Cancer prevention: past challenges and future directions

Almost 70 years have passed since the molecular mechanism of carcinogenesis was hypothesized to involve multiple gene mutations. More than 1,000 cancer-related genes, including oncogenes and tumor suppressor genes, accelerate carcinogenesis by altering molecular functions and gene expression through mutations and epigenetic changes and have been shown to cause multistep carcinogenesis in several organ cancers. The elucidation of cancer-related gene abnormalities has led to the development of molecular-targeted therapies that focus on driver molecules, known as precision medicine, in addition to conventional treatments such as surgery, radiotherapy, and chemotherapy. Now that the mechanism of cancer development has been largely elucidated, options for cancer treatment and its outcomes have improved, and cancer research is moving to the next stage: cancer prevention. Cancer prevention using chemicals was first proposed approximately 50 years ago. It is the concept of stabilizing, arresting, or reverting precancerous lesions to normal tissues using synthetic vitamin A analogs (retinoids). Cancer chemoprevention is now considered to consist of three elements: "primary prevention," which prevents the development of tumors and prevents benign tumors converting into more malignant ones; "secondary prevention," which aims for early detection through cancer screening and treatment; and "tertiary prevention," which reduces the risk of recurrence and extends the time until death from cancer through treatment. Consequently, there is no clear boundary between the prevention and treatment strategies. Therefore, chemoprevention targets the entire process, from normal cells to precancerous lesions, malignant progression of tumors, and death by cancer. Basic and clinical research has revealed that cancer prevention is influenced by race, regional, and national differences, as well as individual differences such as genetic factors, environmental factors, and lifestyle habits. This review provides an overview of the progress made in cancer prevention and summarizes future directions.

Plasma Iron Levels at Early Breast Cancer Diagnosis Are Associated With Development of Secondary Metastases: A Single-Center Retrospective Cohort Study

Background

Breast cancer is the most common malignancy in women and the leading cause of cancer-related death. Although most early-stage patients are cured, 20% to 30% develop metastases, significantly reducing survival rates. Recent research highlights the role of iron in cancer progression, although its full impact on breast cancer metastasis is not yet fully understood.

Objectives

The aim of this study is to investigate the association between plasma iron levels at diagnosis of early-stage breast cancer and the risk of developing metastatic disease.

Design

Retrospective single-center study.

Methods

Patients with stage I to III breast cancer, diagnosed between 2007 and 2017, and with serum iron, transferrin saturation, and ferritin values available within 1.5 months before or after diagnosis were included. Cox proportional hazard models were applied to determine the association between iron levels and risk of metastasis.

Results

In total, 1113 patients were included, 10% of them developed distant metastasis over a median follow-up period of 7 years. In multivariable analysis adjusting for age, stage, and subtype, transferrin saturation and serum iron were significantly associated with an increased risk of breast cancer metastasis. For each 10% increment of transferrin saturation at baseline, there was a 19% increase in metastatic risk (hazard ratio [HR] = 1.19; 95% confidence interval [CI] = [1.02-1.38]). Similarly, a serum iron increment of 10 µg/dL led to a 6% increase in risk (HR = 1.06; 95% CI = [1.01-1.12]). Ferritin was found not to be associated with metastatic risk (HR = 0.99; 95% CI = [0.98, 1.01]). There was no significant association with metastatic site or breast cancer subtype when adjusting for age and stage.

Conclusion

Elevated transferrin saturation and serum iron at early breast cancer diagnosis are associated with increased risk for metastatic disease but not with location of metastases or breast cancer subtype. Further research is needed to understand the underlying mechanisms and to explore the potential of iron-targeted therapies.

Suppression of colorectal cancer growth: Interplay between curcumin and metformin through DMT1 downregulation and ROS-mediated pathways

The rising incidence of colorectal cancer (CRC) poses significant healthcare challenges. This study explored the therapeutic potential of combined curcumin (CUR) and metformin (MET) treatment in CRC models. Our findings indicate that the combination treatment (COMB) effectively downregulates the expression of divalent metal transporter-1 (DMT-1), leading to a reduction in cell proliferation aligned with suppression of the pAKT/mTOR/Cyclin D1 signaling pathway. The COMB increased reactive oxygen species (ROS) production, triggering activation of the NRF2/KEAP1 pathway. This pathway elicits an antioxidant response to manage oxidative stress in CRC cell lines. Interestingly, the response of NRF2 varied between CT26 and HCT116 cells. Moreover, our study highlights the induction of apoptosis and autophagy, as evidenced by upregulations in Bax/Bcl-2 ratios and autophagy-related protein expressions. Notably, the COMB promoted lipid peroxidation and downregulated xCT levels, suggesting the induction of ferroptosis. Ferroptosis has been shown to activate autophagy, which helps eliminate cells potentially damaged by the increased oxidative stress. Furthermore, the COMB effectively diminished the migratory ability of CRC cells. In vivo experiments using CRC-bearing mouse models, the results confirmed the anti-tumor efficacy of the COMB, leading to substantial inhibition of tumor growth without inducing general toxicity. In conclusion, our study suggests that combining CUR with MET holds promise as a potential option for CRC treatment, with critical mechanisms likely involving ROS elevation, autophagy, and ferroptosis.

New Insights into Aspirin's Anticancer Activity: The Predominant Role of Its Iron-Chelating Antioxidant Metabolites

Epidemiological studies have suggested that following long-term, low-dose daily aspirin (LTLDA) administration for more than 5 years at 75-100 mg/day, 20-30% of patients (50-80 years old) had a lower risk of developing colorectal cancer (CRC) and about the same proportion in developing iron deficiency anemia (IDA). In cases of IDA, an increase in iron excretion is suspected, which is caused by aspirin chelating metabolites (ACMs): salicylic acid, salicyluric acid, 2,5-dihydroxybenzoic acid, and 2,3-dihydroxybenzoic acid. The ACMs constitute 70% of the administered aspirin dose and have much longer half-lives than aspirin in blood and tissues. The mechanisms of cancer risk reduction in LTLDA users is likely due to the ACM's targeting of iron involved in free radical damage, iron-containing toxins, iron proteins, and associated metabolic pathways such as ferroptosis. The ACMs from non-absorbed aspirin (about 30%) may also mitigate the toxicity of heme and nitroso-heme and other iron toxins from food, which are responsible for the cause of colorectal cancer. The mode of action of aspirin as a chelating antioxidant pro-drug of the ACMs, with continuous presence in LTLDA users, increases the prospect for prophylaxis in cancer and other diseases. It is suggested that the anticancer effects of aspirin depend primarily on the iron-chelating antioxidant activity of the ACMs. The role of aspirin in cancer and other diseases is incomplete without considering its rapid biotransformation and the longer half-life of the ACMs.

Mechanisms and cross-talk of regulated cell death and their epigenetic modifications in tumor progression

Cell death is a fundamental part of life for metazoans. To maintain the balance between cell proliferation and metabolism of human bodies, a certain number of cells need to be removed regularly. Hence, the mechanisms of cell death have been preserved during the evolution of multicellular organisms. Tumorigenesis is closely related with exceptional inhibition of cell death. Mutations or defects in cell death-related genes block the elimination of abnormal cells and enhance the resistance of malignant cells to chemotherapy. Therefore, the investigation of cell death mechanisms enables the development of drugs that directly induce tumor cell death. In the guidelines updated by the Cell Death Nomenclature Committee (NCCD) in 2018, cell death was classified into 12 types according to morphological, biochemical and functional classification, including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, PARP-1 parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence and mitotic catastrophe. The mechanistic relationships between epigenetic controls and cell death in cancer progression were previously unclear. In this review, we will summarize the mechanisms of cell death pathways and corresponding epigenetic regulations. Also, we will explore the extensive interactions between these pathways and discuss the mechanisms of cell death in epigenetics which bring benefits to tumor therapy.

