crVDAC3 alleviates ferroptosis by impeding HSPB1 ubiquitination and confers trastuzumab deruxtecan resistance in HER2-low breast cancer

Knockdown of NDUFAF6 inhibits breast cancer progression via promoting mitophagy and apoptosis

BACKGROUND

While NDUFAF6 is implicated in breast cancer, its specific role remains unclear.

METHODS

The expression levels and prognostic significance of NDUFAF6 in breast cancer were assessed using The Cancer Genome Atlas, Gene Expression Omnibus, Kaplan-Meier plotter and cBio-Portal databases. We knocked down NDUFAF6 in breast cancer cells using small interfering RNA and investigated its effects on cell proliferation and migration ability. We performed gene expression analysis and validated key findings using protein analysis. We also assessed mitochondrial activity and cellular metabolism.

RESULTS

NDUFAF6 was highly expressed in breast cancer, which was associated with a poorer prognosis. Knockdown of NDUFAF6 reduced the proliferation and migration ability of breast cancer cells. Transcriptome analysis revealed 2,101 differentially expressed genes enriched in apoptosis and mitochondrial signaling pathways. Western blot results showed NDUFAF6 knockdown enhanced apoptosis. In addition, differential gene enrichment analysis was related to mitochondrial signaling pathways, and western blot results verified that mitophagy was enhanced in NDUFAF6 knockdown breast cancer cells. JC-1 assay also showed that mitochondrial dysfunction and reactive oxygen species content were increased after knocking down NDUFAF6. In addition, basal and maximal mitochondrial oxygen consumption decreased, and intracellular glycogen content increased.

CONCLUSIONS

Knockdown of NDUFAF6 resulted in apoptosis and mitophagy in breast cancer cells and NDUFAF6 may be a potential molecular target for breast cancer therapy.

Curcumenol inhibits malignant progression and promotes ferroptosis via the SLC7A11/NF‑κB/TGF‑β pathway in triple‑negative breast cancer

Triple‑negative breast cancer (TNBC) exhibits a high degree of malignancy and a propensity for metastasis, ultimately resulting in unfavorable patient outcomes. Curcuma phaeocaulis Valeton is a common herb used in traditional Chinese medicine to treat TNBC. Curcumenol (Cur) is a natural compound derived from C. phaeocaulis Valeton, the effects of which on breast cancer remain under‑reported. The present study elucidated that Cur could effectively inhibit the survival ability of TNBC cells and enhance their sensitivity to paclitaxel. Western blotting (WB) further revealed that Cur modulated apoptosis and epithelial‑mesenchymal transition (EMT) in TNBC. Findings from animal experiments further validated these observations. In the established TNBC mouse model, Cur was shown to exert an inhibitory effect on tumor growth, effectively attenuate EMT and substantially reduce the incidence of lung metastasis. Integrated analyses using RNA sequencing, WB and reverse transcription‑quantitative polymerase chain reaction demonstrated that Cur markedly downregulated the expression levels of solute carrier family 7 member 11 (SLC7A11), phosphorylated‑NF‑κB and TGF‑β. Molecular docking studies further validated that Cur can establish stable interactions with SLC7A11. In‑depth bioinformatics analysis revealed a positive association between high SLC7A11 expression and reduced disease‑free survival in patients with breast cancer. Additionally, in TNBC cells, Cur was revealed to reduce the mitochondrial membrane potential and promote the accumulation of lipid reactive oxygen species. Subsequent experimental investigations demonstrated that Cur can counteract the inhibitory influence of ferrostatin‑1 on ferroptosis. These findings strongly implied a potential underlying mechanism, suggesting that Cur may impede the malignant progression of TNBC via the modulation of ferroptosis. In conclusion, the findings of the present study underscore the marked efficacy of Cur in hampering the progression of TNBC by suppressing the SLC7A11/NF‑κB/TGF‑β signaling pathway.

Clinical approaches to overcome PARP inhibitor resistance

PARP inhibitors have profoundly changed treatment options for cancers with homologous recombination repair defects, especially those carrying BRCA1/2 mutations. However, the development of resistance to these inhibitors presents a significant clinical challenge as it limits long-term effectiveness. This review provides an overview of the current understanding of resistance mechanisms to PARP inhibitors and explores strategies to overcome these challenges. We discuss the basis of synthetic lethality induced by PARP inhibitors and detail diverse resistance mechanisms affecting PARP inhibitors, including homologous recombination restoration, reduced PARP trapping, enhanced drug efflux, and replication fork stabilization. The review then considers clinical approaches to combat resistance, focusing on combination therapies with immune checkpoint inhibitors, DNA damage response inhibitors, and epigenetic drugs. We also highlight ongoing clinical trials and potential biomarkers for predicting treatment response and resistance. The review concludes by outlining future research directions, emphasizing the need for longitudinal studies, advanced resistance monitoring technologies, and the development of novel combination strategies. By tackling PARP inhibitor resistance, this review seeks to aid in the development of more effective cancer therapies, with the potential to improve outcomes for patients with homologous recombination-deficient tumors.

A Feedback Loop Between Fatty Acid Metabolism and Epigenetics in Clear Cell Renal Carcinoma

Lipid storage and epigenetic dysregulation are key features for clear cell renal carcinoma (ccRCC). However, the interplay between fatty acid metabolism and epigenetics in ccRCC remains to be further demonstrated. Here, the landscape of active enhancers is profiled in paired ccRCC samples and identifies 10171 gain variant enhancer loci (VELs) in the tumor tissues. Experimental validation reveals the enhancers targeting FABP5, FABP6, LPCAT1, MET, SEMA5B, SH3GL1, SNX33, and RHBDF2 are oncogenic. Further studies in organoids and animal models prove FABP5 as an oncogene. HIF-2α and ZNF692 transcription factors regulate FABP5 expression through directly binding to its promoter and enhancer. FABP5 is essential for the lipid droplet formation driven by HIFs and critical for H3K27ac and enhancer activity in ccRCC cells. Thus, the study has identified potential targets for drug design and diagnosis and discovered the function of a feedback loop between epigenetics and lipid metabolism regulated by FABP5 in ccRCC.

