Targeting SLC7A11 specifically suppresses the progression of colorectal cancer stem cells via inducing ferroptosis

FADS2 inhibits colorectal cancer cell proliferation by regulating ferroptosis through SLC7A11/GPX4

BACKGROUND

Colorectal cancer (CRC) is a leading factor in cancer mortality globally. Ferroptosis, a regulated cell death described via lipid peroxidation, is crucial in cancer biology. This study explores the link between ferroptosis, FADS2, and CRC, focusing on the prognostic significance and therapeutic potential of targeting FADS2.

METHODS

The differential expression analysis of the Cancer Genome Atlas-colon adenocarcinoma (TCGA-COAD) and GSE36400 datasets was conducted to determine key ferroptosis-related genes, followed by functional enrichment analysis. Prognosis-related genes were assessed utilizing Least Absolute Shrinkage and Selection Operator (LASSO) Cox regression. Genetic variation analysis and immune analysis were employed to evaluate the clinical significance of FADS2. The impacts of FADS2 knockdown on CRC cell migration, proliferation, invasion, and ferroptosis were evaluated by in vitro cell experiments.

RESULTS

64 key ferroptosis-related genes in CRC were highly enriched in pathways such as glutathione metabolism and peroxisome. Eleven prognosis-associated genes were identified, with TP53 showing the highest mutation frequency. High FADS2 expression was linked to poorer prognosis and higher immune cell infiltration. FADS2 knockdown significantly decreased glutathione (GSH) levels, SLC7A11, and GPX4 expression, increased malondialdehyde (MDA) levels, indicating the promotion of ferroptosis. Functional tests revealed knockdown FADS2 repressed CRC cell proliferation, migration, and invasion. SLC7A11 or GPX4 overexpression partially rescued the effects of FADS2 knockdown. Additionally, FADS2 knockdown enhances the chemosensitivity of CRC cells to oxaliplatin.

CONCLUSION

FADS2 is essential for encouraging CRC cell proliferation and tumor growth by preventing ferroptosis. Targeting FADS2 may enhance ferroptosis and suppress CRC progression, offering a possible course of treatment for CRC patients. The knockdown of FADS2 enhances the chemosensitivity of CRC cells to oxaliplatin, providing valuable insights for future clinical applications.

Trifluridine/tipiracil induces ferroptosis by targeting p53 via the p53-SLC7A11 axis in colorectal cancer 3D organoids

Trifluridine/Tipiracil (FTD/TPI, TAS102) has been approved for the treatment of patients with colorectal cancer (CRC) for its promising anticancer activity enabled by its incorporation into double strands during DNA synthesis. However, the mechanisms underlying the anticancer targets of FTD/TPI remain not fully understood. Here we report our observation of the activation of ferroptosis in CRC by FTD/TPI. Mechanistically, FTD/TPI directly promotes the ubiquitination and degradation of MDM2, thereby stabilizing the p53. Nuclear accumulation of p53 subsequently downregulates SLC7A11 expression, leading to ferroptosis. Furthermore, we observed that FTD/TPI combined with sulfasalazine (SAS), a system Xc- inhibitor, works in a synergistic manner to induce ferroptosis and further inhibit the proliferation of CRC cells. Finally, we confirmed the synergistic effect of SAS and FTD/TPI on patient-derived organoids in vitro and patient-derived xenograft mouse models in vivo. Our findings are the first to reveal that FTD/TPI induces ferroptosis via the p53-SLC7A11 axis and that SAS enhances the sensitivity and therapeutic effect of FTD/TPI. These findings suggest that the synergistic effect of FTD/TPI and SAS may represent a new therapeutic strategy for patients with CRC.

Deciphering Ferroptosis: From Molecular Pathways to Machine Learning-Guided Therapeutic Innovation

Ferroptosis is a unique form of cell death reliant on iron and lipid peroxidation. It disrupts redox balance, causing cell death by damaging the plasma membrane, with inducers acting through enzymatic pathways or transport systems. In cancer treatment, suppressing ferroptosis or circumventing it holds significant promise. Beyond cancer, ferroptosis affects aging, organs, metabolism, and nervous system. Understanding ferroptosis mechanisms holds promise for uncovering novel therapeutic strategies across a spectrum of diseases. However, detection and regulation of this regulated cell death are still mired with challenges. The dearth of cell, tissue, or organ-specific biomarkers muted the pharmacological use of ferroptosis. This review covers recent studies on ferroptosis, detailing its properties, key genes, metabolic pathways, and regulatory networks, emphasizing the interaction between cellular signaling and ferroptotic cell death. It also summarizes recent findings on ferroptosis inducers, inhibitors, and regulators, highlighting their potential therapeutic applications across diseases. The review addresses challenges in utilizing ferroptosis therapeutically and explores the use of machine learning to uncover complex patterns in ferroptosis-related data, aiding in the discovery of biomarkers, predictive models, and therapeutic targets. Finally, it discusses emerging research areas and the importance of continued investigation to harness the full therapeutic potential of targeting ferroptosis.

Cell Death and Survival Mechanisms in Cholangiocarcinogenesis

Cholangiocarcinoma (CCA) and other liver cancer subtypes often develop in damaged organs. Physiological agents or extrinsic factors such as toxins can induce cell death in such tissues, triggering compensatory proliferation and inflammation. Depending on extracellular and intracellular factors, different mechanisms such as apoptosis, necroptosis, ferroptosis, or autophagy can be triggered. Each of these mechanisms can lead to pro-tumorigenic or anti-tumorigenic events within a cell or through regulation of the microenvironment. However, the exact role of each cell death mechanism in CCA onset, progression, and treatment is not well known. Here, we summarize current knowledge of different cell death and survival mechanisms in patients with CCA and preclinical CCA research. We discuss cell death-related drugs with relevance to CCA treatment and how they could be used in the future to improve targeted CCA therapy.

Ferroptosis: A New Strategy for the Treatment of Fibrotic Diseases

Ferroptosis is a new type of cell death characterized by iron dependence and the excessive accumulation of lipid reactive oxygen species (lipid ROS) that has gradually become better characterized. There is sufficient evidence indicating that ferroptosis is associated with a variety of human life activities and diseases, such as tumor suppression, ischemic organ injury, and degenerative disorders. Notably, ferroptosis is also involved in the initiation and development of fibrosis in various organs, including liver fibrosis, pulmonary fibrosis, renal fibrosis, and cardiac fibrosis, which is usually irreversible and refractory. Although a large number of patients with fibrosis urgently need to be treated, the current treatment options are still limited and unsatisfactory. Organ fibrosis involves a series of complex and orderly processes, such as parenchymal cell damage, recruitment of inflammatory cells and activation of fibroblasts, which ultimately leads to the accumulation of extracellular matrix (ECM) and the formation of fibrosis. An increasing number of studies have confirmed the close association between these pathological processes and ferroptosis. This review summarizes the role and function of ferroptosis in fibrosis and proposes several potential therapeutic strategies and pathways based on ferroptosis.

Application prospects of ferroptosis in colorectal cancer

Colorectal cancer (CRC) is a serious threat to human health with the third morbidity and the second cancer-related mortality worldwide. It is urgent to explore more effective strategy for CRC because of the acquired treatment resistance from the non-surgical conventional therapies, including radiation, chemotherapy, targeted therapy and immunotherapy. Ferroptosis is a novel form of programmed cell death characterized by iron-dependent lipid peroxidation species (ROS) accumulation and has been identified as a promising target for cancer treatment, especially for those with treatment resistance. In this review, we mainly summarize the recent studies on the influence and regulation of ferroptosis by which (including gut microbiota) modulating the metabolism of iron, amino acid and lipid. Thus this analysis may provide potential targets for inducing CRC ferroptosis and shed lights on the future application of ferroptosis in CRC.