Transfusional hemosiderosis in childhood cancer patients and survivors

BACKGROUND

Children treated for cancer are at risk for adverse effects of iron due to transfusions administered during prolonged marrow suppression, which may increase exposure to toxic forms of iron, extrahepatic iron accumulation, and long-term organ damage.

OBJECTIVE

This study aimed to characterize the severity and organ distribution of clinically significant, multisystem iron overload (IO) in an at-risk cohort of pediatric cancer patients.

METHODS

This was a retrospective, cross-sectional study of childhood cancer patients who underwent a magnetic resonance imaging (MRI) due to clinical concern for IO. Data regarding cancer type and treatment, transfusion history, MRI and laboratory results, and treatment for IO were collected. Severity of IO was analyzed by non-parametric tests with respect to clinical characteristics.

RESULTS

Of the 103 patients, 98% of whom had a Cancer Intensity Treatment Rating (ITR-3) of 3 or higher, 53% (54/102) had moderate or greater hepatic siderosis, 80% (77/96) had pancreatic siderosis, 4% (3/80) had cardiac siderosis, and 45% (13/29) had pituitary siderosis and/or volume loss. Pancreatic iron was associated with both cardiac (p = .0043) and pituitary iron (p = .0101). In the 73 off-therapy patients, ferritin levels were lower (p = .0008) with higher correlation with liver iron concentration (LIC) (p = .0016) than on-therapy patients. Fifty-eight subjects were treated for IO.

CONCLUSION

In this heavily treated cohort of pediatric cancer patients, more than 80% had extrahepatic iron loading, which occurs with significant exposure to toxic forms of iron related to decreased marrow activity in setting of transfusions. Further studies should examine the effects of exposure to reactive iron on long-term outcomes and potential strategies for management.

Dietary iron intake predicts all-cause and cardiovascular mortality in patients with diabetes

BACKGROUND

Limited data exists on the link between dietary iron intake and mortality in diabetes. Our investigation aimed to explore how dietary iron intake correlates with overall and cause-specific mortality in diabetic individuals.

METHODS

This analysis encompassed 5970 participants with diabetes from the National Health and Nutrition Examination Survey spanning 1999 to 2014. Baseline data were collected through surveys and examinations, with mortality status tracked via National Death Index records until December 31, 2015. Cox proportional hazard models were utilized to calculate hazard ratios (HR) and 95% confidence intervals (CI) for mortality from various causes, including cardiovascular disease (CVD) and cancer.

RESULTS

The average iron intake among the cohort was 14.1 ± 7.4 mg daily, with an average participant age of 61.3 and 3059 (51.3%) male adults. Over 41,425 person-years of follow-up, 1497 deaths were recorded. Following adjustments for multiple variables, an iron intake between 11.1 and 14.4 mg was associated with the lowest risk of all-cause mortality (HR 0.83 [0.70, 0.99], P < 0.05) compared to the reference group (<8.3 mg). Analysis of dose-response curves revealed an L-shaped pattern in men and a J-shaped pattern in women concerning the relationship between iron intake and all-cause mortality.

CONCLUSIONS

Our findings suggest a nonlinear association between dietary iron intake and all-cause mortality in individuals with diabetes. Specifically, higher iron intake may increase all-cause mortality risk in men, while potentially exert a protective effect in women.

Iron Regulates Cellular Proliferation by Enhancing the Expression of Glucose Transporter GLUT3 in the Liver

Iron is often accumulated in the liver during pathological conditions such as cirrhosis and cancer. Elevated expression of glucose transporters GLUT1 and GLUT3 is associated with reduced overall survival in patients with hepatocellular carcinoma. However, it is not known whether iron can regulate glucose transporters and contribute to tumor proliferation. In the present study, we found that treatment of human liver cell line HepG2 with ferric ammonium citrate (FAC) resulted in a significant upregulation of GLUT3 mRNA and protein in a dose-dependent manner. Similarly, iron accumulation in mice fed with high dietary iron as well as in mice injected intraperitoneally with iron dextran enhanced the GLUT3 expression drastically in the liver. We demonstrated that iron-induced hepatic GLUT3 upregulation is mediated by the LKB1/AMPK/CREB1 pathway, and this activation was reversed when treated with iron chelator deferiprone. In addition, inhibition of GLUT3 using siRNA prevented iron-mediated increase in the expression of cell cycle markers and cellular hyperproliferation. Furthermore, exogenous sodium beta-hydroxybutyrate treatment prevented iron-mediated hepatic GLUT3 activation both in vitro and in vivo. Together, these results underscore the importance of iron, AMPK, CREB1 and GLUT3 pathways in cell proliferation and highlight the therapeutic potential of sodium beta-hydroxybutyrate in hepatocellular carcinoma with high GLUT3 expression.

The Puzzle of Aspirin and Iron Deficiency: The Vital Missing Link of the Iron-Chelating Metabolites

Acetylsalicylic acid or aspirin is the most commonly used drug in the world and is taken daily by millions of people. There is increasing evidence that chronic administration of low-dose aspirin of about 75-100 mg/day can cause iron deficiency anaemia (IDA) in the absence of major gastric bleeding; this is found in a large number of about 20% otherwise healthy elderly (>65 years) individuals. The mechanisms of the cause of IDA in this category of individuals are still largely unknown. Evidence is presented suggesting that a likely cause of IDA in this category of aspirin users is the chelation activity and increased excretion of iron caused by aspirin chelating metabolites (ACMs). It is estimated that 90% of oral aspirin is metabolized into about 70% of the ACMs salicyluric acid, salicylic acid, 2,5-dihydroxybenzoic acid, and 2,3-dihydroxybenzoic acid. All ACMs have a high affinity for binding iron and ability to mobilize iron from different iron pools, causing an overall net increase in iron excretion and altering iron balance. Interestingly, 2,3-dihydroxybenzoic acid has been previously tested in iron-loaded thalassaemia patients, leading to substantial increases in iron excretion. The daily administration of low-dose aspirin for long-term periods is likely to enhance the overall iron excretion in small increments each time due to the combined iron mobilization effect of the ACM. In particular, IDA is likely to occur mainly in populations such as elderly vegetarian adults with meals low in iron content. Furthermore, IDA may be exacerbated by the combinations of ACM with other dietary components, which can prevent iron absorption and enhance iron excretion. Overall, aspirin is acting as a chelating pro-drug similar to dexrazoxane, and the ACM as combination chelation therapy. Iron balance, pharmacological, and other studies on the interaction of iron and aspirin, as well as ACM, are likely to shed more light on the mechanism of IDA. Similar mechanisms of iron chelation through ACM may also be implicated in patient improvements observed in cancer, neurodegenerative, and other disease categories when treated long-term with daily aspirin. In particular, the role of aspirin and ACM in iron metabolism and free radical pathology includes ferroptosis, and may identify other missing links in the therapeutic effects of aspirin in many more diseases. It is suggested that aspirin is the first non-chelating drug described to cause IDA through its ACM metabolites. The therapeutic, pharmacological, toxicological and other implications of aspirin are incomplete without taking into consideration the iron binding and other effects of the ACM.

Iron status determined changes in health measures induced by nordic walking with time-restricted eating in older adults- a randomised trial

BACKGROUND AND AIMS

This study evaluated whether stored iron determines the adaptive response induced by Nordic walking (NW) training combined with 10 hours' time-restricted eating (TRE) in older adults.

TRIAL DESIGN AND METHODS

Twenty-four participants underwent 12-week NW training supported by 10 h of TRE. The group was divided due to baseline ferritin concentration low < 75 ng/ml (LF) and high level ≥ 75 ng/ml (HF). Body composition, physical fitness and blood collection were assessed at baseline and post-intervention.

RESULTS

NW + TRE induced a statistically significant decrease in ferritin levels in all participants (p = 0.01). Additionally, statistically significant intergroup differences in the LF vs. HF in the reduction of serum ferritin levels (p = 0.04) were observed. The procedure NW + TRE diminished HbA1c levels (p < 0.01) and glucose in all participants (p = 0.05). The range of HbA1c drop was more pronounced among those participants who experienced a greater decrease in the stored iron (p = 0.04, [Formula: see text]=0.17, F=4.59). Greater changes in body weight and percent of body fat were recorded in the HF group (for both p<0.01).