The crosstalk between glutathione metabolism and non-coding RNAs in cancer progression and treatment resistance

Excessive reactive oxygen species (ROS) are closely associated with the initiation and progression of cancers. As the most abundant intracellular antioxidant, glutathione (GSH) plays a critical role in regulating cellular ROS levels, modulating physiological processes, and is intricately linked to tumor progression and drug resistance. However, the underlying mechanisms remain not fully elucidated. Non-coding RNAs (ncRNAs), including long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), are key regulators of GSH levels. Different ncRNAs modulate various pathways involved in GSH metabolism, and these regulatory targets have the potential to serve as therapeutic targets for enhancing cancer treatment. In this review, we summarize the functions of GSH metabolism and highlight the significance of ncRNA-mediated regulation of GSH in cancer progression, drug resistance, and clinical applications.

Role of ferroptosis in breast cancer: Molecular mechanisms and therapeutic interventions

Ferroptosis, an iron-dependent cell death pathway distinct from apoptosis, is crucial in breast cancer (BC) research, especially for overcoming resistance in triple-negative breast cancer (TNBC). Unlike traditional apoptosis, ferroptosis involves the glutathione (GSH)/glutathione peroxidase 4 (GPX4) axis, iron-driven oxidative reactions, and phospholipid peroxidation. TNBC, characterized by the absence of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2), is particularly prone to ferroptosis due to acyl-coenzyme A synthetase (ACSL) 4-related lipid changes and solute carrier family 7 member 11 (SLC7A11)-mediated cystine transport. Recent advancements in biomarkers and therapeutic strategies targeting ferroptosis hold significant promise for the diagnosis and prognosis of TNBC. Notable innovations encompass the development of small-molecule compounds and various methodologies designed to enhance ferroptosis. Combination therapies have demonstrated improved antitumor efficacy by counteracting chemotherapy resistance and inducing immunogenic cell death. Nonetheless, challenges persist in optimizing drug delivery mechanisms and minimizing off-target effects. This review underscores the progress in ferroptosis research and proposes precision oncology strategies that exploit metabolic flexibility in BC, intending to transform TNBC treatment and enhance therapeutic outcomes.

Role of the Wnt signaling pathway in the complex microenvironment of breast cancer and prospects for therapeutic potential (Review)

The focus on breast cancer treatment has shifted from the cytotoxic effects of single drugs on tumor cells to multidimensional multi‑pathway synergistic intervention strategies targeting the tumor microenvironment (TME). The activation of the Wnt signaling pathway in the TME of breast cancer cells serves a key regulatory role in tissue homeostasis and is a key driver of the carcinogenic process. Modulating the crosstalk between the Wnt pathway and TME of breast cancer is key for understanding the biological behavior of breast cancer and advancing the development of novel antitumor drugs. The present review aimed to summarize the complex mechanisms of the Wnt signaling pathway in the breast cancer TME, interactions between the Wnt signaling pathway and components of the breast cancer TME and breast cancer‑associated genes, as well as the interactions between the Wnt signaling pathway and other signaling cascades at the molecular level. Furthermore, the present review aimed to highlight the unique advantages of the Wnt signaling pathway in the macro‑regulation of the TME and the current therapeutic strategies targeting the Wnt signaling pathway, their potential clinical value and future research directions in breast cancer treatment.

Reshaping the immune microenvironment and reversing immunosenescence by natural products: Prospects for immunotherapy in gastric cancer

Gastric cancer (GC) represents a global health-care challenge. Recent progress in immunotherapy has elicited attracted considerable attention as a viable treatment option through modulating the host immune system and unleashing pre-existing immunity, which has profoundly revolutionized oncology, especially GC. Nonetheless, low clinical response and intrinsic and acquired resistance remain persistently challenging. The microenvironment of GC comprising multifarious stromal cell types has remarkable immunosuppressive elements that may impact the efficacy of immunotherapy. Immunosenescence is increasingly regarded as a factor that contributes to cancer development, remodels the tumor microenvironment and affects the efficacy of immunotherapy. Natural products are at the forefront of traditional medicine. Senotherapeutics is a class of drugs and natural products capable of delaying, preventing, or reversing the senescence process (i.e., senolytics) or suppressing senescence-associated secretory phenotype (i.e., senomorphics). Emerging evidence supports that natural products can improve the efficacy of existing immunotherapy and expand their indications in GC mainly based upon remodeling the immunosuppressive microenvironment and reversing immunosenescence. The review provides an integrated review of previously reported and ongoing clinical trials with immunotherapeutic regimens in GC and discusses current challenges. Next, we focus on natural compounds that exert anti-GC functions and possess immunomodulatory properties. More attention is paid to the potential of these natural compounds in modulating the immune microenvironment and immunosenescence. Lastly, we discuss the nanomedicine that can overcome the deficiencies of natural products. Altogether, our review suggests the enormous potential of natural compounds in GC immunotherapy, and provides an important direction for future research.