Targeting ferroptosis in gastrointestinal tumors: Interplay of iron-dependent cell death and autophagy

Ferroptosis is a regulated cell death mechanism distinct from apoptosis, autophagy, and necroptosis, marked by iron accumulation and lipid peroxidation. Since its identification in 2012, it has developed into a potential therapeutic target, especially concerning GI disorders like PC, HCC, GC, and CRC. This interest arises from the distinctive role of ferroptosis in the progression of diseases, presenting a new avenue for treatment where existing therapies fall short. Recent studies emphasize the promise of focusing on ferroptosis to fight GI cancers, showcasing its unique pathophysiological mechanisms compared to other types of cell death. By comprehending how ferroptosis aids in the onset and advancement of GI diseases, scientists aim to discover novel drug targets and treatment approaches. Investigating ferroptosis in gastrointestinal disorders reveals exciting possibilities for novel therapies, potentially revolutionizing cancer treatment and providing renewed hope for individuals affected by these tumors.

Influence of Mesalazine on Ferroptosis-Related Gene Expression in In Vitro Colorectal Cancer Culture

Background/Objectives: Colorectal cancer (CRC) is one of the most common oncological disorders. Its fundamental treatments include surgery and chemotherapy, predominantly utilizing 5-fluorouracil (5-FU). Despite medical advances, CRC continues to present a high risk of recurrence, metastasis and low survival rates. Consequently, significant emphasis has been directed towards exploring novel types of cell death, particularly ferroptosis. Ferroptosis is characterized by iron imbalance and the accumulation of lipid peroxides and reactive oxygen species (ROS), leading to cellular damage and death. Thus, the discovery of safe inducers of ferroptosis, offering new hope in the struggle against CRC, remains crucial. In this study, we applied the concept of drug repositioning, selecting mesalazine (MES), a non-steroidal anti-inflammatory drug (NSAID), for investigation. Methods: The study was conducted on the colon cancer cell line DLD-1 and normal intestinal epithelial cells from the CCD 841 CoN cell line. Both cell lines were treated with MES solutions at concentrations of 10, 20, 30, 40, and 50 mM. Cytotoxicity was assessed using the MTT assay, while ferroptosis-related gene expression analysis was performed using oligonucleotide microarrays, with RT-qPCR used for validation. Results: MES effectively reduces the viability of DLD-1 cells while minimally affecting normal intestinal cells. Subsequent oligonucleotide microarray analysis revealed that MES significantly alters the expression of 56 genes associated with ferroptosis. Conclusions: Our results suggest that MES may induce ferroptosis in CRC, providing a foundation for further research in this area.

A hydrogen sulfide-activated Pd@Cu2O nanoprobe for NIR-II photoacoustic imaging of colon cancer and photothermal-enhanced ferroptosis therapy

Imaging guided cancer therapy is a comprehensive strategy that combines the diagnosis and treatment to eradicate tumors. Ferroptosis is a distinct programmed cell death and holds great potential in cancer therapy. In this study, a hydrogen sulfide (H2S)-activated PEGylated Pd@Cu2O core-shell nanocomposite (termed PCO) that in situ transformed into Pd@Cu2-xS (termed PCS) at colorectal tumor tissues is developed for colorectal cancer photoacoustic (PA) imaging and photothermal-enhanced ferroptosis therapy in NIR-II window. The Cu+ on the surface of PCS can catalyze the Fenton-like reaction with overexpressed H2O2 in the colon tumor tissues, yielding hydroxyl radicals (·OH) and Cu2+. Moreover, the PCS accelerates the Fenton-like reaction to generate more ·OH. The PCS displays dual peroxidase- and glutathione oxidase-mimic enzymatic activity in weakly acidic tumor microenvironment (TME). Additionally, the glutathione depletion by Cu2+ results in the production of Cu+ and glutathione disulfide as well as the down-regulation of glutathione peroxidase 4. The interaction of polyunsaturated fatty acids with ·OH induces the up-regulation of lipid peroxides on cellular membrane, thereby causing ferroptosis. Hence, this study has developed the H2S-activated PCO that in situ transforms into PCS, as a novel colon cancer diagnosis-treatment nanoprobe, for PA imaging guided precise diagnosis and efficient therapy of colon cancer.

Regulation of SLC7A11 as an unconventional checkpoint in tumorigenesis through ferroptosis

Although cell-cycle arrest, senescence, and apoptosis are well accepted as the classic barriers in tumorigenesis, recent studies indicate that metabolic regulation is equally important as a major checkpoint in cancer development. It is well accepted that ferroptosis, an iron-dependent programmed cell death, acts as a new type of tumor suppression mechanism tightly linked with numerous metabolic pathways. SLC7A11 is a transmembrane cystine/glutamate transporter protein that plays a vital role in controlling ferroptosis in vivo. The levels of SLC7A11 are dynamically regulated by various types of stresses, such as oxidative stress, nutrient deprivation, endoplasmic reticulum stress, radiation, oncogenic stress, DNA damage, and immune stress. SLC7A11 can be transcriptionally regulated by both activators such as ATF4, NRF2, and ETS1, and repressors including BACH1, p53, ATF3, and STAT1 during stress responses. Moreover, SLC7A11 activity and its protein stability and cellular localization are also modulated upon stress. Patients' data show that SLC7A11 is overexpressed in various types of human cancers, and higher levels of SLC7A11 predict poorer overall survival. Growing evidence also suggests that targeting SLC7A11 is a promising approach in cancer therapy by effectively inhibiting tumor proliferation, invasion, and metastasis, as well as counteracting cancer stem cells and overcoming chemoresistance. This review highlights the regulation of SLC7A11 as an unconventional checkpoint in tumorigenesis through modulating ferroptotic responses under various types of stress.

Overexpression of ELF3 in the PTEN-deficient lung epithelium promotes lung cancer development by inhibiting ferroptosis

Ferroptosis has been shown to play a crucial role in preventing cancer development, but the underlying mechanisms of dysregulated genes and genetic alternations driving cancer development by regulating ferroptosis remain unclear. Here, we showed that the synergistic role of ELF3 overexpression and PTEN deficiency in driving lung cancer development was highly dependent on the regulation of ferroptosis. Human ELF3 (hELF3) overexpression in murine lung epithelial cells only caused hyperplasia with increased proliferation and ferroptosis. hELF3 overexpression and Pten genetic disruption significantly induced lung tumor development with increased proliferation and inhibited ferroptosis. Mechanistically, we found it was due to the induction of SCL7A11, a typical ferroptosis inhibitor, and ELF3 directly and positively regulated SCL7A11 in the PTEN-deficient background. Erastin-mediated inhibition of SCL7A11 induced ferroptosis in cells with ELF3 overexpression and PTEN deficiency and thus inhibited cell colony formation and tumor development. Clinically, human lung tumors showed a negative correlation between ELF3 and PTEN expression and a positive correlation between ELF3 and SCL7A11 in a subset of human lung tumors with PTEN-low expression. ELF3 and SCL7A11 expression levels were negatively associated with lung cancer patients' survival rates. In summary, ferroptosis induction can effectively attenuate lung tumor development induced by ELF3 overexpression and PTEN downregulation or loss-of-function mutations.

Association between serum iron status and the risk of colorectal cancer in US adults: a cross-sectional analysis of NHANES 2001-2020

BACKGROUND

Maintaining iron homeostasis is crucial for preventing the development of colorectal cancer (CRC). However, Evidence regarding the correlation between serum iron status and CRC has been inconsistent. This population-based study aims to explore the potential association between serum iron status and CRC risk.

METHODS

Using data from the National Health and Nutrition Examination Survey (NHANES) registry spanning from 2001 to 2020, a cross-sectional study involving 9504 participants was performed to assess the relationship between serum iron status and CRC risk. The study encompassed men and women of various racial backgrounds, aged 20 to 80, from across the United States. Participants' characteristics were presented using mean or proportion. The possible risk factor for CRC was examined using both univariable and multivariable analysis. A logistic regression model was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) of CRC in accordance with each quantile increment in serum iron item levels.

