Iron and hepcidin mediate human colorectal cancer cell growth

Recent advancements in nanomaterial-mediated ferroptosis-induced cancer therapy: Importance of molecular dynamics and novel strategies

Ferroptosis is a novel type of controlled cell death resulting from an imbalance between oxidative harm and protective mechanisms, demonstrating significant potential in combating cancer. It differs from other forms of cell death, such as apoptosis and necrosis. Molecular therapeutics have hard time playing the long-acting role of ferroptosis induction due to their limited water solubility, low cell targeting capacity, and quick metabolism in vivo. To this end, small molecule inducers based on biological factors have long been used as strategy to induce cell death. Research into ferroptosis and advancements in nanotechnology have led to the discovery that nanomaterials are superior to biological medications in triggering ferroptosis. Nanomaterials derived from iron can enhance ferroptosis induction by directly releasing large quantities of iron and increasing cell ROS levels. Moreover, utilizing nanomaterials to promote programmed cell death minimizes the probability of unfavorable effects induced by mutations in cancer-associated genes such as RAS and TP53. Taken together, this review summarizes the molecular mechanisms involved in ferroptosis along with the classification of ferroptosis induction. It also emphasized the importance of cell organelles in the control of ferroptosis in cancer therapy. The nanomaterials that trigger ferroptosis are categorized and explained. Iron-based and noniron-based nanomaterials with their characterization at the molecular and cellular levels have been explored, which will be useful for inducing ferroptosis that leads to reduced tumor growth. Within this framework, we offer a synopsis, which traverses the well-established mechanism of ferroptosis and offers practical suggestions for the design and therapeutic use of nanomaterials.

Ferroptosis: a new hunter of hepatocellular carcinoma

Ferroptosis is an iron ion-dependent, regulatory cell death modality driven by intracellular lipid peroxidation that plays a key role in the development of HCC. Studies have shown that various clinical agents (e.g., sorafenib) have ferroptosis inducer-like effects and can exert therapeutic effects by modulating different key factors in the ferroptosis pathway. This implies that targeting tumor cell ferroptosis may be a very promising strategy for tumor therapy. In this paper, we summarize the prerequisites and defense systems for the occurrence of ferroptosis and the regulatory targets of drug-mediated ferroptosis action in HCC, the differences and connections between ferroptosis and other programmed cell deaths. We aim to summarize the theoretical basis, classical inducers of ferroptosis and research progress of ferroptosis in HCC cells, clued to the treatment of HCC by regulating ferroptosis network. Further investigation of the specific mechanisms of ferroptosis and the development of hepatocellular carcinoma and interventions at different stages of hepatocellular carcinoma will help us to deepen our understanding of hepatocellular carcinoma, with a view to providing new and more precise preventive as well as therapeutic measures for patients.

Iron metabolism in colorectal cancer: a balancing act

BACKGROUND

Colorectal cancer (CRC) is the third most commonly diagnosed cancer and the second deadliest malignancy worldwide. Current dietary habits are associated with increased levels of iron and heme, both of which increase the risk of developing CRC. The harmful effects of iron overload are related to the induction of iron-mediated pro-tumorigenic pathways, including carcinogenesis and hyperproliferation. On the other hand, iron deficiency may also promote CRC development and progression by contributing to genome instability, therapy resistance, and diminished immune responses. In addition to the relevance of systemic iron levels, iron-regulatory mechanisms in the tumor microenvironment are also believed to play a significant role in CRC and to influence disease outcome. Furthermore, CRC cells are more prone to escape iron-dependent cell death (ferroptosis) than non-malignant cells due to the constitutive activation of antioxidant genes expression. There is wide evidence that inhibition of ferroptosis may contribute to the resistance of CRC to established chemotherapeutic regimens. As such, ferroptosis inducers represent promising therapeutic drugs for CRC.

CONCLUSIONS AND PERSPECTIVES

This review addresses the complex role of iron in CRC, particularly in what concerns the consequences of iron excess or deprivation in tumor development and progression. We also dissect the regulation of cellular iron metabolism in the CRC microenvironment and emphasize the role of hypoxia and of oxidative stress (e.g. ferroptosis) in CRC. Finally, we underline some iron-related players as potential therapeutic targets against CRC malignancy.