New developments in the role of ferroptosis in sepsis‑induced cardiomyopathy (Review)

Sepsis is a life‑threatening organ dysfunction disorder caused by dysfunctional host response to infection. Sepsis‑induced cardiomyopathy (SIC) is a common and serious complication of sepsis, and it is associated with increased mortality rates; however, its specific pathogenesis is still unclear. Ferroptosis, which is an iron‑dependent form of programmed cell death, is involved in the pathophysiology of SIC. Further study on the mechanism and therapeutic targets of ferroptosis in SIC may provide new strategies for clinical diagnosis and treatment of this condition. The present article reviews the mechanisms between SIC and ferroptosis, summarizes the progress in research of the involvement of ferroptosis in SIC and provides new potential strategies for further research and treatment in the future.

Anticancer Potential of Prebiotics: Targeting Estrogen Receptors and PI3K/AKT/mTOR in Breast Cancer

Estrogen receptors (ERs) play a critical role in breast cancer (BC) development and progression, with ERα being oncogenic and ERβ exhibiting tumor-suppressive properties. The interaction between ER signaling and other molecular pathways, such as PI3K/AKT/mTOR, influences tumor growth and endocrine resistance. Emerging research highlights the role of prebiotics in modulating gut microbiota, which may influence estrogen metabolism, immune function, and therapeutic responses in BC. This review explores the impact of prebiotics on estrogen receptor modulation, gut microbiota composition, immune regulation, and metabolic pathways in breast cancer. The potential of prebiotics as adjunctive therapies to enhance treatment efficacy and mitigate chemotherapy-related side effects is discussed. A comprehensive analysis of recent preclinical and clinical studies was conducted, examining the role of prebiotics in gut microbiota modulation, immune regulation, and metabolic reprogramming in breast cancer. The impact of short-chain fatty acids (SCFAs) derived from prebiotic fermentation on epigenetic regulation and endocrine resistance was also evaluated. Prebiotics were found to modulate the gut microbiota-estrogen axis, reduce inflammation, and influence immune responses. SCFAs demonstrated selective estrogen receptor downregulation and metabolic reprogramming, suppressing tumor growth. Synbiotic interventions mitigate chemotherapy-related side effects, improving the quality of life in breast cancer patients. Prebiotics offer a promising avenue for breast cancer prevention and therapy by modulating estrogen metabolism, immune function, and metabolic pathways. Future clinical trials are needed to validate their efficacy as adjunctive treatments in breast cancer management.

Efficacy and safety of pyrotinib in the treatment of HER2-positive liver metastatic advanced breast cancer

Background

This study aimed to evaluate the efficacy and safety of pyrotinib in the treatment of HER2-positive breast cancer patients with and without liver metastasis.

Methods

A retrospective analysis was conducted on 91 patients with HER2-positive advanced breast cancer, who were treated with pyrotinib between March 2019 and April 2022. The patients were categorized into two groups based on the presence or absence of liver metastases, and their overall survival (OS), progression-free survival (PFS), and their response to pyrotinib were compared. Adverse effects in the patients were analyzed to assess the safety of pyrotinib.

Results

The cohort include 29 patients with liver metastasis and 62 without. The median overall survival was significantly shorter in the liver metastasis group (15.8 months) than that in the non-liver metastasis group (31.4 months, P = 0.0036). A statistically significant difference was observed in the median PFS between the liver metastasis and the non-liver metastasis groups (8.7 vs. 18.4 months) (P = 0.0272). Univariate analysis revealed that patients with younger age (<60 years) (P < 0.0001), negative progesterone receptor expression (P = 0.0028), higher Ki67 expression levels (P < 0.0001), and absence of lymph node metastasis (P < 0.0001) were more likely to benefit from pyrotinib treatment. Comparative analysis between groups showed significantly higher incidence rates of anemia (58.6% vs. 40.3%) and elevated aspartate transaminase level (31.0% vs 8.1%) in the liver metastasis group compared to the non-liver metastasis (P < 0.05).

Conclusions

Pyrotinib-based therapy is efficacious and safe for patients with HER2-positive advanced breast cancer with liver metastases, while further large-scale clinical trials are warranted to validate these results.

EBF1-induced CSRP2 boosts the progression of B-cell acute lymphocytic leukemia by inhibiting ferroptosis

B-cell acute lymphocytic leukemia (B-ALL) is a highly aggressive malignancy with poor prognosis. Developing diagnostic markers and therapeutic targets to identify and treat B-ALL early would improve the outcomes of B-ALL patients. Here, we conducted RNA next-generation sequencing using bone marrow (BM) specimens obtained from 7 B-ALL patients and 7 healthy donors. We found cysteine and glycine-rich protein 2 (CSRP2) upregulated in B-ALL. Down-regulation of CSRP2 resulted in suppressed cell proliferation and enhanced cell apoptosis in B-ALL. In addition, inhibition of CSRP2 increased cell ferroptosis in B-ALL cells. Mechanically, we revealed that transcription factor early B cell factor 1 (EBF1) regulated CSRP2 levels in B-ALL, and inhibition of EBF1 decreased CSRP2 levels in B-ALL. In conclusion, the dysregulation EBF1 led to CSRP2 upregulation and resulting in progression of B-ALL. The EBF1/CSRP2 axis could be of great potential as therapeutic targets for B-ALL treatment.

Circular RNAs modulate cancer drug resistance: advances and challenges

Acquired drug resistance is a main factor contributing to cancer therapy failure and high cancer mortality, highlighting the necessity to develop novel intervention targets. Circular RNAs (circRNAs), an abundant class of RNA molecules with a closed loop structure, possess characteristics including high stability, which provide unique advantages in clinical application. Growing evidence indicates that aberrantly expressed circRNAs are associated with resistance against various cancer treatments, including targeted therapy, chemotherapy, radiotherapy, and immunotherapy. Therefore, targeting these aberrant circRNAs may offer a strategy to improve the efficiency of cancer therapy. Herein, we present a summary of the most recently studied circRNAs and their regulatory roles on cancer drug resistance. With the advances in artificial intelligence (AI)-based bioinformatics algorithms, circRNAs could emerge as promising biomarkers and intervention targets in cancer therapy.

