Head and neck cancer (HNC) is a common disease in otorhinolaryngology. Its prevalence is higher in men than in women and is mostly related to tobacco, alcohol and viral infections. Despite significant advances in the treatment of HNC in recent years, the mortality rate is still high and most patients are diagnosed at an advanced stage, and the prognosis for these patients is even worse. Earlier metastasis makes the treatment of HNC trickier. Therefore, actively seeking ways to treat HNC more effectively has been the goal of head and neck surgeons. Potassium (K+) channels are the most diverse ion channels found in all areas of life. Voltage-gated potassium (Kv) channels are the most important subfamily of K+ channels. Multiple Kv channels are associated with the development of HNC. This review focuses on several Kv channels associated with HNC.

Voltage-gated potassium channel subfamily B member 1 (KCNB1) encodes the α-subunit of the Kv2.1 channel and mediates transmembrane potassium transport. The functions and mechanisms underlying KCNB1 activation have been examined in various cancer types; however, its role in esophageal squamous cell carcinoma (ESCC) remains unclear. Therefore, the present study investigated the involvement of KCNB1 in tumor progression and the clinicopathological significance of its expression in ESCC.

Knockdown experiments using KCNB1 small interfering RNA were performed on the human ESCC cell lines, KYSE70 and TE5, and changes in cell proliferation, the cell cycle, apoptosis, migration, and invasion were assessed. Gene expression profiles were examined using a microarray analysis. An immunohistochemical (IHC) analysis was performed on 129 primary tumor samples from ESCC patients who underwent curative esophagectomy.

Cell proliferation, G2-M phase progression, migration, and invasion were inhibited, and apoptosis was induced in KCNB1-depleted cells. Microarray results showed that KCNB1 gene expression affected Ephrin receptor signaling by suppressing EPHB1, EPHB2, and ERK1/2 gene expression. IHC results revealed a relationship between high KCNB1 expression and a poor prognosis. High KCNB1 expression was extracted as an independent prognostic factor in a multivariate analysis of 5-year relapse-free survival in ESCC patients (p = 0.0197).

Cell proliferation is controlled by KCNB1 through its regulation of ERK1/2 gene expression via ephrin receptor signaling. A relationship was observed between KCNB1 and the prognosis of ESCC patients, indicating its potential as a biomarker for cancer progression and in targeted therapy for ESCC.

Ion channels play instrumental roles in regulating membrane potential and cross-membrane signal transduction, thus making them attractive targets for understanding various physiological processes and associated diseases. Gaining a deeper understanding of their structural and functional properties has significant implications for developing therapeutic interventions. In recent years, nanobodies, single-domain antibody fragments derived from camelids, have emerged as powerful tools in ion channel and synthetic biology research. Their small size, high specificity, and ability to recognize difficult-to-reach epitopes offer advantages over conventional antibodies and biologics. Furthermore, their resemblance to the variable region of human IgG family III reduces immunogenicity concerns. Nanobodies have introduced new opportunities for exploring ion channel structure-function relationships and offer a promising alternative to conventional drugs, which often face challenges such as off-target effects and toxicity. This review highlights recent progress in applying nanobodies to interrogate and modulate ion channel activity, with an emphasis on their potential to overcome current technical and therapeutic limitations.

Insect spermatogenesis is a complex process. Numerous genes are involved in sperm motility, which is crucial for male fertility. Few long non-coding RNAs (lncRNAs) in the testis regulate insect spermatogenesis. We previously identified 364 testis-enriched lncRNAs in the globally invasive pest Zeugodacus cucurbitae Coquillett. One of these lncRNAs, lnc94641, is abundantly expressed in the testis; however, its role in spermatogenesis remains unknown.

Suppression of lnc94641 expression led to a 60% decrease in spermatozoa count and a 29% decrease in offspring hatchability. A microRNA (miRNA), miR-957-3p, was experimentally demonstrated to bind to lnc94641 competitively. miR-957-3p overexpression recapitulated reproductive defect phenotypes similar to those caused by lnc94641 knockdown. Furthermore, target gene predictions combined with quantitative reverse transcription PCR, RNA pull-down, and dual luciferase reporter assays confirmed that miR-957-3p targets voltage-gated potassium channel 5 (VGKC5) and odorant receptor 85c (OR85c), elucidating a functional lncRNA-miRNA-mRNA competing endogenous RNA (ceRNA) regulatory axis. Fluorescence in situ hybridization (FISH) assays demonstrated the co-localization of lnc94641, miR-957-3p, and VGKC5/OR85c in the mature and transformed regions of the testes. Suppression of VGKC5/OR85c expression resulted in a 68% and 50% decrease in spermatozoa number and an 18% and 21% decrease in offspring hatchability, mirroring the phenotype observed with lnc94641-silencing, thereby reinforcing the mechanistic coherence of this regulatory network.

These results revealed a ceRNA axis mediated by 'lnc94641-miR957-3p-VGKC5/OR85c' involved in spermatogenesis that impairs male fertility in the melon fly. Molecular perturbations (lncRNA knockdown or miRNA overexpression) consistently impair sperm production and offspring viability by dysregulating ion channels and chemosensory genes. This mechanistically resolved pathway, centered on the core components VGKC5 and OR85c, revealed conserved reproductive vulnerabilities that could enable the targeted genetic control of this agricultural pest. © 2025 Society of Chemical Industry.