Preoperative intravenous iron treatment - a cohort study on colorectal cancer recurrence

Background

Intravenous (i.v.) iron treatment has been speculated to increase the malignant potential of colorectal malignancies but also to enhance the immune systems potential to fight the invasive tumor. Clinical data however is very limited. We investigate if preoperative i.v. iron treatment is associated with colorectal cancer (CRC) recurrence.

Methods

Retrospective cohort study on surgical CRC patients with iron deficiency anemia (1st March 2013 - 31st December 2019). Patients were grouped based on whether they had received preoperative treatment with i.v. iron. Local data was combined with data from the National Danish Health registries to identify recurrences, death, and emigration. Survival analysis, including Kaplan-Meyer curves and multivariate competing risk analysis adjusting for sex, age, ASA-group, tumor stage, surgical radicality, and miss match repair status was performed.

Results

Of 1228 patients, 125 were available for analysis. 89 patients had received preoperative i.v. iron and 36 had not. The two groups were comparable on baseline and surgical characteristics. Median follow-up times were 4.74 in iron treated patients and 5 years in patients not receiving iron treatment. Five-year rate of non-recurrence was 85 % (0.74-0.91) in the i.v. iron treated group vs. 82 % (0.64-0.91) in the control group, non-significant difference. Multivariate survival analysis did not find iron treatment to be associated with recurrence rates (Hazard Ratio 0.88 (95 % ci; 0.31-2.51).

Conclusion

No association between preoperative i.v. iron treatment and the five-year cancer recurrence rate in iron deficient anemic CRC patients was found.

Exploration of novel clusters and prognostic value of immune‑related signatures and identify HAMP as hub gene in colorectal cancer

Immune checkpoint inhibitors currently serve an important role in prolonging patients' overall survival. However, the prognostic signatures of immune checkpoint inhibitors in colorectal cancer (CRC) remain uncertain and more knowledge on the genetic characteristics of colorectal cancer is needed. Patients with CRC from The Cancer Genome Atlas were classified into high-immunity group and low-immunity group based on median scores from single-sample gene set enrichment analysis using the GSVA package. We explored immune status by immune scores, stromal scores and tumor purity scores in ESTIMATE package and surveyed the difference of immune cells distribution with CIBERSORT package. Eighteen genes were selected using the LASSO Cox regression method and a prognostic risk model was constructed. Compared with patients in the low-risk group, those in the high-risk group had a significantly shorter survival time. For assessment of the prognostic validity of the risk model, receiver operating characteristic curves with areas under the curve of 0.769, 0.774 and 0.771 for 1, 3 and 5 years respectively. Differences in molecular mechanisms between high- and low-risk groups were analyzed using the clusterProfiler package. Tumor Immune Dysfunction and Exclusion data were downloaded and analyzed. The top 5 enriched pathways in the high-risk group involved 'calcium signaling', 'dilated cardiomyopathy', 'extracellular matrix receptor interaction', 'hypertrophic cardiomyopathy' and 'neuroactive ligand receptor interaction'. HAMP was identified as a hub gene, which was highly expressed in tumor samples. The results of the present study indicate that the prognostic model based on both immune-related genes and HAMP has the potential to support personalized treatment.

HIF2α, Hepcidin and their crosstalk as tumour-promoting signalling

Not all aspects of the disruption of iron homeostasis in cancer have been fully elucidated. Iron accumulation in cancer cells is frequent for many solid tumours, and this is often accompanied by the contemporary rise of two key iron regulators, HIF2α and Hepcidin. This scenario is different from what happens under physiological conditions, where Hepcidin parallels systemic iron concentrations while HIF2α levels are inversely associated to Hepcidin. The present review highlights the increasing body of evidence for the pro-tumoral effect of HIF2α and Hepcidin, discusses the possible imbalance in HIF2α, Hepcidin and iron homeostasis during cancer, and explores therapeutic options relying on these pathways as anticancer strategies.

Construction of a prognostic signature associated with liver metastases for prognosis and immune response prediction in colorectal cancer

Background

As the most common gastrointestinal malignancy worldwide, liver metastases occur in half colorectal cancer (CRC) patients. Early detection can help treat them early and reduce mortality in patients with colorectal cancer liver metastases (CRLM). Finding useful biomarkers for CRLM is thus essential.