Paeonol ameliorates ferroptosis and inflammation in chondrocytes through AMPK/Nrf2/GPX4 pathway

Introduction

Chondrocyte ferroptosis is an important component of the pathogenesis of osteoarthritis. Paeonol, the main pharmacologically active ingredient of the Paeonia suffruticosa Andrews, is a natural radical scavenger with potent biological activities, including antioxidant, anti-inflammatory, and cartilage protection effects. However, the molecular mechanisms underlying its role in regulating chondrocytes ferroptosis remain unclear.

Methods

To investigate the effect of paeonol on ferroptosis and inflammation of chondrocytes through interleukin-1β (IL-1β), the proliferation activity, lipid peroxidation level, endogenous antioxidant capacity, and mitochondrial membrane potential of chondrocytes were evaluated in detail. Intracellular ferrous ion concentration was detected by FerroOrange fluorescent probe staining. Western blotting and immunofluorescence staining were used to detect biomarker proteins of ferroptosis, inflammation, and AMPK/Nrf2/GPX4 signaling pathway proteins.

Results

The results showed that paeonol significantly depressed IL-1β-induced ferroptosis and inflammation in chondrocytes. Specifically, paeonol protects cell viability, reduces lipid peroxidation damage, maintains mitochondrial function, and inhibits pro-ferroptosis and pro-inflammation biomarker proteins. In addition, the anti-inflammatory ability of paeonol was partially inhibited after the addition of ferroptosis agonist erastin, suggesting that paeonol protects against inflammatory injury in part by inhibiting ferroptosis. Further studies showed that paeonol activated AMPK phosphorylation and promoted Nrf2 nuclear translocation and Keap1 degradation. Finally, the AMPK-Nrf2-GPX4 signaling pathway was confirmed to be the underlying mechanism of paeonol against ferroptosis by the simultaneous use of the AMPK agonist and Nrf2 inhibitor.

Conclusion

These results indicate that paeonol significantly inhibits IL-1β-induced ferroptosis and inflammation in chondrocytes, and the underlying mechanism of paeonol against ferroptosis is partly through the AMPK/Nrf2/GPX4 axis.

Antibody-drug conjugates in breast cancer treatment: resistance mechanisms and the role of therapeutic sequencing

Antibody-drug conjugates (ADCs) are a transformative approach in breast cancer therapy, offering targeted treatment with reduced toxicity by selectively delivering cytotoxic agents to cancer cells. While ADCs like trastuzumab emtansine (T-DM1), trastuzumab deruxtecan (T-DXd), and sacituzumab govitecan have shown significant efficacy, resistance mechanisms such as antigen loss, impaired internalization, and efflux of cytotoxic payloads challenge their effectiveness. This review discusses these resistance mechanisms and explores advanced strategies to overcome them, including innovations in linker chemistry, multi-antigen targeting, and biomarker-driven personalization. Additionally, therapeutic sequencing - determining the optimal order of ADCs with other treatments such as chemotherapy, endocrine therapy, and immunotherapy - is examined as a crucial approach to maximize ADC efficacy and manage resistance. Evidence-based sequencing strategies, particularly for human epidermal growth factor receptor 2 (HER2)-positive and triple-negative breast cancer (TNBC), are supported by clinical trials demonstrating the benefits of ADCs in both early-stage and metastatic settings. The potential of combination therapies, such as ADCs with immune checkpoint inhibitors (ICIs), further highlights the evolving landscape of breast cancer treatment. As ADC technology advances, personalized approaches integrating biomarkers and optimized sequencing protocols offer promising avenues to enhance treatment outcomes and combat resistance in breast cancer.

Triple‑negative breast cancer cell‑derived piR‑31115 promotes the proliferation and migration of endothelial cells via METTL3‑mediated m6A modification of YAP1

Triple‑negative breast cancer (TNBC), a highly malignant breast cancer subtype with a pronounced metastatic propensity, forms the focus of the present investigation. MDA‑MB‑231, a prevalently utilized TNBC cell line in cancer research, was employed. In accordance with the tumour angiogenesis theory, cancer cells are capable of instigating angiogenesis and the formation of a novel vascular system within the tumour microenvironment, which subsequently sustains malignant proliferation and metastasis. Consequently, impeding the growth of tumour blood vessels holds substantial significance in suppressing TNBC metastasis. Piwi‑interacting RNAs (piRNAs), a category of endogenous non‑coding RNAs, have been demonstrated to modulate cancer progression. However, studies regarding the role of piRNAs in regulating angiogenesis within cancer cells are relatively scant. In the present study, via cell co‑culture experiments, it was revealed that piR‑31115 (a kind of piRNA) in MDA‑MB‑231 cells notably enhanced the recruitment of a human microvascular endothelial cell line (HMEC‑1). Moreover, the conditioned medium (CM, which was obtained from MDA‑MB‑231 cells via a specific culturing methodology and was employed for the subsequent treatment of HMEC‑1 cells to explore its impacts on the biological behaviors such as the proliferation and migration of HMEC‑1 cells) derived from MDA‑MB‑231 cells with upregulated piR‑31115 expression stimulated the proliferation and migration of HMEC‑1 cells. These findings suggest that piR‑31115 in MDA‑MB‑231 cells may play a pivotal role in modulating tumour angiogenesis. Further studies disclosed that the CM from MDA‑MB‑231 cells augmented the N6‑methyladenosine (m6A) RNA modification level via METTL3 in HMEC‑1 cells. Transcriptome sequencing revealed that METTL3 functions as an m6A writer protein for Yes‑associated protein 1 (YAP1), which exerts a positive influence on promoting the proliferation and migration of HMEC‑1 cells. Concurrently, the IGF2BP plays a crucial role in stabilizing YAP1 protein expression. Collectively, the present findings identified a signalling pathway through which MDA‑MB‑231 cells induce HMEC‑1 cell proliferation and migration by regulating m6A RNA methylation.

