Ferroptosis: Exploiting Cancer’s Addiction to Iron

In pivotal research published in 2004 and again in 2023, many contemporary cancer drugs were shown to have little impact on enhancing the quality of life or prolonging the lives of those with metastatic cancer (click here and click here). Advanced-stage cancer is often associated with reduced survival rates because alternative approaches are limited when cancer cells evolve and acquire multi-drug resistance. Therefore, there is an urgent need to develop new treatment methods. Fortunately, scientists are constantly researching new ways to treat cancer. One potentially promising approach is targeting iron metabolism.

Oxidative stress manipulation in cancer treatment:

Ferroptosis is a form of programmed cell death driven by the accumulation of reactive oxygen species (ROS), specifically lipid peroxides caused by iron-dependent oxidative stress. Inducing ferroptosis to amplify tumor-associated ROS is being explored as a strategy to improve anticancer therapy due to the unique metabolic and oxidative stress conditions of cancer cells and cancer stem cells. Here’s how this strategy can potentially enhance the effectiveness of cancer treatment:

1. Increased vulnerability of cancer cells: Cancer cells often have higher levels of ROS compared to normal cells due to their rapid proliferation and altered metabolism. While they develop mechanisms to survive this oxidative stress, they are also more vulnerable to further oxidative damage. By amplifying ROS levels using ferroptosis, it’s possible to push the cancer cells beyond their survival threshold, leading to cell death.
2. Enhanced efficacy of therapeutics: Many chemotherapy drugs and radiation therapy work by inducing oxidative stress in cancer cells. Increasing tumor-associated ROS can magnify the oxidative damage caused by these treatments, leading to enhanced cell death. This means potentially lower doses of chemotherapy could be used, reducing side effects while maintaining or improving therapeutic outcomes.
3. Disruption of redox homeostasis: Cancer cells tightly regulate their internal redox balance to survive the high levels of ROS. Disrupting this balance can lead to malfunctioning of cellular processes, cell-cycle arrest, and apoptosis. Agents that specifically target and disrupt the redox homeostasis in cancer cells can selectively kill them without harming normal cells.
4. Stimulation of immune response: High levels of ROS can lead to increased presentation of tumor antigens and stimulation of an immune response. This can make tumor cells more recognizable and attackable by the immune system. When used in combination with immunotherapies, amplifying ROS could potentially improve the recognition and destruction of cancer cells.
5. Targeting cancer stem cells: Cancer stem cells are a subpopulation within tumors that can drive metastasis and cancer recurrence. They are usually resistant to conventional therapies. Increasing ROS may specifically target these cells, which are believed to have lower antioxidant capacities compared to the bulk tumor cells.
6. Overcoming drug resistance: Resistance to chemotherapy is a significant challenge in cancer treatment. It’s thought that by modulating ROS levels, it might be possible to sensitize cancer cells to drugs they previously resisted, potentially reversing or preventing resistance mechanisms.

Ferroptosis as a new frontier in cancer therapy:

Cancer cells have been shown to have much higher iron requirements to the point of being called “iron addiction” by leading scientists. Cancer cells grow and divide faster than normal cells. To support this rapid growth and cellular division, cancer cells have to take in much more iron than normal cells. This extreme need for iron plays a central role in the following activities:

1. Increased proliferation: Cancer cells divide and grow rapidly, leading to a higher demand for iron, which is essential for DNA synthesis and cell division.
2. Enhanced metabolic activity: Cancer cells have a high metabolic rate and require iron to produce energy through processes such as glycolysis and mitochondrial respiration.
3. Iron-dependent enzymes: Cancer cells rely on iron-dependent enzymes, such as ribonucleotide reductase, for DNA replication and repair. Increased activity of these enzymes contributes to cancer cell survival and proliferation.
4. Role in angiogenesis: Iron is necessary for the formation of new blood vessels (angiogenesis), which supply tumors with nutrients and oxygen, enabling their growth and spread.
5. Immune evasion: High levels of iron can suppress the immune system, allowing cancer cells to evade immune surveillance and escape destruction by immune cells.
6. Iron-dependent gene regulation: Iron can influence the expression of genes involved in cell growth, differentiation, and survival, contributing to cancer cell growth and maintenance.
7. Epithelial-mesenchymal transition (EMT): Iron can promote EMT, a process through which cancer cells acquire invasive and metastatic properties.

