Iron overload and its impact on outcome of patients with hematological diseases

Iron overload mediates cytarabine resistance in AML by inhibiting the TP53 signaling pathway

Currently, chemotherapy remains the primary treatment for acute myeloid leukemia (AML). Drug resistance in AML cells is a critical factor contributing to the failure of chemotherapy remission and subsequent relapse. Iron overload frequently occurs in AML patients because of hematopoietic suppression or supportive blood transfusion therapy. Previous studies have indicated that iron overload may promote the progression of AML; however, the underlying mechanisms remain unclear. Our results demonstrate that, compared with TP53-wild-type AML cells, TP53-mutant AML cells exhibit increased resistance to cytarabine-induced cytotoxicity. Moreover, reducing TP53 expression in wild-type AML cells diminishes their sensitivity to cytarabine. The TP53 signaling pathway is essential for mediating cytarabine-induced apoptosis in AML cells. In this study, an iron overload model in AML cells via the use of ferric citrate is constructed. Our data indicate that iron overload can suppress the TP53/BCL2/BAX signaling pathway, counteracting cytarabine-induced apoptosis. In TP53 wild-type AML cells, TFR1 participates in iron-mediated resistance to cytarabine by regulating the entry of iron into the cells. These findings provide a foundation for further exploration of the molecular mechanisms involved in AML resistance to cytarabine.

Prevalence of pulmonary dysfunction and its risk factors in patients with transfusion-dependent thalassaemia: protocol for a systematic review and meta-analysis

INTRODUCTION

Pulmonary complications frequently occur as comorbidities in individuals with transfusion-dependent thalassaemia (TDT). Despite their clinical significance, the existing literature lacks a systematic review and meta-analysis examining the prevalence and risk factors for pulmonary dysfunction in this patient cohort. Therefore, we propose to conduct a systematic review and meta-analysis to report the prevalence and associated risk factors of pulmonary dysfunction in TDT patients.

METHODS AND ANALYSIS

This systematic review and meta-analysis will adhere to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols guidelines. We will search PubMed, EMBASE, the Cochrane Library, Scopus and Web of Science to identify English-language literature from the inception of each database up to 31 May 2024. We will include studies that involve TDT patients and report on the method of pulmonary function assessment, the proportion of pulmonary dysfunction and the analysis of risk factors for pulmonary dysfunction. The study designs included will be cohort, case-control and cross-sectional studies. Exclusions will apply to studies on non-TDT or patients with other diseases, reviews, case reports and animal experiments, as well as duplicated published studies, studies without full-text availability or studies from which raw data cannot be extracted. The screening process, including title, abstract and full texts, will be conducted independently by two reviewers. Data extraction will be performed following standardised protocols. The quality of the included studies will be assessed using the Newcastle-Ottawa Scale and the Agency for Healthcare Research and Quality criteria. The meta-analysis will be conducted using Stata 14.0 and Review Manager (RevMan) 5.4 software, incorporating subgroup analyses, heterogeneity assessments and publication bias evaluations to ensure the robustness and reliability of the findings.

ETHICS AND DISSEMINATION

As the data for this systematic review and meta-analysis are sourced exclusively from previously published literature, there is no requirement for ethical approval. The dissemination of the results will occur through publication in a peer-reviewed scholarly journal and presentations at relevant scientific conferences.

PROSPERO REGISTRATION NUMBER

CRD42024504353.

Associations between iron status and diabetic kidney disease: A nationwide study

BACKGROUND AND AIM

Iron status plays a crucial role in various physiological processes, and its dysregulation is associated with numerous health conditions. However, research on the relationship between iron status and diabetic kidney disease (DKD) is quite limited. Therefore, this study aims to investigate the connection between iron status and DKD.

METHODS AND RESULTS

This population-based cross-sectional survey included adult diabetes patients from five National Health and Nutrition Examination Survey (NHANES) cycles spanning 1999 to 2006 and 2017 to 2018. Regression models were used to assess the impact of iron status on the prevalence of diabetic nephropathy. Restricted cubic spline models further explored potential nonlinear dose-response relationships. Subgroup analyses clarified the effects of other covariates on these associations. Iron and TIBC were negatively correlated with DKD, albuminuria, and low estimated glomerular filtration rate (eGFR). TSAT was negatively correlated with DKD and showed an "L"-shaped nonlinear correlation with albuminuria and low-eGFR. Ferritin exhibited a "J"-shaped nonlinear correlation with DKD, albuminuria, and low-eGFR. Subgroup analysis revealed that the association between TIBC and reduced risk of low eGFR was more pronounced in individuals with hypertension. The associations between iron and TSAT with a reduced risk of DKD were more significant in smokers, while the association between ferritin and an increased risk of albuminuria was also more pronounced in smokers.