The intake of micronutrients is linked to cancer risk, but their specific mechanisms in skin cancer remain unclear. This study systematically investigated the causal effects of 15 micronutrients on non-melanoma skin cancer (NMSC) and malignant melanoma (MM) using Mendelian Randomization (MR).

Genetically predicted levels of 15 micronutrients served as instrumental variables in a two-sample MR analysis, utilizing data from the Finnish FinnGen database (version R10). To address potential horizontal pleiotropy and heterogeneity, sensitivity analyses included inverse-variance weighted (IVW), weighted median, MR Egger regression, and MR PRESSO. The study analyzed data from 650,657 European participants, including 19,077 NMSC and 3,194 MM cases.

Selenium (p = 0.0001, OR 0.788, 95% CI 0.703-0.883) and Potassium (p = 0.045, OR 0.463, 95% CI 0.219-0.982) were significantly negatively associated with MM risk, suggesting a protective effect. Conversely, Calcium (p = 0.025, OR 1.257, 95% CI 1.030-1.534) was positively associated with NMSC risk, indicating it may be a risk factor. Vitamin B6 (p = 0.004, OR 0.741, 95% CI 0.604-0.909) also showed a significant protective effect against NMSC.The remaining 11 micronutrients showed no significant causal association with NMSC or MM (p > 0.05).

This study highlights that Selenium and Potassium may protect against MM, while Calcium increases NMSC risk, with Vitamin B6 providing protection against NMSC. These findings enhance our understanding of micronutrients in skin cancer mechanisms and inform potential prevention strategies.

Kir4.2 is a member of the inward rectifying potassium channel family, encoded by the KCNJ15 gene. The Kir4.2 protein is expressed in various organs including the kidneys, liver, pancreas, bladder, stomach, and lungs. Kir4.2 not only forms functional homomeric channels, but also heteromeric channels with Kir5.1. An increasing number of studies indicate that the function of the Kir4.2 channel should not be underestimated. Kir4.2 participates in cell electrotaxis chemotaxis by sensing extracellular electric fields and functions as a K + sensor in the proximal tubules of the kidney, playing a crucial role in maintaining acid-base and potassium balance. This article provides a comprehensive review of the main physiological characteristics of the Kir4.2 channel, the various pathological processes it is involved in, and the human diseases resulting from Kir4.2 dysfunction.

Temozolomide (TMZ) concomitant with radiotherapy is the first-line treatment for glioblastoma. However, treatment resistance is frequently observed in patients. Cellular senescence (CSEN) induced by TMZ has been proposed to be one underlying mechanism resulting in resting cells, causing inflammation and possibly recurrences if senescent cells re-enter the cell cycle after treatment. Inhibition of the K+ channels human ether-à-go-go type 1 (Eag1) and human ether-à-go-go-related gene (hERG) has shown promising effects in several tumor types including glioblastoma through growth inhibition and induction of apoptosis. In the present study, we analyzed the impact of hERG/Eag1 inhibition on apoptosis and CSEN on its own and in combination with TMZ in a panel of human glioblastoma cell lines and primary glioblastoma cells. hERG/Eag1 protein expression was determined by Western blotting and immunocytochemistry. Cytotoxicity of astemizole and terfenadine alone or in combination with TMZ was assessed by MTT assays. Apoptotic yields were determined by Annexin V/propidium iodide staining, and CSEN was quantified by determining SA-β-galactosidase levels through flow cytometry. We observed a similar protein expression of hERG and Eag1 in all glioblastoma cell lines and primary glioblastoma cells. Astemizole and terfenadine were cytotoxic in glioblastoma cells at low micromolar concentrations (5-10 µM range) through induction of apoptosis. In combination with TMZ, both drugs synergistically sensitized glioblastoma cells to TMZ-induced apoptosis. Moreover, astemizole reduced significantly the TMZ-induced CSEN level, indicating its impact on CSEN induction. Here, we show for the first time that blocking hERG/Eag1 channels in glioblastoma cells can relief TMZ-induced CSEN and synergistically ameliorates cytotoxicity through the induction of apoptosis.

Vanilloid1 (TRPV1), a subfamily of transient receptor channels, is one of the non-selective calcium channels, which is a bridge between cellular response and extracellular environmental networks, and is involved in a variety of pathophysiological processes. It is also involved in the process of cancer occurrence and progression, and researchers are revealing its role in cancer. In this paper, we review the expression and significance of TRPV1 receptor in various cancer cell types, the role of TRPV1 in the apoptosis-proliferation balance, cancer cell invasion and metastasis, and tumor micro-environment, with emphasis on the mechanisms by which TRPV1 receptor mediates inflammatory response, immune system, and thus regulates cancer. We discussed the latest directions and current challenges of TRPV1 receptor-targeting therapy for cancer, and summarized the odorous traditional herbs that modulate TRPV1 receptors, with a view to developing anti-tumor drugs targeting TRPV1 receptors in the future.