CONCLUSION

Body iron stores determine the effects of a 12-week NW + TRE intervention on serum ferritin. The changes in HbA1c are more pronounced in subjects with a higher decrease in serum ferritin.

TRIAL REGISTRATION

All experimental protocols were approved by the Bioethical Committee of the Regional Medical Society in Gdansk, Poland (NKBBN/330/2021) according to the Declaration of Helsinki. We confirm that all methods were carried out in accordance with relevant guidelines and regulations. The trial was registered as a clinical trial (NCT05229835, date of first registration: 14/01/2022, direct link: https://classic.

CLINICALTRIALS

gov/ct2/show/NCT05229835 ). Informed consent was obtained from all subjects.

Hypoxia-Induced Signaling in Gut and Liver Pathobiology

Oxygen (O2) is essential for cellular metabolism and biochemical reactions. When the demand for O2 exceeds the supply, hypoxia occurs. Hypoxia-inducible factors (HIFs) are essential to activate adaptive and survival responses following hypoxic stress. In the gut (intestines) and liver, the presence of oxygen gradients or physiologic hypoxia is necessary to maintain normal homeostasis. While physiologic hypoxia is beneficial and aids in normal functions, pathological hypoxia is harmful as it exacerbates inflammatory responses and tissue dysfunction and is a hallmark of many cancers. In this review, we discuss the role of gut and liver hypoxia-induced signaling, primarily focusing on HIFs, in the physiology and pathobiology of gut and liver diseases. Additionally, we examine the function of HIFs in various cell types during gut and liver diseases, beyond intestinal epithelial and hepatocyte HIFs. This review highlights the importance of understanding hypoxia-induced signaling in the pathogenesis of gut and liver diseases and emphasizes the potential of HIFs as therapeutic targets.

Micronutrients Importance in Cancer Prevention-Minerals

Cancer, a non-communicable disease with diverse kinds is one of the major global problems with high incidence and no proven method to prevent or treat. Minerals including trace elements are significant micronutrients for preserving the body's typical physiological function. In contrast to extremely processed industrial food, they are rich in natural sources of food and frequently included in nutritional supplements. The daily intake, storage capacities, and homeostasis of micronutrients depend on specific dietary practices in contemporary civilization and can be disturbed by various malignancies. Varied minerals have different effects on the status of cancer depending on how they affect these pathways. The outcomes could differ depending on the mineral such as calcium's supply and the cancer's location. A mineral called zinc helps the immune system function better and aids in wound healing. On the other hand, selenium exhibits anti-oxidant functions and has a dose-response relationship with many cancer types. However, this component can make the patient's condition worse. Although the body produces free radicals when iron is deficient, anaemia affects a patient's quality of life and ability to receive therapy. This chapter compiles the knowledge of minerals connected to unusual accumulation or depletion states in various malignancies.

Association of plasma iron with the risk of incident cancer in Chinese adults with hypertension: a nested case-control study

Background

Iron is an essential element for organismal health but excessive iron is potentially toxic. However, few observational studies link plasma iron (PI) concentrations and cancer risk, and the results are inconsistent.

Objective

This study aimed to explore the associations of PI concentrations with cancer risk in Chinese adults with hypertension.

Methods

We conducted a nested, case-control study, including 223 pairs of incident cancer cases and matched controls from the China Stroke Primary Prevention Trial. The median time between blood sample collection and subsequent cancer event occurrence was 2.13 years. The odds ratio (OR) and 95% confidence interval (CI) for the risk of cancer by PI were estimated from multivariable conditional logistic regression models.

Results

There was a nonlinear association between PI concentrations and total cancer risk. When compared with participants in tertile 2 of PI, the ORs of total cancer were 2.17 (95%CI: 1.25-3.85) and 1.29 (95%CI: 0.77-2.19) in participants in PI tertiles 3 and 1, respectively. Furthermore, higher PI was associated with increased digestive system cancer risk (OR=3.25, 95%CI:1.29-8.90), while lower PI was associated with increased risk of non-digestive system cancer (OR=3.32, 95%CI: 1.39-8.71). In a sensitivity analysis, the increases in total cancer risk or digestive system cancer risk were still observed with higher PI after excluding cancer cases occurring within the first year.

Conclusion

Our results showed an increased risk of cancer related to higher PI or lower PI in Chinese adults with hypertension. Higher iron levels were linked to an increased risk of digestive system cancers, whereas lower iron levels were linked to an increased risk of non-digestive system cancers.

Three-Dimensional Regulation of Ferroptosis at the Intersection of Iron, Sulfur, and Oxygen Executing Scrap and Build Toward Evolution

Significance: Iron is an essential element for every life on earth as a primary media for electron flow. Sulfur compounds as sulfhydryls counteract catalytic activity of iron whereas sulfur overdose is also toxic. In aerobic organisms, oxygen is the major media for electron transfer with higher intracellular mobility, which cooperates with the iron system. Based on the importance of iron, there is no active pathway to excrete iron outside the body in higher species. Whereas bacterial infection causes a scramble for iron in situ, cancer can be the outcome of the side effects of long use of iron and oxygen. Recent Advances: Ferroptosis is a recently coined cell death, defined as catalytic Fe(II)-dependent regulated necrosis accompanied by lipid peroxidation. Researchers recently recognized that ferroptosis is involved in a variety of physiological and pathological contexts, including embryonic erythropoiesis, aging, neurodegeneration and cancer cell death. Alternatively, carcinogenesis is a process to obtain iron addiction with ferroptosis-resistance, based on rodent animal studies. Critical Issues: Here we propose that ferroptosis is three-dimensionally regulated by iron, sulfur and oxygen, which correspond to oxidants, antioxidants and membrane fluidity with susceptibility to lipid peroxidation, respectively. Future Directions: Whereas life attempts to prevent ferroptosis, ferroptotic cells eventually emit iron-loaded ferritin as extracellular vesicles to maintain monopoly of iron. Antioxid. Redox Signal. 39, 807-815.

Nutritional Aspects of Iron in Health and Disease

Dietary iron assimilation is critical for health and essential to prevent iron-deficient states and related comorbidities, such as anemia. The bioavailability of iron is generally low, while its absorption and metabolism are tightly controlled to satisfy metabolic needs and prevent toxicity of excessive iron accumulation. Iron entry into the bloodstream is limited by hepcidin, the iron regulatory hormone. Hepcidin deficiency due to loss-of-function mutations in upstream gene regulators causes hereditary hemochromatosis, an endocrine disorder of iron overload characterized by chronic hyperabsorption of dietary iron, with deleterious clinical complications if untreated. The impact of high dietary iron intake and elevated body iron stores in the general population is not well understood. Herein, we summarize epidemiological data suggesting that a high intake of heme iron, which is abundant in meat products, poses a risk factor for metabolic syndrome pathologies, cardiovascular diseases, and some cancers. We discuss the clinical relevance and potential limitations of data from cohort studies, as well as the need to establish causality and elucidate molecular mechanisms.

Consensus Statement on the definition and classification of metabolic hyperferritinaemia

Hyperferritinaemia is a common laboratory finding that is often associated with metabolic dysfunction and fatty liver. Metabolic hyperferritinaemia reflects alterations in iron metabolism that facilitate iron accumulation in the body and is associated with an increased risk of cardiometabolic and liver diseases. Genetic variants that modulate iron homeostasis and tissue levels of iron are the main determinants of serum levels of ferritin in individuals with metabolic dysfunction, raising the hypothesis that iron accumulation might be implicated in the pathogenesis of insulin resistance and the related organ damage. However, validated criteria for the non-invasive diagnosis of metabolic hyperferritinaemia and the staging of iron overload are still lacking, and there is no clear evidence of a benefit for iron depletion therapy. Here, we provide an overview of the literature on the relationship between hyperferritinaemia and iron accumulation in individuals with metabolic dysfunction, and on the associated clinical outcomes. We propose an updated definition and a provisional staging system for metabolic hyperferritinaemia, which has been agreed on by a multidisciplinary global panel of expert researchers. The goal is to foster studies into the epidemiology, genetics, pathophysiology, clinical relevance and treatment of metabolic hyperferritinaemia, for which we provide suggestions on the main unmet needs, optimal design and clinically relevant outcomes.