Researchers are exploring ways to therapeutically exploit this “Achilles’ heel” of iron dependency through a process called ferroptosis. The prefix “ferro” is derived from the Latin word “ferrum,” meaning iron. The suffix “ptosis” is derived from the Greek word “ptosis,” meaning a falling or dropping. This suffix is used in various terms that describe different types of cell death processes, such as apoptosis. First discovered in 2003 and later named in 2012, ferroptosis is an iron-mediated, pro-oxidative form of programmed cell death that is distinct from apoptosis.

With ferroptosis, when excess iron accumulates in cancer cells, it can oxidize unsaturated fatty acids in the cell membrane and form lethal lipid peroxides. If there are insufficient antioxidants to neutralize these peroxides, the integrity of the lipid membrane is compromised, which leads to the death of the cells if the damage is not repaired.

The potential of ferroptosis induction in managing aggressive and metastatic cancers is gaining attention. This approach can diminish cancer’s resistance to traditional treatments like chemotherapy, radiation, and immunotherapy. It holds significant promise, particularly for cancer stem cells, which are pivotal in metastasis, treatment resistance, and cancer recurrence. These cells depend extensively on iron, rendering them more vulnerable to ferroptosis. Hence, focusing on ferroptosis could be an essential tactic in tackling difficult-to-treat cancers.

Ferroptosis essentially allows us to exploit cancer’s love of iron and turn it into its worst nightmare. The protocol below is designed to take therapeutic advantage of this vulnerability and eliminate both cancer cells and cancer stem cells by inducing oxidative damage to their lipid membranes. All components of the protocol are done simultaneously. The scientific rationale is supported by the extensive references listed at the bottom. 

Ferroptosis protocol:

1. Promote iron overload: Increase the amount of free (unbound) and ferroptosis-inducing iron in cancer cells and cancer stem cells by a) upregulating transferrin receptors to escalate iron inflow and downregulating ferroportin receptors to restrict iron outflow using a compound called ruscogenin found in the herb Butcher’s Broom; and b) using artemisinin to stimulate ferritinophagy, a process that releases iron bound to ferritin—a protein that cancer cells use to sequester excess iron.
2. Impair antioxidant defenses: To protect themselves from the deadly consequences of ferroptosis, cancer cells have a robust antioxidant defense system. To block cancer’s ability to neutralize oxidative stress from ferroptosis, cancer’s chief protective antioxidants (glutathione and thioredoxin) must be impaired. Also, a backup system called ferroptosis suppressor protein 1 (FSP1) must be blocked. To inhibit glutathione synthesis, sulfasalazine is used. To inhibit thioredoxin, we use piperlongumine. To inhibit the CoQ10-dependent ferroptosis suppressor protein, we use simvastatin. 
3. Target tumor hypoxia: Due to inadequate blood flow, many parts of a tumor don’t get enough oxygen. This is called tumor hypoxia, and the lack of oxygen activates a protein called hypoxia-inducible factor-1 alpha (HIF-1α). When HIF-1α is active, it makes cancer cells resistant to ferroptosis. Hypoxia alleviation and inhibition of HIF-1α sensitizes cancer cells to ferroptosis. To improve tumor oxygenation, pentoxifylline is used. To inhibit HIF-1α, disulfiram is used and is augmented with superoxide dismutase (SOD) to boost the anti-cancer performance of disulfiram.
4. Downregulate anti-ferroptotic gene expression: Nuclear factor erythroid 2-related factor 2 (Nrf2) is a key transcription factor that regulates the expression of genes involved in cellular antioxidant responses. The Nrf2 pathway acts as a cellular defense mechanism against ferroptotic cell death. When activated, Nrf2 promotes the transcription of genes that facilitate the reduction of lipid peroxides and manage intracellular iron levels, thereby mitigating the conditions that lead to ferroptosis. We use Brucea javanica fruit extract which contains a natural compound called brusatol. Brusatol has garnered interest for its various antitumor properties resulting from downregulating the Nrf2 pathway.
5. Saturate cell membranes with polyunsaturated fatty acids: For ferroptosis to occur, there must be an abundance of unsaturated fatty acids in the membranes of cancer cells. These unsaturated fatty acids contain numerous carbon-carbon double bonds vulnerable to oxidation. The susceptibility to oxidation increases with the number of double bonds in a lipid. Therefore, cell membranes rich in saturated fatty acids (SFAs) with no double bonds, or monounsaturated fatty acids (MUFAs) with a single double bond, are more resistant to ferroptosis compared to membranes containing an abundance of polyunsaturated fatty acids (PUFAs) with 2 to 6 double bonds. PUFAs are highly susceptible to oxidative damage whereas MUFAs and SFAs are resistant. As such, diets high in PUFAs have been found to promote ferroptosis, whereas diets high in MUFAs and SFAs have been found to inhibit ferroptosis.