RESULTS

After making full adjustment, our analysis did not reveal a statistically significant association between serum iron, ferritin, transferrin saturation (TSAT), total iron-binding capacity (TIBC) and the risk of CRC. While there was no statistically significant difference observed, an increasing ferritin concentration appeared to be associated with a decreased CRC risk when compared to the lowest quantile. Specifically, the ORs and 95% CIs for the second, third, and fourth quantiles (Q2, Q3, and Q4) versus the lowest quantile (Q1) were as follows: Q2 (vs. Q1) OR 0.403, 95% CI 0.063-2.568; Q3 (vs. Q1) OR 0.316, 95% CI 0.059-1.687; Q4 (vs. Q1) OR 0.250, 95% CI 0.050-1.258. However, this trend did not reach statistical significance (P for trend = 0.381).

CONCLUSION

Our analyze did not demonstrate a statistically significant correlation between serum iron status and the risk of CRC.

Ferroptosis and immunosenescence in colorectal cancer

Colorectal cancer (CRC), ranked as the globe's third leading malignancy. Despite advancements in therapeutic approaches, the mortality rate remains distressingly high for those afflicted with advanced stages of the disease. Ferroptosis is a programmed form of cell death. The ways of ferroptosis mainly include promoting the accumulation of cellular ROS and increasing the level of cellular Labile iron pool (LIP). Immunosenescence is characterized by a gradual deterioration of the immune system's ability to respond to pathogens and maintain surveillance against cancer cells. In CRC, this decline is exacerbated by the tumor microenvironment, which can suppress the immune response and promote tumor progression. This paper reviews the relationship between iron prolapse and immune senescence in colorectal cancer, focusing on the following aspects: firstly, the different pathways that induce iron prolapse in colorectal cancer; secondly, immune-immune senescence in colorectal cancer; and lastly, the interactions between immune senescence and iron prolapse in colorectal cancer, e.g., immune-immune senescent cells often exhibit increased oxidative stress, leading to the accumulation of ROS, and consequently to lipid peroxidation and induction of iron-induced cell death. At the same time, ferroptosis induces immune cell senescence as well as alterations in the immune microenvironment by promoting the death of damaged or diseased cells and leading to the inflammation usually associated with it. In conclusion, by exploring the potential targets of ferroptosis and immune senescence in colorectal cancer therapy, we hope to provide a reference for future research.

The metabolic crosstalk of cancer-associated fibroblasts and tumor cells: Recent advances and future perspectives

Tumor cells grow in a microenvironment with a lack of nutrients and oxygen. Cancer-associated fibroblasts (CAFs) as one major component of tumor microenvironment have strong ability to survive under stressful conditions through metabolic remodelling. Furthermore, CAFs are educated by tumor cells and help them adapt to the hostile microenvironment through their metabolic communication. By inducing catabolism, CAFs release nutrients into the microenvironment which are taken up by tumor cells to satisfy their metabolic requirements. Furthermore, CAFs can recycle toxic metabolic wastes produced by cancer cells into energetic substances, allowing cancer cells to undergo biosynthesis. Their metabolic crosstalk also enhances CAFs' pro-tumor phenotype and reshape the microenvironment facilitating tumor cells' metastasis and immune escape. In this review, we have analyzed the effect and mechanisms of metabolic crosstalk between tumor cells and CAFs. We also analyzed the future perspectives in this area from the points of CAFs heterogeneity, spatial metabonomics and patient-derived tumor organoids (PDOs). These information may deepen the knowledge of tumor metabolism regulated by CAFs and provide novel insights into the development of metabolism-based anti-cancer strategies.

Progress in research of ferroptosis in gastrointestinal tumors

Ferroptosis is a non-apoptotic and oxidation-damaged regulated cell death caused by iron accumulation, lipid peroxidation, and subsequent plasma membrane rupture. Ferroptosis is the main cause of tissue damage caused by iron overload and lipid peroxidation. With the deepening of the research in recent years, the understanding of the occurrence and treatment of tumors has made a major breakthrough, which brings new strategies for anti-cancer treatment. This paper reviews the relationship between ferroptosis and gastrointestinal tumors, the research of ferroptosis in cancer prevention and treatment, and the role of ferroptosis in the prevention and treatment of gastrointestinal tumors.

UBR5 mediates colorectal cancer chemoresistance by attenuating ferroptosis via Lys 11 ubiquitin-dependent stabilization of Smad3-SLC7A11 signaling

Chemoresistance remains a principal culprit for the treatment failure in colorectal cancer (CRC), especially for patients with recurrent or metastatic disease. Deciphering the molecular basis of chemoresistance may lead to novel therapeutic strategies for this fatal disease. Here, UBR5, an E3 ubiquitin ligase frequently overexpressed in human CRC, is demonstrated to mediate chemoresistance principally by inhibiting ferroptosis. Paradoxically, UBR5 shields oxaliplatin-activated Smad3 from proteasome-dependent degradation via Lys 11-linked polyubiquitination. This novel chemical modification of Smad3 facilitates the transcriptional repression of ATF3, induction of SLC7A11 and inhibition of ferroptosis, contributing to chemoresistance. Consequently, targeting UBR5 in combination with a ferroptosis inducer synergistically sensitizes CRC to oxaliplatin-induced cell death and control of tumor growth. This study reveals, for the first time, a major clinically relevant chemoresistance mechanism in CRC mediated by UBR5 in sustaining TGFβ-Smad3 signaling and tuning ferroptosis, unveiling its potential as a viable therapeutic target for chemosensitization.

Prognostic Values of Ferroptosis-Related Proteins ACSL4, SLC7A11, and CHAC1 in Cholangiocarcinoma

BACKGROUND

The epithelial malignant tumor known as cholangiocarcinoma (CCA) is most commonly found in Southeast Asia, particularly in northeastern Thailand. Previous research has indicated that the overexpression of acyl-CoA synthetase long-chain family member 4 (ACSL4), solute carrier family 7 member 11 (SLC7A11), and ChaC glutathione-specific γ-glutamylcyclotransferase (CHAC1) as ferroptosis-related proteins is associated with poorer prognosis in several cancers. The role of these three proteins in CCA is still unclear. The present study aimed to investigate the expression levels of ACSL4, SLC7A11, and CHAC1, all potential ferroptosis biomarkers, in CCA.

METHODS

The ACSL4, SLC7A11, and CHAC1 protein expression levels in 137 CCA tissues were examined using immunohistochemistry, while 61 CCA serum samples were evaluated using indirect ELISA. The associations between the expression levels of ACSL4, SLC7A11, and CHAC1 and patient clinicopathological data were evaluated to determine the clinical significance of these proteins.

RESULTS

The expression levels of ACSL4, SLC7A11, and CHAC1 were assessed in CCA tissues. A significant association was observed between high ACSL4 levels and extrahepatic CCA, tumor growth type, and elevated alanine transferase (ALT). There was also a positive association between elevated SLC7A11 levels and tumor growth type. Additionally, the upregulation of CHAC1 was significantly associated with a shorter survival time in patients. High levels of ACSL4 and SLC7A11 in CCA sera were both significantly associated with advanced tumor stages and abnormal liver function test results, indicating that they could be used as a reliable prognostic biomarker panel in patients with CCA.

CONCLUSIONS

The results of the present study demonstrated that the upregulation of ACSL4, SLC7A11, and CHAC1 could be used as a valuable biomarker panel for predicting prognosis parameters in CCA. Furthermore, ACSL4 and SLC7A11 could potentially serve as complementary markers for improving the accuracy of prognosis prediction when CCA sera is used. These less invasive biomarkers could facilitate effective treatment planning.

Microsporidian EnP1 alters host cell H2B monoubiquitination and prevents ferroptosis facilitating microsporidia survival

Microsporidia are intracellular eukaryotic pathogens that pose a substantial threat to immunocompromised hosts. The way these pathogens manipulate host cells during infection remains poorly understood. Using a proximity biotinylation strategy we established that microsporidian EnP1 is a nucleus-targeted effector that modifies the host cell environment. EnP1's translocation to the host nucleus is meditated by nuclear localization signals (NLSs). In the nucleus, EnP1 interacts with host histone H2B. This interaction disrupts H2B monoubiquitination (H2Bub), subsequently impacting p53 expression. Crucially, this inhibition of p53 weakens its control over the downstream target gene SLC7A11, enhancing the host cell's resilience against ferroptosis during microsporidian infection. This favorable condition promotes the proliferation of microsporidia within the host cell. These findings shed light on the molecular mechanisms by which microsporidia modify their host cells to facilitate their survival.

