condition found tbRes List
dietMet, diet Methionine-Restricted Diet: Click to Expand ⟱
Features:
Methionine (MET) restriction (MR) has been shown to arrest cancer growth and sensitizes tumors to chemotherapy.
-Many cancer cells rely heavily on exogenous methionine to sustain rapid growth and proliferation because they often have impaired methionine salvage pathways.
-Methionine contributes to the synthesis of glutathione, a key antioxidant. (Methionine is a precursor of glutathione, a tripeptide that reduces reactive oxygen species.)
-MR diets might influence the redox state of cancer cells, increasing oxidative stress and thereby leading to cell death in metabolically compromised tumor cells.
-Proliferation and growth of several types of cancer cells are inhibited by MR, while normal cells are unaffected by limiting methionine as long as homocysteine is present.
-Methionine restriction is effective when the non-essential amino acid, cysteine, is absent from the diet or media. methionine is the precursor for cysteine which is essential for the formation of GSH.
-Malignant cells lack the enzyme required to recycle homocysteine therefore giving methionine restriction the capacity to alter cancer cells while maintaining normal, healthy cells.

While vegan diets are typically low in methionine, some nuts and legumes (such as Brazil nuts and kidney beans) are rich in methionine.

Foods to avoid for MR diet:
Animal Proteins:
-Red Meat (Beef, Pork, Lamb):
-Poultry (Chicken, Turkey):
-Fish and Seafood:
-Eggs: Both the egg whites and yolks are protein rich.
-Dairy Products: Milk, cheese, and yogurt
Certain Plant Proteins:
-Soy Products:
-Legumes:
Protein Supplements:

Foods Lower in Methionine (Often Favorable on an MR Diet)
Fruits & Vegetables: leafy greens, berries, apples, and citrus fruits.
Grains & Cereals: rice, oats, and barley
Nuts and Seeds: can vary in methionine content.
Alternative Protein Sources: emphasize protein sources with a lower methionine-to-cysteine ratio.
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.

"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: 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: 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:regulates the expression of antioxidant genes. Inhibiting SIRT1 can increase ROS levels
• AMPK: regulates energy metabolism and can increase ROS levels when activated.
• mTOR: regulates cell growth and metabolism. Inhibiting mTOR can increase ROS levels
• HSP90: 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 Melavonate 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
-Lycopene typically 100mg/day range

Dual Role of Reactive Oxygen Species and their Application in Cancer Therapy

Scientific Papers found: Click to Expand⟱
2273- dietMet,    Methionine and cystine double deprivation stress suppresses glioma proliferation via inducing ROS/autophagy
- in-vitro, GBM, U87MG - in-vitro, GBM, U251 - in-vivo, NA, NA
ROS↑, Met-Cys double deprivation had synergistic action on elevating ROS level, decreased GSH level and inhibition of glioma cell proliferation.
GSH↓,
TumCP↓,
TumAuto↑, triggered autophagy of glioma cells both in vitro and in vivo
LC3II↑, Met-Cys deprivation strongly gave rise to the formation of the autophagosome and increased LC3-II protein expression, both of which are autophagy related indicators