Disitamab vedotin in preclinical models of HER2-positive breast and gastric cancers resistant to trastuzumab emtansine and trastuzumab deruxtecan

BACKGROUND

Most HER2-positive breast or gastric cancers eventually become resistant to the approved anti-HER2 antibody-drug conjugates (ADC) trastuzumab emtansine (T-DM1) and trastuzumab deruxtecan (T-DXd). Disitamab vedotin (DV) is a novel anti-HER2 ADC that binds to a different epitope on HER2 compared to trastuzumab. We assessed the efficacy of DV in breast and gastric cancer cell lines and xenografts, including tumor models resistant to T-DM1 and T-DXd. Additionally, we investigated whether combining two anti-HER2 ADCs could enhance the efficacy of the individual ADCs.

METHODS

The efficacy of DV, T-DM1, and T-DXd, both as single agents and in combinations, was assessed using an AlamarBlue cell proliferation assay in HER2-positive breast and gastric cancer cell lines, including those resistant to T-DM1 and T-DXd. The efficacy of DV was evaluated also in breast and gastric cancer SCID mouse xenografts that had progressed on T-DM1 and/or T-DXd. ADC combinations were tested in breast and gastric cancer xenografts.

RESULTS

DV was effective in cell lines resistant to T-DM1 and/or T-DXd, and it inhibited the growth of breast and gastric cancer xenografts that had progressed on T-DM1 and/or T-DXd. The combinations of DV plus T-DM1 and DV plus T-DXd showed greater efficacy than the corresponding single agents in both breast and gastric cancer cell lines and xenografts.

CONCLUSIONS

DV was effective in treating breast and gastric cancer xenograft tumors resistant to T-DM1 and/or T-DXd. The combination of DV with T-DM1 or T-DXd demonstrated promising activity.

Sciatic nerve stimulation enhances NK cell cytotoxicity through dopamine signaling and synergizes immunotherapy in triple-negative breast cancer

AIMS

Triple-negative breast cancer (TNBC) has shown resistance to immunotherapy. Stimulating ProkR2-bearing sensory neurons of the sciatic nerve has been reported to regulate immune function by catecholamine release through the vagal-adrenal axis. We aimed to investigate the impact of sciatic nerve stimulation on anti-tumor immune responses and immunotherapy efficacy in TNBC.

METHODS

We implemented ProkR2-bearing neuron stimulation in a TNBC mouse model. Single-cell RNA sequencing, flow cytometry, and immunohistochemistry were employed to uncover alterations in the tumor immune microenvironment. Immune cell depletion and receptor inhibitors were used to verify the cellular and molecular mechanisms by which neurostimulation regulates anti-tumor immunity.

RESULTS

Sciatic nerve stimulation inhibited 4T1 tumor growth by activating natural killer (NK) cells in the tumor microenvironment. The D1-like dopamine receptor-cAMP-PKA-CREB signaling pathway is essential for enhanced NK cell cytotoxicity and tumor inhibition induced by neurostimulation. Neurostimulation upregulated tumor PD-L1 expression through IFN-gamma pathway. Combining sciatic nerve stimulation with anti-PD-1 therapy resulted in superior tumor control compared to either approach alone and demonstrated good safety.

CONCLUSIONS

This research addresses a long-standing gap in understanding neuro-immune regulation in cancer treatment, presenting a promising strategy for overcoming immunoresistance in TNBC.

M2 Macrophage-Derived Exosomal circ_0088494 Inhibits Ferroptosis via Promoting H3K4me1 Modification of STEAP3 in Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (cSCC) is a common type of cutaneous cancer globally. M2 macrophage-derived exosomes (M2 exosomes) facilitate the development of cancer. Ferroptosis, a newly uncovered form of cell death, is linked to cancer progression. The present research planned to study the function and potential mechanism of M2 exosomes on ferroptosis in cSCC. Patients with cSCC were recruited to gather adjacent noncancerous specimens and cSCC tissues. Mononuclear macrophage (THP-1) cells were differentiated into M2 macrophages before exosome extraction, and then the exosomes were added into cSCC cells (A431 and SCL-1). Erastin was applied to induce ferroptosis. Cell viability, mitochondrial superoxide, lipid-ROS, malondialdehyde (MDA), and iron level were detected to validate ferroptosis in cSCC cells. Proteins and RNAs were tested by applying western blot and RT-qPCR. The combination between molecules was validated by ChIP and RIP. Six-transmembrane epithelial antigen of the prostate 3 (STEAP3) was elevated in cSCC specimens, which correlated to reduced ferroptosis. cSCC tissues presented an increase in the number of M2 macrophages. Erastin-elicited ferroptosis was repressed by M2 macrophages, while exosome inhibitor GW4869 neutralized the outcome of M2 macrophages. Furthermore, M2 exosomes repressed ferroptosis of cSCC cells via circ_0088494, which might be related to the upregulation of STEAP3. M2 exosomes-derived circ_0088494 promoted histone 3 lysine 4 monomethylation (H3K4me1) modification of STEAP3 by recruiting histone-lysine N-methyltransferase 2D (KMT2D). The effect of circ_0088494-silenced M2 exosomes on ferroptosis was antagonized by STEAP3 overexpression. M2 exosomes-derived circ_0088494 recruited KMT2D to promote H3K4me1 modification of STEAP3, thereby inhibiting ferroptosis in cSCC. This study might provide a novel target for cSCC treatment.