Ferroptosis mechanism and Alzheimer's disease

Regulated cell death is a genetically determined form of programmed cell death that commonly occurs during the development of living organisms. This process plays a crucial role in modulating homeostasis and is evolutionarily conserved across a diverse range of living organisms. Ferroptosis is a classic regulatory mode of cell death. Extensive studies of regulatory cell death in Alzheimer's disease have yielded increasing evidence that ferroptosis is closely related to the occurrence, development, and prognosis of Alzheimer's disease. This review summarizes the molecular mechanisms of ferroptosis and recent research advances in the role of ferroptosis in Alzheimer's disease. Our findings are expected to serve as a theoretical and experimental foundation for clinical research and targeted therapy for Alzheimer's disease.

CircCOL5A1 is involved in proliferation, invasion, and inhibition of ferroptosis of colorectal cancer cells via miR-1287-5p/SLC7A11

Colorectal cancer (CRC) is the leading cause of cancer-related death globally. Circular RNA circCOL5A1 plays an oncogene function in a variety of tumors. However, the function of circCOL5A1 in CRC is still unknown. Here, we aimed to elucidate the function and mechanism of circCOL5A1 in CRC. The correlation between circCOL5A1 and CRC clinicopathological was assessed through chi-square. The relevance between circCOL5A1 and CRC patient survival time was evaluated by Kaplan-Meier analysis. The expressions of circCOL5A1 in CRC were determined via quantitative real-time PCR. The function of circCOL5A1 in CRC was analyzed with Cell Counting Kit-8, EdU assay, Transwell, detection of reactive oxygen species and Fe2+ levels, and Western blot analysis. Moreover, the mechanism of circCOL5A1 was determined by dual-luciferase reporter assay, RNA immunoprecipitation, and RNA pull-down. Finally, the role of circCOL5A1 in vivo was elucidated through a mouse xenograft model, hematoxylin-eosin staining, and immunohistochemistry. CircCOL5A1 expression was increased in CRC, and increased circCOL5A1 levels were related to TNM stage, lymph node metastasis, distant metastasis, and tumor differentiation in CRC patients, and CRC patients with high circCOL5A1 levels had a low overall survival rate. For the circCOL5A1 function in CRC, we found that circCOL5A1 knockdown weakened CRC cell proliferation and invasion, and enhanced cell ferroptosis. For the circCOL5A1 mechanism in CRC, we further confirmed that circCOL5A1 bound to miR-1287-5p, miR-1287-5p bound to SLC7A11. SLC7A11 was negatively interrelated to miR-1287-5p and was positively interrelated to circCOL5A1 in CRC tissues. Furthermore, interfering circCOL5A1 decreased SLC7A11 expression, and this trend was abolished through miR-1287-5p cotransfection. Rescue assays further demonstrated that circCOL5A1 knockdown alleviated CRC cell malignant phenotype via miR-1287-5p/SLC7A11. Moreover, interference with circCOL5A1 reduced CRC growth in vivo. CircCOL5A1 functioned as an oncogene in CRC via miR-1287-5p/SLC7A11.

Ferroptosis-related gene signature and clinical prognostic factors as prognostic marker for colon adenocarcinoma

Aim

To build a ferroptosis-related prognostic model for patients with colon adenocarcinoma (COAD).

Methods

COAD expression profiles from The Cancer Genome Atlas were used as the training set and GSE39582 from Gene Expression Omnibus as the validation set. Differentially expressed ferroptosis-related genes between patients with COAD and normal controls were screened, followed by tumor subtype exploration based on ferroptosis-related gene expression levels. A ferroptosis score (FS) model was constructed using least absolute shrinkage and selection operator penalized Cox analysis. Based on FS, patients were subgrouped into high- and low-risk subgroups and overall survival was predicted. The potential prognostic value of the FS model and the clinical characteristics were investigated using receiver operating characteristic curves.

Results

Twenty-four differentially expressed ferroptosis-related genes were identified, four of which (CYBB, PRNP, ACSL4, and ACSL6) were included in the prognostic signature. Moreover, age, pathological T stage, and tumor recurrence were independent prognostic factors for COAD. The FS model combined with three independent prognostic factors showed the best prognostic value (The Cancer Genome Atlas: area under the curve = 0.897; GSE39582: area under the curve = 0.858).

Conclusion

The novel prognostic model for patients with COAD constructed by pairing the FS model with three important independent prognostic factors showed promising clinical predictive value.

Research Progress on Micro(nano)plastic-Induced Programmed Cell Death Associated with Disease Risks

Due to their robust migration capabilities, slow degradation, and propensity for adsorbing environmental pollutants, micro(nano)plastics (MNPs) are pervasive across diverse ecosystems. They infiltrate various organisms within different food chains through multiple pathways including inhalation and dermal contact, and pose a significant environmental challenge in the 21st century. Research indicates that MNPs pose health threats to a broad range of organisms, including humans. Currently, extensive detection data and studies using experimental animals and in vitro cell culture indicate that MNPs can trigger various forms of programmed cell death (PCD) and can induce various diseases. This review provides a comprehensive and systematic analysis of different MNP-induced PCD processes, including pyroptosis, ferroptosis, autophagy, necroptosis, and apoptosis, based on recent research findings and focuses on elucidating the links between PCD and diseases. Additionally, targeted therapeutic interventions for these diseases are described. This review provides original insights into the opportunities and challenges posed by current research findings. This review evaluates ways to mitigate various diseases resulting from cell death patterns. Moreover, this paper enhances the understanding of the biohazards associated with MNPs by providing a systematic reference for subsequent toxicological research and health risk mitigation efforts.

Amino acid transporters within the solute carrier superfamily: Underappreciated proteins and novel opportunities for cancer therapy

BACKGROUND

Solute carrier (SLC) transporters, a diverse family of membrane proteins, are instrumental in orchestrating the intake and efflux of nutrients including amino acids, vitamins, ions, nutrients, etc, across cell membranes. This dynamic process is critical for sustaining the metabolic demands of cancer cells, promoting their survival, proliferation, and adaptation to the tumor microenvironment (TME). Amino acids are fundamental building blocks of cells and play essential roles in protein synthesis, nutrient sensing, and oncogenic signaling pathways. As key transporters of amino acids, SLCs have emerged as crucial players in maintaining cellular amino acid homeostasis, and their dysregulation is implicated in various cancer types. Thus, understanding the intricate connections between amino acids, SLCs, and cancer is pivotal for unraveling novel therapeutic targets and strategies.

SCOPE OF REVIEW

In this review, we delve into the significant impact of amino acid carriers of the SLCs family on the growth and progression of cancer and explore the current state of knowledge in this field, shedding light on the molecular mechanisms that underlie these relationships and highlighting potential avenues for future research and clinical interventions.

MAJOR CONCLUSIONS

Amino acids transportation by SLCs plays a critical role in tumor progression. However, some studies revealed the tumor suppressor function of SLCs. Although several studies evaluated the function of SLC7A11 and SLC1A5, the role of some SLC proteins in cancer is not studied well. To exert their functions, SLCs mediate metabolic rewiring, regulate the maintenance of redox balance, affect main oncogenic pathways, regulate amino acids bioavailability within the TME, and alter the sensitivity of cancer cells to therapeutics. However, different therapeutic methods that prevent the function of SLCs were able to inhibit tumor progression. This comprehensive review provides insights into a rapidly evolving area of cancer biology by focusing on amino acids and their transporters within the SLC superfamily.

Iron metabolism: backfire of cancer cell stemness and therapeutic modalities

Cancer stem cells (CSCs), with their ability of self-renewal, unlimited proliferation, and multi-directional differentiation, contribute to tumorigenesis, metastasis, recurrence, and resistance to conventional therapy and immunotherapy. Eliminating CSCs has long been thought to prevent tumorigenesis. Although known to negatively impact tumor prognosis, research revealed the unexpected role of iron metabolism as a key regulator of CSCs. This review explores recent advances in iron metabolism in CSCs, conventional cancer therapies targeting iron biochemistry, therapeutic resistance in these cells, and potential treatment options that could overcome them. These findings provide important insights into therapeutic modalities against intractable cancers.