Environmental impact on carcinogenesis under BRCA1 haploinsufficiency

Cancer is the primary cause of human mortality in Japan since 1981. Although numerous novel therapies have been developed and applied in clinics, the number of deaths from cancer is still increasing worldwide. It is time to consider the strategy of cancer prevention more seriously. Here we propose a hypothesis that cancer can be side effects of long time-use of iron and oxygen and that carcinogenesis is an evolution-like cellular events to obtain "iron addiction with ferroptosis-resistance" where genes and environment interact each other. Among the recognized genetic risk factors for carcinogenesis, we here focus on BRCA1 tumor suppressor gene and how environmental factors, including daily life exposure and diets, may impact toward carcinogenesis under BRCA1 haploinsufficiency. Although mice models of BRCA1 mutants have not been successful for decades in generating phenotype mimicking the human counterparts, a rat model of BRCA1 mutant was recently established that reasonably mimics the human phenotype. Two distinct categories of oxidative stress, one by radiation and one by iron-catalyzed Fenton reaction, promoted carcinogenesis in Brca1 rat mutants. Furthermore, mitochondrial damage followed by alteration of iron metabolism finally resulted in ferroptosis-resistance of target cells in carcinogenesis. These suggest a possibility that cancer prevention by active pharmacological intervention may be possible for BRCA1 mutants to increase the quality of their life rather than preventive mastectomy and/or oophorectomy.

The Role of Iron and Cobalt in Gynecological Diseases

Iron and cobalt are micronutrients that play an important role in the regulation of cellular processes, being part of the centre of catalases, peroxidases, cytochromes and metalloproteins such as hemoglobin and myoglobin (Fe). Cobalt primarily functions as a component of hydroxycobalamin, which is essential for regulating red blood cell production. Maintaining normal levels of cobalt and iron in the human body is important, as a deficiency can lead to anaemia. These elements are also involved in reactions during which oxidative stress occurs and are therefore considered to be a cause of tumor formation. This paper will discuss aspects of the influence of cobalt and iron on mechanisms that may contribute to the growth of gynecological tumors, as well as other obstetric-gynecological disease entities, by altering the conditions of the microenvironment. In addition, the following review also highlights the role of cobalt and iron in the treatment of gynecological tumors.

Iron accumulation typifies renal cell carcinoma tumorigenesis but abates with pathological progression, sarcomatoid dedifferentiation, and metastasis

Iron is a potent catalyst of oxidative stress and cellular proliferation implicated in renal cell carcinoma (RCC) tumorigenesis, yet it also drives ferroptosis that suppresses cancer progression and represents a novel therapeutic target for advanced RCC. The von Hippel Lindau (VHL)/hypoxia-inducible factor-α (HIF-α) axis is a major regulator of cellular iron, and its inactivation underlying most clear cell (cc) RCC tumors introduces both iron dependency and ferroptosis susceptibility. Despite the central role for iron in VHL/HIF-α signaling and ferroptosis, RCC iron levels and their dynamics during RCC initiation/progression are poorly defined. Here, we conducted a large-scale investigation into the incidence and prognostic significance of total tissue iron in ccRCC and non-ccRCC patient primary tumor cancer cells, tumor microenvironment (TME), metastases and non-neoplastic kidneys. Prussian Blue staining was performed to detect non-heme iron accumulation in over 1600 needle-core sections across multiple tissue microarrays. We found that RCC had significantly higher iron staining scores compared with other solid cancers and, on average, >40 times higher than adjacent renal epithelium. RCC cell iron levels correlated positively with TME iron levels and inversely with RCC levels of the main iron uptake protein, transferrin receptor 1 (TfR1/TFRC/CD71). Intriguingly, RCC iron levels, including in the TME, decreased significantly with pathologic (size/stage/grade) progression, sarcomatoid dedifferentiation, and metastasis, particularly among patients with ccRCC, despite increasing TfR1 levels, consistent with an increasingly iron-deficient tumor state. Opposite to tumor iron changes, adjacent renal epithelial iron increased significantly with RCC/ccRCC progression, sarcomatoid dedifferentiation, and metastasis. Lower tumor iron and higher renal epithelial iron each predicted significantly shorter ccRCC patient metastasis-free survival. In conclusion, iron accumulation typifies RCC tumors but declines toward a relative iron-deficient tumor state during progression to metastasis, despite precisely opposite dynamics in adjacent renal epithelium. These findings raise questions regarding the historically presumed selective advantage for high iron during all phases of cancer evolution, suggesting instead distinct tissue-specific roles during RCC carcinogenesis and early tumorigenesis versus later progression. Future study is warranted to determine how the relative iron deficiency of advanced RCC contributes to ferroptosis resistance and/or introduces a heightened susceptibility to iron deprivation that might be therapeutically exploitable.

Minerals and Cancer: Overview of the Possible Diagnostic Value

Cancer is the second leading cause of death worldwide and is expected to increase by one-third over the next two decades, in parallel with the growing proportion of the elderly population. Treatment and control of cancer incidence is a global issue. Since there is no clear way to prevent or cure this deadly malignancy, diagnostic, predictive, and prognostic markers for oncological diseases are of great therapeutic value. Minerals and trace elements are important micronutrients for normal physiological function of the body. They are abundant in natural food sources and are regularly included in dietary supplements whereas highly processed industrial food often contains reduced or altered amounts of them. In modern society, the daily intake, storage pools, and homeostasis of these micronutrients are dependent on certain dietary habits and can be thrown out of balance by malignancies. The current work summarizes the data on minerals and trace elements associated with abnormal accumulation or depletion states in tumor patients and discusses their value as potential tumor-associated biomarkers that could be introduced into cancer therapy.

Nrf2 Is a Potential Modulator for Orchestrating Iron Homeostasis and Redox Balance in Cancer Cells

Iron is an essential trace mineral element in almost all living cells and organisms. However, cellular iron metabolism pathways are disturbed in most cancer cell types. Cancer cells have a high demand of iron. To maintain rapid growth and proliferation, cancer cells absorb large amounts of iron by altering expression of iron metabolism related proteins. However, iron can catalyze the production of reactive oxygen species (ROS) through Fenton reaction. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is an important player in the resistance to oxidative damage by inducing the transcription of antioxidant genes. Aberrant activation of Nrf2 is observed in most cancer cell types. It has been revealed that the over-activation of Nrf2 promotes cell proliferation, suppresses cell apoptosis, enhances the self-renewal capability of cancer stem cells, and even increases the chemoresistance and radioresistance of cancer cells. Recently, several genes involving cellular iron homeostasis are identified under the control of Nrf2. Since cancer cells require amounts of iron and Nrf2 plays pivotal roles in oxidative defense and iron metabolism, it is highly probable that Nrf2 is a potential modulator orchestrating iron homeostasis and redox balance in cancer cells. In this hypothesis, we summarize the recent findings of the role of iron and Nrf2 in cancer cells and demonstrate how Nrf2 balances the oxidative stress induced by iron through regulating antioxidant enzymes and iron metabolism. This hypothesis provides new insights into the role of Nrf2 in cancer progression. Since ferroptosis is dependent on lipid peroxide and iron accumulation, Nrf2 inhibition may dramatically increase sensitivity to ferroptosis. The combination of Nrf2 inhibitors with ferroptosis inducers may exert greater efficacy on cancer therapy.