CONCLUSIONS

In diabetic patients, iron status is closely associated with DKD. Monitoring these iron status markers can help improve the prevention and management of kidney health in diabetic patients.

Concentration of serum trace elements in leukemia and lymphoma: A case-control study

Objective

Trace elements (TEs) have electrochemical and catalytic effects and play a crucial role in metabolism. A change in the concentrations of specific TEs may be associated with the incidence of various diseases such as solid tumors and hematological malignancies. By comparing the concentrations of TEs in the cases and controls, this study aims to provide insights into the possible impacts of TEs concentration on the incidence of leukemia and lymphoma.

Materials and methods

In the current study, the serum concentrations of Zn, Cu, Cd, Fe, and Se were analyzed for 20 patients with leukemia and lymphoma and 20 healthy individuals. Those concentrations were measured by atomic absorption spectroscopy.

Results

The serum Zn concentration in the cases was significantly lower than that in the controls (P < 0.05). The serum concentrations of Cu, Cd and Fe were also lower in the cases than in the controls. However, no significant difference was found (P > 0.05). Also, the serum concentration of Se was higher in the patients than in the controls, but no significant difference was found (P > 0.05).

Conclusion

The results indicate that a low serum concentration of Zn may be associated with the incidence of leukemia and lymphoma. The assessment of TEs in hematological malignancies may be of a prognostic value and provide knowledge about the side effects of alterations in the concentration of those elements. It may also lead to the use of suitable strategies to better manage the clinical conditions of patients.

[Clinical analysis on the impact of pretransplant iron overload on allogeneic hematopoietic stem cell transplantation for patients with acquired severe aplastic anemia in pediatric]

This study aimed to investigate the effect of iron overload on the transplant outcomes of pediatric patients with severe aplastic anemia (SAA) undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). A retrospective analysis was conducted on the clinical data of 74 children with SAA who received allo-HSCT at the Hematology Department of Wuhan Children's Hospital between January 2018 and August 2022. Children with iron overload (serum ferritin >1 000 μg/L) before transplantation had a longer disease course, received more red blood cell transfusions, and had a higher number of CD34(+) cells infused. Moreover, iron overload significantly delayed the reconstitution of regulatory T cells after transplantation, increasing the incidence of hemorrhagic cystitis and grade Ⅲ-Ⅳ acute graft-versus-host disease after transplantation. However, iron overload did not significantly affect the overall survival and failure-free survival rates of the children.

Deferasirox Causes Leukaemia Cell Death through Nrf2-Induced Ferroptosis

Acute lymphoblastic leukaemia (ALL) is the most prevalent cancer in children, and excessive iron buildup resulting from blood transfusions and chemotherapy potentially has a negative impact on treatment outcomes and prognosis in patients with ALL. Therefore, initiating early iron chelation therapy during ALL treatment is a logical approach. Ideally, the selected iron chelator should also possess anti-leukaemia properties. The aim of the present study was to explore the potential impact and underlying mechanism of deferasirox (DFX) in ALL therapy. This study proved that DFX, an iron chelator, is capable of inducing leukaemia cell death through ferroptosis, which is achievable by increasing the expression of acetylated nuclear factor erythroid 2-related factor 2 (NRF2). More specifically, NRF2 acetylation on Lys599 was facilitated by acetyltransferase-p300/CBP. These findings indicate that DFX could serve as a potent adjunctive medication for patients with ALL. Moreover, DFX may offer dual benefits in ALL treatment, functioning as both an iron chelator and NRF2-modulating agent. Further research and clinical trials are necessary to fully elucidate the therapeutic potential of DFX in patients with ALL and incorporate it into treatment protocols.