ANALYSIS AND IDENTIFICATION OF FERROPTOSIS-RELATED GENE SIGNATURE FOR ACUTE LUNG INJURY

ABSTRACT

Background: Recent studies have shown that ferroptosis is involved in the evolution of acute lung injury (ALI), a serious respiratory pathological process leading to death. However, the regulatory mechanisms underlying ferroptosis in ALI remain largely unknown. The current study analyzed and identified a ferroptosis-related gene signature for ALI. Methods: Key genes associated with ferroptosis in ALI were identified by bioinformatics analysis. GSE104214, GSE18341, and GSE17355 datasets were downloaded from the Gene Expression Omnibus database. The signature genes were screened by least absolute shrinkage and selection operator regression, and the key genes of ALI were screened by weighted correlation network analysis (WGCNA), followed by immune infiltration analysis and functional enrichment analysis. In addition, mRNA expression of key genes in the lungs of mice with hemorrhagic shock (HS) and sepsis was verified. Results: A total of 2,132 differential genes were identified by various analyses, and 9 characteristic genes were detected using Lasso regression. We intersected nine signature genes with WGCNA module genes and finally determined four key genes ( PROK2 , IL6 , TNF , SLC7A11 ). All four key genes were closely correlated with immune cells and regulatory genes of ALI, and the expression of the four genes was significantly different in the lung tissues of HS and sepsis models. Besides, the ferroptosis-related molecules GPX4 and ACSL4 showed remarkable difference in these models. Conclusion: These results indicate that PROK2 , IL6 , TNF , and SLC7A11 may be key regulatory targets of ferroptosis during ALI. This study proved that ferroptosis is a common pathophysiological process in three ALI models.

Identification and validation of stemness-based and ferroptosis-related molecular clusters in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy with an extremely poor prognosis. Cancer stem cells (CSCs) are considered to be responsible for the poor survival, recurrence and therapy resistance of PDAC. Ferroptosis plays a crucial role in the sustain and survival of CSCs. Here, we employed a rigorous evaluation of multiple datasets to identify a novel stemness-based and ferroptosis-related genes (SFRGs) signature to access the potential prognostic application. This work we retrieved RNA-sequencing and clinical annotation data from the TCGA, ICGC, GTEx and GEO database, and acquired 26 stem cell gene sets and 259 ferroptosis genes from StemChecker database and FerrDb database, respectively. Based on consensus clustering and ssGSEA analysis, we identified two expression patterns of CSCs traits (C1 and C2). Then, WGCNA analysis was implemented to screen out hub module genes correlated with stemness. Furthermore, differential expression analysis, Pearson correlation analysis, and the Least absolute shrinkage and selection operator (LASSO) and Cox regression were performed to identify the SFRGs and to construct model. In addition, the differences in prognosis, tumor microenvironment (TME) components and therapy responses were evaluated between two risk groups. Finally, we verified the most influential marker ARNTL2 experimentally by western blot, qRT-PCR, sphere formation assay, mitoscreen assay, intracellular iron concentration determination and MDA determination assays. In conclusion, we developed a stemness-based and ferroptosis-related prognostic model, which could help predict overall survival for PDAC patients. Targeting ferroptosis may be a promising therapeutic strategy to inhibit PDAC progression by suppressing CSCs.

Protective Effect of Compound Tongluo Decoction on Brain Vascular Endothelial Cells after Ischemia-Reperfusion by Inhibition of Ferroptosis Through Regulating Nrf2/ARE/SLC7A11 Signaling Pathway

Cerebral infarction is one of the most common diseases for aged people. Compound Tongluo Decoction (CTLD), a classic traditional Chinese Medicine prescription, has been widely used in the treatment of ischemic cerebral infarction. Transient middle cerebral artery occlusion (tMCAO) rat model is established for the animal experiment and oxygen-glucose deprivation and reperfusion (OGD/R) human umbilical vein endothelial cells (HUVECs) model are established for the cell experiment. This also use Nrf2-/- rats to detect the role of nuclear factor erythroid 2-related factor 2 (Nrf2). Longa score, Evans blue staining, brain water content measurement, and histological observation are done. The levels of reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), and other ferroptosis-related components are detected respectively. In the vivo experiment, CTLD relieved ischemia-reperfusion (IR) injury symptoms and attenuated IR injury in brain tissues of tMCAO rats by relieving peroxidation injury in brain tissues and inhibiting ferroptosis in tMCAO rats. Moreover, CTLD reversed OGD/R-induced oxidative damage of endothelial cells via suppressing ferroptosis. After knocking out the Nrf2 gene, the protective effect of CTLD is sharply reduced. This study put forward that CTLD can inhibit ferroptosis in I/R-injured vascular endothelium by regulating Nrf2/ARE/SLC7A11 signaling to improve the relative symptoms of rats after cerebral I/R injury, thus providing a viable treatment option for cerebrovascular disease.

Erianin suppressed lung cancer stemness and chemotherapeutic sensitivity via triggering ferroptosis

The previous research has focused on the suppressive effects of Erianin on tumor progression, but its impact on cancer stemness has not been reported. This study aimed to investigate the effects of Erianin on lung cancer stemness. First, we screened various concentrations Erianin to ensure that it did not affect lung cancer cell viability. Subsequently, we found that Erianin significantly attenuated lung cancer stemness through various analyses, including qRT-PCR, western blot, sphere-formation, and ALDH activity detection. Furthermore, Erianin was shown to enhance chemosensitivity of lung cancer cells. Mechanistically, three inhibitors (cell apoptosis inhibitor, necrosis inhibitor, and ferroptosis inhibitor) were added into lung cancer cells with Erianin treatment, respectively, and we found that Erianin mainly suppressed lung cancer stemness through ferroptosis. Taken together, this study reveals that Erianin has the potential to suppress lung cancer stemness and could be a valuable chemotherapeutic enhancer for lung cancer.

Ferroptosis: a promising candidate for exosome-mediated regulation in different diseases

Ferroptosis is a newly discovered form of cell death that is featured in a wide range of diseases. Exosome therapy is a promising therapeutic option that has attracted much attention due to its low immunogenicity, low toxicity, and ability to penetrate biological barriers. In addition, emerging evidence indicates that exosomes possess the ability to modulate the progression of diverse diseases by regulating ferroptosis in damaged cells. Hence, the mechanism by which cell-derived and noncellular-derived exosomes target ferroptosis in different diseases through the system Xc-/GSH/GPX4 axis, NAD(P)H/FSP1/CoQ10 axis, iron metabolism pathway and lipid metabolism pathway associated with ferroptosis, as well as its applications in liver disease, neurological diseases, lung injury, heart injury, cancer and other diseases, are summarized here. Additionally, the role of exosome-regulated ferroptosis as an emerging repair mechanism for damaged tissues and cells is also discussed, and this is expected to be a promising treatment direction for various diseases in the future. Video Abstract.

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.

Unraveling the Clinical Relevance of Ferroptosis-Related Genes in Human Ovarian Aging

Ferroptosis, a recently discovered form of cell death, has been implicated in various diseases. However, the genetic relationship between ferroptosis and ovarian aging has not been thoroughly investigated through informatics analysis. In this study, we conducted bioinformatics analysis using ovarian aging and ferroptosis datasets to identify potential ferroptosis-related genes using R software. The expression levels of these genes at different ages were analyzed using the GTEx public database. To validate these findings at the genetic level, we performed clinical infertility biopsies. Bioinformatics analysis of a mouse ovary dataset revealed significantly higher expression of Tfrc, Ncoa4, and Slc3a2 in the aging group compared to the young group, while Gpx4 showed the opposite pattern. Consistent results were observed in biopsies from clinically aged infertile patients. This study is the first to identify a ferroptosis-related gene associated with ovarian aging, highlighting its potential as a diagnostic biomarker.