Methods

The TCGA and GEO databases were used to download the expression profiles and clinical data of the patients. Differential analysis screened for genes associated with CRLM, and univariate Cox regression analysis identified genes associated with prognosis. The least absolute shrinkage and selection operator (LASSO) method further preferred genes to construct a prognostic signature. Kaplan-Meier survival curves were used to show patients' overall survival (OS). Receiver operating characteristic (ROC) curves showed the accuracy of the model. Risk scores and clinical characteristics of patients were included in multivariate Cox regression analysis to identify independent risk factors, and a nomogram was constructed. The proportion of immune cells and infiltration were assessed using the 'CIBERSORT' package and the 'ESTIMATE' package.

Results

We constructed a signature consisting of seven CRLM-associated genes, and signature-based risk scores have great potential in estimating the prognosis of CRC patients. Moreover, the poor response to immunotherapy in high-risk patients might contribute to the poor prognosis of individuals. Furthermore, we found that overexpression of Hepcidin antimicrobial peptide (HAMP), the only gene highly expressed in CRC and liver metastatic tissues, promoted CRC development and that it was associated with tumor mutation burden (TMB), DNA mismatch repair (MMR) genes, and microsatellite instability (MSI) in various tumors. Finally, we found that in CRC patients, low expression of HAMP also represented a better immunotherapeutic outcome, reflecting the critical role of HAMP in guiding immunotherapy.

Conclusion

We identified a prognostic signature containing 7 CRLM-associated genes, and the signature was specified as an independent predictor and a nomogram containing the risk score was built accordingly. In addition, the derived gene HAMP could help guide the exploration of profitable immunotherapeutic strategies.

Iron Metabolism in Cancer and Senescence: A Cellular Perspective

Iron participates in a number of biological processes and plays a crucial role in cellular homeostasis. Alterations in iron metabolism are considered hallmarks of cancer and drivers of aggressive behaviors, such as uncontrolled proliferation, resistance to apoptosis, enhanced metastatic ability, increased cell plasticity and stemness. Furthermore, a dysregulated iron metabolism has been associated with the development of an adverse tumor microenvironment. Alterations in iron metabolism have been described in cellular senescence and in aging. For instance, iron has been shown to accumulate in aged tissues and in age-related diseases. Furthermore, in vitro studies demonstrate increases in iron content in both replicative and stress-induced senescent cells. However, the role, the mechanisms of regulation and dysregulation and the effects of iron metabolism on senescence remain significantly less characterized. In this review, we first provide an overview of iron metabolism and iron regulatory proteins. Then, we summarize alterations in iron homeostasis in cancer and senescence from a cellular point of view.

Pyroptosis, ferroptosis, and autophagy cross-talk in glioblastoma opens up new avenues for glioblastoma treatment

Glioma is a common primary tumor of the central nervous system (CNS), with glioblastoma multiforme (GBM) being the most malignant, aggressive, and drug resistant. Most drugs are designed to induce cancer cell death, either directly or indirectly, but malignant tumor cells can always evade death and continue to proliferate, resulting in a poor prognosis for patients. This reflects our limited understanding of the complex regulatory network that cancer cells utilize to avoid death. In addition to classical apoptosis, pyroptosis, ferroptosis, and autophagy are recognized as key cell death modalities that play significant roles in tumor progression. Various inducers or inhibitors have been discovered to target the related molecules in these pathways, and some of them have already been translated into clinical treatment. In this review, we summarized recent advances in the molecular mechanisms of inducing or inhibiting pyroptosis, ferroptosis, or autophagy in GBM, which are important for treatment or drug tolerance. We also discussed their links with apoptosis to better understand the mutual regulatory network among different cell death processes. Video Abstract.

Prognostic Significance of Iron Metabolism Related Genes in Human Lung Adenocarcinoma

Background

Iron metabolism related genes participate in cell proliferation, cell growth, and redox cycling in multiple cancers. Limited studies have revealed the roles and clinical significance of iron metabolism in the pathogenesis and prognosis of lung cancer.

Methods

A total of 119 iron metabolism related genes were extracted from MSigDB database and their prognostic values were determined in The Cancer Genome Atlas lung adenocarcinoma (TCGA-LUAD) dataset and the Gene Expression Profiling Interactive Analysis 2 (GEPIA 2) database. Immunohistochemistry technique and correlations with immune cell infiltration, gene mutation and drug resistance were used to identify the potential and underlying mechanisms of STEAP1 and STEAP2 as prognostic biomarkers of LUAD.