Here is a list of prominent sources of PUFAs:

Oils:
Corn oil
Fish oils (especially from salmon, mackerel, herring, and sardines; consume as little as possible)
Flaxseed oil
Grapeseed oil
Hempseed oil
Safflower oil
Soybean oil
Sunflower oil
Walnut oil

Nuts and seeds:
Chia seeds
Flaxseeds
Hemp seeds
Pine nuts
Pumpkin seeds
Sunflower seeds
Walnuts

Animal protein (eat as little as possible):
Fatty fish (salmon, mackerel, herring, and sardines)
Grass-fed beef
Skinless organic chicken

Here is a list of foods that are rich in MUFAs and/or SFAs that need to be avoided:

Oils:
Almond oil
Avocado oil
Canola oil
Cocoa butter
Coconut oil
Hazelnut oil
Macadamia nut oil
Olive oil
Palm oil
Peanut oil

Nuts and seeds:
Almonds
Brazil nuts
Cashews
Cocoa beans/seeds
Hazelnuts
Macadamia nuts
Peanuts
Pecans
Pistachios
Sesame seeds

Foods:
Avocados
Chocolate (due to cocoa butter content)
Dairy products (milk, cheese, butter, yogurt, ice cream, sour cream, cottage cheese, cream cheese)
Eggs
Corn-feed beef
Olives
Pork

In addition to incorporating more PUFAs into the diet and avoiding MUFAs and SFAs, to further promote ferroptosis, we incorporate the polyunsaturated fat called gamma-linolenic acid (GLA) from borage oil. GLA is converted in the body to dihomo-gamma-linolenic acid (DGLA) by the enzyme delta-6-desaturase. DGLA is a potent inducer of ferroptosis.

Lastly, besides avoiding exogenous (dietary) MUFAs, it is equally important to target endogenous (internally-produced) MUFAs. Stearoyl-CoA desaturase-1 (SCD-1) is the enzyme that catalyzes the synthesis of MUFAs from SFAs from the diet or made by the liver. SCD-1 helps shift the cellular lipid membrane towards a higher proportion of MUFAs, which are more resistant to oxidation. By doing so, SCD-1 reduces the pool of oxidation-prone PUFAs and thus inhibits ferroptosis. To help overcome this, we reduce endogenous MUFAs by using sterculic acid to inhibit SCD-1.