KCNN4, a Ca2+-activated K+ channel, is involved in various physiological and pathological processes. It is essential for epithelial transport, immune system, and other physiological mechanisms, but its activation is also involved in cancer pathophysiology as well as red blood cell (RBC) disorders. The activation of KCNN4 in RBC leads to loss of KCl and water, a mechanism known as the "Gardos effect" described 70 years ago. This Ca2+-induced dehydration is irreversible in human RBC and must be tightly controlled to prevent not only hemolysis but also alterations in RBC rheological properties. In this study, we have investigated the regulation of KCNN4 activity after changes in RBC Ca2+ concentration. Using electrophysiology, immunoprecipitation, and proximity ligation assay in human embryonic kidney 293-transfected cells, K562 cells, or RBCs, we have found that KCNN4 and the Ca2+ pump PMCA4b (plasma membrane calcium-transporting ATPase 4b) interact tightly with each other, such that the C-terminal domain of PMCA4b regulates KCNN4 activity, independently of the Ca2+ extrusion activity of the pump. This regulation was not restricted to KCNN4: the small-conductance Ca2+-activated K+ channel KCNN2 was similarly regulated by the calcium pump. We propose a new mechanism that could control KCNN4 activity by a molecular inhibitory interaction with PMCA4b. It is suggested that this mechanism could attenuate erythrocyte dehydration in response to an increase in intracellular Ca2+.

The central nervous system (CNS) is increasingly recognized as a critical modulator in the oncogenesis of glioblastoma multiforme (GBM), with interactions between cancer and local neuronal circuits frequently leading to epilepsy; however, the relative contributions of these factors remain unclear. Here, we report a coordinated intratumor shift among distinct cancer subtypes within progenitor-like families of epileptic GBM patients, revealing an accumulation of oligodendrocyte progenitor (OPC)-like subpopulations at the cancer-neuron interface along with heightened electrical signaling activity in the surrounding neuronal networks. The OPC-like cells associated with epilepsy express KCND2, which encodes the voltage-gated K+ channel KV4.2, enhancing neuronal excitability via accumulation of extracellular K+, as demonstrated in patient-derived ex vivo slices, xenografting models, and engineering organoids. Together, we uncovered the essential local circuitry, cellular components, and molecular mechanisms facilitating cancer-neuron interaction at peritumor borders. KCND2 plays a crucial role in mediating nervous system-cancer electrical communication, suggesting potential targets for intervention.

Distinguishing tumor maintenance genes from initiation, progression, and passenger genes is critical for developing effective therapies. We employed a functional genomic approach using the Lazy Piggy transposon to identify tumor maintenance genes in vivo and applied this to sonic hedgehog (SHH) medulloblastoma (MB). Combining Lazy Piggy screening in mice and transcriptomic profiling of human MB, we identified the voltage-gated potassium channel KCNB2 as a candidate maintenance driver. KCNB2 governs cell volume of MB-propagating cells (MPCs), with KCNB2 depletion causing osmotic swelling, decreased plasma membrane tension, and elevated endocytic internalization of epidermal growth factor receptor (EGFR), thereby mitigating proliferation of MPCs to ultimately impair MB growth. KCNB2 is largely dispensable for mouse development and KCNB2 knockout synergizes with anti-SHH therapy in treating MB. These results demonstrate the utility of the Lazy Piggy functional genomic approach in identifying cancer maintenance drivers and elucidate a mechanism by which potassium homeostasis integrates biomechanical and biochemical signaling to promote MB aggression.

The normal functioning of every cell in the body depends on its bioelectric properties and many diseases are caused by genetic and/or epigenetic dysregulation of the underlying ion channels. Metastasis, the main cause of death from cancer, is a complex multi-stage process in which cells break away from a primary tumour, invade the surrounding tissues, enter the circulation by encountering a blood vessel and spread around the body, ultimately lodging in distant organs and reproliferating to form secondary tumours leading to devastating organ failure. Such cellular behaviours are well known to involve ion channels. The CELEX model offers a novel insight to metastasis where it is the electrical excitation of the cancer cells that is responsible for their aggressive and invasive behaviour. In turn, the hyperexcitability is underpinned by concomitant upregulation of functional voltage-gated sodium channels and downregulation of voltage-gated potassium channels. Here, we update the in vitro and in vivo evidence in favour of the CELEX model for carcinomas. The results are unequivocal for the sodium channel. The potassium channel arm is also broadly supported by existing evidence although these data are complicated by the impact of the channels on the membrane potential and consequent secondary effects. Finally, consistent with the CELEX model, we show (i) that carcinomas are indeed electrically excitable and capable of generating action potentials and (ii) that combination of a sodium channel inhibitor and a potassium channel opener can produce a strong, additive anti-invasive effect. We discuss the possible clinical implications of the CELEX model in managing cancer.

Preclinical evidence suggests that voltage gradients can act as a kind of top-down master regulator during embryogenesis and orchestrate downstream molecular-genetic pathways during organ regeneration or repair. Moreover, electrical stimulation shifts response to injury toward regeneration instead of healing or scarring. Cancer and embryogenesis not only share common phenotypical features but also commonly upregulated molecular pathways. Voltage-gated ion channel activity is directly or indirectly linked to the pathogenesis of cancer hallmarks, while experimental and clinical studies suggest that their modulation, e.g., by anesthetic agents, may exert antitumor effects. A large recent clinical trial served as a proof-of-principle for the benefit of preoperative use of topical sodium channel blockade as a potential anticancer strategy against early human breast cancers. Regardless of whether ion channel aberrations are primary or secondary cancer drivers, understanding the functional consequences of these events may guide us toward the development of novel therapeutic approaches.

