Tomatidine targets ATF4-dependent signaling and induces ferroptosis to limit pancreatic cancer progression

B3GNT5 is a novel marker correlated with malignant phenotype and poor outcome in pancreatic cancer

Pancreatic cancer (PC) is one of the most lethal malignancies and new therapeutic strategies are urgently needed. β1,3-N-acetylglucosaminyltransferase V (B3GNT5) may be a potential option for cancer treatment, but its role in PC remains unknown. In this study, we first demonstrated through bioinformatics analysis that B3GNT5 was high expression in PC and predicted poor prognosis. We further constructed B3GNT5 overexpression or knockdown cell lines by employing lentivirus packaging techniques and confirmed that B3GNT5 could promote tumor cell viability and autonomous growth using cultured cells and vivo xenograft models. In addition, we found that knockdown of B3GNT5 in PC cells inhibited cell migration, invasion, and angiogenesis, as well as stemness of cancer stem cells and enhanced chemotherapy sensitivity to gemcitabine. Mechanistically, overexpression of the transcription factor STAT5B in PC cells enhanced the transcriptional activity of the B3GNT5 promoter. Our work confirmed a tumor-promotive role of B3GNT5 in PC pathogenesis.

Overexpression of ATF4 Inhibits Ferroptosis to Alleviate Anxiety Disorders by Activating the TGF-β Signaling Pathway

Background

Anxiety disorders seriously impair patients' mental health and quality of life, with limited effectiveness of current treatments. Dysregulation of activating transcription factor 4 (ATF4) is involved in various mental diseases, but the research on its potential roles in alleviating anxiety disorders remains limited.

Methods

ATF4 was screened out by bioinformatic analysis and its expression was verified in vivo. Mice were treated with 21 d of chronic restraint stress to establish the anxiety mice model. The anxiolytic effect of ATF4 was assessed by a battery of behavior tests and evaluation of hippocampal tissue damage after overexpressing ATF4. Ferroptosis-related indicators were detected by enzyme-linked immunosorbent assay and Western blotting. Then the transforming growth factor beta (TGF-β) signaling pathway was predicted as the downstream regulatory pathway of ATF4 by bioinformatic methods. Western blotting was conducted to detect the protein expression level of TGF-β1, small mothers against decapentaplegic 3 (Smad3), and phospho-Smad3 (p-Smad3).

Results

ATF4 was screened out as a ferroptosis-related anxiolytic gene after bioinformatics analysis and was down-regulated in the anxiety mice model. Mice with ATF4 overexpression spent more time in the open arms in the elevated plus-maze test, appeared more frequently in the central area in the open-field test, and decreased the immobility time in the forced swimming and tail suspension tests. Hippocampal tissue damage was alleviated, ferroptosis was suppressed, and the levels of TGF-β1 and p-Smad3/Smad3 were increased by AFT4 overexpression.

Conclusion

ATF4 overexpression can repress ferroptosis to improve anxiety disorders by activating the TGF-β signaling pathway.

MMP9 drives ferroptosis by regulating GPX4 and iron signaling

Ferroptosis, defined by the suppression of glutathione peroxidase-4 (GPX4) and iron overload, is a distinctive form of regulated cell death. Our in-depth research identifies matrix metalloproteinase-9 (MMP9) as a critical modulator of ferroptosis through its influence on GPX4 and iron homeostasis. Employing an innovative MMP9 construct without collagenase activity, we reveal that active MMP9 interacts with GPX4 and glutathione reductase, reducing GPX4 expression and activity. Furthermore, MMP9 suppresses key transcription factors (SP1, CREB1, NRF2, FOXO3, and ATF4), alongside GPX1 and ferroptosis suppressor protein-1 (FSP1), thereby disrupting the cellular redox balance. MMP9 regulates iron metabolism by modulating iron import, storage, and export via a network of protein interactions. LC-MS/MS has identified 83 proteins that interact with MMP9 at subcellular levels, implicating them in ferroptosis regulation. Integrated pathway analysis (IPA) highlights MMP9's extensive influence on ferroptosis pathways, underscoring its potential as a therapeutic target in conditions with altered redox homeostasis and iron metabolism.