Results

The expression of STEAP1 and STEAP2 are negatively associated with the prognosis of LUAD patients both at the mRNA and protein level. The expression of STEAP1 and STEAP2 was not only negatively correlated with the trafficking degree of CD4+ T immune cells and positively related to most immune cells' trafficking degree, but also significantly associated with gene mutation status, particularly with mutations on TP53 and STK11. Four types of drug resistance showed significant correlation with the expression level of STEAP1 while 13 types of drug resistance were associated with the expression level of STEAP2.

Conclusion

Multiple iron metabolism related genes including STEAP1 and STEAP2 are significantly associated with the prognosis of LUAD patients. STEAP1 and STEAP2 might affect the prognosis of LUAD patients partially through immune cell infiltration, gene mutation and drug resistance, which indicated they were independent prognostic factors for LUAD patients.

Progress in the study of ferroptosis in cancer treatment: State-of-the-Art

As a regulatory cell death mode defined in recent years, Ferroptosis is mainly characterized by increased intracellular free iron and the accumulation of lipid peroxides. Ferroptosis is closely related to iron ion metabolism, lipid metabolism, and amino acid metabolism. Cancer is the second leading cause of death worldwide, and effective removal of tumour cells while protecting normal cells is the key to tumour treatment. The continuous development and refinement of molecular mechanisms related to ferroptosis have shown promising applications in tumour therapy. There is increasing evidence that triggering ferroptosis in tumour cells is expected to be a new therapeutic strategy for tumour treatment.

Mechanism and application of ferroptosis in colorectal cancer

Colorectal cancer (CRC) is the third most common malignant tumor in the world. CRC has high morbidity and mortality rates and it is a serious threat to human health. Ferroptosis is a unique form of iron-dependent oxidative cell death that is usually accompanied by iron accumulation and lipid peroxidation. Ferroptosis has attracted worldwide attention since it was first proposed. It plays an important role in the development of a variety of diseases, such as tumors, ischemia/reperfusion injury, nervous system diseases, and kidney damage, and it may serve as a new therapeutic target. This article reviews the mechanism of ferroptosis and the possibility to target ferroptosis pathways in CRC, providing new ideas for the diagnosis and treatment of CRC.

Distinctive modulation of hepcidin in cancer and its therapeutic relevance

Hepcidin, a short peptide synthesized primarily by hepatocytes in response to increased body iron and inflammation, is a crucial iron-regulating factor. Hepcidin regulates intestinal iron absorption and releases iron from macrophages into plasma through a negative iron feedback mechanism. The discovery of hepcidin inspired a torrent of research into iron metabolism and related problems, which have radically altered our understanding of human diseases caused by an excess of iron, an iron deficiency, or an iron disparity. It is critical to decipher how tumor cells manage hepcidin expression for their metabolic requirements because iron is necessary for cell survival, particularly for highly active cells like tumor cells. Studies show that tumor and non-tumor cells express and control hepcidin differently. These variations should be explored to produce potential novel cancer treatments. The ability to regulate hepcidin expression to deprive cancer cells of iron may be a new weapon against cancer cells.

High Hepcidin expression predicts poor prognosis in patients with clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is a growing public health challenge worldwide. Hepcidin antimicrobial peptide (HAMP) is differentially expressed in various tumors. However, the roles and functions of HAMP in ccRCC remain unclear. In the present study, we integrated systematic bioinformatics approaches to investigate the roles and functions of HAMP and its association with immune cell infiltration in ccRCC. Compared with paracancerous tissue, HAMP expression was significantly upregulated in ccRCC patients. Meanwhile, we found good diagnostic performance of HAMP for ccRCC patients and its close associations with the clinicopathological features of ccRCC patients. In addition, we found that HAMP is closely related to multiple immune pathways and positively correlated with various immune cells. HAMP was a significant independent predictor for ccRCC. High expression of HAMP was associated with worse clinical prognosis and more immune cell infiltration in ccRCC patients. HAMP may offer potential as a biomarker to predict prognosis and the clinical treatment outcome of ccRCC patients.