A Risk Stratification System in Myeloma Patients with Autologous Stem Cell Transplantation

Autologous stem cell transplantation (ASCT) has been a mainstay in myeloma treatment for over three decades, but patient prognosis post-ASCT varies significantly. In a retrospective study of 5259 patients with multiple myeloma (MM) at the University of Arkansas for Medical Sciences undergoing ASCT with a median 57-month follow-up, we divided the dataset into training (70%) and validation (30%) subsets. Employing univariable and multivariable Cox analyses, we systematically assessed 29 clinical variables, identifying crucial adverse prognostic factors, such as extended duration between MM diagnosis and ASCT, elevated serum ferritin, and reduced transferrin levels. These factors could enhance existing prognostic models. Additionally, we pinpointed significant poor prognosis markers like high serum calcium and low platelet counts, though they are applicable to a smaller patient population. Utilizing seven easily accessible high-risk variables, we devised a four-stage system (ATM4S) with primary stage borders determined through K-adaptive partitioning. This staging system underwent validation in both the training dataset and an independent cohort of 514 ASCT-treated MM patients from the University of Iowa. We also explored cytogenetic risk factors within this staging system, emphasizing its potential clinical utility for refining prognostic assessments and guiding personalized treatment approaches.

Iron overload promotes the progression of MLL-AF9 induced acute myeloid leukemia by upregulation of FOS

Systemic iron overload is a common clinical challenge leading to significantly serious complications in patients with acute myeloid leukemia (AML), which affects both the quality of life and the overall survival of patients. Symptoms can be relieved after iron chelation therapy in clinical practice. However, the roles and mechanisms of iron overload on the initiation and progression of leukemia remain elusive. Here we studied the correlation between iron overload and AML clinical outcome, and further explored the role and pathophysiologic mechanism of iron overload in AML by using two mouse models: an iron overload MLL-AF9-induced AML mouse model and a nude xenograft mouse model. Patients with AML had an increased ferritin level, particularly in the myelomonocytic (M4) or monocytic (M5) subtypes. High level of iron expression correlated with a worsened prognosis in AML patients and a shortened survival time in AML mice. Furthermore, iron overload increased the tumor load in the bone marrow (BM) and extramedullary tissues by promoting the proliferation of leukemia cells through the upregulation of FOS. Collectively, our findings provide new insights into the roles of iron overload in AML. Additionally, this study may provide a potential therapeutic target to improve the outcome of AML patients and a rationale for the prospective evaluation of iron chelation therapy in AML.

Dual role of Nrf2/HO-1 pathway in Z-ligustilide-induced ferroptosis against AML cells

BACKGROUND

The scarcity of drugs targeting AML cells poses a significant challenge in AML management. Z-Ligustilide (Z-LIG), a phthalide compound, shows promising pharmacological potential as a candidate for AML therapy. However, its precise selective mechanism remains unclear.

PURPOSE

In order to assess the selective inducement effects of Z-LIG on ferroptosis in AML cells and explore the possible involvement of the Nrf2/HO-1 pathway in the regulation of ferroptosis.

METHODS

Through in vitro cell proliferation and in vivo tumor growth tests, the evaluation of Z-LIG's anticancer activity was conducted. Ferroptosis was determined by the measurement of ROS and lipid peroxide levels using flow cytometry, as well as the observation of mitochondrial morphology. To analyze the iron-related factors, western blot analysis was employed. The up-regulation of the Nrf2/HO-1 axis was confirmed through various experimental techniques, including CRISPR/Cas9 gene knockout, fluorescent probe staining, and flow cytometry. The efficacy of Z-LIG in inducing ferroptosis was further validated in a xenograft nude mouse model.

RESULTS

Our study revealed that Z-LIG specifically triggered lipid peroxidation-driven cell death in AML cells. Z-LIG downregulated the total protein and nuclear entrance levels of IRP2, resulting in upregulation of FTH1 and downregulation of TFR1. Z-LIG significantly increased the susceptibility to ferroptosis by upregulating ACSL4 levels and simultaneously suppressing the activity of GPX4. Notably, the Nrf2/HO-1 pathway displayed a twofold impact in the ferroptosis induced by Z-LIG. Mild activation suppressed ferroptosis, while excessive activation promoted it, mainly driven by ROS-induced labile iron pool (LIP) accumulation in AML cells, which was not observed in normal human cells. Additionally, Nrf2 knockout and HO-1 knockdown reversed iron imbalance and mitochondrial damage induced by Z-LIG in HL-60 cells. Z-LIG effectively inhibited the growth of AML xenografts in mice, and Nrf2 knockout partially weakened its antitumor effect by inhibiting ferroptosis.

CONCLUSION

Our study presents biological proof indicating that the selective initiation of ferroptosis in leukemia cells is credited to the excessive activation of the Nrf2/HO-1 pathway triggered by Z-LIG.

