Search Results (5,817)

Glioblastoma multiforme (GBM) is characterized by aggressive growth, extensive vascularization, high metabolic malleability, and a striking capacity for therapy resistance. Current treatments involve surgical resection and concomitant radiation therapy and chemotherapy, prolonging survival times marginally due to the therapy resistance that is built up by the tumor cells. A growing body of research has identified exosomes as critical enablers of therapy resistance. These nanoscale vesicles enable GBM cells to disseminate oncogenic proteins, nucleic acids, and lipids that collectively promote angiogenesis, maintain autophagy under metabolic pressure, and suppress apoptosis. As interest grows in targeting tumor communication networks, exosome-based therapeutic strategies have emerged as promising avenues for improving therapeutic outcomes in GBM. This review integrates current insights into two complementary therapeutic strategies: inhibiting exosome biogenesis and secretion, and engineering exosomes as precision vehicles for the delivery of anti-tumor molecular cargo. Key molecular regulators of exosome formation—including the endosomal sorting complex required for transport (ESCRT) machinery, tumor susceptibility gene 101 (TSG101) protein, ceramide-driven pathways, and Rab GTPases—govern the sorting and release of factors that enhance GBM survival. Targeting these pathways through pharmacological or genetic means has shown promise in suppressing angiogenic signaling, disrupting autophagic flux via modulation of autophagy-related gene (ATG) proteins, and sensitizing tumor cells to apoptosis by destabilizing mitochondria and associated survival networks. In parallel, advances in exosome engineering—encompassing siRNA loading, miRNA enrichment, and small-molecule drug packaging—offer new routes for delivering therapeutic agents across the blood–brain barrier with high cellular specificity. Engineered exosomes carrying anti-angiogenic, autophagy-inhibiting, or pro-apoptotic molecules can reprogram the tumor microenvironment and activate both the intrinsic mitochondrial and extrinsic ligand-mediated apoptotic pathways. Collectively, current evidence underscores the potential of strategically modulating endogenous exosome biogenesis and harnessing exogenous engineered therapeutic exosomes to interrupt the angiogenic and autophagic circuits that underpin therapy resistance, ultimately leading to the induction of apoptotic cell death in GBM. Full article

Background/Objectives: Breast cancer cells rely on both mitochondrial metabolism and proteostatic mechanisms for cell fitness. The mitochondrial enzyme IDH2 supports redox balance and biosynthesis, while the ubiquitin-proteasome system (UPS) preserves protein quality. This study aimed to determine whether inhibiting IDH2 enhances sensitivity to proteasome-targeting agents across breast cancer subtypes. Methods: A panel of human and murine breast cancer cell lines was treated with the IDH2 inhibitor AGI-6780, alone or in combination with the proteasome inhibitor carfilzomib (CFZ) or the E1 ubiquitin-activating enzyme inhibitor TAK-243. Synergy was evaluated using Bliss scoring. Apoptosis, clonogenicity, and pathway modulation were assessed through Western blotting, colony-formation assays, and reverse-phase protein array (RPPA) profiling. Results: We observed that co-targeting IDH2 and the UPS produced strong synergistic cytotoxicity in multiple breast cancer models, including in triple-negative MDA-MB-231 and 4T1 cells (Bliss > 25). Combination treatments led to pronounced apoptosis, evidenced by cleaved PARP-1 and Caspase-3 cleavage, and a marked loss of clonogenic potential. RPPA analysis revealed significant alterations in key survival and stress-response pathways, including NF-κB, PI3K-p85, Src, and p38-MAPK. Conclusions: Inhibition of IDH2 markedly enhances the cytotoxic effects of proteasome-targeting by disrupting metabolic–proteostatic balance and promoting apoptotic cell death. These findings identify a growth-inhibitory effect that may be leveraged to improve functional dependency in breast cancer, particularly in triple-negative breast cancer, which currently lacks efficient drug treatments. Full article

