNA damage can increase ROS
• Epigenetic regulation: process by which gene expression is regulated.
    -Increasing epigenetic regulation can increase ROS levels

-PKM2, but not PKM1, can be inhibited by direct oxidation of cysteine 358 as an adaptive response to increased intracellular reactive oxygen species (ROS)

ProOxidant Strategy:(inhibit the Mevalonate Pathway (likely will also inhibit GPx)
-HydroxyCitrate (HCA) found as supplement online and typically used in a dose of about 1.5g/day or more
-Atorvastatin typically 40-80mg/day, -Dipyridamole typically 200mg 2x/day Combined effect research
-Lycopene typically 100mg/day range (note debatable as it mainly lowers NRF2)

Dual Role of Reactive Oxygen Species and their Application in Cancer Therapy
ROS-Inducing Interventions in Cancer — Canonical + Mechanistic Reference
-generated from AI and Cancer database
ROS rating:  +++ strong | ++ moderate | + weak | ± mixed | 0 none
NRF2:        ↓ suppressed | ↑ activated | ± mixed | 0 none
Conditions:  [D] dose  [Fe] metal  [M] metabolic  [O₂] oxygen
             [L] light [F] formulation [T] tumor-type [C] combination

Item ROS NRF2 Condition Mechanism Class Remarks
ROS">Piperlongumine +++ [D][T] ROS-dominant
ROS">Shikonin +++↓/±[D][T]ROS-dominant
ROS">Vitamin K3 (menadione) +++[D]ROS-dominant
ROS">Copper (ionic / nano) +++[Fe][F]ROS-dominant
ROS">Sodium Selenite +++[D]ROS-dominant
ROS">Juglone +++[D]ROS-dominant
ROS">Auranofin +++[D]ROS-dominant
ROS">Photodynamic Therapy (PDT) +++0[L][O₂]ROS-dominant
ROS">Radiotherapy / Radiation +++0[O₂]ROS-dominant
ROS">Doxorubicin +++[D]ROS-dominant
ROS">Cisplatin ++[D][T]ROS-dominant
ROS">Salinomycin ++[D][T]ROS-dominant
ROS">Artemisinin / DHA ++[Fe][T]ROS-dominant
ROS">Sulfasalazine ++[C][T]ROS-dominant
ROS">FMD / fasting ++[M][C][O₂]ROS-dominant
ROS">Vitamin C (pharmacologic) ++[Fe][D]ROS-dominant
ROS">Silver nanoparticles ++±[F][D]ROS-dominant
ROS">Gambogic acid ++[D][T]ROS-dominant
ROS">Parthenolide ++[D][T]ROS-dominant
ROS">Plumbagin ++[D]ROS-dominant
ROS">Allicin ++[D]ROS-dominant
ROS">Ashwagandha (Withaferin A) ++[D][T]ROS-dominant
ROS">Berberine ++[D][M]ROS-dominant
ROS">PEITC ++[D][C]ROS-dominant
ROS">Methionine restriction +[M][C][T]ROS-secondary
ROS">DCA +±[M][T]ROS-secondary
ROS">Capsaicin +±[D][T]ROS-secondary
ROS">Galloflavin +0[D]ROS-secondary
ROS">Piperine +±[D][F]ROS-secondary
ROS">Propyl gallate +[D]ROS-secondary
ROS">Scoulerine +?[D][T]ROS-secondary
ROS">Thymoquinone ±±[D][T]Dual redox
ROS">Emodin ±±[D][T]Dual redox
ROS">Alpha-lipoic acid (ALA) ±[D][M]NRF2-dominant
ROS">Curcumin ±↑/↓[D][F]NRF2-dominant
ROS">EGCG ±↑/↓[D][O₂]NRF2-dominant
ROS">Quercetin ±↑/↓[D][Fe]NRF2-dominant
ROS">Resveratrol ±[D][M]NRF2-dominant
ROS">Sulforaphane ±↑↑[D]NRF2-dominant
ROS">Lycopene 0Antioxidant
ROS">Rosmarinic acid 0Antioxidant
ROS">Citrate 00Neutral