Tomatidine, a Steroidal Alkaloid, Synergizes with Cisplatin to Inhibit Cell Viability and Induce Cell Death Selectively on FLT3-ITD+ Acute Myeloid Leukemia Cells

BACKGROUND

Acute Myeloid Leukemia (AML) is a hematological cancer that frequently presents with a range of side effects and drug resistance during anticancer drug treatment. The current study aims to achieve increased efficacy by combining lower doses of cisplatin with increasing concentrations of tomatidine in AML cells to increase efficacy.

METHODS

Anti-proliferative effects of single and combination of cisplatin and tomatidine were assessed via MTT cell viability assay. The Annexin V/Propidium Iodide Double Staining method was used to measure the apoptotic effects of combined tomatidine and cisplatin treatment. Then, Western Blot analysis was performed to measure Poly (ADP-ribose) polymerase (PARP) and Caspase-3 protein expression levels.

RESULTS

Cisplatin treatment with lower concentrations displayed high cytotoxic effects on AML cells, compared with tomatidine. The combination of the Inhibitory Concentration (IC) 20 value of cisplatin and increasing doses of tomatidine exhibited a significant decrease in cell viability relative to single treatments. The combination index analysis revealed a mild synergistic effect of cisplatin IC20 and varying tomatidine doses. The apoptosis induced when cisplatin was combined with 500 µM tomatidine by almost 20%, while the percentage of apoptosis in combination with 1 mM tomatidine was measured by 50% for both cell lines. The upregulation of proapoptotic cleaved-PARP (3.2 and 1.08-fold for THP-1 and MOLM-13, respectively) and downregulation in Caspase-3 (0.23 and 0.13-fold for THP-1 and MOLM-13, respectively) was detected.

CONCLUSIONS

Together, the study indicated that when tomatidine combined with cisplatin on AML cell lines, a combinatorial anti-proliferative and apoptotic effect is observed. The combination of cisplatin with tomatidine may be a promising approach.

The application of alkaloids in ferroptosis: A review

Alkaloids have remarkable biological and pharmacological properties and have recently garnered extensive attention. Various alkaloids, including commercially available drugs such as berberine, substantially affect ferroptosis. In addition to the three main pathways of ferroptosis, iron metabolism, phospholipid metabolism, and the glutathione peroxidase 4-regulated pathway, novel mechanisms of ferroptosis are continuously being identified. Alkaloids can modulate the progression of various diseases through ferroptosis and exhibit the ability to exert varied effects depending on dosage and tissue type underscores their versatility. Therefore, this review comprehensively summarizes primary targets and the latest advancements of alkaloids in ferroptosis, as well as the dual roles of alkaloids in inhibiting and promoting ferroptosis.

ATF family members as therapeutic targets in cancer: From mechanisms to pharmacological interventions

The activating transcription factor (ATF)/ cAMP-response element binding protein (CREB) family represents a large group of basic zone leucine zip (bZIP) transcription factors (TFs) with a variety of physiological functions, such as endoplasmic reticulum (ER) stress, amino acid stress, heat stress, oxidative stress, integrated stress response (ISR) and thus inducing cell survival or apoptosis. Interestingly, ATF family has been increasingly implicated in autophagy and ferroptosis in recent years. Thus, the ATF family is important for homeostasis and its dysregulation may promote disease progression including cancer. Current therapeutic approaches to modulate the ATF family include direct modulators, upstream modulators, post-translational modifications (PTMs) modulators. This review summarizes the structural domain and the PTMs feature of the ATF/CREB family and comprehensively explores the molecular regulatory mechanisms. On this basis, their pathways affecting proliferation, metastasis, and drug resistance in various types of cancer cells are sorted out and discussed. We then systematically summarize the status of the therapeutic applications of existing ATF family modulators and finally look forward to the future prospect of clinical applications in the treatment of tumors by modulating the ATF family.