Prostate cancer (PCa) is the most common male cancer and the second leading cause of cancer death in men. Androgen deprivation therapy (ADT) has been widely used as the first-line treatment for PCa. However, most PCa will progress to castration-resistant PCa (CRPC) that resists ADT 1 to 3 years after the treatment. Steroidogenesis from cholesterol is one of the mechanisms leading to ADT resistance. In PCa cells, low-density lipoprotein (LDL) mediated uptake is the major venue to acquire cholesterol. However, the mechanism of regulating this process is not fully understood. Fibroblast growth factor receptor 1 (FGFR1) is a receptor tyrosine kinase (RTK) that is ectopically expressed in PCa cells and promotes PCa progression by activating downstream signaling pathways. To comprehensively determine the roles of FGFR1 in PCa, we generated FGFR1-null DU145 cells and compared the transcriptomes of FGFR1-null and wild-type cells. We found that ablation of FGFR1 reduced the expression of genes promoting LDL uptake and de novo synthesis of cholesterol, thereby reducing the overall cholesterol pool in PCa cells. Detailed mechanistic studies further revealed that FGFR1 boosted the activation of sterol regulatory element-binding protein 2 (SREBP2) through ERK-dependent phosphorylation and cleavage, which, in turn, increased the expression of low-density lipoprotein receptor (LDLR) and enzymes involved in de novo cholesterol synthesis. Furthermore, in silico analyses demonstrated that high expression of FGFR1 was associated with high LDLR expression and clinicopathological features in PCa. Collectively, our data unveiled a previously unrecognized therapeutic avenue for CRPC by targeting FGFR1-driven cholesterol uptake and de novo synthesis. Full article

Background/Objectives: Triple negative breast cancer (TNBC) is an aggressive subtype treated primarily with chemotherapy, which often leads to drug resistance (DR) and reduced effectiveness. Phytochemicals, including anthocyanins from dark sweet cherry (ACN), have emerged as potential adjuvants to overcome DR, though mechanisms remain unclear. This study examines ACN effects on canonical and non-canonical antioxidant pathways (Nrf2-Keap1 and p62) as a mechanism to overcome DR in 4T1 TNBC cells with acquired DR. Methods: Two conditions were tested: ACN with basal doxorubicin (DOX) as resistance-maintaining conditions and ACN with DOX at IC₅₀ to induce oxidative stress (OS). Results: Under resistance-maintaining conditions, ACNs activated the canonical Nrf2-Keap1 pathway at high doses, which can potentially contribute to DR development due to its cellular protection effects. However, at a low dose, ACN did not trigger an antioxidant response linked to GST and GGT enzyme activities and instead impaired autophagy, increasing OS. Under OS, ACN activated the non-canonical antioxidant pathway mediated by p62 while deactivating Nrf2, leading to autophagy-induced cell death and further impairing autophagy at a low dose. Notably, inflammation persisted at both treatment levels without being relieved, keeping stress signaling active. At both conditions, ACN at doses likely attainable under physiological conditions effectively impaired autophagy and elevated OS, resulting in cell death. Conclusions: These results underscore the context-dependent dual function of polyphenols in cancer therapy, demonstrating their potential to enhance cellular sensitivity to chemotherapy and providing guidance for their strategic use as adjuvants in treating TNBC and overcoming DR. However, this study was limited to a single cell line derived from a murine model. Future research should include comparative studies using human TNBC cell lines to validate these findings and better assess their translational relevance. Full article

Asparagine synthetase (AS) is a key enzyme in plant nitrogen metabolic network. Beyond its canonical role as a major nitrogen transport and storage molecule, asparagine also serves critical functions in plant immunity and tolerance to environmental stresses. This review systematically summarizes the characteristics of the core AS-mediated asparagine biosynthesis pathway and two other minor pathways in plants. It details the distribution of the AS gene family, protein structure, and evolutionary classification. The mechanisms governing AS expression are analyzed, revealing tissue-specific patterns and precise regulation by nitrogen availability, abiotic stresses, and exogenous hormones, mediated through an interactive network of cis-acting elements and transcription factors. Furthermore, the biological functions of AS are multifaceted: it influences plant biomass and nitrogen use efficiency by regulating nitrogen uptake, transport, and recycling during growth and development; it contributes to abiotic stress tolerance by synthesizing asparagine to maintain cellular osmotic balance and scavenge reactive oxygen species; and it indirectly enhances antibacterial and antiviral capacity by activating the SA signaling pathway and modulating programmed cell death. Current knowledge gaps remain regarding the crosstalk between AS-mediated signaling pathways, the upstream transcriptional regulatory network, and the balance between nitrogen utilization and disease resistance in crop breeding. Future research aimed at addressing these questions will provide a theoretical foundation and molecular targets for improving crop nitrogen use efficiency and breeding resistant cultivars. Full article