6. Inhibit membrane-repair mechanism: When there’s a disruption in the cell membrane, cells employ several mechanisms to promptly repair the damage. A chief repair mechanism is the Endosomal Sorting Complex Required for Transport-III (ESCRT-III) system. The components of the ESCRT-III system quickly localize to the site of membrane damage, where they facilitate the removal of the damaged portions of the membrane. This action helps to restore the membrane’s integrity. By effectively repairing disruptions in the cell membrane, the ESCRT-III system prevents prolonged membrane damage that can drive the cell toward ferroptotic death. Hence, a functional ESCRT-III system can enhance the resistance of cancer cells to ferroptosis-inducing agents and conditions. To promote ferroptotic cell death, we use tauroursodeoxycholic acid to inhibit the ESCRT-III membrane-repair system.
7. Augment ferroptosis using oral ozonated oil: Ozonated oil has very high ozonide levels that are extremely pure, highly bioavailable, and devoid of antioxidants. These ozonides have been found to increase the level of oxidative stress in cancer cells and cancer stem cells, causing irreparable damage to the cell membrane and mitochondria, the release of intracellular calcium, and activation of apoptosis. Additionally. ozone oil has been shown to a) increase oxygen tissue availability, thereby counteracting angiogenesis and metastasis triggered by tumor hypoxia, b) decrease inflammation, c) promote immune destruction of cancer cells by inhibiting tumor-associated macrophages (TAMs), and d) improve the quality of life of those receiving chemotherapy or radiation therapy.

To help visualize all of this, think of ferroptosis as a cellular “house fire.” Iron is the spark that ignites the fire. PUFAs are the combustible fuel that is consumed by the fire. Antioxidants are the firemen at the scene and sending them home allows the fire to rage on. And the membrane-repair mechanisms are the emergency reconstruction crew that quickly rebuilds and restores damaged structures to their original state.

The lymphatic system and ferroptosis connection:

Cancer patients rarely die from the original (primary) tumor but rather from the metastases (secondary tumors). These secondary tumors often invade vital organs, disrupting their life-sustaining functions. Cancer cells can spread to other parts of the body early in the disease when the primary tumor is still very small and may not have been discovered yet.

The lymphatic system is an extensive network of vessels and nodes that carry a clear fluid called lymph that plays a crucial role in the body’s immune response. The lymphatic system also plays a role in the spread of metastatic cancer cells, both to the bloodstream and to new (secondary) sites. Here’s how it typically works:

1. Transport to new sites through the lymphatic system: Cancer cells and cancer stem cells can break away from the primary tumor and enter lymph vessels. The lymphatic system can then transport these cells to nearby lymph nodes. If the cells are not destroyed in the lymph nodes, they can continue to travel through the lymphatic system to other parts of the body, forming new (secondary) tumors.
2. Entering the bloodstream: While the primary role of the lymphatic system is to transport lymph, it can also be a pathway for cancer cells to enter the bloodstream. This happens when metastatic cancer cells, having traveled through the lymphatic system and potentially multiplied in lymph nodes, find their way into the bloodstream. Once in the bloodstream, these cells can travel to distant organs and tissues, establishing new sites of cancer.

Here are the types of cancer that are known to spread through the lymphatic system:

1. Bladder
2. Breast
3. Cervical
4. Colorectal
5. Endometrial (uterine)
6. Gastric (stomach)
7. Head and neck
8. Lung
9. Lymphoma
10. Melanoma
11. Ovarian
12. Prostate
13. Testicular

The above cancers tend to metastasize regionally through the lymphatic system before they enter the bloodstream and metastasize systemically. Exposure to lymph fluid has been found to protect cancer cells from ferroptosis and increase their ability to survive during subsequent emergence to secondary tumor sites and further metastasis upon entering the bloodstream. Differences between lymph fluid and blood plasma that contribute to this are the high levels of ferroptosis-inhibiting glutathione and MUFAs (such as oleic acid), along with much lower iron levels in the lymph fluid. To help induce ferroptosis, it is important to decrease the ability of metastasizing cancer cells to utilize the lymphatic system.

To help suppress the metastatic potential of the cancer cells via the lymphatic system and promote ferroptosis, artemisinin and disulfiram are used. Artemisinin inhibits vascular endothelial growth factor C (VEGF-C). VEGF-C plays a significant role in lymphangiogenesis, which is the formation of new lymphatic vessels, crucial for the lymphatic spread of cancer. Disulfiram has been found to inhibit transforming growth factor-β-induced protein (TGFBIp). TGFBIp increases the permeability of lymph vessels allowing cancer cells to enter the lymphatic system more easily. Inhibition of TGFBIp in cancer cells has been shown to dramatically reduce tumor metastasis.