Scientific Papers found: Click to Expand⟱
5270- 5-ALA,  PDT,    5-Aminolevulinic Acid as a Theranostic Agent for Tumor Fluorescence Imaging and Photodynamic Therapy
- Review, Var, NA
other↝, ROS↑, other↝, mtDam↑, Ca+2↑, ER Stress↑, Apoptosis↑, TumAuto↑, other↝, Dose↝, Imm↑,
335- AgNPs,  PDT,    Biogenic Silver Nanoparticles for Targeted Cancer Therapy and Enhancing Photodynamic Therapy
- Review, NA, NA
ROS↑, GSH↓, GPx↑, Catalase↓, SOD↓, p38↑, BAX↑, Bcl-2↓,
5975- AgNPs,  PDT,  CDT,  RF,    Recent Advances in the Application of Silver Nanoparticles for Enhancing Phototherapy Outcomes
- Review, Var, NA - Review, BPH, NA
ROS↑, EPR↓, eff↑, Bacteria↓, eff↑, eff↑, TumVol↓,
4564- AgNPs,  GoldNP,  Cu,  Chemo,  PDT  Cytotoxicity and targeted drug delivery of green synthesized metallic nanoparticles against oral Cancer: A review
- Review, Var, NA
ROS↑, DNAdam↑, TumCCA↑, eff↑, Apoptosis↑, eff↓, ChemoSen↑,
2681- BBR,  PDT,    Berberine-photodynamic induced apoptosis by activating endoplasmic reticulum stress-autophagy pathway involving CHOP in human malignant melanoma cells
- in-vitro, Melanoma, NA
Apoptosis↑, cl‑Casp3↑, LC3s↑, ER Stress↑, ROS↑, CHOP↑,
1374- BBR,  PDT,    Berberine associated photodynamic therapy promotes autophagy and apoptosis via ROS generation in renal carcinoma cells
- in-vitro, RCC, 786-O - in-vitro, RCC, HK-2
ROS↑, TumAuto↑, Apoptosis↑, Casp3↑, eff↑,
2680- BBR,  PDT,    Photodynamic therapy-triggered nuclear translocation of berberine from mitochondria leads to liver cancer cell death
- in-vitro, Liver, HUH7
TumCD↑, ROS↑, TumCCA↑, ER Stress↑,
6069- CHL,  PDT,    Anti-Cancer Effect of Chlorophyllin-Assisted Photodynamic Therapy to Induce Apoptosis through Oxidative Stress on Human Cervical Cancer
- in-vitro, Cerv, HeLa
eff↑, ROS↑, Casp8↓, Casp9↑, BAX↑, Cyt‑c↑, Bcl-2↓, AKT1↓,
1175- IVM,  PDT,    Drug induced mitochondria dysfunction to enhance photodynamic therapy of hypoxic tumors
- in-vitro, Var, NA
Hypoxia↓, mitResp↓, ROS↑,
2533- M-Blu,  PDT,    Methylene blue-mediated photodynamic therapy enhances apoptosis in lung cancer cells
- in-vitro, Lung, A549
MMP↓, p‑MAPK↑, ROS↑, cl‑PARP↑, Bcl-2↓, Mcl-1↓, eff↓,
2534- M-Blu,  doxoR,  PDT,    Methylene Blue-Mediated Photodynamic Therapy in Combination With Doxorubicin: A Novel Approach in the Treatment of HT-29 Colon Cancer Cells
- in-vitro, CRC, HT-29
LDH↑, ROS↑,
1476- SFN,  PDT,    Enhancement of cytotoxic effect on human head and neck cancer cells by combination of photodynamic therapy and sulforaphane
- in-vitro, HNSCC, NA
eff↑, tumCV↓, ROS↑, eff↓, Casp↑,
1834- VitK3,  PDT,    Effects of Vitamin K3 Combined with UVB on the Proliferation and Apoptosis of Cutaneous Squamous Cell Carcinoma A431 Cells
- in-vitro, Melanoma, A431
eff↑, TumCG↓, TumCP↓, ROS↑, MMP↓,
1838- VitK3,  PDT,    Photodynamic Effects of Vitamin K3 on Cervical Carcinoma Cells Activating Mitochondrial Apoptosis Pathways
- in-vitro, Cerv, NA
eff↑, ROS↑, tumCV↓, TumCG↓, Apoptosis↑, cl‑Casp3↑, cl‑Casp9↑, Bcl-xL↑, Cyt‑c↑, Bcl-2↓,

Showing Research Papers: 1 to 14 of 14

* indicates research on normal cells as opposed to diseased cells
Total Research Paper Matches: 14

Pathway results for Effect on Cancer / Diseased Cells:


Redox & Oxidative Stress

Catalase↓, 1,   GPx↑, 1,   GSH↓, 1,   ROS↑, 14,   SOD↓, 1,  

Mitochondria & Bioenergetics

mitResp↓, 1,   MMP↓, 2,   mtDam↑, 1,  

Core Metabolism/Glycolysis

AKT1↓, 1,   LDH↑, 1,  

Cell Death

Apoptosis↑, 5,   BAX↑, 2,   Bcl-2↓, 4,   Bcl-xL↑, 1,   Casp↑, 1,   Casp3↑, 1,   cl‑Casp3↑, 2,   Casp8↓, 1,   Casp9↑, 1,   cl‑Casp9↑, 1,   Cyt‑c↑, 2,   p‑MAPK↑, 1,   Mcl-1↓, 1,   p38↑, 1,   TumCD↑, 1,  

Transcription & Epigenetics

other↝, 3,   tumCV↓, 2,  

Protein Folding & ER Stress

CHOP↑, 1,   ER Stress↑, 3,  

Autophagy & Lysosomes

LC3s↑, 1,   TumAuto↑, 2,  

DNA Damage & Repair

DNAdam↑, 1,   cl‑PARP↑, 1,  

Cell Cycle & Senescence

TumCCA↑, 2,  

Proliferation, Differentiation & Cell State

TumCG↓, 2,  

Migration

Ca+2↑, 1,   TumCP↓, 1,  

Angiogenesis & Vasculature

EPR↓, 1,   Hypoxia↓, 1,  

Immune & Inflammatory Signaling

Imm↑, 1,  

Drug Metabolism & Resistance

ChemoSen↑, 1,   Dose↝, 1,   eff↓, 3,   eff↑, 9,  

Clinical Biomarkers

LDH↑, 1,  

Functional Outcomes

TumVol↓, 1,  

Infection & Microbiome

Bacteria↓, 1,  
Total Targets: 47

Pathway results for Effect on Normal Cells:


Total Targets: 0

Scientific Paper Hit Count for: ROS, Reactive Oxygen Species
14 Photodynamic Therapy
3 Silver-NanoParticles
3 Berberine
2 Methylene blue
2 VitK3,menadione
1 5-Aminolevulinic acid
1 chemodynamic therapy
1 EMF
1 Gold NanoParticles
1 Copper and Cu NanoParticles
1 Chemotherapy
1 Chlorophyllin
1 Ivermectin
1 doxorubicin
1 Sulforaphane (mainly Broccoli)
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#:175  Target#:275  State#:%  Dir#:2
wNotes=0 sortOrder:rid,rpid

 

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