The endoplasmic reticulum (ER) is critical in aiding cells in ensuring that proteins are folded and processed correctly, particularly during stressful situations. ER oxidoreductin-1 alpha (ERO1α) is an enzyme that is responsible for the formation of disulfide bonds during protein folding, along with protein disulfide isomerase (PDI). This redox pathway is often highly upregulated in cancer cells, allowing tumors to survive harsh conditions such as hypoxia and nutrient deprivation. This review discusses the role of the ERO1α–PDI system in cancer development through the regulation of oxidative stress, redox homeostasis, and tumor plasticity. It further shows the therapeutic potential of interrupting the ERO1α–PDI axis, which could lead to protein misfolding; enhanced generation of reactive oxygen species (ROS); and, eventually, cancer cell death. Full article

The past decade has witnessed an unprecedented transformation in breast cancer management, driven by parallel advances in targeted therapies, immunomodulation, drug-delivery technologies, and molecular diagnostic tools. This review summarizes the key achievements of 2015–2025, encompassing all major biological subtypes of breast cancer as well as technological innovations with substantial clinical relevance. In hormone receptor-positive (HR+)/HER2− disease, the integration of CDK4/6 inhibitors, modulators of the PI3K/AKT/mTOR pathway, oral Selective Estrogen Receptor Degraders (SERDs), and real-time monitoring of Estrogen Receptor 1 (ESR1) mutations has enabled clinicians to overcome endocrine resistance and dynamically tailor treatment based on evolving molecular alterations detected in circulating biomarkers. In HER2-positive breast cancer, treatment paradigms have been revolutionized by next-generation antibody–drug conjugates, advanced antibody formats, and technologies facilitating drug penetration across the blood–brain barrier, collectively improving systemic and central nervous system disease control. The most rapid progress has occurred in triple-negative breast cancer (TNBC), where synergistic strategies combining selective cytotoxicity via Antibody-Drug Conjugates (ADCs), DNA damage response inhibitors, immunotherapy, epigenetic modulation, and therapies targeting immunometabolic pathways have markedly expanded therapeutic opportunities for this historically challenging subtype. In parallel, photodynamic therapy has emerged as an investigational and predominantly local phototheranostic approach, incorporating nanocarriers, next-generation photosensitizers, and photoimmunotherapy capable of inducing immunogenic cell death and modulating antitumor immune responses. A defining feature of the past decade has been the surge in patent-driven innovation, encompassing multispecific antibodies, optimized ADC architectures, novel linker–payload designs, and advanced nanotechnological and photoactive delivery systems. By integrating data from clinical trials, molecular analyses, and patent landscapes, this review illustrates how multimechanistic, biomarker-guided therapies supported by advanced drug-delivery technologies are redefining contemporary precision oncology in breast cancer. The emerging therapeutic paradigm underscores the convergence of targeted therapy, immunomodulation, synthetic lethality, and localized immune-activating approaches, charting a path toward further personalization of treatment in the years ahead. Full article