Iron and copper: Dual executioners of cancer cells and cancer stem cells:

Normal cells need small amounts of copper to be able to carry out vital biological processes. Cancer cells and cancer stem cells, on the other hand, are greatly dependent on copper and contain much higher levels than normal cells. Copper is a critical component for cancer cell growth and proliferation. However, if copper levels are increased beyond tolerable limits (i.e., copper overload), it can induce multiple forms of cell death, including apoptosis and autophagy, as well as promote ferroptosis.

Also known as cuproptosis (from the Latin “cuprum,” meaning copper), copper overload increases reactive oxygen species (ROS), and if there are insufficient levels of protective antioxidants (glutathione and thioredoxin reductase), this can lead to excessive oxidative stress, irreparable damage to the mitochondria and DNA of tumor cells, apoptotic and autophagic cell death, and like with ferroptosis, lethal peroxidation of the lipid membrane.

Excess copper can also lead to the demise of tumor cells by proteasome inhibition. This refers to the process of blocking the activity of proteasomes, which are protein complexes in cells that degrade unneeded or damaged proteins by proteolysis, a chemical reaction that breaks peptide bonds. Proteasomes play a crucial role in maintaining the cell’s homeostasis (balance) by regulating the concentration of specific proteins and degrading misfolded proteins. In the context of cancer, proteasome inhibition can be a therapeutic strategy for several reasons, including:

1. Cancer cell proliferation: Cancer cells often have high levels of protein synthesis as they rapidly divide and grow. They rely heavily on the proteasome for the degradation of these proteins. Inhibiting the proteasome can lead to the accumulation of damaged and misfolded proteins, which can trigger cell stress and eventually lead to cell death (apoptosis). This is particularly effective against cancer cells because they are typically more sensitive to stress on their protein-degradation systems compared to normal cells.
2. Regulation of cell cycle and apoptosis: Proteasomes degrade various cell-cycle regulatory proteins and proteins involved in apoptosis. By inhibiting proteasomes, these regulatory proteins can accumulate, leading to cell cycle arrest (stopping cell division) and the induction of programmed cell death, both of which are beneficial in the treatment of cancer.
3. Resistance to chemotherapy: Some cancer cells develop resistance to chemotherapy drugs. Proteasome inhibitors can help overcome this resistance and can be used in combination with other chemotherapeutic agents to enhance their efficacy.

Disulfiram serves as an ionophore (ion carrier) that binds to copper ions and carries them into cancer cells, thereby increasing the intracellular level of copper leading to copper overload. For maximum anti-cancer efficacy, studies have shown that high and potentially toxic doses of copper must be administered with disulfiram. Fortunately, new data has shown that exogenous superoxide dismutase (SOD), through its generation of extracellular hydrogen peroxide (H₂O₂), promotes the anti-cancer activity of disulfiram without having to co-administer copper.

In summary, the strategic manipulation of copper and iron levels within cancer cells and cancer stem cells is merging as a potentially promising avenue for cancer therapy. While normal cells require minimal amounts of copper and iron for essential functions, cancer cells possess a heightened dependency on these metals, making them vulnerable to copper- and iron-mediated toxicity. Excess copper triggers a cascade of deleterious events in cancer cells, including increased reactive oxygen species, lipid peroxidation, mitochondrial and DNA damage, and proteasome inhibition, ultimately leading to various forms of cell death.

The use of disulfiram and superoxide dismutase presents a novel approach to enhance copper’s cytotoxic effects on cancer cells without necessitating high, potentially harmful doses of copper. This innovative strategy underscores the intricate balance between essential nutrient requirements and cellular toxicity, offering a unique therapeutic opportunity to target the Achilles’ heel of cancer cells and stem cells with more precision and efficacy.