The KCa3.1 channel (also known as the KCNN4, IK1, or SK4 channel) is an intermediate-conductance calcium-activated potassium channel that regulates the membrane potential and maintains calcium homeostasis. Recently, KCa3.1 channels have attracted increasing attention because of their diverse roles in various types of cancers. In cancer cells, KCa3.1 channels regulate key processes, including cell proliferation, cell cycle, migration, invasion, tumor microenvironments, and therapy resistance. In addition, abnormal KCa3.1 expression in cancers is utilized to distinguish between tumor and normal tissues, classify cancer stages, and predict patient survival outcomes. This review comprehensively examines the current understanding of the contribution of KCa3.1 channels to tumor formation, metastasis, and its mechanisms. We evaluated the potential of KCa3.1 as a biomarker for cancer diagnosis and prognosis. Finally, we discuss the advances and challenges of applying KCa3.1 modulators in cancer treatment and propose approaches to overcome these obstacles. In summary, this review highlights the importance of this ion channel as a potent therapeutic target and prognostic biomarker of cancer.

Paclitaxel (PTX) has been used as a chemotherapeutic agent for several malignancies, including breast cancer, and efforts to increase the efficiency of PTX are continuous. Previous studies have shown that the voltage-gated K+ channels are over-expressed in breast cancer cell lines; therefore, blocking this type of K+ channel reduces cell proliferation and viability.

In this study, FDA-approved 4-aminopyridine (4-AP), a voltage-gated potassium channel blocker, was used in combination with PTX to improve the anticancer activity of PTX in MCF-7 and MDA-MB-231 cell lines.

Viability was determined with trypan blue, a clonogenic assay was performed, and the cell cycle was determined with a flow cytometer and immunochemistry. To gain an insight into the mechanism, intracellular K+ concentration, intracellular Ca2+ (calcium) concentration, and transmembrane potential measurements were made with corresponding fluorescent dyes. The apoptotic cell number was determined using Annexin /PI method by flow cytometer. Viability decreased with combination therapy and the clonogenic assay proved decreased colony formation. The apoptotic cell number was increased after treatment with the combination in both cell lines. Cell cycle measurements showed G1 arrest for both MCF-7 and MDA-MB-231 cell lines upon 4-AP treatment. PTX caused G1 arrest in MCF-7 cells and S phase arrest in MDA-MB-231 cells. Combination treatment caused S phase arrest in MCF-7 cells and S phase and G2/M phase arrest in MDA-MB-231 cells. Intracellular K+ concentration was increased after all treatments in both cell lines. Ca2+ concentration was increased significantly after combination treatment. Depolarization in the transmembrane potential was observed after all treatments in both cell lines.

Biophysical parameters like the transmembrane potential and ion fluxes have been defined in cancer progression which can provide new aspects for cancer treatments. This study shows that the combination of 4-AP with PTX is a promising alternative the mechanism of which needs further investigation considering the results obtained for Ca2+, K+, and membrane potential.

Transmembrane ion transport modality has received a widespread attention due to its apoptotic activation toward anticancer cell activities. In this study, G-quadruplex-based potassium-specific transmembrane channels have been developed to facilitate the intracellular K+ efflux, which perturbs the cellular ion homeostasis thereby inducing cancer cell apoptosis. Cholesterol-tag, a lipophilic anchor moiety, serves as a rudiment for the G-quadruplex immobilization onto the membrane, while G-quadruplex channel structure as a transport module permits ion binding and migration along the channels. A c-Myc sequence tagged with two-cholesterol is designed as a representative lipophilic G-quadruplex, which forms intramolecular parallel G-quadruplex with three stacks of G-quartets (Ch2-Para3). Fluorescence transport assay demonstrates Ch2-Para3 a high transport activity (EC50 = 10.9 × 10-6 m) and an ion selectivity (K+/Na+ selectivity ratio of 84). Ch2-Para3 mediated K+ efflux in cancer cells is revealed to purge cancer cells through K+ efflux-mediated cell apoptosis, which is confirmed by monitoring the changes in membrane potential of mitochondria, leakage of cytochrome c, reactive oxygen species yield, as well as activation of a family of caspases. The lipophilic G-quadruplex exhibits obvious antitumor activity in vivo without systemic toxicity. This study provides a functional scheme aimed at generating DNA-based selective artificial membrane channels for the purpose of regulating cellular processes and inducing cell apoptosis, which shows a great promising for anticancer therapy in the future.

Transmembrane potassium ion channels are crucial for ion transport, metabolism, and signaling, and serve as promising targets for anti-cancer therapies. However, their hydrophobic transmembrane nature requires detergents, posing a major bottleneck for experimental handling. In this paper, we present a structural bioinformatics study of six experimentally determined and twelve modeled potassium channel structures, in which hydrophobic amino acids (L, I/V, and F) were systematically replaced with neutral hydrophilic ones (Q, T, and Y), making the proteins more water-soluble. QTY (computationally predicted) and native (experimental and repredicted) variants show remarkable structural similarity (RMSD: ~0.50 Å - ~2.14 Å) despite significant sequence differences. QTY variants, both rigid and refined with MD simulations, maintain comparable to native variants stability, solvent-accessible surface area (SASA), and ionic, aromatic, and van der Waals interactions but differ in the grand average of hydropathy (GRAVY), solubility, and hydrophobic contacts. Overall, our study presents a computational approach for designing hydrophilic potassium ion channels while maintaining the native global structure that could potentially simplify their practical use by eliminating the need for detergents.