Optimal serum ferritin level range: iron status measure and inflammatory biomarker

This report provides perspectives concerning dual roles of serum ferritin as a measure of both iron status and inflammation. We suggest benefits of a lower range of serum ferritin as has occurred for total serum cholesterol and fasting blood glucose levels. Observations during a prospective randomized study using phlebotomy in patients with peripheral arterial disease offered unique insights into dual roles of serum ferritin both as an iron status marker and acute phase reactant. Robust positive associations between serum ferritin, interleukin 6 [IL-6], tissue necrosis factor-alpha, and high sensitivity C-reactive protein were discovered. Elevated serum ferritin and IL-6 levels associated with increased mortality and with reduced mortality at ferritin levels <100 ng mL-1. Epidemiologic studies demonstrate similar outcomes. Extremely elevated ferritin and IL-6 levels also occur in individuals with high mortality due to SARS-CoV-2 infection. Disordered iron metabolism reflected by a high range of serum ferritin level signals disease severity and outcomes. Based upon experimental and epidemiologic data, we suggest testing the hypotheses that optimal ferritin levels for cardiovascular mortality reduction range from 20 to 100 ng mL-1 with % transferrin levels from 20 to 50%, to ensure adequate iron status and that ferritin levels above 194 ng mL-1 associate with all-cause mortality in population cohorts.

Iron overload-induced oxidative stress in myelodysplastic syndromes and its cellular sequelae

The myelodysplastic syndromes (MDS) are clonal hematopoietic stem cell disorders. MDS patients often require red blood cell transfusions, resulting in iron overload (IOL). IOL increases production of reactive oxygen species (ROS), oxygen free radicals. We review and illustrate how IOL-induced ROS influence cellular activities relevant to MDS pathophysiology. ROS damage lipids, nucleic acids in mitochondrial and nuclear DNA, structural proteins, transcription factors and enzymes. Cellular consequences include decreased metabolism and tissue and organ dysfunction. In hematopoietic stem cells (HSC), consequences of ROS include decreased glycolysis, shifting the cell from anaerobic to aerobic metabolism and causing HSC to exit the quiescent state, leading to HSC exhaustion or senescence. ROS oxidizes DNA bases, resulting in accumulation of mutations. Membrane oxidation alters fluidity and permeability. In summary, evidence indicates that IOL-induced ROS alters cellular signaling pathways resulting in toxicity to organs and hematopoietic cells, in keeping with adverse clinical outcomes in MDS.

Siderophores: Importance in bacterial pathogenesis and applications in medicine and industry

Iron is an essential element for all microorganisms. Siderophores are low-weight, high-affinity iron chelating molecules produced in response to iron deficiency by Gram-positive and Gram-negative bacteria which also known as essential virulence factors of bacteria. Several studies have indicated that defective production and/or function of these molecules as well as iron acquisition systems in pathogens are associated with a reduction in pathogenicity of bacteria. Because of their potential role in various biological pathways, siderophores have been received special attention as secondary metabolites. Siderophores can detect iron levels in a variety of environments with a biosensor function. In medicine, siderophores are used to deliver antibiotics (Trojan horse strategy) to resistant bacteria and to treat diseases such as cancer and malaria. In this review, we discuss the iron acquisition pathways in Gram-positive and -negative bacteria, importance of siderophore production in pathogenesis of bacteria, classification of siderophores, and main applications of siderophores in medicine and industry.

Nutrient status and growth in vegan children

Vegan diets have risen in popularity over the past 9 years. However, few studies have examined nutrient status and the effect of a vegan diet on the growth of children. This study analysed the existing literature on the health impact and growth impact of selected nutrients in vegan children. We assessed the intake of calories and protein, as well as the nutrients iron, calcium, vitamin D, cobalamin and folate. With a small percentage of outliers, vegan children showed normal growth and were less often obese. We found limited evidence that children on a vegan diet can obtain all the examined nutrients. Furthermore, as proper planning and supplementation by caregivers is needed, it is currently unknown how often vegan children follow well-planned diets. Deficiencies in cobalamin, calcium, and vitamin D seem to be the biggest risks associated with a poorly planned vegan diet. For a more definitive assessment, data on the intake and nutrient status of omega-3 fatty acids, zinc, iodine, and selenium in vegan children are needed. Future research should account for demographic shifts in those following a vegan diet, and should discriminate between vegan sub-populations that are open or closed towards scientific approaches, towards health in general, and toward supplementation. Studies should assess the modes and dosages of supplementation and the use of fortified foods or drinks, as well as adherence to the diet itself. Plant ferritin as a source of iron and endogenous cobalamin synthesis warrants further scientific inquiry. In summary, the current literature suggests that a well-planned vegan diet using supplementation is likely to provide the recommended amounts of critical nutrients to provide for normal progression of height and weight in children, and can be beneficial in some aspects. However, data on 5 critical nutrients are still missing, hampering a more definitive conclusion.

Role of iron in cancer

Iron is an essential metal for cellular metabolism. The reduced form of iron is a cofactor in numerous redox reactions in the cell and is therefore required for many vital physiological functions. Since iron is an oxidatively active metal, its homeostasis is tightly regulated in healthy cell. Most of iron exists in a protein-bound form, in erythrocytes as the heme compound hemoglobin, and in storage proteins such as ferritin, hemosiderin and myoglobin. Iron also is bound to proteins and non-heme enzymes involved in oxidation-reduction reactions and the transfer of electrons. There is no free iron inside the cell, however a small fraction of loosely bound iron is found in the cytoplasm. This poorly defined pool of ferrous iron is called labile iron pool. Under pathological conditions iron homeostasis may be disrupted at different levels including absorption, systemic transportation, and cellular uptake and storage. Cancer cells display dysregulated iron homeostasis and, for reasons yet poorly understood, require more iron for their metabolism and growth. As a result, in cancer cells labile iron pool is increased, and loosely bound iron catalyzes Fenton reaction and perhaps other reactions that generate reactive oxygen species. Oxygen-derived free radicals produce DNA mutations, damage proteins and lipids resulting in either cell death or cell transformation.

Menopause Delays the Typical Recovery of Pre-Exercise Hepcidin Levels after High-Intensity Interval Running Exercise in Endurance-Trained Women

Menopause commonly presents the gradual accumulation of iron in the body over the years, which is a risk factor for diseases such as cancer, osteoporosis, or cardiovascular diseases. Running exercise is known to acutely increase hepcidin levels, which reduces iron absorption and recycling. As this fact has not been studied in postmenopausal women, this study investigated the hepcidin response to running exercise in this population. Thirteen endurance-trained postmenopausal women (age: 51.5 ± 3.89 years; height: 161.8 ± 4.9 cm; body mass: 55.9 ± 3.6 kg; body fat: 24.7 ± 4.2%; peak oxygen consumption: 42.4 ± 4.0 mL·min^-1·kg^-1) performed a high-intensity interval running protocol, which consisted of 8 × 3 min bouts at 85% of the maximal aerobic speed with 90-second recovery. Blood samples were collected pre-exercise, 0, 3, and 24 hours post-exercise. As expected, hepcidin exhibited higher values at 3 hours post-exercise (3.69 ± 3.38 nmol/L), but also at 24 hours post-exercise (3.25 ± 3.61 nmol/L), in comparison with pre-exercise (1.77 ± 1.74 nmol/L; p = 0.023 and p = 0.020, respectively) and 0 hour post-exercise (2.05 ± 2.00 nmol/L; p = 0.021 and p = 0.032, respectively) concentrations. These differences were preceded by a significant increment of interleukin-6 at 0 hour post-exercise (3.41 ± 1.60 pg/mL) compared to pre-exercise (1.65 ± 0.48 pg/m, p = 0.003), 3 hours (1.50 ± 0.00 pg/mL, p = 0.002) and 24 hours post-exercise (1.52 ± 0.07 pg/mL, p = 0.001). Hepcidin peaked at 3 hours post-exercise as the literature described for premenopausal women but does not seem to be fully recovered to pre-exercise levels within 24 hours post-exercise, as it would be expected. This suggests a slower recovery of basal hepcidin levels in postmenopausal women, suggesting interesting applications in order to modify iron homeostasis as appropriate, such as the prevention of iron accumulation or proper timing of iron supplementation.