NEDD4L in human tumors: regulatory mechanisms and dual effects on anti-tumor and pro-tumor

Tumorigenesis and tumor development are closely related to the abnormal regulation of ubiquitination. Neural precursor cell expressed developmentally downregulated 4-like (NEDD4L), an E3 ubiquitin ligase critical to the ubiquitination process, plays key roles in the regulation of cancer stem cells, as well as tumor cell functions, including cell proliferation, apoptosis, cell cycle regulation, migration, invasion, epithelial-mesenchymal transition (EMT), and tumor drug resistance, by controlling subsequent protein degradation through ubiquitination. NEDD4L primarily functions as a tumor suppressor in several tumors but also plays an oncogenic role in certain tumors. In this review, we comprehensively summarize the relevant signaling pathways of NEDD4L in tumors, the regulatory mechanisms of its upstream regulatory molecules and downstream substrates, and the resulting functional alterations. Overall, therapeutic strategies targeting NEDD4L to treat cancer may be feasible.

Anaplastic thyroid cancer cells reduce CD71 levels to increase iron overload tolerance

BACKGROUND

Follicular thyroid cancer (FTC) is a prevalent form of differentiated thyroid cancer, whereas anaplastic thyroid cancer (ATC) represents a rare, fast-growing, undifferentiated, and highly aggressive tumor, posing significant challenges for eradication. Ferroptosis, an iron-dependent cell death mechanism driven by the excessive production of reactive oxygen species and subsequent lipid peroxidation, emerges as a promising therapeutic strategy for cancer. It has been observed that many cancer cells exhibit sensitivity to ferroptosis, while some other histotypes appear to be resistant, by counteracting the metabolic changes and oxidative stress induced by iron overload.

METHODS

Here we used human biopsies and in vitro approaches to analyse the effects of iron-dependent cell death. We assessed cell proliferation and viability through MTT turnover, clonogenic assays, and cytofluorimetric-assisted analysis. Lipid peroxidation assay and western blot were used to analyse molecular mechanisms underlying ferroptosis modulation. Two distinct thyroid cancer cell lines, FTC-133 (follicular) and 8505C (anaplastic), were utilized. These cell lines were exposed to ferroptosis inducers, Erastin and RSL3, while simulating an iron overload condition using ferric ammonium citrate.

RESULTS

Our evidence suggests that FTC-133 cell line, exposed to iron overload, reduced their viability and showed increased ferroptosis. In contrast, the 8505C cell line seems to better tolerate ferroptosis, responding by modulating CD71, which is involved in iron internalization and seems to have a role in resistance to iron overload and consequently in maintaining cell viability.

CONCLUSIONS

The differential tolerance to ferroptosis observed in our study may hold clinical implications, particularly in addressing the unmet therapeutic needs associated with ATC treatment, where resistance to ferroptosis appears more pronounced compared to FTC.

Research on ferroptosis as a therapeutic target for the treatment of neurodegenerative diseases

Ferroptosis is an iron- and lipid peroxidation (LPO)-mediated programmed cell death type. Recently, mounting evidence has indicated the involvement of ferroptosis in neurodegenerative diseases, especially in Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), Huntington's disease (HD), and so on. Treating ferroptosis presents opportunities as well as challenges for neurodegenerative diseases. This review provides a comprehensive overview of typical features of ferroptosis and the underlying mechanisms that contribute to its occurrence, as well as their implications in the pathogenesis and advancement of major neurodegenerative disorders. Meanwhile, we summarize the utilization of ferroptosis inhibition in both experimental and clinical approaches for the treatment of major neurodegenerative disorders. In addition, we specifically summarize recent advances in developing therapeutic means targeting ferroptosis in these diseases, which may guide future approaches for the effective management of these devastating medical conditions.

Cancer metastasis: Molecular mechanisms and clinical perspectives

Metastatic progression combined with non-responsiveness towards systemic therapy often shapes the course of disease for cancer patients and commonly determines its lethal outcome. The complex molecular events that promote metastasis are a combination of both, the acquired pro-metastatic properties of cancer cells and a metastasis-permissive or -supportive tumor micro-environment (TME). Yet, dissemination is a challenging process for cancer cells that requires a series of events to enable cancer cell survival and growth. Metastatic cancer cells have to initially detach themselves from primary tumors, overcome the challenges of their intravasal journey and colonize distant sites that are suited for their metastases. The implicated obstacles including anoikis and immune surveillance, can be overcome by intricate intra- and extracellular signaling pathways, which we will summarize and discuss in this review. Further, emerging modulators of metastasis, like the immune-microenvironment, microbiome, sublethal cell death engagement, or the nervous system will be integrated into the existing working model of metastasis.

CD98 heavy chain as a prognostic biomarker and target for cancer treatment

The SLC3A2 gene encodes for a cell-surface transmembrane protein CD98hc (4F2). CD98hc serves as a chaperone for LAT1 (SLC7A5), LAT2 (SLC7A8), y+LAT1 (SLC7A7), y+LAT2 (SLC7A6), xCT (SLC7A11) and Asc1 (SLC7A10) providing their recruitment to the plasma membrane. Together with the light subunits, it constitutes heterodimeric transmembrane amino acid transporters. CD98hc interacts with other surface molecules, such as extracellular matrix metalloproteinase inducer CD147 (EMMPRIN) and adhesion receptors integrins, and regulates glucose uptake. In this way, CD98hc connects the signaling pathways sustaining cell proliferation and migration, biosynthesis and antioxidant defense, energy production, and stem cell properties. This multifaceted role makes CD98hc one of the critical regulators of tumor growth, therapy resistance, and metastases. Indeed, the high expression levels of CD98hc were confirmed in various tumor tissues, including head and neck squamous cell carcinoma, glioblastoma, colon adenocarcinoma, pancreatic ductal adenocarcinoma, and others. A high expression of CD98hc has been linked to clinical prognosis and response to chemo- and radiotherapy in several types of cancer. In this mini-review, we discuss the physiological functions of CD98hc, its role in regulating tumor stemness, metastases, and therapy resistance, and the clinical significance of CD98hc as a tumor marker and therapeutic target.

Jian Yun Qing Hua Decoction inhibits malignant behaviors of gastric carcinoma cells via COL12A1 mediated ferroptosis signal pathway

BACKGROUND

Jian Yun Qing Hua Decoction (JYQHD), a traditional Chinese medicine decoction, which has been applied in the treatment of gastric cancer (GC). We attempt to confirm the anti-gastric cancer effect of JYQHD and explore the mechanism of JYQHD.

METHODS

Acute toxicity test was used to understand the toxicity of JYQHD. We studied the expression and prognostic outcome of COL12A1 within GC tissues through the network databases. Using several web-based databases, we analyzed the major components and targets of JYQHD, as well as known therapeutic targets in gastric cancer. The Venn diagram was utilized to obtain the overlapped genes. Lentiviral vector, shRNAs and plasmids, were used to transfect GC cells. Cell counting kit-8 (CCK8), sphere formation, malondialdehyde (MDA), glutathione (GSH), reactive oxygen species (ROS), Fe2+, transmission electron microscopy (TEM), quantitative Real-Time Polymerase Chain Reaction (qRT-PCR), Western-Blot (WB), and immunohistochemical (IHC) assays were employed to investigate the role and mechanism of COL12A1 and JYQHD in GC.

RESULTS

The results showed that JYQHD was non-toxic and safe. JYQHD inhibited growth and sphere formation ability through inducing the ferroptosis of GC cells, and suppressed the GC cells induced subcutaneous xenograft tumor growth. COL12A1 was highly expressed in gastric cancer tissues, indicating poor prognosis. COL12A1 specifically enhanced GC cell progression and stemness via suppressing ferroptosis. JYQHD down-regulated COL12A1 in order to suppress the stemness of GC cells via inducing ferroptosis.

CONCLUSION

COL12A1 inhibited ferroptosis and enhanced stemness in GC cells. JYQHD inhibited the development of GC cells by inhibiting cancer cell stemness via the ferroptosis pathway mediated by COL12A1.