Liver fibrosis is a life-threatening disease that currently lacks clinically effective therapeutic agents. Given the close correlation between dysregulated intracellular K+ homeostasis and the progression of liver fibrosis, developing artificial K+ transporters mimicking the essential function of their natural counterparts in regulating intracellular K+ levels might offer an appealing yet unexplored treatment strategy. Here, we present an unconventional class of artificial K+ transporters involving the "motional" collaboration between two K+ transporter molecules. In particular, 6C6 exhibits an impressive EC50 value of 0.28 μM (i.e., 0.28 mol % relative to lipid) toward K+ and an exceptionally high K+/Na+ selectivity of 15.5, representing one of the most selective artificial K+ transporters reported to date. Most importantly, our study demonstrates, for the first time, the potential therapeutic effect of K+-selective artificial ion transporters in reversing liver fibrosis both in vitro and in vivo.

Mitochondria, pivotal organelles crucial for energy generation, apoptosis regulation, and cellular metabolism, have spurred remarkable advancements in targeted material development. This review surveys recent breakthroughs in targeted mitochondrial nanomaterials, illuminating their potential in drug delivery, disease management, and biomedical imaging. This review approaches from various application perspectives, introducing the specific applications of mitochondria-targeted materials in cancer treatment, probes and imaging, and diseases treated with mitochondria as a therapeutic target. Addressing extant challenges and elucidating potential therapeutic mechanisms, it also outlines future development trajectories and obstacles. By comprehensively exploring the diverse applications of targeted mitochondrial nanomaterials, this review aims to catalyze innovative treatment modalities and diagnostic approaches in medical research. STATEMENT OF SIGNIFICANCE: This review presents the latest advancements in mitochondria-targeted nanomaterials for biomedical applications, covering diverse fields such as cancer therapy, bioprobes, imaging, and the treatment of various systemic diseases. The novelty and significance of this work lie in its systematic analysis of the intricate relationship between mitochondria and different diseases, as well as the ingenious design strategies employed to harness the therapeutic potential of nanomaterials. By providing crucial insights into the development of mitochondria-targeted nanomaterials and their applications, this review offers a valuable resource for researchers working on innovative treatment modalities and diagnostic approaches. The scientific impact and interest to the readership lie in the identification of promising avenues for future research and the potential for clinical translation of these cutting-edge technologies.

Gliomas are highly malignant brain tumours that remain refractory to treatment. Treatment is typically surgical intervention followed by concomitant temozolomide and radiotherapy; however patient prognosis remains poor. Voltage gated ion channels have emerged as novel targets in cancer therapy and inhibition of a potassium selective subtype (hERG, Kv11.1) has demonstrated antitumour activity. Unfortunately blockade of hERG has been limited by cardiotoxicity, however hERG channel agonists have produced similar chemotherapeutic benefit without significant side effects. In this study, electrophysiological recordings suggest the presence of hERG channels in the anaplastic astrocytoma cell line SMA-560, and treatment with the hERG channel agonist NS1643, resulted in a significant reduction in the proliferation of SMA-560 cells. In addition, NS1643 treatment also resulted in a reduction of the secretion of matrix metalloproteinase-9 and SMA-560 cell migration. When combined with temozolomide, an additive impact was observed, suggesting that NS1643 may be a suitable adjuvant to temozolomide and limit the invasiveness of glioma.

Kv1.3 is a multifunctional potassium channel implicated in multiple pathologies, including cancer. However, how it is involved in disease progression is not fully clear. We interrogated the interactome of Kv1.3 in intact cells using BioID proximity labeling, revealing that Kv1.3 interacts with STAT3- and p53-linked pathways. To prove the relevance of Kv1.3 and of its interactome in the context of tumorigenesis, we generated stable melanoma clones, in which ablation of Kv1.3 remodeled gene expression, reduced proliferation and colony formation, yielded fourfold smaller tumors, and decreased metastasis in vivo in comparison to WT cells. Kv1.3 deletion or pharmacological inhibition of mitochondrial Kv1.3 increased mitochondrial Reactive Oxygen Species release, decreased STAT3 phosphorylation, stabilized the p53 tumor suppressor, promoted metabolic switch, and altered the expression of several BioID-identified Kv1.3-networking proteins in tumor tissues. Collectively, our work revealed the tumor-promoting Kv1.3-interactome landscape, thus opening the way to target Kv1.3 not only as an ion-conducting entity but also as a signaling hub.