Iron: An Essential Element of Cancer Metabolism

Cancer cells undergo considerable metabolic changes to foster uncontrolled proliferation in a hostile environment characterized by nutrient deprivation, poor vascularization and immune infiltration. While metabolic reprogramming has been recognized as a hallmark of cancer, the role of micronutrients in shaping these adaptations remains scarcely investigated. In particular, the broad electron-transferring abilities of iron make it a versatile cofactor that is involved in a myriad of biochemical reactions vital to cellular homeostasis, including cell respiration and DNA replication. In cancer patients, systemic iron metabolism is commonly altered. Moreover, cancer cells deploy diverse mechanisms to increase iron bioavailability to fuel tumor growth. Although iron itself can readily participate in redox reactions enabling vital processes, its reactivity also gives rise to reactive oxygen species (ROS). Hence, cancer cells further rely on antioxidant mechanisms to withstand such stress. The present review provides an overview of the common alterations of iron metabolism occurring in cancer and the mechanisms through which iron promotes tumor growth.

Carcinogenesis as Side Effects of Iron and Oxygen Utilization: From the Unveiled Truth toward Ultimate Bioengineering

Simple Summary

Cancer is a major cause of human mortality worldwide. No life on earth can live without iron. Persistent oxidative stress resulting from continuous use of iron and oxygen may be a fundamental cause of carcinogenesis. Many animal models demonstrated that excess iron may lead to carcinogenesis. This is supported by a variety of human epidemiological data on cancer risk and prognosis. Cancer is basically a disease of the genome with persistently activated oncogenes and inactivated tumor suppressor genes through which iron addiction with ferroptosis-resistance is established. We predict that fine use of nanomaterials and non-thermal plasma may be able to reverse this situation.

Abstract

Evolution from the first life on earth to humans took ~3.8 billion years. During the time there have been countless struggles among the species. Mycobacterium tuberculosis was the last major uncontrollable species against the human public health worldwide. After the victory with antibiotics, cancer has become the leading cause of death since 1981 in Japan. Considering that life inevitably depends on ceaseless electron transfers through iron and oxygen, we believe that carcinogenesis is intrinsically unavoidable side effects of using iron and oxygen. Many animal models unequivocally revealed that excess iron is a risk for carcinogenesis. This is supported by a variety of human epidemiological data on cancer risk and prognosis. Cancer is basically a disease of the genome with persistently activated oncogenes and inactivated tumor suppressor genes through which iron addiction with ferroptosis-resistance is maintained. Engineering has made a great advance in the past 50 years. In particular, nanotechnology is distinct in that the size of the engineered molecules is similar to that of our biomolecules. While some nano-molecules are found carcinogenic, there are principles to avoid such carcinogenicity with a smart possibility to use nano-molecules to specifically kill cancer cells. Non-thermal plasma is another modality to fight against cancer.

Deferasirox-Dependent Iron Chelation Enhances Mitochondrial Dysfunction and Restores p53 Signaling by Stabilization of p53 Family Members in Leukemic Cells

Iron is crucial to satisfy several mitochondrial functions including energy metabolism and oxidative phosphorylation. Patients affected by Myelodysplastic Syndromes (MDS) and acute myeloid leukemia (AML) are frequently characterized by iron overload (IOL), due to continuous red blood cell (RBC) transfusions. This event impacts the overall survival (OS) and it is associated with increased mortality in lower-risk MDS patients. Accordingly, the oral iron chelator Deferasirox (DFX) has been reported to improve the OS and delay leukemic transformation. However, the molecular players and the biological mechanisms laying behind remain currently mostly undefined. The aim of this study has been to investigate the potential anti-leukemic effect of DFX, by functionally and molecularly analyzing its effects in three different leukemia cell lines, harboring or not p53 mutations, and in human primary cells derived from 15 MDS/AML patients. Our findings indicated that DFX can lead to apoptosis, impairment of cell growth only in a context of IOL, and can induce a significant alteration of mitochondria network, with a sharp reduction in mitochondrial activity. Moreover, through a remarkable reduction of Murine Double Minute 2 (MDM2), known to regulate the stability of p53 and p73 proteins, we observed an enhancement of p53 transcriptional activity after DFX. Interestingly, this iron depletion-triggered signaling is enabled by p73, in the absence of p53, or in the presence of a p53 mutant form. In conclusion, we propose a mechanism by which the increased p53 family transcriptional activity and protein stability could explain the potential benefits of iron chelation therapy in terms of improving OS and delaying leukemic transformation.

Mitochondrion-mediated iron accumulation promotes carcinogenesis and Warburg effect through reactive oxygen species in osteosarcoma

Background

Iron metabolism disorder is closely associated with several malignant tumors, however the mechanisms underlying iron and the carcinogenesis in osteosarcoma are not yet well understood.

Methods

Cell proliferation ability of osteosarcoma cell lines was measured by CCK-8, EdU incorporation and colony formation assays. Cell cycle analysis was detected by flow cytometry. The carcinogenesis of osteosarcoma was measured by soft-agar formation, trans-well and Wound healing-scratch assay. Warburg effect was detected by Seahorse respirometry assays. Reactive oxygen species (ROS) level was measured by Dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescent probes. Western blotting was used to measure the expression of mitoferrin 1 (SLC25A37) and mitoferrin 2 (SLC25A28). Iron level in vitro and vivo was detected by iron assay kit. RNAi stable cell lines was generated using shRNA.

Results

Iron promoted proliferation, carcinogenesis and Warburg effect of osteosarcoma cells. Iron-induced reactive oxygen species (ROS) played an important role in these processes. Iron accumulated more in mitochondrion than in cytoplasm, suggesting mitochondrion-mediated iron accumulation was involved in the development of osteosarcoma. Moreover, iron upregulated the expression of mitoferrin 1 (SLC25A37) and mitoferrin 2 (SLC25A28). Knock-down of mitoferrin 1 (SLC25A37) and mitoferrin 2 (SLC25A28) decreased the production of ROS. In addition, iron increased the expression of Warburg key enzymes HK2 and Glut1, and affected AMPK/mTORC1 signaling axis.

Conclusions

Mitochondrion-mediated iron accumulation promotes carcinogenesis and Warburg effect of osteosarcoma cells. Meanwhile, iron deprivation might be a novel effective strategy in the treatment of osteosarcoma.

Iron: The cancer connection

Iron plays an essential role in normal biological processes: The generation of cellular energy, oxygen transport, DNA synthesis and repair are all processes that require iron-coordinated proteins, either as elemental iron, heme or iron-sulfur clusters. As a transition metal with two major biological oxidation states, iron is also a critical intermediate in the generation of reactive oxygen species that can damage cellular structures and contribute to both aging and cancer. In this review, we focus on experimental and epidemiologic evidence that links iron and cancer, as well as strategies that have been proposed to either reduce or increase cellular iron for cancer therapy.