Hepcidin Upregulation in Colorectal Cancer Associates with Accumulation of Regulatory Macrophages and Epithelial-Mesenchymal Transition and Correlates with Progression of the Disease

Advanced, metastatic colorectal cancer (CRC) is associated with high rate of mortality because of its poor responsiveness to chemotherapy/immunotherapy. Recent studies have shown that hepcidin, a peptide hormone produced mainly by hepatocytes, is expressed by and enhances the growth of tumor cells. We here assessed whether hepcidin expression helps identify subsets of CRC with advanced and aggressive course. By integrating results of in vitro/ex vivo studies with data of bioinformatics databases, we initially showed that hepcidin RNA and protein expression was more pronounced in tissue samples taken from the tumor area, as compared to the macroscopically unaffected, adjacent, colonic mucosa of CRC patients. The induction of hepcidin in the colonic epithelial cell line HCEC-1ct by interleukin (IL)-6, IL-21 and IL-23 occurred via a Stat3-dependent mechanism and, in primary CRC cells, hepcidin co-localized with active Stat3. In CRC tissue, hepcidin content correlated mainly with macrophage accumulation and IL-10 and CD206 expression, two markers of regulatory macrophages. Consistently, both IL-10 and CD206 were up-regulated by hepcidin in blood mononuclear cells. The highest levels of hepcidin were found in metastatic CRC and survival analysis showed that high expression of hepcidin associated with poor prognosis. Moreover, hepcidin expression correlated with markers of epithelial-to-mesenchymal transition and the silencing of hepcidin in CRC cells reduced epithelial-to-mesenchymal transition markers. These findings indicate that hepcidin is markedly induced in the advanced stages of CRC and suggest that it could serve as a prognostic biomarker in CRC.

HAMP as a Prognostic Biomarker for Colorectal Cancer Based on Tumor Microenvironment Analysis

Colorectal cancer (CRC) is the most common digestive tumor in the world and has a high mortality rate. The development and treatment of CRC are related to the immune microenvironment, but immune response-related prognostic biomarkers are lacking. In this study, we used The Cancer Genome Atlas (TCGA) to explore the tumor microenvironment (TME) and weighted gene coexpression network analysis (WGCNA) to identify significant prognostic genes. We also identified differentially expressed genes in the TCGA data and explored immune-related genes and transcription factors (TFs). Then, we built a TF regulatory network and performed a comprehensive prognostic analysis of an lncRNA-associated competitive endogenous RNA network (ceRNA network) to build a prognostic model. CCR8 and HAMP were identified both in the WGCNA key module and as immune-related genes. HAMP had good prognostic value for CRC and was highly expressed in CRC tissues and had a negative correlation with CD4⁺ T cells and M0 macrophages based on immunohistochemistry and immunofluorescence staining of clinical specimens.We found that HAMP had high prognostic and therapeutic target value for CRC and was associated with liver metastasis. These analysis results revealed that HAMP may be a candidate immune-related prognostic biomarker for CRC.

Synthesis and bioimaging of a BODIPY-based fluorescence quenching probe for Fe3

Iron is the main substance for maintaining life. Real-time determination of ferric ion (Fe³⁺) in living cells is of great significance for understanding the relationship of Fe³⁺ concentration changes with various physiological and pathological processes. Fluorescent probes are suitable for the detection of trace metal ions in cells due to their low toxicity and high sensitivity. In this work, a boron-dipyrromethene-based fluorescent probe (BODIPY-CL) for selective detection of Fe³⁺ was synthesized. The fluorescence emission of BODIPY-CL was determined at 516 nm. In a pH range of 1 to 10, the probe BODIPY-CL exhibits a quenching response to Fe³⁺. Meanwhile, BODIPY-CL showed a highly selective response to Fe³⁺ compared with 16 kinds of metal ions. The stoichiometry ratio of BODIPY-CL bound to Fe³⁺ was nearly 2 : 1. The fluorescence quenching response obtained by the sensor was linear with the Fe³⁺ concentration in the range of 0-400 μM, and the detection limit was 2.9 μM. BODIPY-CL was successfully applied to image Fe³⁺ in cells. This study provides a promising fluorescent imaging probe for further research on the physiological and pathological effects of Fe³⁺.