Background: Triple-negative breast cancer (TNBC) represents the most aggressive breast cancer subtype, characterized by high genomic instability, metabolic stress, and limited therapeutic options. Ferroptosis, an iron-dependent form of regulated cell death, has emerged as a promising vulnerability in TNBC, yet its subtype-specific regulatory landscape remains insufficiently defined. Methods: Using transcriptomic (METABRIC, TCGA, GEO) and proteomic (CPTAC) datasets, ferroptosis-related genes were profiled across PAM50 breast cancer subtypes. Differential expression, univariate Cox regression, LASSO modeling, survival analyses, GSEA, and dimensionality reduction (PCA, t-SNE) were applied. A Ferroptosis Index (FI) was calculated using β-coefficients from the Cox/LASSO regression model. Single-cell RNA-seq data was used to map ferroptosis-associated signature across tumor and microenvironmental compartments. Results: Basal-like tumors exhibited the strongest ferroptosis-associated transcriptional shift, characterized by upregulation of ACSL4 and EZH2 and downregulation of AR, GPX4, and CIRBP. Sixteen ferroptosis-related genes were associated with overall survival, forming a ferroptosis-associated signature. The FI was significantly higher in Basal-like tumors, indicating elevated ferroptosis-associated transcriptional state. GSEA revealed enrichment of cell cycle, mitotic, cytoskeletal, and metabolic stress pathways. Single-cell analysis demonstrated expression of ferroptosis markers across cancer epithelial, stromal, and myeloid populations. Conclusions: Basal-like tumors harbor a distinct ferroptosis-associated transcriptional state linked to tumor aggressiveness and poor prognosis. These findings provide a biologically grounded framework for ferroptosis-related stratification and support future functional and translational studies targeting ferroptosis vulnerabilities in aggressive breast cancer. Full article

Colorectal cancer (CRC) remains a major cause of cancer-related deaths in advanced disease, and activating KRAS/NRAS mutations limit the use of anti-EGFR antibodies to RAS–wild-type tumors. The cellular prion protein (PrP^C) has been linked to aggressive and chemoresistant CRC, but its extracellular partners and functional relevance in KRAS-mutant disease are not fully defined. Here, we examined extracellular PrP^C complexes and PrP^C-associated signaling in CRC cell lines and xenografts using a neutralizing PrP^C monoclonal antibody. Across a CRC panel that included SNU-C5/WT and its 5-fluorouracil- and oxaliplatin-resistant derivatives, HT-29 (KRAS–wild-type), and HCT-8 and LoVo (KRAS-mutant), co-immunoprecipitation showed that PrP^C forms complexes with the 37/67 kDa laminin receptor (RPSA), with PrP^C–RPSA association particularly increased in KRAS-mutant HCT-8 and LoVo cells. PrP^C protein levels were higher in KRAS-mutant HCT-8, SW620, and SNU-407 cells than in HT-29, and PrP^C neutralization reduced viability in all four lines. Accordingly, we assessed upstream RAS activity and found that active RAS (RAS-GTP) was higher in KRAS-mutant cells than in HT-29, and PrP^C treatment was associated with reduced RAS-GTP levels. In the same KRAS-mutant setting, basal AKT phosphorylation exceeded that in HT-29, and PrP^C treatment lowered AKT phosphorylation without changing total AKT. Moreover, PrP^C treatment was associated with reduced ERK1/2 phosphorylation in KRAS-mutant cells, suggesting attenuation of downstream RAS pathway output. These signaling changes coincided with a decrease in the S-phase fraction and an increase in G1. In an HCT-8 (KRAS G13D) xenograft model, PrP^C monotherapy inhibited tumor growth in a dose-dependent manner, and 5-fluorouracil (5-FU) monotherapy produced an intermediate effect. The combination of PrP^C (10 mg/kg) and 5-FU (20 mg/kg) yielded the greatest tumor growth inhibition among the tested regimens. Consistent with this enhanced tumor control, immunofluorescence of xenograft tissues showed that PrP^C, particularly with 5-FU, reduced intratumoral PrP^C and PCNA and decreased CD31-positive microvessels and α-SMA–positive vessel structures. Taken together, these findings suggest that extracellular PrP^C supports RAS–AKT signaling, proliferation, and tumor-associated angiogenesis in KRAS-mutant colorectal cancer, and that PrP^C neutralization additively enhances 5-fluorouracil activity in KRAS-mutant models. The data provide a preclinical basis for evaluating PrP^C antibodies in combination with fluoropyrimidine-based regimens in patients with KRAS-mutant CRC. Full article