Ferroptosis, immunogenic cell death, and hyperthermia:

Successful antitumor immunity typically provides systemic protection effect against untreated tumors and plays a vital role in attacking metastatic tumors, preventing tumor recurrence, and maintaining a long-term antitumor effect. Immunogenic cell death (ICD) is a form of cell death in cancer cells that triggers an immune response against the dying cells. When cancer cells undergo ICD, they release specific molecules known as damage-associated molecular patterns (DAMPs). These DAMPs act as signals to the immune system, specifically attracting dendritic cells which engulf the dying cancer cells. Following this, the dendritic cells process the cancer cell antigens and present them to T-cells, effectively “educating” the T-cells about the cancer. This process results in the activation and proliferation of T-cells that can recognize and attack similar cancer cells throughout the body. ICD not only eliminates the initial cancer cells but also primes the immune system to fight against potential future cancerous growths.

Recent studies have suggested a connection between ferroptosis and the induction of immunogenic cell death (ICD). Here’s how ferroptosis can induce ICD:

1. Molecular signals: When a cell undergoes ferroptosis, it releases specific damage-associated molecular patterns (DAMPs), similar to ICD. These DAMPs can include molecules like calreticulin and High Mobility Group Box 1 (HMGB1).
2. Calreticulin exposure: One hallmark of ICD is the exposure of calreticulin on the cell surface, which acts as an “eat-me” signal to dendritic cells. Ferroptotic cells have been observed to expose calreticulin, thereby attracting and activating dendritic cells.
3. HMGB1 release: HMGB1, a non-histone chromatin-binding protein, is another crucial DAMP. During ferroptosis, HMGB1 can be released from the cell, signaling the immune system of the cell’s distressed state and further promoting an immune response.
4. Dendritic cell activation: The DAMPs released during ferroptosis can attract dendritic cells. These cells engulf the dying ferroptotic cells, process the tumor antigens, and then present these antigens to T-cells. This process “educates” the T-cells about the tumor, leading to a more targeted immune response against the cancer cells.
5. Enhanced anti-tumor immunity: The combination of DAMPs and the engulfment of ferroptotic cells by dendritic cells can lead to a potent T-cell response. This enhanced T-cell response can target and eliminate other tumor cells in the body, thereby amplifying anti-tumor immunity.
6. Activation of memory CD4⁺ T cells: One of the key benefits of memory CD4⁺ T cells in the context of cancer is the potential for long-lasting immunity. After the initial elimination of cancer cells, these memory cells persist in the body for years, sometimes for a lifetime. This long-term presence allows them to quickly respond to and eliminate cancer cells if they reappear, which is particularly valuable in preventing cancer recurrence.

Hyperthermia is a medical treatment that heats tumor tissue above the cytotoxic threshold of 42.5° C (108.5° F) while having little effect on surrounding normal tissue. The underlying mechanism involves the abnormal and inadequate blood flow within tumors, which leads to slower heat dissipation. As a result, cancer cells are more sensitive to heat compared to normal cells. Hyperthermia has been used to improve the efficacy of chemotherapy and radiotherapy and has recently been found to enhance the induction of ferroptotic ICD. Here’s how hyperthermia applied to the primary tumor site can systemically enhance the immunogenicity as well as the overall efficacy of ferroptosis:

1. Enhanced lipid peroxidation: Hyperthermia can increase the susceptibility of cells to oxidative stress. Elevated temperatures can amplify the production of reactive oxygen species (ROS) and reduce the activity of antioxidant systems, leading to increased lipid peroxidation—a key event in ferroptosis.
2. Altered iron metabolism: Hyperthermia can affect iron metabolism within cells. By doing so, it can lead to increased intracellular iron levels, which in turn promotes the iron-dependent oxidative reactions characteristic of ferroptosis.
3. Increased membrane fluidity: The elevated temperatures of hyperthermia can enhance cell membrane fluidity. This change can facilitate the interaction and movement of lipid peroxides and other ferroptosis-related molecules within the membrane, promoting ferroptotic cell death.
4. Enhanced release of DAMPs: As mentioned above, ferroptotic cells release damage-associated molecular patterns (DAMPs) that can induce ICD. In iron-loaded cancer cells, hyperthermia can enhance the release or exposure of these DAMPs, thereby amplifying the immunogenic response.
5. Increased uptake by dendritic cells: Hyperthermia can lead to changes in the tumor microenvironment, making it more conducive for dendritic cells to infiltrate and engulf ferroptotic tumor cells. This uptake can enhance the presentation of tumor antigens to T-cells, leading to a stronger anti-tumor immune response.
6. Synergy with other therapies: Hyperthermia can sensitize tumor cells to other treatments, such as chemotherapy and radiation. When these therapies are combined with hyperthermia, there may be an enhanced induction of ferroptosis and subsequently, ICD.
7. Abscopal effect: This is where localized treatment causes the regression of tumors in tumor sites that were not treated. The tumor treated with ferroptosis plus hyperthermia essentially becomes a “vaccine” where the immune system is “awakened” and enabled to recognize tumors throughout the body. This is like how a vaccine works, where the immune system is trained to recognize and respond to specific antigens, leading to an immune response throughout the body. Locally triggering immunogenic hyperthermia augmented by ferroptosis can induce a potent systemic (body-wide) antitumor immunity effect. 