The events that control breast cancer progression and metastasis are complex and intertwined. Hypoxia plays a key role both in oncogenic transformation and in fueling the metastatic potential of breast cancer cells. Here we review the impact of hypoxia on epigenetic regulation of breast cancer, by interfering with multiple aspects of the tumour microenvironment. The co-dependent relationship between oxygen depletion and metabolic shift to aerobic glycolysis impacts on a range of enzymes and metabolites available in the cell, promoting posttranslational modifications of histones and chromatin, and changing the gene expression landscape to facilitate tumour development. Hormone signalling, particularly through ERα, is also tightly regulated by hypoxic exposure, with HIF-1α expression being a prognostic marker for therapeutic resistance in ER+ breast cancers. This highlights the strong need to understand the hypoxia-endocrine signalling axis and exploit it as a therapeutic target. Furthermore, hypoxia has been shown to enhance metastasis in TNBC cells, as well as promoting resistance to taxanes, radiotherapy and even immunotherapy through microRNA regulation and changes in histone packaging. Finally, several other mediators of the hypoxic response are discussed. We highlight a link between ionic dysregulation and hypoxia signalling, indicating a potential connection between HIF-1α and tumoural Na+ accumulation which would be worth further exploration; we present the role of Ca2+ in mediating hypoxic adaptation via chromatin remodelling, transcription factor recruitment and changes in signalling pathways; and we briefly summarise some of the findings regarding vesicle secretion and paracrine induced epigenetic reprogramming upon hypoxic exposure in breast cancer. By summarising these observations, this article highlights the heterogeneity of breast cancers, presenting a series of pathways with potential for therapeutic applications.

Pancreatic adenocarcinomas (PAADs) often exhibit a "cold" or immunosuppressive tumor milieu, which is associated with resistance to immune checkpoint blockade therapy; however, the underlying mechanisms are incompletely understood. Here, we aimed to improve our understanding of the molecular mechanisms occurring in the tumor microenvironment and to identify biomarkers, therapeutic targets, and potential drugs to improve PAAD treatment.

Patients were categorized according to immunologically hot or cold PAAD subtypes with distinct disease outcomes. Cox regression and weighted correlation network analysis were performed to construct a novel gene signature, referred to as 'Downregulated in hot tumors, Prognostic, and Immune-Related Genes' (DPIRGs), which was used to develop prognostic models for PAAD via machine learning (ML). The role of DPIRGs in PAAD was comprehensively analyzed, and biomarker genes able to distinguish PAAD immune subtypes and predict prognosis were identified by ML. The expression of biomarkers was verified using public single-cell transcriptomic and proteomic resources. Drug candidates for turning cold tumors hot and corresponding target proteins were identified via molecular docking studies.

Using the DPIRG signature as input data, a combination of survival random forest and partial least squares regression Cox was selected from 137 ML combinations to construct an optimized PAAD prognostic model. The effects and molecular mechanisms of DPIRGs were investigated by analysis of genetic/epigenetic alterations, immune infiltration, pathway enrichment, and miRNA regulation. Biomarkers and potential therapeutic targets, including PLEC, TRPV1, and ITGB4, among others, were identified, and the cell type-specific expression of the biomarkers was validated. Drug candidates, including thalidomide, SB-431542, and bleomycin A2, were identified based on their ability to modulate DPIRG expression favorably.

By combining multiple ML algorithms, we developed a novel prognostic model with excellent performance in PAAD cohorts. ML also proved to be powerful for identifying biomarkers and potential targets for improved PAAD patient stratification and immunotherapy.

The ability to sense and respond to osmotic fluctuations is critical for the maintenance of cellular integrity. We used gene co-essentiality analysis to identify an unappreciated relationship between TSC22D2, WNK1, and NRBP1 in regulating cell volume homeostasis. All of these genes have paralogs and are functionally buffered for osmo-sensing and cell volume control. Within seconds of hyperosmotic stress, TSC22D, WNK, and NRBP family members physically associate into biomolecular condensates, a process that is dependent on intrinsically disordered regions (IDRs). A close examination of these protein families across metazoans revealed that TSC22D genes evolved alongside a domain in NRBPs that specifically binds to TSC22D proteins, which we have termed NbrT (NRBP binding region with TSC22D), and this co-evolution is accompanied by rapid IDR length expansion in WNK-family kinases. Our study reveals that TSC22D, WNK, and NRBP genes evolved in metazoans to co-regulate rapid cell volume changes in response to osmolarity.

Pancreas ductal adenocarcinoma belongs to the most common cancers, but also to the tumors with the poorest prognosis. Here, we pharmacologically targeted a mitochondrial potassium channel, namely mitochondrial Kv1.3, and investigated the role of sphingolipids and mutated Kirsten Rat Sarcoma Virus (KRAS) in Kv1.3-mediated cell death. We demonstrate that inhibition of Kv1.3 using the Kv1.3-inhibitor PAPTP results in an increase of sphingosine and superoxide in membranes and/or membranes associated with mitochondria, which is enhanced by KRAS mutation. The effect of PAPTP on sphingosine and mitochondrial superoxide formation as well as cell death is prevented by sh-RNA-mediated downregulation of Kv1.3. Induction of sphingosine in human pancreas cancer cells by PAPTP is mediated by activation of sphingosine-1-phosphate phosphatase and prevented by an inhibitor of sphingosine-1-phosphate phosphatase. A rapid depolarization of isolated mitochondria is triggered by binding of sphingosine to cardiolipin, which is neutralized by addition of exogenous cardiolipin. The significance of these findings is indicated by treatment of mutated KRAS-harboring metastasized pancreas cancer with PAPTP in combination with ABC294640, a blocker of sphingosine kinases. This treatment results in increased formation of sphingosine and death of pancreas cancer cells in vitro and, most importantly, prolongs in vivo survival of mice challenged with metastatic pancreas cancer. KEY MESSAGES: Pancreatic ductal adenocarcinoma (PDAC) is a common tumor with poor prognosis. The mitochondrial Kv1.3 ion channel blocker induced mitochondrial sphingosine. Sphingosine binds to cardiolipin thereby mediating mitochondrial depolarization. Sphingosine is formed by a PAPTP-mediated activation of S1P-Phosphatase. Inhibition of sphingosine-consumption amplifies PAPTP effects on PDAC in vivo.