The homeostasis balance of copper, as an essential trace element for life activities, is crucial for maintaining the normal function of cells. Cuproptosis, discovered in recent years, is a novel type of programmed cell death triggered by the accumulation of excessive copper ions in mitochondria. The core mechanism lies in that copper ions, after being reduced by ferridoxin (FDX1), directly target and induce the oligomerization of the acylated tricarboxylic acid (TCA) cycle enzyme, thereby triggering fatal protein toxic stress. This distinctive mechanism operates independently of other recognized pathways of cell death, offering a novel perspective for elucidating the pathological processes underlying various diseases. A review of pertinent research conducted over the past four years reveals that cuproptosis is not only significantly implicated in the onset, progression, and treatment resistance of tumors but is also intricately associated with diverse pathological processes, including neurodegenerative diseases, cardiovascular diseases, metabolic disorders, and immune abnormalities. This article conducts a multi-level summary from molecular mechanisms to physiological and pathological significance; deeply explores the interaction between cuproptosis and various subcellular structures, as well as their complex signal regulatory network; and systematically expounds the cutting-edge strategies for treating cuproptosis, including traditional copper chelating agents, ion carriers, and copper-based nanomedicines, with a particular focus on the latest progress in the field of natural product research. This review has systematically summarized the therapeutic potential demonstrated by numerous natural active ingredients when precisely regulating the cuproptosis pathway to provide a theoretical reference for future research in this field. Full article

Breast cancer remains one of the leading causes of cancer-related mortality among women worldwide. Although cisplatin is widely used in chemotherapy, its clinical efficacy is often limited by adverse effects and resistance. Thus, natural bioactive compounds are gaining attention as complementary therapeutic agents. This study aimed to evaluate the anti-tumor effects of Annona muricata leaf extract on murine breast cancer 4T1 cells, used alone or in combination with cisplatin. Cisplatin induced intrinsic apoptosis through mitochondrial membrane disruption, up-regulation of the Bax gene and inhibition of the PI3K/AKT/mTOR signaling pathway. Cisplatin also promoted hypoxia by HIF1α gene expression, inflammation by TNFα and IL-6 gene expression, and induced cell cycle arrest at the sub-G1 phase by down-regulation of cyclin D1 and cyclin E1 genes. Annona muricata leaf extract triggered autophagy-mediated 4T1 cell death through mainly mTOR down-regulation and increased expression of Beclin1 and LC3 genes. It also induced cell cycle arrest at sub-G1 and S phases in a concentration- and time-dependent manner. When, combined with cisplatin, Annona muricata extract shifts the cell death pathway from intrinsic apoptosis toward autophagy by reduced caspase-3 gene expression and activity and enhanced LC3-I to LC3-II conversion. Moreover, Annona muricata extract attenuated cisplatin-induced inflammation by inhibiting TNFα and IL-6 gene expression and reinforced cell cycle arrest through suppression of the cyclin D1 gene. In conclusion, our results suggest that Annona muricata leaf extract exerts significant anti-tumor activity in breast cancer cells and may enhance cisplatin efficacy by shifting the signaling pathway from intrinsic apoptosis toward autophagy, and attenuating inflammation-related effects, supporting its potential use as a complementary therapeutic strategy. Full article

Orthodontic tooth movement (OTM), a complex biological process driven by orchestrated bone remodeling, involves osteoclastic bone resorption and osteoblastic bone formation in response to mechanical force. Traditionally, OTM-related cell death has been discussed in terms of apoptosis and necrosis. However, recent advances in cell death research have revealed various forms of regulated cell death (RCD) beyond these conventional categories. This review summarizes the current understanding of the diverse RCD pathways and their roles in various cell populations during OTM. It delineates the involvement of distinct RCD mechanisms, including apoptosis, autophagy, pyroptosis, ferroptosis, and necroptosis. On the compression side, these RCD pathways in periodontal ligament (PDL) cells, cementoblasts, cementocytes, and bone-related cells actively drive inflammatory responses, promote bone resorption, and contribute to root resorption. Conversely, on the tension side, specific RCD pathways, notably autophagy in the PDL and osteocytes, play crucial roles in promoting osteogenesis and tissue repair. Collectively, cell death is not merely a passive elimination of cells but actively functions as a critical switch for alveolar bone remodeling during OTM. Understanding these multifaceted RCD mechanisms provides novel insights into the biological regulation of tooth movement and identifies potential therapeutic targets for enhancing tooth movement efficiency and mitigating adverse effects. Full article