Current Status and Future Directions of Ferroptosis Research in Breast Cancer: Bibliometric Analysis

BACKGROUND

Ferroptosis, as a novel modality of cell death, holds significant potential in elucidating the pathogenesis and advancing therapeutic strategies for breast cancer.

OBJECTIVE

This study aims to comprehensively analyze current ferroptosis research and future trends, guiding breast cancer research advancements and innovative treatment strategies.

METHODS

This research used the R package Bibliometrix (Department of Economic and Statistical Sciences at the University of Naples Federico II), VOSviewer (Centre for Science and Technology Studies at Leiden University), and CiteSpace (Drexel University's College of Information Science and Technology), to conduct a bibliometric analysis of 387 papers on breast cancer and ferroptosis from the Web of Science Core Collection. The analysis covers authors, institutions, journals, countries or regions, publication volumes, citations, and keywords.

RESULTS

The number of publications related to this field has surged annually, with China and the United States collaborating closely and leading in output. Sun Yat-sen University stands out among the institutions, while the journal Frontiers in Oncology and the author Efferth T contribute significantly to the field. Highly cited papers within the domain primarily focus on the induction of ferroptosis, protein regulation, and comparisons with other modes of cell death, providing a foundation for breast cancer treatment. Keyword analysis highlights the maturity of glutathione peroxidase 4-related research, with breast cancer subtypes emerging as motor themes and the tumor microenvironment, immunotherapy, and prognostic models identified as basic themes. Furthermore, the application of nanoparticles serves as an additional complement to the basic themes.

CONCLUSIONS

The current research status in the field of ferroptosis and breast cancer primarily focuses on the exploration of relevant theoretical mechanisms, whereas future trends and mechanisms emphasize the investigation of therapeutic strategies, particularly the clinical application of immunotherapy related to the tumor microenvironment. Nanotherapy has demonstrated significant clinical potential in this domain. Future research directions should deepen the exploration in this field and accelerate the clinical translation of research findings to provide new insights and directions for the innovation and development of breast cancer treatment strategies.

HER2-low status as a distinct breast cancer subtype: myth or truth? Analysis of the WSG trials WSG-ADAPT-HR+/HER2-, WSG-PlanB, and WSG-ADAPT-TN

BACKGROUND

New data show that not only HER2-overexpressing breast cancer (BC) tumors but also HER2-low tumors, classically considered as HER2-negative, respond to HER2-targeting antibody-drug-conjugates. Our objective was to analyze the prevalence of HER2-low BC in a pooled analysis of contemporary early BC trials and to evaluate its role as a prognostic factor in terms of survival in comparison to HER2-zero BC.

METHODS

We evaluated 5598 patients with locally HR + /HER2- BC from the screening cohort of WSG-ADAPT-HR + /HER2-, 2592 patients with HR + /HER2- or HR-/HER2- from the adjuvant WSG-PlanB trial, and 336 patients from the WSG-ADAPT-TN trial. Central HER2 testing was performed prospectively in WSG-ADAPT and retrospectively in WSG-PlanB. Following ASCO/CAP guidelines, HER2-low status was defined as immunohistochemistry (IHC) 1 + or 2 + and in situ hybridization (ISH)-negative, and HER2-zero was defined as IHC 0. Agreement between HER2 assessments was evaluated with Cohen's kappa coefficient, and effects of HER2 status on pathological complete response (pCR) and on survival were analyzed with logistic regression and Cox proportional hazards models, respectively.

FINDINGS

In WSG-ADAPT-HR + /HER2-, 3198 (64.6%) tumors were HER2-low by the central and 3096 (55.6%) by the local histology (agreement for HER2-low status was 61.0%). In HR + /HER2- cases from WSG-PlanB, 601 tumors (28.7%) were HER2-low. In both cohorts, HER2-low status was significantly associated with higher ERBB2 mRNA expression by Oncotype DX test in comparison to HER2-zero: mean 9.3 vs. 9.1 (p < .001) by local HER2 assessment in WSG-ADAPT and mean 9.2 vs. 8.8 (p < .001) in WSG-PlanB. Furthermore, patients with HER2-low tumors in WSG-ADAPT-HR + /HER2- significantly less often had a pCR compared to the HER2-zero tumors (p = .015). No significant difference was observed in (invasive and/or distant) disease-free survival (DFS) between centrally HER2-low and HER2-zero tumors in both HR + /HER2- cohorts (WSG-ADAPT-HR + /HER2- distant DFS: unadjusted HR = 1.06, 95%CI 0.83-1.36, similar results for local assessment; WSG-PlanB DFS: unadjusted HR = 1.28, 95%CI 0.91-1.82). In the HR-/HER2- WSG-PlanB cohort, centrally HER2-low tumors (10.5%) were associated with better DFS (unadjusted HR = 0.21, 95%CI 0.05-0.83), this association was not observed in the WSG-ADAPT-TN.

CONCLUSION

The prevalence of HER2-low status varied between the analyzed trials. Our results show that survival does not differ between HER2-low and HER2-zero tumors in HR + /HER2- cohorts; however, HER2-low status appears to have an inconsistent impact on survival in TNBC. Therefore, our findings do not support the characterization of HER2-low status as a distinct BC subtype.