Recent progress of ferroptosis in cancers and drug discovery

Ferroptosis is a nonapoptotic form of cell death characterized by iron dependence and lipid peroxidation. Ferroptosis is involved in a range of pathological processes, such as cancer. Many studies have confirmed that ferroptosis plays an essential role in inhibiting cancer cell proliferation. In addition, a series of small-molecule compounds have been developed, including erastin, RSL3, and FIN56, which can be used as ferroptosis inducers. The combination of ferroptosis inducers with anticancer drugs can produce a significant synergistic effect in cancer treatment, and patients treated with these combinations exhibit a better prognosis than patients receiving traditional therapy. Therefore, a thorough understanding of the roles of ferroptosis in cancer is of great significance for the treatment of cancer. This review mainly elaborates the molecular biological characteristics and mechanism of ferroptosis, summarizes the function of ferroptosis in cancer development and treatment,illustrates the application of ferroptosis in patient's prognosis prediction and drug discovery, and discusses the prospects of targeting ferroptosis.

Novel insights into the activating transcription factor 4 in Alzheimer's disease and associated aging-related diseases: Mechanisms and therapeutic implications

Ageing is inherent to all human beings, most mechanistic explanations of ageing results from the combined effects of various physiological and pathological processes. Additionally, aging pivotally contributes to several chronic diseases. Activating transcription factor 4 (ATF4), a member of the ATF/cAMP response element-binding protein family, has recently emerged as a pivotal player owing to its indispensable role in the pathophysiological processes of Alzheimer's disease and aging-related diseases. Moreover, ATF4 is integral to numerous biological processes. Therefore, this article aims to comprehensively review relevant research on the role of ATF4 in the onset and progression of aging-related diseases, elucidating its potential mechanisms and therapeutic approaches. Our objective is to furnish scientific evidence for the early identification of risk factors in aging-related diseases and pave the way for new research directions for their treatment. By elucidating the signaling pathway network of ATF4 in aging-related diseases, we aspire to gain a profound understanding of the molecular and cellular mechanisms, offering novel strategies for addressing aging and developing related therapeutics.

Regulation of cardiac ferroptosis in diabetic human heart failure: uncovering molecular pathways and key targets

Diabetes significantly increases the risk of heart failure by inducing myocardial cell death, potentially through ferroptosis-an iron-dependent, non-apoptotic cell death pathway characterized by lipid peroxidation. The role of cardiac ferroptosis in human heart failure, however, remains poorly understood. In this study, we compared cardiac ferroptosis in humans with diabetic heart failure to that in healthy controls. Our findings reveal that diabetes not only intensifies myocardial cell death but also upregulates markers of ferroptosis in human hearts. This is linked to decreased transcription and activity of glutathione peroxidase-4 (GPX4), influenced by reduced levels of activating transcription factor-4 (ATF4) and nuclear factor erythroid-2-related factor-2 (NRF2), and downregulation of glutathione reductase (GSR). Additionally, diabetic hearts showed an increased labile iron pool due to enhanced heme metabolism by heme oxygenase-1 (HMOX1), elevated iron import via divalent metal transporter-1 (DMT1), reduced iron storage through ferritin light chain (FLC), and decreased iron export via ferroportin-1 (FPN1). The reduction in FPN1 levels likely results from decreased stabilization by amyloid precursor protein (APP) and diminished NRF2-mediated transcription. Furthermore, diabetes upregulates lysophosphatidylcholine acyltransferase-3 (LPCAT3), facilitating the integration of polyunsaturated fatty acids (PUFA) into phospholipid membranes, and downregulates acyl-CoA thioesterase-1 (ACOT1), which further promotes ferroptosis. LC-MS/MS analysis identified several novel proteins implicated in diabetes-induced cardiac ferroptosis, including upregulated ceruloplasmin, which enhances iron metabolism, and cytochrome b-245 heavy chain (CYBB), a key component of NADPH oxidase that aids in the production of reactive oxygen species (ROS), along with downregulated voltage-dependent anion-selective channel protein-2 (VDAC2), essential for maintaining mitochondrial membrane potential. In conclusion, our study not only confirms the presence and potentially predominant role of cardiac ferroptosis in humans with diabetic heart failure but also elucidates its molecular mechanisms, offering potential therapeutic targets to mitigate heart failure complications in diabetic patients.