2272- dietMet,    Methionine restriction - Association with redox homeostasis and implications on aging and diseases
- Review, Nor, NA
*OS↑, MR seems to be an approach to prolong lifespan which has been validated extensively in various animal models
*mt-ROS↓, Mitochondrial ROS reduction by methionine restriction (MR) maintains redox balance
*H2S↑, MR ameliorates oxidative stress by autophagy activation and hepatic H2S generation.
*FGF21↑, MR impact on cognition by upregulation of FGF21 and alterations of gut microbiome.
*cognitive↑,
*GutMicro↑,
*IGF-1↓, long-term, low-fat, whole-food vegan diet may increase life expectancy in humans by down-regulating IGF-I activity
*mTOR↓, Suppression of the mTOR pathway by MR can also lead to increased H2S production,
*GSH↑, 80% MR increases the GSH content in erythrocytes of rats,
*SOD↑, A diet restricting methionine to 80% (0.17% Met) significantly increases plasma SOD and decreases MDA levels while increasing mRNA expression of Nrf2, HO-1, and NQO-1 in the heart of HFD-fed mice with cardiovascular impairment
*MDA↓,
*NRF2↑,
*HO-1↑,
*NQO1↑,
*GLUT4↑, In skeletal muscle, MR improved expression and transport of GLUT4 and glycogen levels and increased the expression of glycolysis-related genes (HK2, PFK, PKM) in HFD-fed mice
*Glycolysis↑,
*HK2↑,
*PFK↑,
*PKM2↑,
*GlucoseCon↑, promoting glucose uptake and glycogen synthesis, glycolysis, and aerobic oxidation in skeletal muscle.
*ATF4↑, MR can increase the expression of hepatic FGF21 by activating GCN2/ATF4/PPARα signaling in liver cells, thereby improving insulin sensitivity, accelerating energy expenditure, and promoting fat oxidation and glucose metabolism
*PPARα↑,
GSH↓, MR was able to decrease GSH in HepG2 cells, thereby regulating the activation state of protein tyrosine phosphatases such as PTEN.
GSTs↑, decrease of GSH by MR also triggers upregulation of glutathione S-transferase
ROS↑, Double deprivation of methionine and cystine both in vitro and in vivo resulted in a decrease in GSH content, an increase in ROS levels, and an induction of autophagy in glioma cells
*neuroP↑, A neuroprotective role of FGF21

2271- dietMet,    A review of methionine dependency and the role of methionine restriction in cancer growth control and life-span extension
- Review, Nor, NA
*eff↑, The development of methioninase which depletes circulating levels of methionine may be another useful strategy in limiting cancer growth.
*OS↓, methionine restricted diet have reported inhibition of cancer growth and extension of a healthy life-span.
*ROS↓, 40% dietary methionine restriction in male Wistar rats decreases production of ROS in the brain and kidney mitochondria without inhibition of body weight gain which may occur at 80% dietary methionine restriction
*Weight↓, These data suggest that methionine restriction in humans is relatively safe and tolerable over a period of 18 weeks, but the consequences of further weight loss in such cancer patients have not been explored

2267- dietMet,    Role of amino acids in regulation of ROS balance in cancer
- Review, Var, NA
TumCG↓, Indeed, restriction of methionine, which is an essential amino-acid, decreases tumor-growth in patient-derived xenograft mouse models of colorectal cancer by affecting the 1-C metabolism.
GSH↓, Interestingly, methionine restriction leads to a decrease in GSH pool and consequently to a ROS imbalance that affects tumor cell proliferation and can be alleviated by antioxidant treatment.
ROS↑,

2266- dietMet,    Cysteine dietary supplementation reverses the decrease in mitochondrial ROS production at complex I induced by methionine restriction
- in-vivo, Nor, NA
*ROS↓, decrease in mitochondrial ROS generation induced by methionine restriction at complex I
eff↓, results obtained in liver showed that cysteine supplementation reverses the decrease in mitochondrial ROS generation induced by methionine restriction

2264- dietMet,    Methionine restriction for cancer therapy: From preclinical studies to clinical trials
- Review, Var, NA
TumCP↓, methionine restriction (MR) reduces cancer cell proliferation via different mechanisms
*ROS?, MR lowers sulfur-containing metabolite levels, reduces oxidative stress, and enhances the immune response
ChemoSen↑, may sensitize tumors to chemo/radiotherapy
RadioS↑,
eff↑, therapeutic potential of MR lies in its ability to synergize with other therapies, enhancing overall antitumor efficacy.
ROS↑, increases ROS, weaking cancer cell defense (from graphical abstract). In colon cancer, MR increases oxidative stress, induces cell cycle arrest, and promotes the apoptosis of p53(Tumor Protein 53)-deleted cells
selectivity↑, methionine-depleted media significantly impaired the growth of malignant cells while leaving normal cell growth unchanged.
TS↓, MR also targets thymidylate synthase (TS), a key enzyme in nucleotide synthesis, enhancing the chemotherapeutic efficacy of 5-FU by lowering TS activity and expression
eff↑, duration of methionine deprivation can significantly affect the tumor cell response. Intermittent methionine deprivation appears particularly beneficial, enhancing tumor cell sensitivity to CD8+ T cell-mediated cytotoxicity