Association between Blood Donation and Malignant and Benign Tumour Risk: A Population-Based Study of 3.4 Million Participants in China

This study aims to identify the relationship between blood donation and malignant and benign tumour hospitalization risk. The cohort study was constructed in Shaanxi, China, to include blood donors and match nonblood donors one-to-one by gender, age, and county of residence. The study compared the hospitalization records of two groups from 2012 to 2018. A log-binomial regression model was used to estimate the relative risk (RR) of tumour risk between donors and nonblood donors among different age groups. A total of 1,625,599 donors were recruited (including 968,823 males) and compared with the matched nonblood donor group. Significantly lower risk of malignancy in males was found among donors (adjusted RR: 0.82, 95% CI: 0.75–0.92). Lower risks for specific types of tumours among donors were observed, including liver (0.42, [0.28–0.67]), lung (0.74, [0.59–0.87]), lymphoma (0.75, [0.62–0.85]), and oesophagus (0.55, [0.41–0.72]). However, the risk of brain cancer was higher among male donors (RR 1.19 [1.06–1.29]). Among female donors, lower risk of liver (0.57, [0.42–0.79]) and oesophagus malignancy (0.73, [0.62–0.88]) was observed. For benign tumours, male donors have a lower risk of benign skin tumour (0.79, [0.62–0.94]) and hemangioma and lymphangioma (0.75, [0.51–0.89]), while female donors have a lower risk in hemangioma and lymphangioma (0.65, [0.44–0.83]). We also found that the risk decreased with age among donors in the prevalence of tumours compared to that in nonblood donors ( $p<0.05$ ). Blood donation appears to be significantly associated with various tumour risks among both males and females. Overall, the risk of tumours decreased more substantially with age in blood donors compared with nonblood donors. Further research is warranted to investigate the impact of ‘health donor effects’ on these findings.

An Integrated Systematic Analysis and the Clinical Significance of Hepcidin in Common Malignancies of the Male Genitourinary System

Tumors of the male genitourinary system are of great concern to the health of men worldwide. Although emerging experiment-based evidence indicates an association between hepcidin and such cancers, an integrated analysis is still lacking. For this reason, in this study, we determined the underlying oncogenic functions of hepcidin in common male genitourinary system tumors, including bladder urothelial carcinoma (BLCA), kidney chromophobe (KICH), kidney renal clear cell carcinoma (KIRC), kidney renal papillary cell carcinoma (KIRP), prostate adenocarcinoma (PRAD), and testicular germ cell tumors (TGCT) according to the data from The Cancer Genome Atlas. We found that hepcidin was highly expressed in kidney and testicular cancers. Meanwhile, the expression level of hepcidin was distinctly associated with the prognosis and immune cell infiltration in male patients with certain genitourinary system cancers, especially in KIRC. Elevated hepcidin levels also present as a risk factor in male genitourinary system tumors. Moreover, enrichment analyses revealed that some of the principal associated signaling pathways involving hepcidin and its related genes are identified as tumorigenesis-related. Immunofluorescence staining confirmed the conclusion of our immune infiltration analysis in KIRC tissue. In this study, for the first time, we provided evidence for the oncogenic function of hepcidin in different types of male genitourinary system tumors.

Double chelation of Iron through dimer formation of favipiravir: Density functional theory analysis

This work was performed to examine an idea about full chelation of Iron (Fe) by well-known favipiravir (Fav) as a possible mechanism of action for medication of COVID-19 patients. To this aim, formations of Fe- mediated dimers of Fav were investigated by performing density functional theory (DFT) computations of electronic and structural features for singular and dimer models. The results indicated that the models of dimers were suitable for formation, in which two cis (D1) and trans (D2) models were obtained regarding the configurations of two Fav counterparts towards each other. Energy results indicated that formation of D1 was slightly more favorable than formation of D2. Molecular orbital features affirmed hypothesized interacting sites of Fav for Fe-mediated dimers formations, in which atomic charges and other molecular orbital related representations affirmed such achievements. Moreover, detection of such dimer formation was also possible by monitoring variations of molecular orbitals features. As a consequence, formations of Fe-mediated dimers of Fav could be achievable for possible removal of excess of Fe as a proposed mechanism of action for Fav in medication of COVID-19 patients.

The Role of Iron in Cancer Progression

Iron is an essential trace element for the human body, and its deficiency or excess can induce a variety of biological processes. Plenty of evidences have shown that iron metabolism is closely related to the occurrence and development of tumors. In addition, iron plays an important role in cell death, which is very important for the development of potential strategies for tumor treatment. Here, we reviewed the latest research about iron metabolism disorders in various types of tumors, the functions and properties of iron in ferroptosis and ferritinophagy, and new opportunities for iron-based on treatment methods for tumors, providing more information regarding the prevention and treatment of tumors.