Note: Saunas and heating pads can offer relaxation and may provide pain relief for some individuals. PEMF mats, like the Bemer, have been touted for their potential wellness benefits. However, these should not be confused with radiofrequency or microwave medical hyperthermia machines that provide high-intensity focused heat, deep penetration, and precise tumor-temperature control.

In summary, ferroptosis can induce ICD by releasing specific molecular signals that attract and activate components of the immune system, especially dendritic cells. This interaction can lead to a robust anti-tumor immune response, making the study of ferroptosis particularly intriguing for potential cancer therapies. Furthermore, the combination of hyperthermia with ferroptosis holds promise for improving cancer treatment outcomes. Hyperthermia can act as a potent enhancer of ferroptotic ICD by directly promoting the mechanisms of ferroptosis and by amplifying the immune response against ferroptotic tumor cells. 

AMPK activation as a hidden barrier to ferroptosis:

When using nutrient deprivation to “starve” cancer cells as an anti-cancer strategy, the resultant energy stress has been recently found to suppress ferroptosis. The critical player in this is AMP-activated protein kinase (AMPK), which acts as a monitor for cellular energy levels and gets activated during conditions that either produce or simulate energy stress. Cancer cells with high AMPK activity from energy restriction were found to be more resistant to ferroptosis. Based on this important new finding, when targeting ferroptosis, you should avoid the following that can activate AMPK:

• Fasting (intermittent or prolonged)
• Low-glycemic or ketogenic diet
• Prolonged low-protein diet
• 2-deoxy-D-glucose (2DG)
• Alpha-lipoic acid (ALA)
• Aspirin
• Berberine
• Curcumin
• Dichloroacetate (DCA)
• EGCG (green tea extract)
• Glucosamine
• Hydroxycitrate
• Melatonin
• Metformin
• NAD+ boosters
• Quercetin
• Rapamycin
• Resveratrol

Antioxidants and their role in ferroptosis suppression:

Large clinical studies found that cancer patients taking antioxidant supplements had poorer treatment outcomes. Antioxidants can suppress the lipid peroxidation associated with ferroptosis in the following ways:

• Direct neutralization of free radicals (oxidants): Antioxidants can directly neutralize free radicals by donating an electron, which prevents the radicals from reacting with lipids. This halts the chain reaction of lipid peroxidation.
• Iron chelation: Some antioxidants can bind to iron and reduce its availability, thereby limiting its participation in ferroptosis.
• Restoring endogenous antioxidant Levels: Glutathione is a key endogenous antioxidant that plays a central role in defending against lipid peroxidation. Many exogenous antioxidants can help restore or maintain cellular glutathione levels, thereby bolstering the cell’s natural defense against peroxidation.
• Inhibiting enzymatic reactions leading to peroxidation: Some enzymes, like lipoxygenases, play a role in lipid peroxidation during ferroptosis. Many antioxidant supplements can suppress the activity of these enzymes, thereby reducing lipid peroxidation.
• Enhancing repair mechanisms: After lipid damage has occurred, some antioxidants help to repair or remove the damaged lipids, preventing further damage and potential initiation of ferroptosis.
• Affecting lipid composition: Some antioxidants can influence the composition of cellular lipids, making them less susceptible to peroxidation.

