olaparib/LYNPARZA / ROS Cancer Research Results

OL, olaparib/LYNPARZA: Click to Expand ⟱
Features: PARP inhibitor

Olaparib

Olaparib (brand name Lynparza; developmental name AZD2281) is an orally active poly(ADP-ribose) polymerase (PARP) inhibitor used as an anticancer pharmaceutical. It inhibits PARP-mediated DNA repair and produces the greatest cytotoxicity in tumour cells with deficient homologous recombination repair, particularly cells carrying deleterious BRCA1 or BRCA2 alterations.

Classification

Field Information
Product type Pharmaceutical; targeted anticancer agent
Drug class PARP inhibitor
Primary targets PARP1, PARP2 and PARP3
Mechanistic category DNA-damage response inhibitor; synthetic-lethality agent
Common brand name Lynparza
Developmental name AZD2281

Major Mechanisms and Targets

Target or Process Direction Effect
PARP1 Down Inhibits catalytic activity and promotes PARP1 trapping on damaged DNA.
PARP2 Down Inhibits PARP2-dependent detection and repair of DNA strand breaks.
PARP3 Down Inhibits an additional PARP-family enzyme involved in the DNA-damage response.
Poly(ADP-ribosyl)ation / PARylation Down Reduces PARP-dependent modification and recruitment of DNA-repair proteins.
PARP–DNA complexes / PARP trapping Up Stabilizes cytotoxic PARP–DNA complexes that obstruct replication-fork progression.
Single-strand DNA-break repair Down Prevents efficient repair of DNA single-strand lesions.
Replication-fork stalling and collapse Up Unrepaired lesions and trapped PARP complexes impede DNA replication.
DNA double-strand breaks Up Replication of unrepaired DNA lesions produces potentially lethal double-strand breaks.
DNA damage Up Causes progressive accumulation of genomic lesions in susceptible tumour cells.
γH2AX Up Increases a marker of DNA double-strand-break signalling.
Homologous recombination repair dependence Up Forces damaged cells to depend more strongly on BRCA-mediated homologous recombination.
Synthetic lethality Up Selectively kills cells that combine PARP inhibition with deficient homologous recombination repair.
BRCA1/BRCA2-deficient cell survival Down HR-deficient cells cannot adequately repair olaparib-induced double-strand DNA breaks.
Genomic instability Up Increases chromosome and replication-associated damage beyond tolerable levels.
Cell-cycle arrest Up Activates DNA-damage checkpoints and inhibits progression through the cell cycle.
Apoptosis Up Induces programmed cell death following irreparable DNA damage.
Tumour-cell proliferation Down Suppresses proliferation, particularly in BRCA-mutated or HR-deficient tumour cells.
Tumour growth Down Reduces tumour growth in responsive preclinical and clinical settings.
Platinum sensitivity Up / predictive association Tumours with homologous-recombination defects may be sensitive to both platinum agents and PARP inhibition.

Biomarkers Associated with Response

Biomarker Association
BRCA1 mutation or loss Generally associated with increased olaparib sensitivity.
BRCA2 mutation or loss Generally associated with increased olaparib sensitivity.
Homologous recombination deficiency (HRD) May identify tumours with impaired double-strand-break repair and greater benefit.
Genomic instability Can serve as an indirect measure of historical homologous-recombination deficiency.
Platinum sensitivity Often correlates with PARP-inhibitor responsiveness but is not a definitive biomarker.

Resistance Mechanisms

Resistance Mechanism Effect
BRCA1/BRCA2 reversion mutations Restore the reading frame and homologous-recombination repair capacity.
Restoration of homologous recombination Allows repair of olaparib-induced double-strand DNA breaks.
Replication-fork stabilization Protects stalled replication forks from degradation and collapse.
Reduced PARP1 expression or altered PARP1 Can reduce formation of cytotoxic trapped PARP–DNA complexes.
Drug-efflux transporters Increased ABC transporter activity may lower intracellular olaparib exposure.
Loss of 53BP1 pathway activity May partially restore DNA-end resection and homologous recombination in BRCA1-deficient cells.

Clinical Cancer Applications

Depending on jurisdiction, tumour biomarkers, disease stage and prior therapy, olaparib is used in selected ovarian, fallopian-tube, primary peritoneal, breast, pancreatic and prostate cancers. Some indications require a germline or somatic BRCA1/2 alteration, homologous-recombination deficiency, or another qualifying homologous-recombination-repair alteration.

Typical Pharmaceutical Dose

A commonly used adult tablet regimen is 300 mg orally twice daily. Dose reduction, temporary interruption or discontinuation may be required for toxicity, renal impairment or clinically significant drug interactions. Olaparib capsules and tablets are not milligram-for-milligram interchangeable.

Major Adverse Effects and Precautions

  • Anaemia, neutropenia, leukopenia and thrombocytopenia
  • Nausea, vomiting, diarrhoea, dyspepsia and reduced appetite
  • Fatigue or asthenia
  • Headache and dizziness
  • Elevated serum creatinine related partly to transporter inhibition
  • Rare but serious myelodysplastic syndrome or acute myeloid leukaemia
  • Rare pneumonitis
  • Embryo-fetal toxicity
  • Potential clinically significant CYP3A-mediated drug interactions

Summary

Olaparib inhibits PARP catalytic activity and traps PARP proteins on damaged DNA. This suppresses DNA strand-break repair, obstructs replication forks and increases double-strand DNA breaks. Tumour cells with defective BRCA-dependent homologous recombination cannot adequately repair this damage, producing synthetic lethality, cell-cycle arrest and apoptosis. Olaparib should therefore be classified primarily as a PARP1/PARP2 inhibitor, PARP-trapping agent, DNA-repair inhibitor and synthetic-lethality pharmaceutical.



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)
ROS Homeostasis in Cancer Cells and Its Potential as a Therapeutic Target

"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⟱
7033- GA,  OL,    Gallic Acid Enhances Olaparib-Induced Cell Death and Attenuates Olaparib Resistance in Human Osteosarcoma U2OS Cell Line
- in-vitro, OS, U2OS
tumCV↓, angioG↓, DNAdam↑, Apoptosis↑, cl‑PARP↓, Bcl-2↓, BAX↑, ROS↓, eff↑, TumCMig↓, VEGF↓, Casp9↑, P53↑, selectivity↑,

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(tgid=1)

ROS↓, 1,  

Cell Death(tgid=5)

Apoptosis↑, 1,   BAX↑, 1,   Bcl-2↓, 1,   Casp9↑, 1,  

Transcription & Epigenetics(tgid=7)

tumCV↓, 1,  

DNA Damage & Repair(tgid=10)

DNAdam↑, 1,   P53↑, 1,   cl‑PARP↓, 1,  

Migration(tgid=13)

TumCMig↓, 1,  

Angiogenesis & Vasculature(tgid=14)

angioG↓, 1,   VEGF↓, 1,  

Drug Metabolism & Resistance(tgid=21)

eff↑, 1,   selectivity↑, 1,  
Total Targets: 14

Pathway results for Effect on Normal Cells:


Total Targets: 0

Scientific Paper Hit Count for: ROS, Reactive Oxygen Species
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#:426  Target#:275  State#:%  Dir#:1
wNotes=0 sortOrder:rid,rpid

 

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