Hypoferremia of inflammation: Innate host defense against infections

Iron is an essential nutrient for microbes, plants and animals. Multicellular organisms have evolved multiple strategies to control invading microbes by restricting microbial access to iron. Hypoferremia of inflammation is a rapidly-acting organismal response that prevents the formation of iron species that would be readily accessible to microbes. This review takes an evolutionary perspective to explore the mechanisms and host defense function of hypoferremia of inflammation and its clinical implications.

Association of iron status with all-cause and cause-specific mortality in individuals with diabetes

AIMS

Current evidence regarding iron status and mortality risk among patients with diabetes is limited. This study aimed to evaluate association of iron indices with all-cause and cause-specific mortality risk among patients with diabetes.

METHODS

The current study included 2080 (with ferritin data), 1974 (with transferrin saturation (Tsat) data), and 1106 (with soluble transferrin receptor (sTfR) data) adults with diabetes from NHANES 1999-2018. Death outcomes were obtained from National Death Index through December 31, 2019. Cox proportional hazards models were employed to calculate hazard ratios and 95% confidence intervals for mortality.

RESULTS

Association with all-cause mortality was demonstrated to be J-shaped for serum ferritin (Pnonlinearity < 0.01), U-shaped for Tsat (Pnonlinearity < 0.01) and linear for sTfR (Plinearity < 0.01). Ferritin 300-500 ng/mL possessed lower all-cause mortality risk than ferritin ≤ 100 ng/mL, 100-300 ng/mL, and > 500 ng/mL. Tsat 25-32 % showed a protective effect on all-cause mortality risk compared with Tsat ≤ 20 %, 20-25 %, and > 32 %. Individuals with sTfR < 4 mg/L were associated with a lower risk of all-cause mortality than those with higher sTfR.

CONCLUSIONS

Moderate levels of serum ferritin (300-500 ng/mL), Tsat (25 %-32 %) and a lower concentration of sTfR (< 4 mg/L) identified adults with diabetes with lower all-cause mortality risk, adding novel modifiers to diabetes management.

Diagnostic and prognostic value of ferroptosis-related genes in patients with Myelodysplastic neoplasms

This study delves into the emerging role of ferroptosis in Myelodysplastic Neoplasms (MDS) and aims to identify a prognostic ferroptosis-related gene signature for MDS. Utilizing RNA-seq data and clinical information from the Gene Expression Omnibus database, the researchers extracted ferroptosis-related genes from the FerrDb website and conducted differential expression analysis using the 'limma' package in R. Hub ferroptosis-related genes in MDS were screened using the "RandomForest" and "carat" R packages. Kaplan -Meier and Cox regression analyses were employed to assess the prognostic role of three identified hub genes (BNIP3, MDM2, and RRM2). Receiver operator characteristic curve analysis confirmed the diagnostic efficacy of these genes. The study delved further into immune infiltration correlations, ncRNA-transcription factor coregulatory network analysis, and the identification of potential therapeutic drugs targeting hub ferroptosis-related genes in MDS. The researchers constructed a 3-gene signature-based risk score using datasets GSE58831 and GSE19429, demonstrating high accuracy (AUC > 0.75) in both datasets for survival prediction in MDS. A nomogram analysis reinforced the prognostic value of the risk-scoring model. Immunological analysis revealed an association between the risk score and immune infiltration. Quantitative reverse transcription polymerase chain reaction (qPCR) data indicated significant expression differences in MDM2, RRM2, and BNIP3 between MDS and healthy bone marrow samples. Notably, MDM2 and RRM2 showed decreased expression, while BNIP3 exhibited increased expression in MDS samples. This comprehensive study concludes that BNIP3, MDM2, and RRM2 hold diagnostic and prognostic significance in MDS and provide valuable insights into immune cell landscapes and potential therapeutic avenues for this condition.

Non-transferrin-bound iron determination in blood serum using microsequential injection solid phase spectrometry- proof of concept

Non-transferrin-bound iron (NTBI) is a group of circulating toxic iron forms, which occur in iron overload or health conditions with dysregulation of iron metabolism. NTBI is responsible for increased oxidative stress and tissue iron loading. Despite its relevance as a biochemical marker in several diseases, a standardized assay is still lacking. Several methods were developed to quantify NTBI, but results show high inter-method and even inter-laboratory variability. Thus, the development of a consistent NTBI assay is a major goal in the management of iron overload and related clinical conditions. In this work, a micro sequential injection lab-on-valve (μSI-LOV) method in a solid phase spectrophotometry (SPS) mode was developed for the quantification of NTBI, using a bidentate 3,4-hydroxypyridinone (3,4-HPO) ligand anchored to sepharose beads as a chromogenic reagent. To attain SPS, the functionalized beads were packed into a column in the flow cell, and the analyte, NTBI retained as iron (III), formed a colored complex at the beads while eliminating the sample matrix. The dynamic concentration range was 1.62-7.16 μmol L^-1 of iron (III), with a limit of detection of 0.49 μmol L^-1 and a limit of quantification of 1.62 μmol L^-1. The proposed μSI-LOV-SPS method is a contribution to the development of an automatic method for the quantification of the NTBI in serum samples.