A highly effective "turn-on" camphor-based fluorescent probe for rapid and sensitive detection and its biological imaging of Fe2

In this work, a novel fluorescent probe CBO was synthesized for detecting Fe²⁺ using the natural monoterpenketone camphor as the starting material. The probe CBO displayed turn-on fluorescence to Fe²⁺ accompanied by the solution change from colorless to green. As expected, there was an excellent linear relationship between the fluorescence intensity of probe CBO and the concentration of Fe²⁺ (0-20 μM), and the detection limit was as low as 1.56×10^-8 M. In particular, CBO could selectively sense Fe²⁺ more than other analytes (Fe³⁺ included) through the N-oxide strategy, and quickly responded to Fe²⁺ (60 s) over a wide pH (4-14) range. Additionally, based on the rapid fluorescence response of CBO to Fe²⁺, a simple test strip-based detector was designed for boosting practical applicability. The probe CBO had been successfully applied to the fluorescence imaging of Fe²⁺ in onion cells and living zebrafish. The probe CBO was a powerful tool of detecting Fe²⁺ level in organisms, which was of significance to understand the role of Fe²⁺ in Fe²⁺-related physical processes and diseases.

An Original Ferroptosis-Related Gene Signature Effectively Predicts the Prognosis and Clinical Status for Colorectal Cancer Patients

Background

Colorectal cancer (CRC) is one of the most common malignant tumors in the world. Ferroptosis is a newly defined form of cell death, distinguished by different morphology, biochemistry, and genetics, and involved in CRC progression and treatment. This study aims to establish a predictive model to elucidate the relationship between ferroptosis and prognosis of CRC patients, to explore the potential value of ferroptosis in therapeutic options.

Methods

The ferroptosis-related genes were obtained from the GeneCards and FerrDb websites. The limma R package was used to screen the differential ferroptosis-related genes (DEGs) in CRC from The Cancer Genome Atlas (TCGA) dataset. The least absolute shrinkage and selection operator (LASSO) and multivariate Cox regressions were to establish the 10-gene prognostic signature. The survival and receiver operating characteristic (ROC) curves were illustrated to evaluate the predictive effect of the signature. Besides, independent prognostic factors, downstream functional enrichment, drug sensitivity, somatic mutation status, and immune feature were analyzed. Moreover, all these conclusions were verified by using multiple datasets in International Cancer Genome Consortium (ICGC) and Gene Expression Omnibus (GEO).

Results

Ten ferroptosis-related gene signature (TFAP2C, SLC39A8, NOS2, HAMP, GDF15, FDFT1, CDKN2A, ALOX12, AKR1C1, ATP6V1G2) was established to predict the prognosis of CRC patients by Lasso cox analysis, demonstrating a good performance on Receiver operating characteristic (ROC) and Kaplan–Meier (K–M) analyses. The CRC patients in the high- or low-risk group showed significantly different fractions of immune cells, such as macrophage cells and CD8+ T cells. Drug sensitivity and somatic mutation status like TP53 were also closely associated with the risk scores.

Conclusions

In this study, we identified a novel ferroptosis-related 10-gene signature, which could effectively predict the prognosis and survival time of CRC patients, and provide meaningful clinical implications for targeted therapy or immunotherapy. Targeting ferroptosis is a good therapeutic option for CRC patients. Further studies are needed to reveal the underlying mechanisms of ferroptosis in CRC.

Iron Dysregulation in Human Cancer: Altered Metabolism, Biomarkers for Diagnosis, Prognosis, Monitoring and Rationale for Therapy

Simple Summary

Iron is the more abundant metal ion in humans. It is essential for life as it has a role in various cellular processes involved, for instance, in cell metabolism and DNA synthesis. These functions are crucial for cell proliferation, and it is therefore not surprising that iron is accumulated in tumors. In this review, we describe normal and altered iron homeostasis mechanisms. We also provide a vision of iron-related proteins with altered expression in cancers and discuss their potential as diagnostic and/or prognostic biomarkers. Finally, we give an overview of therapeutic strategies acting on iron metabolism to fight against cancers.