Iron Status in Elderly Women Impacts Myostatin, Adiponectin and Osteocalcin Levels Induced by Nordic Walking Training

Impaired iron metabolism is associated with increased risk of many morbidities. Exercise was shown to have a beneficial role; however, the mechanism is not well understood. The purpose of this study was to assess the relationship between exerkines and iron metabolism in elderly women before and after 12 weeks of Nordic Walking (NW) training. Exerkines like myostatin, adiponectin, and osteocalcin have been shown to have several positive effects on metabolism. Thirty-six post-menopausal women (66 ± 5 years old, mean ± SD) were randomly assigned to a NW intervention group (n = 18; body mass, 68.8 ± 11.37 kg; fat, 23.43 ± 7.5 kg; free fat mass, 45.37 ± 5.92 kg) or a control group (n = 18; body mass, 68.34 ± 11.81 kg; fat, 23.61 ± 10.03 kg; free fat mass, 44.73 ± 3.9 kg). The training was performed three times a week for 12 weeks, with the intensity adjusted to 70% of the individual maximum ability. Before and one day after the 12-weeks intervention, performance indices were assessed using a senior fitness test. Blood samples (5 mL) were obtained from the participants between 7 and 8 AM, following an overnight fast, at baseline and one day immediately after the 12-week training program. A significant and large time × group interaction was observed for iron (NW: 98.6 ± 26.68 to 76.1 ± 15.31; CON: 100.6 ± 25.37 to 99.1 ± 27.2; p = 0.01; ηp2 = 0.21), myostatin (NW: 4.42 ± 1.97 to 3.83 ± 1.52; CON: 4.11 ± 0.95 to 4.84 ± 1.19; p = 0.00; ηp2 = 0.62), adiponectin (NW: 12.0 ± 9.46 to 14.6 ± 10.64; CON: 12.8 ± 8.99 to 11.9 ± 8.53; p = 0.00; ηp2 = 0.58), and osteocalcin (NW: 38.9 ± 26.04 to 41.6 ± 25.09; CON: 37.1 ± 33.2 to 37.2 ± 32.29; p = 0.03; ηp2 = 0.13). Furthermore, we have observed the correlations: basal ferritin levels were inversely correlated with changes in myostatin (r = −0.51, p = 0.05), change in adiponectin, and change in serum iron (r = −0.45, p = 0.05), basal iron, and osteocalcin after training (r = -0.55, p = 0.04). These findings indicate that iron modulates NW training-induced changes in exerkine levels.

Marathon Run-induced Changes in the Erythropoietin-Erythroferrone-Hepcidin Axis are Iron Dependent

Alterations in iron metabolism after physical activity are manifested through the rise of blood hepcidin (Hpc) levels. However, in many athletes, no changes in Hpc levels are observed after exercise despite the presence of inflammation. The missing links could be erythropoietin (EPO) and erythroferrone (ERFE), which down-regulate Hpc biosynthesis. EPO, ERFE and Hpc biosynthesis is modified by serum iron through transferrin receptor 2. Consequently, we investigated whether marathon-induced changes in EPO, ERFE and Hpc levels are blood iron-dependent. Twenty-nine healthy male marathon runners were analyzed. Serum iron, ferritin, transferrin, EPO, ERFE and Hpc levels were assessed before, immediately after, and 9 ± 2 days after the marathon. The runners whose serum Hpc decreased after the marathon (n = 15), showed a significant increase in ERFE levels. In athletes whose serum iron levels were below 105 µg/day (n = 15), serum EPO (p = 0.00) and ERFE levels (p = 0.00) increased with no changes in Hpc concentration. However, in athletes with low serum iron, no changes in EPO levels were observed when serum ferritin exceeded 70 ng/mL (n = 7). Conversely, an increase in ERFE levels was observed in marathoners with low serum iron, independently of serum ferritin (n = 7). This indicates modulation of blood iron may affect exercise-induced changes in the EPO/ERFE/Hpc axis. Further study is needed to fully understand the physiological meaning of the interdependence between iron and the EPO/ERFE/Hpc axis.

Serum Levels of Selenium, Zinc, Copper, Manganese, and Iron in Prostate Cancer Patients

Backgrounds

Variations of trace element contents may be associated with several diseases including metabolic disorders, cellular growth disturbance, mutation and tumorigenesis. Prostate cancer is the second most common male cancer worldwide and stand fifth most common male cancer in Saudi Arabia.

Objective

In the present study, Serum levels of selenium, zinc, copper, manganese, and iron were measured in patients with BPH and prostate cancer aiming to explore the association between these elements and prostate cancer.

Patients and Methods

The study included 40 newly diagnosed prostate cancer patients, 22 patients with BPH and 30 healthy male subjects. All participant groups had similar socio-economic levels. Fasting blood samples were collected from all subjects and before any intervention for the patients. Serum PSA concentrations were analyzed by ELIZA and trace elements Se, Zn, Cu, Mn and Fe were measured by ICP-MS.

Results

Serum Se, Zn, and Mn levels of prostate cancer patients were significantly decreased compared to control groups. The levels of serum Cu and Fe were significantly higher in prostate cancer patients than in control groups.

Conclusion

In the present study, an association was noticed between serum trace elements disturbance and prostate cancer. The decreased levels of Se, Zn, and Mn, and increased Cu and Fe levels may play significant roles in the initiation of prostate cancer. However, future prospective studies on the causes of trace elements alteration in prostate cancer patients are needed as well as to illustrate the relation between different prostate cancer stages and trace elements concentrations.

Iron Status and Cancer Risk in UK Biobank: A Two-Sample Mendelian Randomization Study

We conducted a two-sample Mendelian randomization study to explore the associations of iron status with overall cancer and 22 site-specific cancers. Single-nucleotide polymorphisms for iron status were obtained from a genome-wide association study of 48,972 European-descent individuals. Summary-level data for breast and other cancers were obtained from the Breast Cancer Association Consortium and UK Biobank. Genetically predicted iron status was positively associated with liver cancer and inversely associated with brain cancer but not associated with overall cancer or the other 20 studied cancer sites at p < 0.05. The odds ratios of liver cancer were 2.45 (95% CI, 0.81, 7.45; p = 0.11), 2.11 (1.16, 3.83; p = 0.02), 10.89 (2.44, 48.59; p = 0.002) and 0.30 (0.17, 0.53; p = 2 × 10-5) for one standard deviation increment of serum iron, transferrin saturation, ferritin and transferrin levels, respectively. For brain cancer, the corresponding odds ratios were 0.69 (0.48, 1.00; p = 0.05), 0.75 (0.59, 0.97; p = 0.03), 0.41 (0.20, 0.88; p = 0.02) and 1.49 (1.04, 2.14; p = 0.03). Genetically high iron status was positively associated with liver cancer and inversely associated with brain cancer.

Frequency and Causes of Deferral among Blood Donors Presenting to Combined Military Hospital Multan

Background & Aim

It is of great importance to carefully choose appropriate donors according to strict eligibility criteria, so as to guarantee an adequate and safe blood supply. The aim of this study was to determine the rate of deferral in blood donors and evaluate the different causes of deferral in Multan.

Materials & Methods

This prospective study was carried out at the Blood Bank of Combined Military Hospital (CMH) Multan. All donors who came for the donation of blood from 1st February to 30th September 2019 were evaluated after taking their consent. The data was analyzed to determine the frequency and causes of deferral using Statistical Package for the Social Sciences (SPSS) version 20.

Results

Among 3348 individuals presenting for blood donation, 433 (12.9%) were deferred (427 males and only six females). The mean age of deferred individuals was 28.96 + 6.42 years. The youngest individual was 18 years, while the eldest one was 51 years of age. Almost 65% of the individuals were less than 30 years of age. The most frequent cause of deferral was low hemoglobin. Anemia was the leading cause of deferral in more than half of the individuals (n = 221). Hepatitis C virus (HCV) infection was the second most frequent cause of deferral, seen in 83 (19.2%), followed by hepatitis B virus (HBV) infection (n = 49, 11.3%), syphilis (n = 36, 8.3%), thrombocytopenia (n = 18, 4.2%), and active infection (n = 14, 3.2%). Other rarer causes included early donation, thrombocytosis, polycythemia, pancytopenia, malaria, allergies, insulin, and tuberculosis.

Conclusion

Deferral for blood donation is a significant problem in Multan and accounts for almost 13% of all prospective blood donors. Our results stress the importance of addressing the problem of anemia which is the most prevalent cause of temporary deferral for blood donation in this region of the world.