Current Understanding of Flavonoids in Cancer Therapy and Prevention

Cancer is a major cause of death worldwide, with multiple pathophysiological manifestations. In particular, genetic abnormalities, inflammation, bad eating habits, radiation exposure, work stress, and toxin consumption have been linked to cancer disease development and progression. Recently, natural bioactive chemicals known as polyphenols found in plants were shown to have anticancer capabilities, destroying altered or malignant cells without harming normal cells. Flavonoids have demonstrated antioxidant, antiviral, anticancer, and anti-inflammatory effects. Flavonoid type, bioavailability, and possible method of action determine these biological actions. These low-cost pharmaceutical components have significant biological activities and are beneficial for several chronic disorders, including cancer. Recent research has focused primarily on isolating, synthesizing, and studying the effects of flavonoids on human health. Here we have attempted to summarize our current knowledge of flavonoids, focusing on their mode of action to better understand their effects on cancer.

Impact of iron overload in hematopoietic stem cell transplantation

Iron overload (IOL) is a common condition in patients with hematological malignancies(HMs) undergoing hematopoietic stem cell transplantation (HSCT). Pathophysiologically, IOL results in iron-induced toxicity in HSCT by producing reactive oxygen species (ROS), which leads to detrimental effects on hematopoiesis, clonal evolution, and immunosuppression. IOL, therefore, may have a negative impact on the clinical outcomes of HSCT. For patients at a higher risk of developing IOL before HSCT, it is necessary to monitor red blood cell transfusion units, serum ferritin (SF) levels and MRI image of organs, and initiate iron removal therapy as soon as possible. Iron chelating therapy (ICT) might be safe and efficient in the post-HSCT period. We provide an overview of results from experimental and clinical evidence on the current understanding of IOL in patients with HMs undergoing HSCT, involving the underlying pathophysiological and clinical impact of IOL, as well as the significance of iron reduction therapy.

Iron Metabolism in Cardiovascular Disease: Physiology, Mechanisms, and Therapeutic Targets

The cardiovascular system requires iron to maintain its high energy demands and metabolic activity. Iron plays a critical role in oxygen transport and storage, mitochondrial function, and enzyme activity. However, excess iron is also cardiotoxic due to its ability to catalyze the formation of reactive oxygen species and promote oxidative damage. While mammalian cells have several redundant iron import mechanisms, they are equipped with a single iron-exporting protein, which makes the cardiovascular system particularly sensitive to iron overload. As a result, iron levels are tightly regulated at many levels to maintain homeostasis. Iron dysregulation ranges from iron deficiency to iron overload and is seen in many types of cardiovascular disease, including heart failure, myocardial infarction, anthracycline-induced cardiotoxicity, and Friedreich's ataxia. Recently, the use of intravenous iron therapy has been advocated in patients with heart failure and certain criteria for iron deficiency. Here, we provide an overview of systemic and cellular iron homeostasis in the context of cardiovascular physiology, iron deficiency, and iron overload in cardiovascular disease, current therapeutic strategies, and future perspectives.

Plasma Non-transferrin-Bound Iron Could Enter into Mice Duodenum and Negatively Affect Duodenal Defense Response to Virus and Immune Responses