The metastasis of tumors into bone tissue typically leads to intractable pain that is both very disabling and particularly difficult to manage. We investigated here whether riluzole could have beneficial effects for the treatment of prostate cancer-induced bone pain and how it could influence the development of bone metastasis.

We used a bone pain model induced by intratibial injection of human PC3 prostate cancer cells into male SCID mice treated or not with riluzole administered in drinking water. We also used riluzole in vitro to assess its possible effect on PC3 cell viability and functionality, using patch-clamp.

Riluzole had a significant preventive effect on both evoked and spontaneous pain involving the TREK-1 potassium channel. Riluzole did not interfere with PC3-induced bone loss or bone remodeling in vivo. It also significantly decreased PC3 cell viability in vitro. The antiproliferative effect of riluzole is correlated with a TREK-1-dependent membrane hyperpolarization in these cells.

The present data suggest that riluzole could be very useful to manage evoked and spontaneous hypersensitivity in cancer-induced bone pain and has no significant adverse effect on cancer progression.

Breast cancer is the most prevalent malignancy and the most significant contributor to mortality in female oncology patients. Potassium Two Pore Domain Channel Subfamily K Member 1 (KCNK1) is differentially expressed in a variety of tumors, but the mechanism of its function in breast cancer is unknown. In this study, we found for the first time that KCNK1 was significantly up-regulated in human breast cancer and was correlated with poor prognosis in breast cancer patients. KCNK1 promoted breast cancer proliferation, invasion, and metastasis in vitro and vivo. Further studies unexpectedly revealed that KCNK1 increased the glycolysis and lactate production in breast cancer cells by binding to and activating lactate dehydrogenase A (LDHA), which promoted histones lysine lactylation to induce the expression of a series of downstream genes and LDHA itself. Notably, increased expression of LDHA served as a vicious positive feedback to reduce tumor cell stiffness and adhesion, which eventually resulted in the proliferation, invasion, and metastasis of breast cancer. In conclusion, our results suggest that KCNK1 may serve as a potential breast cancer biomarker, and deeper insight into the cancer-promoting mechanism of KCNK1 may uncover a novel therapeutic target for breast cancer treatment.

Membrane proteins play critical physiological roles as receptors, channels, pumps, and transporters. Despite their importance, however, low expression levels often hamper the experimental characterization of membrane proteins. We present an automated and web-accessible design algorithm called mPROSS (https://mPROSS.weizmann.ac.il), which uses phylogenetic analysis and an atomistic potential, including an empirical lipophilicity scale, to improve native-state energy. As a stringent test, we apply mPROSS to the Kv1.2-Kv2.1 paddle chimera voltage-gated potassium channel. Four designs, encoding 9-26 mutations relative to the parental channel, were functional and maintained potassium-selective permeation and voltage dependence in Xenopus oocytes with up to 14-fold increase in whole-cell current densities. Additionally, single-channel recordings reveal no significant change in the channel-opening probability nor in unitary conductance, indicating that functional expression levels increase without impacting the activity profile of individual channels. Our results suggest that the expression levels of other dynamic channels and receptors may be enhanced through one-shot design calculations.

Research has shown a connection between vasculogenic mimicry (VM) and cancer progression. However, the functions of genes related to VM in the emergence and progression of TNBC have not been completely elucidated.

A survival risk model was constructed by screening biomarkers using DESeq2 and WGCNA based on public TNBC transcriptome data. Furthermore, gene set enrichment analysis was performed, and tumor microenvironment and drug sensitivity were analyzed. The selected biomarkers were validated via quantitative PCR detection, immunohistochemical staining, and protein detection in breast cancer cell lines. Biomarkers related to the proliferation and migration of TNBC cells were validated via in vitro experiments.

The findings revealed that 235 target genes were connected to the complement and coagulation cascade pathways. The risk score was constructed using KCND2, NRP1, and VSTM4. The prognosis model using the risk score and pathological T stage yielded good validation results. The clinical risk of TNBC was associated with the angiogenesis signaling pathway, and the low-risk group exhibited better sensitivity to immunotherapy. Quantitative PCR and immunohistochemistry indicated that the expression levels of KCND2 in TNBC tissues were higher than those in adjacent nontumor tissues. In the TNBC cell line, the protein expression of KCND2 was increased. Knockdown of KCND2 and VSTM4 inhibited the proliferation and migration of TNBC cells in vitro.

In this study, three VM-related biomarkers were identified, including KCND2, NRP1, and VSTM4. These findings are likely to aid in deepening our understanding of the regulatory mechanism of VM in TNBC.

