Jiayi Wang

Ferroptosis is an iron-dependent form of regulated cell death driven by the lethal accumulation of lipid peroxides. Accumulating evidence indicates that the extracellular landscape, the acellular functional subset of the tumor microenvironment (TME) comprising the extracellular matrix, soluble metabolites, cytokines, extracellular vesicles (EVs), and physicochemical conditions such as pH and oxygen content, actively determines cellular susceptibility to ferroptosis. Extracellular nutrients, acidic and hypoxic conditions modulate intracellular redox homeostasis, while ferroptosis-related signals are transmitted between cells through EVs, cytokines, and metabolites. Ferroptosis in turn bidirectionally shapes anti-tumor immunity, acting as immunogenic cell death yet also releasing immunosuppressive mediators that impair T cells. This review summarizes the canonical intracellular mechanisms of ferroptosis, highlights the bidirectional crosstalk between cells and the extracellular landscape, and discusses therapeutic strategies targeting this landscape, including reshaping nutrient availability, engineering EV-based delivery systems, and designing microenvironment-responsive nanomaterials. Key limitations of the field and perspectives are also outlined for safe and effective ferroptosis-based anti-tumor therapies.

Background: Lung adenocarcinoma (LUAD) continues to be the primary contributor to cancer mortality. Macropinocytosis is a bulk nutrient uptake pathway known to support tumor growth in various cancers, but its functional role and molecular effectors in LUAD cell malignant phenotypes remain unclear. KCNH1 has been reported to modulate progression in multiple types of cancer, yet it has never been linked to macropinocytosis. This study aims to investigate whether macropinocytosis enhances LUAD cell proliferation, migration, and invasion and to identify its key downstream targets. Methods: Two LUAD cell lines, NCI-H358 (KRAS-G12C mutant) and NCI-H1975 (KRAS wild-type), were used. For pharmacological inhibition, cells were treated with 5-(N-ethyl-N-isopropyl)-amiloride (EIPA) (25 μM, 24 h) or dimethyl sulfoxide (DMSO) control. For genetic manipulations, CRISPR/Cas9 knockout and lentiviral overexpression were established, with wild-type (WT) cells and empty vector as controls. Functional effects on proliferation [Cell Counting Kit-8 (CCK-8)], apoptosis (flow cytometry), migration (wound healing), and invasion (Transwell) were evaluated. Transcriptomic changes were analyzed by RNA-sequencing (RNA-seq), with candidate gene expression validated by quantitative real-time polymerase chain reaction (qPCR) and Western blot. Dual-luciferase reporter assay was performed to assess KCNH1 promoter activity. The involvement of the AKT signaling pathway was examined by Western blot. Clinical relevance was examined using The Cancer Genome Atlas (TCGA) database. Results: Inhibition of macropinocytosis significantly reduced the invasion (PKCNH1 as a commonly downregulated target upon EIPA treatment. Dual-luciferase reporter assay confirmed that EIPA treatment directly reduced KCNH1 promoter activity, indicating transcriptional regulation by macropinocytosis. Further experiments established a unidirectional regulatory axis: KCNH1 expression was positively regulated by macropinocytosis at both the mRNA and protein levels, whereas genetic modulation of KCNH1 did not alter macropinocytic activity. Functionally, overexpression of KCNH1 enhanced malignant phenotypes and conferred partial resistance to EIPA, while its knockout suppressed proliferation, migration, and invasion. Mechanistically, KCNH1 modulated AKT phosphorylation, and this pathway mediated its effects on LUAD cell malignant phenotypes. TCGA database analysis revealed elevated KCNH1 expression in LUAD tumors relative to normal tissues, suggesting potential clinical relevance. Conclusions: This study demonstrates that macropinocytosis enhances LUAD cell proliferation, migration, and invasion primarily through the transcriptional upregulation of KCNH1. KCNH1 functions as a crucial downstream effector, mediating the pro-tumorigenic effects of macropinocytosis at least in part via AKT phosphorylation. These findings identify the macropinocytosis-KCNH1 axis as a potential therapeutic target for LUAD.

RNA methylation represents a critical epi-transcriptomic modification that regulates cell fate by modulating diverse aspects of RNA metabolism, including splicing, export, translation, and degradation. Among the best-characterized modifications are N⁶-methyladenosine (m⁶A), 5-methylcytosine (m⁵C), N⁷-methylguanosine (m⁷G), and N¹-methyladenosine (m¹A), which are dynamically regulated by specific writer, eraser and reader proteins. Dysregulation of these modifications perturbs multiple regulated cell death pathways, such as apoptosis, autophagy, pyroptosis, necroptosis, ferroptosis, and cuproptosis, thereby promoting tumor progression, immune evasion, and therapeutic resistance. In this review, we summarize the molecular mechanisms by which RNA methylation shapes cell death programs and highlight its potential as a biomarker for cancer diagnosis and prognosis, as well as a promising target for therapeutic intervention.

Ferroptosis is an oxidative, lipid peroxidation-driven form of regulated cell death that occurs when antioxidant and organelle-protective systems are compromised. Increasing evidence implicates ferroptosis as a process that can exert both tumour-suppressive and tumour-promoting effects depending on cellular context at multiple stages of cancer evolution (from tumour initiation to metastatic colonization), sparking substantial interest in therapeutically exploiting this mechanism of cell death. Yet, despite rapid preclinical progress, clinical translation of ferroptosis-based strategies remains nascent. In this Review, we examine the major barriers to translation, including pharmacological limitations, tumour-intrinsic heterogeneity, microenvironmental and immune constraints, and gaps in current preclinical modelling. We also highlight emerging opportunities such as new ferroptosis-inducing agents, biomarker-guided patient selection and rational combinations with chemotherapy, radiotherapy, targeted agents or immunotherapies. Finally, we outline a translational roadmap for integrating ferroptosis-based therapies into oncology practice. By defining key challenges and future directions, this Review aims to position ferroptosis as a viable therapeutic paradigm and to accelerate progress towards clinical application.