Plasma non-transferrin-bound iron (NTBI) exists when the plasma iron content exceeds the carrying capacity of transferrin and can be quickly cleared by the liver, pancreas, and other organs. However, whether it could enter the small intestine and its effects still remain unclear. Herein, these issues were explored. Mice were intravenously administrated of ferric citrate (treatment) or citrate acid (control) 10 min after the saturation of the transferrin. Two hours later, hepatic, duodenal, and jejunal iron content and distribution were measured and duodenal transcriptome sequencing was performed. Significant increase of duodenal and hepatic iron content was detected, indicating that plasma NTBI could be absorbed by the duodenum as well as the liver. A total of 103 differentially expressed genes were identified in the duodenum of mice in the treatment group compared to the control group. Gene Ontology (GO) functional analysis of these genes showed that they were mainly involved in defense response to virus and immune response. The results of Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) analysis revealed that there were major changes in the hematopoietic cell lineage and some virus infection pathways between the two groups. Determination of 7 cytokines in the duodenum were further conducted, which demonstrated that the anti-inflammatory factors interferon (IL)-4 and IL-10 in the duodenum were significantly decreased after NTBI uptake. Our findings revealed that NTBI in plasma can enter the duodenum, which would change the duodenal hematopoietic cell lineage and have a negative impact on defense response to the virus and immune responses.

From iron chelation to overload as a therapeutic strategy to induce ferroptosis in hematologic malignancies

OBJECTIVES

Ferroptosis is an iron-dependent, non-apoptotic mode of cell death characterized by excessive accumulation of reactive oxygen species (ROS). It plays an important role in the occurrence, development and treatment of various cancers, but little is known regarding the role of ferroptosis in hematologic malignancies. This review elaborates the regulatory mechanism of ferroptosis and the treatment opportunities for targeting ferroptosis in hematologic malignancies.

METHODS

A systematic literature review through PubMed was conducted to summarize the published evidence on the therapeutic potential of targeting ferroptosis in hematological malignant tumors. Literature sources published in English were searched, using the terms ferroptosis, leukemia, myelodysplastic syndrome, lymphoma and multiple myeloma.

RESULTS

More and more small molecules have been found to induce ferroptosis in hematologic malignancies through targeted iron metabolism and lipid peroxidation, and some ferroptosis inducers have been proved to have synergistic effect with other chemotherapeutic drugs.

CONCLUSION

This paper discusses the significance of ferroptosis in hematologic malignancies and provides a new way for the treatment of hematologic malignancies, and more experimental studies should be conducted in future.

Melatonin: Potential avenue for treating iron overload disorders

Iron overload as a highly risk factor, can be found in almost all human chronic and common diseases. Iron chelators are often used to treat iron overload; however, patient adherence to these chelators is poor due to obvious side effects and other disadvantages. Numerous studies have shown that melatonin has a high iron chelation ability and direct free radical scavenging activity, and can inhibit the lipid peroxidation process caused by iron overload. Therefore, melatonin may become potential complementary therapy for iron overload-related disorders due to its iron chelating and antioxidant activities. Here, the research progress of iron overload is reviewed and the therapeutic potential of melatonin in the treatment of iron overload is analyzed. In addition, studies related to the protective effects of melatonin on oxidative damage induced by iron overload are discussed. This review provides a foundation for preventing and treating iron homeostasis disorders with melatonin.

Naringenin protects against iron overload-induced osteoarthritis by suppressing oxidative stress

BACKGROUND

The traditional Chinese medicine Gusuibu, the rhizome of Rhizoma Drynariae, is used to treat rheumatism and fractures. Naringenin (NAR) is an active ingredient in Gusuibu and has significant anti-inflammatory and antioxidant effects. However, the role of naringenin in iron overload-induced osteoarthritis (IOOA) is unknown.

HYPOTHESIS

NAR reduces cartilage damage in IOOA.

METHODS

The effects of NAR on the viability of IOOA chondrocytes and the synthesis ability of type II collagen were evaluated using cell counting kit (CCK8) and toluidine blue assays. To determine the mechanism of action and characteristics of NAR, the intracellular iron ion content, apoptosis rate, and mitochondrial membrane potential (MMP) change, and malondialdehyde (MDA) levels, as well as the degree of reactive oxygen species (ROS) and lipid hydroperoxide (LPO) accumulation in the cells were detected in vitro and verified using western blotting and quantitative real-time PCR (qRT-PCR). To verify the role of NAR in vivo, IOOA mice were established using iron dextran and surgery-induced destabilised medial meniscus. Changes in the articular cartilage and subchondral bone were examined using Safranin O-fast Green staining (S-O), haematoxylin-eosin staining (H&E), and microcomputed tomography (μCT).