Most animal cell types are classified as non-excitable because they do not generate action potentials observed in excitable cells, such as neurons and muscle cells. Thus, resolving voltage signals in non-excitable cells demands sensors with exceptionally high voltage sensitivity. In this study, the ultrabright, ultrasensitive, and calibratable genetically encoded voltage sensor rEstus is developed using structure-guided engineering. rEstus is most sensitive in the resting voltage range of non-excitable cells and offers a 3.6-fold improvement in brightness change for fast voltage spikes over its precursor ASAP3. Using rEstus, it is uncovered that the membrane voltage in several non-excitable cell lines (A375, HEK293T, MCF7) undergoes spontaneous endogenous alterations on a second to millisecond timescale. Correlation analysis of these optically recorded voltage alterations provides a direct, real-time readout of electrical cell-cell coupling, showing that visually connected A375 and HEK293T cells are also largely electrically connected, while MCF7 cells are only weakly coupled. The presented work provides enhanced tools and methods for non-invasive voltage imaging in living cells and demonstrates that spontaneous endogenous membrane voltage alterations are not limited to excitable cells but also occur in a variety of non-excitable cell types.

Circadian (~24 h) rhythms are a fundamental feature of life, and their disruption increases the risk of infectious diseases, metabolic disorders, and cancer1-6. Circadian rhythms couple to the cell cycle across eukaryotes7,8 but the underlying mechanism is unknown. We previously identified an evolutionarily conserved circadian oscillation in intracellular potassium concentration, [K+]i9,10. As critical events in the cell cycle are regulated by intracellular potassium11,12, an enticing hypothesis is that circadian rhythms in [K+]i form the basis of this coupling. We used a minimal model cell, the alga Ostreococcus tauri, to uncover the role of potassium in linking these two cycles. We found direct reciprocal feedback between [K+]i and circadian gene expression. Inhibition of proliferation by manipulating potassium rhythms was dependent on the phase of the circadian cycle. Furthermore, we observed a total inhibition of cell proliferation when circadian gene expression is inhibited. Strikingly, under these conditions a sudden enforced gradient of extracellular potassium was sufficient to induce a round of cell division. Finally, we provide evidence that interactions between potassium and circadian rhythms also influence proliferation in mammalian cells. These results establish circadian regulation of intracellular potassium levels as a primary factor coupling the cell- and circadian cycles across diverse organisms.

Clotrimazole is an FDA approved drug and is widely used as an antifungal agent. An extensive body of research is available about its mechanism of action on various cell types but its mode of killing of Leishmania donovani parasites is unknown. L. donovani causes Visceral Leishmaniasis which is a public health problem with limited treatment options. Its present chemotherapy is expensive, has adverse effects and is plagued with drug resistance issues. In this study we have explored the possibility of repurposing clotrimazole as an antileishmanial drug. We have assessed its efficacy on the parasites and attempted to understand its mode of action. We found that it has a half-maximal inhibitory concentration (IC50) of 35.75 ± 1.06 μM, 12.75 ± 0.35 μM and 73 ± 1.41 μM in promastigotes, intracellular amastigotes and macrophages, respectively. Clotrimazole is 5.73 times more selective for the intracellular amastigotes as compared to the mammalian cell. Effect of clotrimazole was reduced by ergosterol supplementation. It leads to impaired parasite morphology. It alters plasma membrane permeability and disrupts plasma membrane potential. Mitochondrial function is compromised as is evident from increased ROS generation, depolarized mitochondrial membrane and decreased ATP levels. Cell cycle analysis of clotrimazole treated parasites shows arrest at sub-G0 phase suggesting apoptotic mode of cell death.

Peptide toxins found in sea anemones venom have diverse properties that make them important research subjects in the fields of pharmacology, neuroscience and biotechnology. This study used high-throughput sequencing technology to systematically analyze the venom components of the tentacles, column, and mesenterial filaments of sea anemone Heteractis crispa, revealing the diversity and complexity of sea anemone toxins in different tissues. A total of 1049 transcripts were identified and categorized into 60 families, of which 91.0% were proteins and 9.0% were peptides. Of those 1049 transcripts, 416, 291, and 307 putative proteins and peptide precursors were identified from tentacles, column, and mesenterial filaments respectively, while 428 were identified when the datasets were combined. Of these putative toxin sequences, 42 were detected in all three tissues, including 33 proteins and 9 peptides, with the majority of peptides being ShKT domain, β-defensin, and Kunitz-type. In addition, this study applied bioinformatics approaches to predict the family classification, 3D structures, and functional annotation of these representative peptides, as well as the evolutionary relationships between peptides, laying the foundation for the next step of peptide pharmacological activity research.

BeKm-1 is a peptide toxin from scorpion venom that blocks the pore of the potassium channel hERG (Kv11.1) in the human heart. Although individual protein structures have been resolved, the structure of the complex between hERG and BeKm-1 is unknown. Here, we used molecular dynamics and ensemble docking, guided by previous double-mutant cycle analysis data, to obtain an in silico model of the hERG-BeKm-1 complex. Adding to the previous mutagenesis study of BeKm-1, our model uncovers the key role of residue Arg20, which forms three interactions (a salt bridge and hydrogen bonds) with the channel vestibule simultaneously. Replacement of this residue even by lysine weakens the interactions significantly. In accordance, the recombinantly produced BeKm-1R20K mutant exhibited dramatically decreased activity on hERG. Our model may be useful for future drug design attempts.