Iron depletion participates in the suppression of cell proliferation induced by lipin1 overexpression

Lipin1 participates in numerous cellular processes, including in the dephosphorylation of phosphatidic acid to diacylglycerol and as a co-transcriptional regulator. Iron is also essential in various critical biological processes. Previous studies have shown that compared to normal tissue cells, lipin1 expression and iron metabolism are abnormal in cancer cells. However, the involvement of lipin1 in the regulation of iron metabolism is unknown. In this study, we compared the contents of eight metal ions (potassium, calcium, sodium, magnesium, manganese, zinc, iron and copper) in human hepatoma carcinoma BEL7402 control cells as well as stable cells overexpressing lipin1 by using ICP-AES. Our results showed that only intracellular iron content was significantly decreased by lipin1 overexpression. Meanwhile, we observed that lipin1 overexpression could inhibit cell proliferation, similar to iron chelator deferoxamine. Western blotting showed that the up-regulation of p53-p21-p27 elicited cell cycle G0/G1 arrest in the stable cells overexpressing lipin1. Conversely, after lipin1 was down regulated with siRNA, we found that cell proliferation was promoted, accompanied by an increase in iron content, and the downregulation of p53 and p21. Our data indicate that lipin1 overexpression may cause reduction of intracellular iron content, which could activate the p53-p21-p27 signaling pathways, leading to cell cycle arrest at the G0/G1 phase in the hepatic carcinoma cells. Subsequently, we identified the putative cause for the decrease of the intracellular iron content induced by lipin1 overexpression. Our results suggested that the intracellular iron reduction was due to the increase in the expression of ferroportin, an iron export protein in the stable cells overexpressing lipin1. In contrast, after transfection with lipin1 siRNA, the decreased expression of ferroportin contributed to an increase in the iron content in BEL7402 cells. It was further confirmed that the intracellular iron content was increased after ferroportin was knocked down by siRNA in BEL7402 cells. Taken together, our findings demonstrate for the first time that lipin1 participates in the regulation of iron metabolism in human hepatic carcinoma cells. This suggests that lipin1 may play an important protective role in inhibiting the development of cancer through the reduction of iron content in tumors, which further demonstrates that iron reduction could be a potential strategy of cancer prevention and treatment.

Iron and Cancer

This review explores the multifaceted role that iron has in cancer biology. Epidemiological studies have demonstrated an association between excess iron and increased cancer incidence and risk, while experimental studies have implicated iron in cancer initiation, tumor growth, and metastasis. The roles of iron in proliferation, metabolism, and metastasis underpin the association of iron with tumor growth and progression. Cancer cells exhibit an iron-seeking phenotype achieved through dysregulation of iron metabolic proteins. These changes are mediated, at least in part, by oncogenes and tumor suppressors. The dependence of cancer cells on iron has implications in a number of cell death pathways, including ferroptosis, an iron-dependent form of cell death. Uniquely, both iron excess and iron depletion can be utilized in anticancer therapies. Investigating the efficacy of these therapeutic approaches is an area of active research that promises substantial clinical impact.

Non-thermal plasma specifically kills oral squamous cell carcinoma cells in a catalytic Fe(II)-dependent manner

Oral cancer accounts for ~2% of all cancers worldwide, and therapeutic intervention is closely associated with quality of life. Here, we evaluated the effects of non-thermal plasma on oral squamous cell carcinoma cells with special reference to catalytic Fe(II). Non-thermal plasma exerted a specific killing effect on oral squamous cell carcinoma cells in comparison to fibroblasts. Furthermore, the effect was dependent on the amounts of catalytic Fe(II), present especially in lysosomes. After non-thermal plasma application, lipid peroxidation occurred and peroxides and mitochondrial superoxide were generated. Cancer cell death by non-thermal plasma was promoted dose-dependently by prior application of ferric ammonium citrate and prevented by desferrioxamine, suggesting the association of ferroptosis. Potential involvement of apoptosis was also observed with positive terminal deoxynucleaotidyl transferase-mediated dUTP nick end labeling and annexin V results. Non-thermal plasma exposure significantly suppressed the migratory, invasive and colony-forming abilities of squamous cell carcinoma cells. The oral cavity is easily observable; therefore, non-thermal plasma can be directly applied to the oral cavity to kill oral squamous cell carcinoma without damaging fibroblasts. In conclusion, non-thermal plasma treatment is a potential therapeutic option for oral cancer.

Dietary and Sentinel Factors Leading to Hemochromatosis

Although hereditary hemochromatosis is associated with the mutation of genes involved in iron transport and metabolism, secondary hemochromatosis is due to external factors, such as intended or unintended iron overload, hemolysis-linked iron exposure or other stress-impaired iron metabolism. The present review addresses diet-linked etiologies of hemochromatosis and their pathogenesis in the network of genes and nutrients. Although the mechanistic association to diet-linked etiologies can be complicated, the stress sentinels are pivotally involved in the pathological processes of secondary hemochromatosis in response to iron excess and other external stresses. Moreover, the mutations in these sentineling pathway-linked genes increase susceptibility to secondary hemochromatosis. Thus, the crosstalk between nutrients and genes would verify the complex procedures in the clinical outcomes of secondary hemochromatosis and chronic complications, such as malignancy. All of this evidence provides crucial insights into comprehensive clinical or nutritional interventions for hemochromatosis.

Iron in the Tumor Microenvironment-Connecting the Dots

Iron metabolism and tumor biology are intimately linked. Iron facilitates the production of oxygen radicals, which may either result in iron-induced cell death, ferroptosis, or contribute to mutagenicity and malignant transformation. Once transformed, malignant cells require high amounts of iron for proliferation. In addition, iron has multiple regulatory effects on the immune system, thus affecting tumor surveillance by immune cells. For these reasons, inconsiderate iron supplementation in cancer patients has the potential of worsening disease course and outcome. On the other hand, chronic immune activation in the setting of malignancy alters systemic iron homeostasis and directs iron fluxes into myeloid cells. While this response aims at withdrawing iron from tumor cells, it may impair the effector functions of tumor-associated macrophages and will result in iron-restricted erythropoiesis and the development of anemia, subsequently. This review summarizes our current knowledge of the interconnections of iron homeostasis with cancer biology, discusses current clinical controversies in the treatment of anemia of cancer and focuses on the potential roles of iron in the solid tumor microenvironment, also speculating on yet unknown molecular mechanisms.

Links Between Iron and Lipids: Implications in Some Major Human Diseases

Maintenance of iron homeostasis is critical to cellular health as both its excess and insufficiency are detrimental. Likewise, lipids, which are essential components of cellular membranes and signaling mediators, must also be tightly regulated to hinder disease progression. Recent research, using a myriad of model organisms, as well as data from clinical studies, has revealed links between these two metabolic pathways, but the mechanisms behind these interactions and the role these have in the progression of human diseases remains unclear. In this review, we summarize literature describing cross-talk between iron and lipid pathways, including alterations in cholesterol, sphingolipid, and lipid droplet metabolism in response to changes in iron levels. We discuss human diseases correlating with both iron and lipid alterations, including neurodegenerative disorders, and the available evidence regarding the potential mechanisms underlying how iron may promote disease pathogenesis. Finally, we review research regarding iron reduction techniques and their therapeutic potential in treating patients with these debilitating conditions. We propose that iron-mediated alterations in lipid metabolic pathways are involved in the progression of these diseases, but further research is direly needed to elucidate the mechanisms involved.

Iron overload in myelodysplastic syndromes: Evidence based guidelines from the Canadian consortium on MDS

In 2008 the first evidence-based Canadian consensus guideline addressing the diagnosis, monitoring and management of transfusional iron overload in patients with myelodysplastic syndromes (MDS) was published. The Canadian Consortium on MDS, comprised of hematologists from across Canada with a clinical and academic interest in MDS, reconvened to update these guidelines. A literature search was updated in 2017; topics reviewed include mechanisms of iron overload induced cellular damage, evidence for clinical endpoints impacted by iron overload including organ dysfunction, infections, marrow failure, overall survival, acute myeloid leukemia progression, and endpoints around hematopoietic stem-cell transplant. Evidence for an impact of iron reduction on the same endpoints is discussed, guidelines are updated, and areas identified where evidence is suboptimal. The guidelines address common questions around the diagnosis, workup and management of iron overload in clinical practice, and take the approach of who, when, why and how to treat iron overload in MDS. Practical recommendations for treatment and monitoring are made. Evidence levels and grading of recommendations are provided for all clinical endpoints examined.