RESULTS

In vitro, NAR attenuated the impairment of cell viability, apoptosis, and MMP caused by ferric ammonium citrate and interleukin-1β co-culture, increased the levels of MDA, reduced the expression of matrix metallopeptidase (MMP)3, MMP13, and Bax, and restored the expression of type II collagen (Col II). NAR showed a slight iron accumulation-reducing effect. NAR alleviated the accumulation of ROS and LPO in IOOA chondrocytes and upregulated antioxidant genes nuclear factor E2-related factor 2 (NRF2) and haem oxygenase 1 (HO-1). When ML385, a specific NRF-2 inhibitor, was added, the protective effect of NAR was significantly inhibited. In vivo, NAR reduced synovitis and attenuated cartilage damage and subchondral bone proliferation in IOOA mice.

CONCLUSIONS

NAR can reduce oxidative stress through the NRF2-HO-1 pathway, alleviate cartilage damage under iron overload, and has the potential to treat IOOA.

Understanding the Potential and Risk of Bacterial Siderophores in Cancer

Siderophores are iron chelating molecules produced by nearly all organisms, most notably by bacteria, to efficiently sequester the limited iron that is available in the environment. Siderophores are an essential component of mammalian iron homeostasis and the ongoing interspecies competition for iron. Bacteria produce a broad repertoire of siderophores with a canonical role in iron chelation and the capacity to perform versatile functions such as interacting with other microbes and the host immune system. Siderophores are a vast area of untapped potential in the field of cancer research because cancer cells demand increased iron concentrations to sustain rapid proliferation. Studies investigating siderophores as therapeutics in cancer generally focused on the role of a few siderophores as iron chelators; however, these studies are limited and some show conflicting results. Moreover, siderophores are biologically conserved, structurally diverse molecules that perform additional functions related to iron chelation. Siderophores also have a role in inflammation due to their iron acquisition and chelation properties. These diverse functions may contribute to both risks and benefits as therapeutic agents in cancer. The potential of siderophore-mediated iron and bacterial modulation to be used in the treatment of cancer warrants further investigation. This review discusses the wide range of bacterial siderophore functions and their utilization in cancer treatment to further expand their functional relevance in cancer detection and treatment.

Transfusional iron overload in heavily transfused patients: real-life data from a 10-year retrospective study of 611 cases managed in a French general hospital

OBJECTIVES

Epidemiological studies on transfusional iron overload (TIO) in the general population of heavily transfused patients are scarce. The aim of this work was to provide a picture on the distribution and management of this complication within the context of unselected individuals attending a general hospital.

METHODS

We retrospectively assessed the characteristics of 611 patients from a single institution having received at least 20 red blood cell (RBC) units over a 10-year period.

RESULTS

About two-thirds of these individuals were males and their median age at the 20^th RBC was 72 years (range: 10-98). Myelodysplastic syndromes (MDS) and acute myeloid leukemia represented the most frequent underlying conditions (53%) but lymphoid malignancies and solid malignancies accounted for 13.6 and 7.3% respectively. In the vast majority of cases various comorbidities (range: 1-6 per patient) were registered including especially cardiovascular disorders. The highest cumulative RBC numbers were observed in MDS patients. Serum ferritin was assessed in 451 patients (73.8%) and ≥ 1000 μg/L in 250 cases, ≥ 2000 μg/L in 100 cases and ≥ 2500 μg/L in 71 cases. Only 97 patients (15.9%) received a treatment for TIO using either a chelator (n=93) or phlebotomy (n=4).

CONCLUSION

TIO is not limited to MDS or hemoglobin disorders. Its assessment and management are suboptimal in clinical practice. The ratio of patients receiving iron chelation is markedly lower than theoretically expected mainly because of comorbidities or drug intolerance.

Gold Nanorods Exhibit Intrinsic Therapeutic Activity via Controlling N6-Methyladenosine-Based Epitranscriptomics in Acute Myeloid Leukemia

Reprograming the N6-methyladenosine (m⁶A) landscape is a promising therapeutic strategy against recalcitrant leukemia. In this study, we synthesized gold nanorods (GNRs) of different aspect ratios using a binary surfactant mixture of hexadecyltrimethylammonium bromide and sodium oleate. Following surface functionalization with chitosan and a 12-mer peptide, GNRa-CSP12 measuring 130 × 21 nm² was selectively taken up by leukemia cells via targeted endocytosis. Low doses of GNRa-CSP12 inhibited the growth of leukemia cells by disrupting the redox balance and inducing ferroptosis. Mechanistically, GNRa-CSP12 abrogated endogenous Fe²⁺-dependent m⁶A demethylase activity, which led to global m⁶A hypomethylation and post-transcriptional regulation of downstream genes that are involved in glycolysis, hypoxia, and immune checkpoint pathways. In addition, combination treatment with GNRa-CSP12 and tyrosine kinases inhibitors (TKIs) synergistically obviated the m⁶A-mediated TKI resistance phenotype. Finally, GNRa-CSP12 as a potential immunotherapeutic agent could enhance immunotherapy outcome in leukemia. Our preclinical findings provide the proof-of-concept for targeting m⁶A-methylation-based epitranscriptomics using nanoparticle as an "epigenetic drug" for cancer therapy.