Background/Objectives: Ischemic stroke is a leading cause of death and disability, and neuroprotection therapies, or those that increase recovery, are not available. While the garlic-derived bioactive compound S-allyl cysteine (SAC) has shown neuroprotective properties, its subacute long-term effects remain underexplored, particularly in females. Methods: We evaluated whether SAC supports functional recovery after ischemia/reperfusion (IR), focusing on neurotrophin signaling, tropomyosin receptor kinase B (TrkB), protein kinase B (AKT), and extracellular signal-regulated kinase (ERK). Adult female Wistar rats underwent 1 h of ischemia and 15 days of reperfusion. SAC (100 mg/kg, i.p.) was administered at the onset of reperfusion and daily for 15 days. Motor and cognitive deficit tests were performed. Infarct area, Ki67, brain-derived neurotrophic factor (BDNF), vascular endothelial growth factor (VEGF), nerve growth factor (NGF), pTrkB, pAKT, and pERK levels were quantified in the cortex, striatum, and hippocampus. Results: MicroPET analysis revealed comparable glucose uptake between the IR and IR + SAC groups, indicating similar ischemic severity. SAC reduced infarct area (54.7%) and significantly improved motor deficits (53.9%), circling behavior (38.9%), and long-term memory compared with ischemia/reperfusion (IR) animals. SAC increased the proportion of Ki67-positive cells (4.3-fold in the cortex and 1.8-fold in the striatum) and enhanced neurotrophin levels, NGF (cortex), BDNF (cortex and striatum), VEGF (striatum), pTrkB, pAKT, and pERK (cortex and striatum). Conclusions: SAC supports post-ischemic recovery, improving motor performance and preserving long-term recognition memory, effects that could be associated with increased cell proliferation, neurotrophin levels, and activation of the TrkB, AKT, and ERK pathways. Full article

Interferon-stimulated gene 15 (ISG15) is an interferon-induced ubiquitin-like protein that plays an important role in antiviral defense and inflammatory responses, primarily through the process of ISGylation, whereby ISG15 is covalently conjugated to target proteins. Beyond its intracellular functions, a portion of free unconjugated ISG15 is also released into the extracellular environment during infections and diseases such as cancer. Extracellular ISG15 is known to regulate immune cell activity and cytokine production. Despite its immune-modulatory role, how ISG15 is released from cells has remained unclear. In this study, we have identified a non-lytic mechanism by which human macrophages release ISG15. Using lipopolysaccharide (LPS) as a stimulus, we show that extracellular LPS triggers unconjugated ISG15 release by utilizing plasma membrane-localized Gasdermin D (GSDMD) pores. Mechanistically, LPS via the autocrine/paracrine action of type-I interferon (IFN) activates caspase-4 (Casp4) to cleave the N-terminal domain of GSDMD for the formation of cell surface GSDMD pores that permit the extracellular release of unconjugated ISG15 in the absence of lytic cell death. Together, our studies have identified the IFN-Casp4-GSDMD axis as a previously unrecognized non-classical pathway for unconjugated ISG15 release from cells. Full article

Cancer remains a significant global health burden despite advances in diagnosis and treatment. In recent years, drug repurposing has emerged as a promising strategy in oncology, offering reduced costs and shorter development timelines compared with de novo drug discovery. Among repurposed agents, the antifungal drug itraconazole has demonstrated anticancer activity across multiple tumor types, particularly when used in combination with other therapeutic modalities. In this review, we summarize current preclinical and clinical evidence supporting the use of itraconazole in cancer therapy, with a specific focus on its combination with chemotherapeutic agents and programmed cell death protein 1 (PD-1) immune checkpoint inhibitors. We highlight proposed mechanisms underlying this synergy, including modulation of tumor metabolism, angiogenesis, and immune signaling pathways. Additionally, we discuss key challenges and limitations, such as drug–drug interactions and toxicity considerations, that must be addressed to optimize clinical translation. Overall, the combination of itraconazole with chemotherapy or anti-PD-1 therapy represents a promising therapeutic strategy warranting further investigation in well-designed trials. Full article