Circular RNAs in cancer

Circular RNA (circRNA), a subtype of noncoding RNA, has emerged as a significant focus in RNA research due to its distinctive covalently closed loop structure. CircRNAs play pivotal roles in diverse physiological and pathological processes, functioning through mechanisms such as miRNAs or proteins sponging, regulation of splicing and gene expression, and serving as translation templates, particularly in the context of various cancers. The hallmarks of cancer comprise functional capabilities acquired during carcinogenesis and tumor progression, providing a conceptual framework that elucidates the nature of the malignant transformation. Although numerous studies have elucidated the role of circRNAs in the hallmarks of cancers, their functions in the development of chemoradiotherapy resistance remain unexplored and the clinical applications of circRNA-based translational therapeutics are still in their infancy. This review provides a comprehensive overview of circRNAs, covering their biogenesis, unique characteristics, functions, and turnover mechanisms. We also summarize the involvement of circRNAs in cancer hallmarks and their clinical relevance as biomarkers and therapeutic targets, especially in thyroid cancer (TC). Considering the potential of circRNAs as biomarkers and the fascination of circRNA-based therapeutics, the "Ying-Yang" dynamic regulations of circRNAs in TC warrant vastly dedicated investigations.

Interactions between ferroptosis and tumour development mechanisms: Implications for gynaecological cancer therapy (Review)

Ferroptosis is a form of programmed cell death that is distinct from apoptosis. The mechanism involves redox‑active metallic iron and is characterized by an abnormal increase in iron‑dependent lipid reactive oxygen species, which results in high levels of membrane lipid peroxides. The relationship between ferroptosis and gynaecological tumours is complex. Ferroptosis can regulate tumour proliferation, metastasis and chemotherapy resistance, and targeting ferroptosis is a promising antitumour approach. Ferroptosis interacts with mechanisms related to tumorigenesis and development, such as macrophage polarization, the neutrophil trap network, mitochondrial autophagy and cuproptosis. The present review examines recent information on the interaction between the molecular mechanism of ferroptosis and other tumour‑related mechanisms, as well as the involvement of ferroptosis in gynaecological tumours, to identify implications for gynaecological cancer therapy.

Dysregulation of transposable elements and PIWI-interacting RNAs in myelodysplastic neoplasms

BACKGROUND

Myelodysplastic neoplasms (MDS) are heterogeneous hematopoietic disorders characterized by ineffective hematopoiesis and genome instability. Mobilization of transposable elements (TEs) is an important source of genome instability leading to oncogenesis, whereas small PIWI-interacting RNAs (piRNAs) act as cellular suppressors of TEs. However, the roles of TEs and piRNAs in MDS remain unclear.

METHODS

In this study, we examined TE and piRNA expression through parallel RNA and small RNA sequencing of CD34+ hematopoietic stem cells from MDS patients.

RESULTS

Comparative analysis of TE and piRNA expression between MDS and control samples revealed several significantly dysregulated molecules. However, significant differences were observed between lower-risk MDS (LR-MDS) and higher-risk MDS (HR-MDS) samples. In HR-MDS, we found an inverse correlation between decreased TE levels and increased piRNA expression and these TE and piRNA levels were significantly associated with patient outcomes. Importantly, the upregulation of PIWIL2, which encodes a key factor in the piRNA pathway, independently predicted poor prognosis in MDS patients, underscoring its potential as a valuable disease marker. Furthermore, pathway analysis of RNA sequencing data revealed that dysregulation of the TE‒piRNA axis is linked to the suppression of processes related to energy metabolism, the cell cycle, and the immune response, suggesting that these disruptions significantly affect cellular activity.

CONCLUSIONS

Our findings demonstrate the parallel dysregulation of TEs and piRNAs in HR-MDS patients, highlighting their potential role in MDS progression and indicating that the PIWIL2 level is a promising molecular marker for prognosis.

Optimizing therapeutic approaches for HR+/HER2- advanced breast cancer: clinical perspectives on biomarkers and treatment strategies post-CDK4/6 inhibitor progression

This review offers an expert perspective on biomarkers, CDK4/6 inhibitor efficacy, and therapeutic approaches for managing hormone receptor-positive (HR+), human epidermal growth factor receptor-negative (HER2-) advanced breast cancer (ABC), particularly after CDK4/6 inhibitor progression. Key trials have demonstrated that combining CDK4/6 inhibitors with endocrine therapy (ET) significantly improves progression-free survival (PFS), with median durations ranging from 14.8 to 26.7 months, and overall survival (OS), with median durations reaching up to 53.7 months. Actionable biomarkers, such as PIK3CA and ESR1 mutations, have emerged as pivotal tools to guide second-line treatment decisions, enabling the use of targeted therapies like alpelisib and elacestrant and emphasizing the important role of biomarkers in guiding the selection of therapy. This overview aims to provide clinicians with a practical and up-to-date framework to inform treatment decisions and improve patient care in the context of this challenging disease. Additionally, we review emerging biomarkers and novel treatment strategies to address this difficult clinical landscape.

Prognostic and diagnostic value of circRNA expression in cervical cancer: a meta analysis

Introduction

Cervical cancer (CC) is a highly prevalent malignancy of the reproductive system. This study aimed to methodically assess the function of circular RNAs (circRNAs) as possible indicators of CC, with a specific emphasis on their usefulness in the identification, prediction, and correlation with clinicopathological elements.

Methods

A comprehensive literature search was conducted using databases such as PubMed, Cochrane Library, Web of Science, Embase, and the China National Knowledge Infrastructure (CNKI). The latest data were extracted on May 3rd, 2024. The diagnostic potential of circRNA expression was evaluated using a range of metrics including sensitivity, specificity, and area under the receiver operating characteristic curve (AUC). The importance of circRNAs was further evaluated in terms of clinical relevance, pathological features, and prognostic value using pooled odds ratios (ORs) and hazard ratios (HRs).