Here is a list of common antioxidants that should be avoided when employing ferroptosis:

• Allicin (garlic extract)
• Alpha-lipoic acid (ALA)
• Astaxanthin
• Beta-carotene
• CoQ10
• Curcumin
• EGCG (green tea extract)
• Glutathione
• Lycopene
• Molecular hydrogen
• N-acetyl cysteine (NAC)
• Quercetin
• Reishi mushroom extract
• Resveratrol
• Selenium
• Vitamin A
• Vitamin B12
• Vitamin C
• Vitamin D
• Vitamin E
• Vitamin K

Ferroptosis-resistance in hormone-driven cancers:

For women with estrogen receptor (ER) positive cancer, such as breast, endometrial (uterine), or ovarian, when incorporating a ferroptosis protocol, there may be benefits from using an ER degrader such as fulvestrant (Faslodex). For men with androgen receptor (AR) positive prostate cancer, there may be benefits from using an anti-AR drug such as enzalutamide (Xtandi). This is because these medications have been found to inhibit hormone-driven MBOAT1 and MBOAT2 respectively.

MBOAT1 (membrane-bound O-acyl transferase 1) is a cell-membrane protein that is upregulated in ER-positive breast, endometrial, or ovarian cancer. MBOAT2 is upregulated in AR-positive prostate cancer. Overexpression of MBOAT1 or MBOAT2 has been shown to inhibit ferroptosis by inducing phospholipid remodeling whereby the lipid membranes of cancer cells are enriched with ferroptosis-resistant monounsaturated fatty acids.

Impairing ER signaling with fulvestrant could sensitize ER-positive cancers to ferroptosis by downregulating MBOAT1. Impairing AR signaling with enzalutamide could sensitize AR-positive cancers to ferroptosis by downregulating MBOAT2. Surprisingly, even when cancer cells were deprived of all ferroptosis-inhibiting glutathione peroxidase 4 (GPX4) and glutathione-independent ferroptosis-suppressor protein 1 (FSP1), the cells were still able to resist ferroptosis when MBOAT1 or MBOAT2 was upregulated. Collectively, these findings highlight MBOAT1 and MBOAT2 as important targets for cancers of the breast, endometrium, ovaries, and prostate.

Patient care and treatment cost:

The average oncologist manages between 250 and 500 patients. Dr. Thomas, on the other hand, only accepts a small and select number of patients. This allows him to maximize the quality of his care and dedicate time to ongoing research on behalf of his patients. The ferroptosis protocol above requires close medical supervision, management, and ongoing support by Dr. Thomas. After an initial in-office physical examination, treatment begins. Follow-up visits are conducted via telemedicine and yearly physical exams are performed. While under his care, patients have unlimited email access to Dr. Thomas.

The cost for our services is a flat rate of $2250 per month without hyperthermia treatment or $4500 per month with hyperthermia treatment. This includes the cost of ozone oil capsules. Our fees are lower than alternative cancer treatment in Mexico or Europe where clinics typically charge $7,000 to $20,000 per week (click here and scroll down to FAQs and click “What are the costs of stage 4 cancer treatments at a clinic?”). Despite their high costs, many of these clinics lack a more comprehensive understanding of tumor biology, which could pose a threat if they fail to target key vulnerabilities of cancer.

Other costs are for the medications available at the local pharmacy and the supplements available online. These total around $200 per month. Treatment is maintained until remission or disease stabilization is achieved. This usually takes 6-18 months. Afterward, we employ a simpler and less expensive protocol (click here).

In conclusion:

Cancer cells and cancer stem cells exhibit a nearly universal addiction to iron, possessing a much higher dependence on it compared to normal cells for a multitude of reasons. Exploiting this addiction by promoting ferroptosis, an iron-mediated form of programmed cell death, should be considered, especially in highly resistant cancers. By leveraging the unique characteristics of cancer cells and their dependence on iron, this innovative approach may offer a promising avenue for more effective cancer treatment.

References:

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Updated December 7, 2023