Regulation of iron metabolism and ferroptosis in cancer stem cells

The ability of cancer stem cells (CSCs) to self-renew, differentiate, and generate new tumors is a significant contributor to drug resistance, relapse, and metastasis. Therefore, the targeting of CSCs for treatment is particularly important. Recent studies have demonstrated that CSCs are more susceptible to ferroptosis than non-CSCs, indicating that this could be an effective strategy for treating tumors. Ferroptosis is a type of programmed cell death that results from the accumulation of lipid peroxides caused by intracellular iron-mediated processes. CSCs exhibit different molecular characteristics related to iron and lipid metabolism. This study reviews the alterations in iron metabolism, lipid peroxidation, and lipid peroxide scavenging in CSCs, their impact on ferroptosis, and the regulatory mechanisms underlying iron metabolism and ferroptosis. Potential treatment strategies and novel compounds targeting CSC by inducing ferroptosis are also discussed.

Establishment and validation of a ferroptosis-related signature predicting prognosis and immunotherapy effect in colon cancer

Background

Ferroptosis, a novel form of regulating cell death, is related to various cancers. However, the role of ferroptosis-related genes (FRGs) on the occurrence and development of colon cancer (CC) needs to be further elucidated.

Method

CC transcriptomic and clinical data were downloaded from TCGA and GEO databases. The FRGs were obtained from the FerrDb database. The consensus clustering was performed to identify the best clusters. Then, the entire cohort was randomly divided into the training and testing cohorts. Univariate Cox, LASSO regression and multivariate Cox analyses were used to construct a novel risk model in training cohort. The testing and the merged cohorts were performed to validate the model. Moreover, CIBERSORT algorithm analyze TIME between high- and low- risk groups. The immunotherapy effect was evaluated by analyzing the TIDE score and IPS between high- and low- risk groups. Lastly, RT-qPCR were performed to analyze the expression of the three prognostic genes, and the 2-years OS and DFS between the high- and low- risk groups of 43 clinical CC samples to further validate the value of the risk model.

Results

SLC2A3, CDKN2A, and FABP4 were identified to construct a prognostic signature. Kaplan-Meier survival curves showed that OS between the high- and low-risk groups were statistically significant (p_merged<0.001, p_training<0.001, p_testing<0.001). TIDE score and IPS were higher in the high-risk group (p_TIDE<0.005, p_Dysfunction<0.005, p_Exclusion<0.001, p_mAb-CTLA-4 = 3e-08, p_mAb-PD-1 = 4.1e-10). The clinical samples were divided into high- and low- risk groups according to the risk score. There was a statistical difference in DFS (p=0.0108).

Conclusion

This study established a novel prognostic signature and provided more insight into the immunotherapy effect of CC.

The Induction Mechanism of Ferroptosis, Necroptosis, and Pyroptosis in Inflammatory Bowel Disease, Colorectal Cancer, and Intestinal Injury

Cell death includes programmed and nonprogrammed cell death. The former mainly includes ferroptosis, necroptosis, pyroptosis, autophagy, and apoptosis, while the latter refers to necrosis. Accumulating evidence shows that ferroptosis, necroptosis, and pyroptosis play essential regulatory roles in the development of intestinal diseases. In recent years, the incidence of inflammatory bowel disease (IBD), colorectal cancer (CRC), and intestinal injury induced by intestinal ischemia-reperfusion (I/R), sepsis, and radiation have gradually increased, posing a significant threat to human health. The advancement in targeted therapies for intestinal diseases based on ferroptosis, necroptosis, and pyroptosis provides new strategies for treating intestinal diseases. Herein, we review ferroptosis, necroptosis, and pyroptosis with respect to intestinal disease regulation and highlight the underlying molecular mechanisms for potential therapeutic applications.

Zooming in and out of ferroptosis in human disease

Ferroptosis is defined as an iron-dependent regulated form of cell death driven by lipid peroxidation. In the past decade, it has been implicated in the pathogenesis of various diseases that together involve almost every organ of the body, including various cancers, neurodegenerative diseases, cardiovascular diseases, lung diseases, liver diseases, kidney diseases, endocrine metabolic diseases, iron-overload-related diseases, orthopedic diseases and autoimmune diseases. Understanding the underlying molecular mechanisms of ferroptosis and its regulatory pathways could provide additional strategies for the management of these disease conditions. Indeed, there are an expanding number of studies suggesting that ferroptosis serves as a bona-fide target for the prevention and treatment of these diseases in relevant pre-clinical models. In this review, we summarize the progress in the research into ferroptosis and its regulatory mechanisms in human disease, while providing evidence in support of ferroptosis as a target for the treatment of these diseases. We also discuss our perspectives on the future directions in the targeting of ferroptosis in human disease.

CircRNA circSTIL inhibits ferroptosis in colorectal cancer via miR-431/SLC7A11 axis

Ferroptosis is an emerging programmed cell death and plays essential roles in tumorigenesis, including colorectal cancer (CRC). The present study intended to disclose the role of a novel oncogene circular RNA (circRNA) circSTIL in CRC phenotypes, especially ferroptosis. The expression of circSTIL was measured in CRC tissues and cells. Then, the impacts of circSTIL expression on the proliferation and ferroptosis of CRC cells were examined by loss-of-function assays in vitro. Bioinformatics, luciferase reporter assay and cell rescue assay were further performed to reveal the ceRNA-associated mechanism of circSTIL. CircSTIL was significantly upregulated in CRC. Cell proliferation was suppressed while ferroptosis was induced with the silencing of circSTIL in CRC cells. Interestingly, circSTIL competed with miR-431 for solute carrier family 7 member 11 (SLC7A11) binding. Additionally, miR-431 suppression or SLC7A11 overexpression overturned circSTIL silencing-mediated cell phenotypes in CRC cells. CircSTIL promotes CRC cell proliferation and suppresses ferroptosis in vitro via miR-431/SLC7A11 signaling, revealing the pathogenesis of CRC, and providing potential therapeutic targets of CRC.

Ferroptosis in cancer stem cells

Ferroptosis is an iron-dependent form of RCD correlates with the accumulation of markers of lipid peroxidation. Bulks of studies focusing on revealing ferroptosis and its regulators involved in oncogenic pathways. Connection between iron metabolism and abnormal iron metabolism in CSCs synergistically making ferroptosis a target process of great potential in combating with CSCs to improve therapeutic effectiveness and reverse resistance. Ferroptosis inducers could specifically induce CSCs death in tumors, predisposing ferroptosis to a target in killing CSCs to overcome cancer resistances. By ferroptosis induction and other cell death pathways in CSCs, cancer therapeutic outcome would be improved.

EZH2-mediated SLC7A11 upregulation via miR-125b-5p represses ferroptosis of TSCC

OBJECTIVE

Tongue squamous cell carcinoma is one of the most common carcinomas in oral cancer with a high morbidity and mortality. Ferroptosis is a novel type of cell death involved in various diseases including cancers. Additionally, Enhancer of Zeste homolog 2 (EZH2) is significantly associated with a poor prognosis in esophageal squamous cell carcinoma patients but its role in TSCC is unclear.

MATERIALS AND METHODS

In this study, we tried to investigate the possible mechanism of EZH2 involved in the ferroptosis of TSCC. Expression of EZH2 and SLC7A11 was determined by RT-qPCR. CCK-8 assays were performed to quantify the cell death rate of TSCC cells. Malondialdehyde (MDA) assays were performed to quantify the lipid accumulation. Western blot was performed to analyze the expression level of SLC7A11. We used dual-luciferase reporter assays to determine the association between EZH2 and miR-125b-5p promoter, and miR-125b-5p and the SLC7A11 3' untranslated region (UTR).

RESULT

Overexpression of EZH2 and SLC7A11 inhibits erastin-induced ferroptosis in TSCC cells. MiR-125b-5p regulates ferroptosis in TSCC cells by targeting SLC7A11. EZH2 inhibits the ferroptosis of TSCC cells by inhibiting miR-125b-5p and enhancing SLC7A11.