2263- dietMet,    Methionine Restriction and Cancer Biology
- Review, Var, NA
AntiCan↑, dependence of many tumor cells on an exogenous source of the sulfur amino acid, methionine, [9,10,11] makes dietary methionine restriction (MR) an exciting potential tool in the treatment of cancer.
TumCP↓, Proliferation and growth of several types of cancer cells are inhibited by MR,
TumCG↓,
selectivity↑, while normal cells are unaffected by limiting methionine as long as homocysteine is present
ChemoSen↓, MR has been shown to enhance efficacy of chemotherapy and radiation therapy in animal models
RadioS↑,
Insulin↓, MR may work by inhibiting prostate cancer cell proliferation, inhibiting the insulin/IGF-1 axis
*GlucoseCon↑, increase in tissue-specific glucose uptake measured during a hyperinsulinemic-euglycemic clamp
*ROS↓, MR does not increase oxidative stress, in part because MR enhances antioxidant capacity and increases proton leak in the liver, likely decreasing ROS production
*antiOx↑,
*GSH↑, ability of MR to increase GSH levels in red blood cells. Surprisingly, when methionine was restricted by 80% in the diet of rats, the level of GSH in the blood actually increased due to adaptations in sulfur-amino acid metabolism
GSH↑, However, GSH concentrations were reduced in the liver
eff↑, Of note, methionine restriction is effective when the non-essential amino acid, cysteine, is absent from the diet or media.
polyA↓, MR may work by inhibiting prostate cancer cell proliferation, inhibiting the insulin/IGF-1 axis, or by reducing polyamine synthesis. MR-induced depletion of polyamines
TS↓, MR selectively reduces TS activity in prostate cancer cells by ~80% within 48 h, but does not affect TS activity in normal prostate epithelial cells
Raf↓, MR inhibits Raf and Akt oncogenic pathways, while increasing caspase-9 and the mitochondrial pro-apoptotic protein, Bak
Akt↓,
Casp9↑,
Bak↑,
P21↑, MR upregulating p21 and p27 (cell cycle inhibitors that halt cell cycle progression) in LNCaP cells
p27↑,
Insulin↓, MR-induced reduction in circulating insulin and IGF1, which have both been linked to tumor growth
IGF-1↓,


* indicates research on normal cells as opposed to diseased cells
Total Research Paper Matches: 7

Results for Effect on Cancer/Diseased Cells:
Akt↓,1,   AntiCan↑,1,   Bak↑,1,   Casp9↑,1,   ChemoSen↓,1,   ChemoSen↑,1,   eff↓,1,   eff↑,3,   GSH↓,3,   GSH↑,1,   GSTs↑,1,   IGF-1↓,1,   Insulin↓,2,   LC3II↑,1,   P21↑,1,   p27↑,1,   polyA↓,1,   RadioS↑,2,   Raf↓,1,   ROS↑,4,   selectivity↑,2,   TS↓,2,   TumAuto↑,1,   TumCG↓,2,   TumCP↓,3,  
Total Targets: 25

Results for Effect on Normal Cells:
antiOx↑,1,   ATF4↑,1,   cognitive↑,1,   eff↑,1,   FGF21↑,1,   GlucoseCon↑,2,   GLUT4↑,1,   Glycolysis↑,1,   GSH↑,2,   GutMicro↑,1,   H2S↑,1,   HK2↑,1,   HO-1↑,1,   IGF-1↓,1,   MDA↓,1,   mTOR↓,1,   neuroP↑,1,   NQO1↑,1,   NRF2↑,1,   OS↓,1,   OS↑,1,   PFK↑,1,   PKM2↑,1,   PPARα↑,1,   ROS?,1,   ROS↓,3,   mt-ROS↓,1,   SOD↑,1,   Weight↓,1,  
Total Targets: 29

Scientific Paper Hit Count for: ROS, Reactive Oxygen Species
7 diet Methionine-Restricted Diet
Filter Conditions: Pro/AntiFlg:%  IllCat:%  CanType:%  Cells:%  prod#:292  Target#:275  State#:%  Dir#:%
  wNotes=on  sortOrder:rid,rpid

 

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