Abstract

Iron (Fe) is a trace element that plays essential roles in various biological processes such as DNA synthesis and repair, as well as cellular energy production and oxygen transport, and it is currently widely recognized that iron homeostasis is dysregulated in many cancers. Indeed, several iron homeostasis proteins may be responsible for malignant tumor initiation, proliferation, and for the metastatic spread of tumors. A large number of studies demonstrated the potential clinical value of utilizing these deregulated proteins as prognostic and/or predictive biomarkers of malignancy and/or response to anticancer treatments. Additionally, the iron present in cancer cells and the importance of iron in ferroptosis cell death signaling pathways prompted the development of therapeutic strategies against advanced stage or resistant cancers. In this review, we select relevant and promising studies in the field of iron metabolism in cancer research and clinical oncology. Besides this, we discuss some co-existing discrepant findings. We also present and discuss the latest lines of research related to targeting iron, or its regulatory pathways, as potential promising anticancer strategies for human therapy. Iron chelators, such as deferoxamine or iron-oxide-based nanoparticles, which are already tested in clinical trials, alone or in combination with chemotherapy, are also reported.

Circulating osteocyte-related biomarkers (vitamin D, sclerostin, dickkopf-1), hepcidin, and oxidative stress markers in early breast cancer: Their impact in disease progression and outcome

Breast cancer (BC) is a major concern to female health worldwide. We assessed the circulating osteocyte-related biomarkers, hepcidin, and oxidative stress status among early-stage BC patients in aspects of clinical severity and impact on the outcome. The study incorporated 73 patients categorized into 57 early-stage BC and 16 benign breast diseases and 30 healthy controls. Serum 25-hydroxyvitamin D [25(OH)D], sclerostin (SOST), dickkopf-1(DKK1), and hepcidin were measured using ELISA, while, serum oxidative stress markers were assessed by spectrophotometry. Our results show that patients with BC showed significant increase in the mean levels of DKK1, SOST, hepcidin, and LPER and significant decrease in the mean levels of 25(OH)D, SOD, GPx, and Hb when compared with controls and benign breast diseases. Significantly higher DKK1, hepcidin, and SOD levels among benign breast diseases were found in comparison to control group. There were significantly lower levels of 25(OH)D, SOD, and Hb and significantly higher levels of SOST, DKK1, hepcidin, No, and LPER with advanced grade. Lower levels of 25(OH)D, SOD and higher levels of SOST, hepcidin were observed with increasing the malignant stage. Reduced levels of 25(OH)D, and SOD were significantly associated with poor prognosis and were strong predictors among BC. There were significant negative correlations between 25(OH)D with LPER, SOST, and hepicidin. We conclude that low 25(OH)D, high SOST, DKK1, and hepcidin, and dysregulated oxidative stress could be helpful in early detection and assessment of BC. 25(OH)D, and SOD were the most relevant to tumor progression and prognosis which indicate a significant role in the BC pathogenesis and could be promising targets in management. Our research paves the way to disrupt vicious circle between these biomarkers to obtain the best care of BC.

General Aspects of Metal Ions as Signaling Agents in Health and Disease

This review focuses on the current knowledge on the involvement of metal ions in signaling processes within the cell, in both physiological and pathological conditions. The first section is devoted to the recent discoveries on magnesium and calcium-dependent signal transduction-the most recognized signaling agents among metals. The following sections then describe signaling pathways where zinc, copper, and iron play a key role. There are many systems in which changes in intra- and extra-cellular zinc and copper concentrations have been linked to important downstream events, especially in nervous signal transduction. Iron signaling is mostly related with its homeostasis. However, it is also involved in a recently discovered type of programmed cell death, ferroptosis. The important differences in metal ion signaling, and its disease-leading alterations, are also discussed.

Influence of Iron on the Gut Microbiota in Colorectal Cancer

Perturbations of the colonic microbiota can contribute to the initiation and progression of colorectal cancer, leading to an increase in pathogenic bacteria at the expense of protective bacteria. This can contribute to disease through increasing carcinogenic metabolite/toxin production, inducing inflammation, and activating oncogenic signaling. To limit disease progression, external factors that may influence the colonic microbiota need to be considered in patients with colorectal cancer. One major factor that can influence the colonic microbiota is iron. Iron is an essential micronutrient that is required by both prokaryotes and eukaryotes for cellular function. Most pathogenic bacteria have heightened iron acquisition mechanisms and therefore tend to outcompete protective bacteria for free iron. Colorectal cancer patients often present with anemia due to iron deficiency, and thus they require iron therapy. Depending upon the route of administration, iron therapy has the potential to contribute to a procarciongenic microbiota. Orally administered iron is the common treatment for anemia in these patients but can lead to an increased gut iron concentration. This suggests the need to reassess the route of iron therapy in these patients. Currently, this has only been assessed in murine studies, with human trials being necessary to unravel the potential microbial outcomes of iron therapy.