CONCLUSION

EZH2 inhibits erastin-induced ferroptosis in TSCC cells via miR-125b-5p/SLC7A11 axis.

Doxorubicin and erastin co-loaded hydroxyethyl starch-polycaprolactone nanoparticles for synergistic cancer therapy

Cancer stem cells (CSCs), enabled to self-renew, differentiate, and initiate the bulk tumor, are recognized as the culprit of treatment resistance, metastasis, and recurrence. Simultaneously eradicating CSCs and bulk cancer cells is crucial for successful cancer therapy. Herein, we reported that doxorubicin (Dox) and erastin co-loaded hydroxyethyl starch-polycaprolactone nanoparticles (DEPH NPs) eliminated CSCs and cancer cells by regulating redox status. We found that an excellently synergistic effect existed when Dox and erastin were co-delivered by DEPH NPs. Specifically, erastin could deplete intracellular glutathione (GSH), thereby inhibiting the efflux of intracellular Dox and boosting Dox-induced reactive oxygen species (ROS) to amplify redox imbalance and oxidative stress. The high ROS levels restrained CSCs self-renewal via downregulating Hedgehog pathways, promoted CSCs differentiation, and rendered differentiated cancer cells vulnerable to apoptosis. As such, DEPH NPs significantly eliminated not only cancer cells but more importantly CSCs, contributing to suppressed tumor growth, tumor-initiating capacity, and metastasis, in various tumor models of triple negative breast cancer. This study demonstrates that the combination of Dox and erastin is potent in elimination of both cancer cells and CSCs, and that DEPH NPs represent a promising treatment against CSCs-rich solid tumors.

Ferroptosis in colorectal cancer: a future target?

Colorectal cancer (CRC) is the third leading cause of cancer deaths worldwide and is characterised by frequently mutated genes, such as APC, TP53, KRAS and BRAF. The current treatment options of chemotherapy, radiation therapy and surgery are met with challenges such as cancer recurrence, drug resistance, and overt toxicity. CRC therapies exert their efficacy against cancer cells by activating biological pathways that contribute to various forms of regulated cell death (RCD). In 2012, ferroptosis was discovered as an iron-dependent and lipid peroxide-driven form of RCD. Recent studies suggest that therapies which target ferroptosis are promising treatment strategies for CRC. However, a greater understanding of the mechanisms of ferroptosis initiation, propagation, and resistance in CRC is needed. This review provides an overview of recent research in ferroptosis and its potential role as a therapeutic target in CRC. We also propose future research directions that could help to enhance our understanding of ferroptosis in CRC.

Ferroptosis in gastrointestinal cancer: From mechanisms to implications

Ferroptosis is a form of regulated cell death that is initiated by excessive lipid peroxidation that results in plasma membrane damage and the release of damage-associated molecular patterns. In recent years, ferroptosis has gained significant attention in cancer research due to its unique mechanism compared to other forms of regulated cell death, especially caspase-dependent apoptotic cell death. Gastrointestinal (GI) cancer encompasses malignancies that arise in the digestive tract, including the stomach, intestines, pancreas, colon, liver, rectum, anus, and biliary system. These cancers are a global health concern, with high incidence and mortality rates. Despite advances in medical treatments, drug resistance caused by defects in apoptotic pathways remains a persistent challenge in the management of GI cancer. Hence, exploring the role of ferroptosis in GI cancers may lead to more efficacious treatment strategies. In this review, we provide a comprehensive overview of the core mechanism of ferroptosis and discuss its function, regulation, and implications in the context of GI cancers.

Ferroptosis open a new door for colorectal cancer treatment

Colorectal cancer (CRC) is the third highest incidence and the second highest mortality malignant tumor in the world. The etiology and pathogenesis of CRC are complex. Due to the long course of the disease and no obvious early symptoms, most patients are diagnosed as middle and late stages. CRC is prone to metastasis, most commonly liver metastasis, which is one of the leading causes of death in CRC patients. Ferroptosis is a newly discovered cell death form with iron dependence, which is driven by excessive lipid peroxides on the cell membrane. It is different from other form of programmed cell death in morphology and mechanism, such as apoptosis, pyroptosis and necroptosis. Numerous studies have shown that ferroptosis may play an important role in the development of CRC. For advanced or metastatic CRC, ferroptosis promises to open a new door in the setting of poor response to chemotherapy and targeted therapy. This mini review focuses on the pathogenesis of CRC, the mechanism of ferroptosis and the research status of ferroptosis in CRC treatment. The potential association between ferroptosis and CRC and some challenges are discussed.

ALKBH5 decreases SLC7A11 expression by erasing m6A modification and promotes the ferroptosis of colorectal cancer cells

BACKGROUND

Colorectal cancer (CRC) is the major subtype of gastrointestinal malignancy and involves cancer-related genes and signaling pathways to regulate ferroptosis. The present study was conducted to analyze the role of alkB homolog 5 (ALKBH5) in the ferroptosis of CRC cells and provide novel targets for CRC treatment.

METHODS

The transcriptional and protein levels of ALKBH5 and solute carrier family 7 members 11 (SLC7A11) in tissues and cells were determined by qRT-PCR and Western blot assay. HCT116 and SW620 cells were transfected with ALKBH5 overexpression vectors to determine cell viability and levels of reactive oxygen species (ROS), Fe⁺, glutathione, and glutathione peroxidase 4 using cell counting kit-8, colony formation, fluorescence probe, assay kits, and Western blot assay. The N6-methyladenosine (m6A) level and the enrichment of m6A on SLC7A11 mRNA were measured by m6A quantitative analysis and m6A methylated RNA immunoprecipitation-qPCR, and the mRNA stability was determined after actinomycin D treatment. CRC cells were treated with the combination of SLC7A11 and ALKBH5 overexpression vectors to confirm the mechanism. Nude mice were subcutaneously injected with CRC cells overexpressing ALKBH5.

RESULTS

ALKBH5 was downregulated in CRC and ALKBH5 overexpression promoted ROS release and ferroptosis. ALKBH5 erased the m6A modification on SLC7A11 mRNA to reduce the mRNA stability of SLC7A11, further reducing SLC7A11 expression. SLC7A11 overexpression reversed the promotive role of ALKBH5 overexpression in ferroptosis. ALKBH5 upregulation mitigated tumor growth in vivo.

CONCLUSIONS

ALKBH5 reduced SLC7A11 transcription by erasing m6A modification, thus promoting the ferroptosis of CRC cells.

Vitamin D Promotes Ferroptosis in Colorectal Cancer Stem Cells via SLC7A11 Downregulation

Colorectal cancer stem cells (CCSCs) play important roles in the prognosis, chemoresistance, and treatment failure of colorectal cancer (CRC). Ferroptosis is an effective treatment for CCSCs. Vitamin D (VD) reportedly inhibits colon cancer cell proliferation. However, information on the relationship between VD and ferroptosis in CCSCs is not well documented. In this study, we aimed to understand the effect of VD on ferroptosis in CCSCs. To this end, we treated CCSCs with different concentrations of VD and performed spheroid formation assay and transmission electron microscopy and determined cysteine (Cys), glutathione (GSH), and reactive oxygen species (ROS) levels. Furthermore, functional experiments, western blotting, and qRT-PCR were performed to explore the downstream molecular mechanisms of VD in vitro and in vivo. Results showed that VD treatment significantly inhibited the proliferation of CCSCs and reduced the number of tumour spheroids in vitro. Further evaluations showed that the VD-treated CCSCs exhibited significantly higher ROS levels and lower levels of Cys and GSH as well as thickened mitochondrial membranes. Furthermore, the mitochondria in CCSCs were narrowed and ruptured after VD treatment. These results indicated that VD treatment significantly induced ferroptosis in CCSCs. Further exploration showed that SLC7A11 overexpression significantly attenuated VD-induced ferroptosis in vitro and in vivo. Hence, we concluded that VD induces ferroptosis in CCSCs by downregulating SLC7A11 in vitro and in vivo. These results provide new evidence for the therapeutic use of VD in treating CRC and new insights into VD-induced ferroptosis in CCSCs.