Results

The meta-analysis included 27 studies, which were categorised based on diagnostic applications (n=3), clinicopathological correlations (n=15), and prognostic evaluations (n=23). Elevated expression levels of oncogenic circRNAs were significantly associated with poor clinical indicators, including tumour size (odds ratio [OR] = 0.425, 95% confidence interval [CI]: 0.267-0.676), International Federation of Gynaecology and Obstetrics (FIGO) stage (OR = 0.315, 95% CI: 0.224-0.443), and lymph node metastasis (OR = 2.975, 95% CI: 1.816-4.872). This upregulation of oncogenic circRNA was also identified as a predictor of worse survival outcomes, with a hazard ratio (HR) of 2.13 (95% CI: 1.73-2.62, P < 0.001). The downregulation of circRNAs with tumour-suppressor properties was similarly associated with poor clinical parameters, such as tumour size (OR = 0.310, 95% CI: 0.102-0.941), FIGO stage (OR = 0.231, 95% CI: 0.101-0.527), and lymph node metastasis (OR = 2.430, 95% CI: 1.156-5.110), and was indicative of a worsened prognosis (HR = 2.20, 95% CI: 1.03-4.70, P = 0.042). In terms of diagnostic value, the pooled sensitivity, specificity, and area under the curve (AUC) were calculated to be 0.85, 0.83, and 0.91, respectively.

Conclusion

The results of our meta-analysis indicate that circRNAs have the potential to serve as promising biomarkers for CC diagnosis, prognosis, and clinicopathology.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42024544997.

Ferroptosis-related signaling pathways in cancer drug resistance

Ferroptosis is an iron-dependent form of programmed cell death induced by lipid peroxidation. This process is regulated by signaling pathways associated with redox balance, iron metabolism, and lipid metabolism. Cancer cells' increased iron demand makes them especially susceptible to ferroptosis, significantly influencing cancer development, therapeutic response, and metastasis. Recent findings indicate that cancer cells can evade ferroptosis by downregulating key signaling pathways related to this process, contributing to drug resistance. This underscores the possibility of modulating ferroptosis as an approach to counteract drug resistance and enhance therapeutic efficacy. This review outlines the signaling pathways involved in ferroptosis and their interactions with cancer-related signaling pathways. We also highlight the current understanding of ferroptosis in cancer drug resistance, offering insights into how targeting ferroptosis can provide novel therapeutic approaches for drug-resistant cancers. Finally, we explore the potential of ferroptosis-inducing compounds and examine the challenges and opportunities for drug development in this evolving field.

Broadening horizons: the multifaceted role of ferroptosis in breast cancer

Breast cancer poses a serious threat to women's health globally. Current radiotherapy and chemotherapy regimens can induce drug-resistance effects in cancer tissues, such as anti-apoptosis, anti-pyroptosis, and anti-necroptosis, leading to poor clinical outcomes in the treatment of breast cancer. Ferroptosis is a novel programmed cell death modality characterized by iron overload, excessive generation of reactive oxygen species, and membrane lipid peroxidation. The occurrence of ferroptosis results from the imbalance between intracellular peroxidation mechanisms (executive system) and antioxidant mechanisms (defensive system), specifically involving iron metabolism pathways, amino acid metabolism pathways, and lipid metabolism pathways. In recent years, it has been found that ferroptosis is associated with the progression of various diseases, including tumors, hypertension, diabetes, and Alzheimer's disease. Studies have confirmed that triggering ferroptosis in breast cancer cells can significantly inhibit cancer cell proliferation and invasion, and improve cancer cell sensitivity to radiotherapy and chemotherapy, making induction of ferroptosis a potential strategy for the treatment of breast cancer. This paper reviews the development of the concept of ferroptosis, the mechanisms of ferroptosis (including signaling pathways such as GSH-GPX4, FSP1-CoQ1, DHODH-CoQ10, and GCH1-BH4) in breast cancer disease, the latest research progress, and summarizes the research on ferroptosis in breast cancer disease within the framework of metabolism, reactive oxygen biology, and iron biology. The key regulatory factors and mechanisms of ferroptosis in breast cancer disease, as well as important concepts and significant open questions in the field of ferroptosis and related natural compounds, are introduced. It is hoped that future research will make further breakthroughs in the regulatory mechanisms of ferroptosis and the use of ferroptosis in treating breast cancer cells. Meanwhile, natural compounds may also become a new direction for potential drug development targeting ferroptosis in breast cancer treatment. This provides a theoretical basis and opens up a new pathway for research and the development of drugs for the prevention and treatment of breast cancer.

Unlocking the potential of extracellular vesicle circRNAs in breast cancer: From molecular mechanisms to therapeutic horizons

Breast cancer remains the leading cause of cancer-related morbidity and mortality among women worldwide, underscoring the urgent need for novel diagnostic and therapeutic strategies. This review explores the emerging roles of circular RNAs (circRNAs) within extracellular vesicles (exosomes) in breast cancer. circRNAs, known for their stability and tissue-specific expression, are aberrantly expressed in breast cancer and regulate critical cellular processes such as proliferation, migration, and apoptosis, positioning them as promising biomarkers. Exosomes facilitate intercellular communication by delivering circRNAs, reflecting the physiological and pathological state of their source cells. This review highlights the multifaceted roles of exosomal circRNAs in promoting tumor growth, metastasis, and drug resistance through their modulation of tumor metabolism, the tumor microenvironment, and immune responses. In particular, we emphasize their contributions to chemotherapy resistance and their potential as both diagnostic markers and therapeutic targets. By synthesizing current research, this review provides novel insights into the clinical applications of exosomal circRNAs, offering a foundation for future studies aimed at improving breast cancer management through non-invasive diagnostics and targeted therapies.