CD200 is overexpressed in the pancreatic tumor microenvironment and predictive of overall survival

Pancreatic cancer is an aggressive disease with a 5 year survival rate of 13%. This poor survival is attributed, in part, to limited and ineffective treatments for patients with metastatic disease, highlighting a need to identify molecular drivers of pancreatic cancer to target for more effective treatment. CD200 is a glycoprotein that interacts with the receptor CD200R and elicits an immunosuppressive response. Overexpression of CD200 has been associated with differential outcomes, depending on the tumor type. In the context of pancreatic cancer, we have previously reported that CD200 is expressed in the pancreatic tumor microenvironment (TME), and that targeting CD200 in murine tumor models reduces tumor burden. We hypothesized that CD200 is overexpressed on tumor and stromal populations in the pancreatic TME and that circulating levels of soluble CD200 (sCD200) have prognostic value for overall survival. We discovered that CD200 was overexpressed on immune, stromal, and tumor populations in the pancreatic TME. Particularly, single-cell RNA-sequencing indicated that CD200 was upregulated on inflammatory cancer-associated fibroblasts. Cytometry by time of flight analysis of PBMCs indicated that CD200 was overexpressed on innate immune populations, including monocytes, dendritic cells, and monocytic myeloid-derived suppressor cells. High sCD200 levels in plasma correlated with significantly worse overall and progression-free survival. Additionally, sCD200 correlated with the ratio of circulating matrix metalloproteinase (MMP) 3: tissue inhibitor of metalloproteinase (TIMP) 3 and MMP11/TIMP3. This study highlights the importance of CD200 expression in pancreatic cancer and provides the rationale for designing novel therapeutic strategies that target this protein.

ATF4 in cellular stress, ferroptosis, and cancer

Activating transcription factor 4 (ATF4), a member of the ATF/cAMP response element-binding (CREB) family, plays a critical role as a stress-induced transcription factor. It orchestrates cellular responses, particularly in the management of endoplasmic reticulum stress, amino acid deprivation, and oxidative challenges. ATF4's primary function lies in regulating gene expression to ensure cell survival during stressful conditions. However, when considering its involvement in ferroptosis, characterized by severe lipid peroxidation and pronounced endoplasmic reticulum stress, the ATF4 pathway can either inhibit or promote ferroptosis. This intricate relationship underscores the complexity of cellular responses to varying stress levels. Understanding the connections between ATF4, ferroptosis, and endoplasmic reticulum stress holds promise for innovative cancer therapies, especially in addressing apoptosis-resistant cells. In this review, we provide an overview of ATF4, including its structure, modifications, and functions, and delve into its dual role in both ferroptosis and cancer.

A benzochalcone derivative synchronously induces apoptosis and ferroptosis in pancreatic cancer cells

Background

Pancreatic cancer is a highly aggressive and lethal disease with limited treatment options. In this study, we investigated the potential therapeutic effects of compound KL-6 on pancreatic cancer cells.

Methods

The study involved assessing the inhibitory effects of KL-6 on cell proliferation, clonogenic potential, cell cycle progression, apoptosis, migration, and invasion. Additionally, we examined the action mechanism of KL-6 by RNA-seq and bioinformatic analysis and validated by qRT-PCR and western blot in pancreatic cancer cells.

Results

Our results demonstrated that KL-6 effectively inhibited the growth of pancreatic cancer cells in a dose-dependent manner. It induced G2/M phase cell cycle arrest and apoptosis, disrupting the cell cycle progression and promoting cell death. KL-6 also exhibited inhibitory effects on cell migration and invasion, suggesting its potential to suppress the metastatic properties of pancreatic cancer cells. Furthermore, KL-6 modulated the expression of genes involved in various cancer-related pathways including apoptosis and ferroptosis.

Conclusion

These findings collectively support the potential of KL-6 as a promising therapeutic option for pancreatic cancer treatment. Further research is needed to fully understand the underlying mechanisms and evaluate the clinical efficacy of KL-6 in pancreatic cancer patients.