Iron overload during the treatment of acute leukemia: pretransplant transfusion experience

BACKGROUND

Recent studies have shown the increased risk of mortality in cases with acute leukemia and iron overload. We aimed to determine the status of iron overload in patients with acute leukemia.

MATERIALS & METHODS

Patients diagnosed with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) between January 2015 and December 2019 were included in the study.

RESULTS

At 6 months, there were statistically more patients with serum ferritin >1000 in the AML group compared to the ALL group (p = 0,011).

CONCLUSION

Iron overload occurs earlier in patients with AML; the difference disappears after 6 months of treatment. It is the correct point to emphasize that iron overload is an important factor of pretransplant morbidity, especially in AML cases.

Role of Flavonoids in the Treatment of Iron Overload

Iron overload, a high risk factor for many diseases, is seen in almost all human chronic and common diseases. Iron chelating agents are often used for treatment but, at present, most of these have a narrow scope of application, obvious side effects, and other disadvantages. Recent studies have shown that flavonoids can affect iron status, reduce iron deposition, and inhibit the lipid peroxidation process caused by iron overload. Therefore, flavonoids with iron chelating and antioxidant activities may become potential complementary therapies. In this study, we not only reviewed the research progress of iron overload and the regulation mechanism of flavonoids, but also studied the structural basis and potential mechanism of their function. In addition, the advantages and disadvantages of flavonoids as plant iron chelating agents are discussed to provide a foundation for the prevention and treatment of iron homeostasis disorders using flavonoids.

EnvIRONmental Aspects in Myelodysplastic Syndrome

Systemic iron overload is multifactorial in patients suffering from myelodysplastic syndrome (MDS). Disease-immanent ineffective erythropoiesis together with chronic red blood cell transfusion represent the main underlying reasons. However, like the genetic heterogeneity of MDS, iron homeostasis is also diverse in different MDS subtypes and can no longer be generalized. While a certain amount of iron and reactive oxygen species (ROS) are indispensable for proper hematological output, both are harmful if present in excess. Consequently, iron overload has been increasingly recognized as an important player in MDS, which is worth paying attention to. This review focuses on iron- and ROS-mediated effects in the bone marrow niche, their implications for hematopoiesis and their yet unclear involvement in clonal evolution. Moreover, we provide recent insights into hepcidin regulation in MDS and its interaction between erythropoiesis and inflammation. Based on Tet methylcytosine dioxygenase 2 (TET2), representing one of the most frequently mutated genes in MDS, leading to disturbances in both iron homeostasis and hematopoiesis, we highlight that different genetic alteration may have different implications and that a comprehensive workup is needed for a complete understanding and development of future therapies.

Clinical and Prognostic Pan-Cancer Analysis of N6-Methyladenosine Regulators in Two Types of Hematological Malignancies: A Retrospective Study Based on TCGA and GTEx Databases

N6-methyladenosine (m6A) is one of the most active modification factors of mRNA, which is closely related to cell proliferation, differentiation, and tumor development. Here, we explored the relationship between the pathogenesis of hematological malignancies and the clinicopathologic parameters. The datasets of hematological malignancies and controls were obtained from the TCGA [AML (n = 200), DLBCL (n = 48)] and GTEx [whole blood (n = 337), blood vascular artery (n = 606)]. We analyzed the m6A factor expression differences in normal tissue and tumor tissue and their correlations, clustered the express obvious clinical tumor subtypes, determined the tumor risk score, established Cox regression model, performed univariate and multivariate analysis on all datasets. We found that the AML patients with high expression of IGF2BP3, ALKBH5, and IGF2BP2 had poor survival, while the DLBCL patients with high expression of METTL14 had poor survival. In addition, "Total" datasets analysis revealed that IGF2BP1, ALKBH5, IGF2BP2, RBM15, METTL3, and ZNF217 were potential oncogenes for hematologic system tumors. Collectively, the expressions of some m6A regulators are closely related to the occurrence and development of hematologic system tumors, and the intervention of specific regulatory factors may lead to a breakthrough in the treatment in the future.