Antibodies Targeting KV Potassium Channels: A Promising Treatment for Cancer

Modulating ion channels with nanobodies

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.

Computational engineering of water-soluble human potassium ion channels through QTY transformation

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.

Potassium Ion Channels in Glioma: From Basic Knowledge into Therapeutic Applications

Ion channels, specifically those controlling the flux of potassium across cell membranes, have recently been shown to exhibit an important role in the pathophysiology of glioma, the most common primary central nervous system tumor with a poor prognosis. Potassium channels are grouped into four subfamilies differing by their domain structure, gating mechanisms, and functions. Pertinent literature indicates the vital functions of potassium channels in many aspects of glioma carcinogenesis, including proliferation, migration, and apoptosis. The dysfunction of potassium channels can result in pro-proliferative signals that are highly related to calcium signaling as well. Moreover, this dysfunction can feed into migration and metastasis, most likely by increasing the osmotic pressure of cells allowing the cells to initiate the "escape" and "invasion" of capillaries. Reducing the expression or channel blockage has shown efficacy in reducing the proliferation and infiltration of glioma cells as well as inducing apoptosis, priming several approaches to target potassium channels in gliomas pharmacologically. This review summarizes the current knowledge on potassium channels, their contribution to oncogenic transformations in glioma, and the existing perspectives on utilizing them as potential targets for therapy.

Comprehensive Analysis of KCNJ14 Potassium Channel as a Biomarker for Cancer Progression and Development

Cancer is a global epidemic that has affected millions of lives. Discovering novel cancer targets is widely viewed as a key step in developing more effective therapies for cancer and other fatal illnesses. More recently, potassium (K+) channels have been studied as a potential biological target for the creation of cancer treatments. Potassium Inwardly Rectifying Channel Subfamily J Member 14 (KCNJ14) is one of the cancer genome's least investigated genes. This study conducted a comprehensive examination of the relationships between KCNJ14 gene expression analysis, survival, RNA modification, immunotherapy participation, and cancer stemness using several databases. KCNJ14 was shown to be dysregulated in a variety of cancers, including lung, intestinal, head and neck, oesophageal, and stomach. Additionally, KCNJ14 was shown to be linked to RNA and DNA stemness in 18 and 15 different tumour types, respectively. Moreover, KCNJ14 was discovered to be positively linked with immunological checkpoints and suppressor cells and to have a negative immunophenoscore (IPS). KCNJ14 was linked to tumour mutation burden (TMB), microsatellite instability (MSI), neoantigen (NEO), and programmed death ligand 1 (PD-L1); all four are potential targets for immunotherapies. In addition, a favourable relationship between genomic-instability markers such as heterozygosity (LOH), homologous recombination deficiency (HRD), and mutant-allele tumour heterogeneity (MATH) was demonstrated with KCNJ14. Based on these novel findings, KCNJ14 may be a useful independent prognostic biomarker for a range of cancers.

The Kv10.1 Channel: A Promising Target in Cancer

Carcinogenesis is a multistage process involving the dysregulation of multiple genes, proteins, and pathways that make any normal cell acquire a cancer cell phenotype. Therefore, it is no surprise that numerous ion channels could be involved in this process. Since their discovery and subsequent cloning, ion channels have been established as therapeutic targets in excitable cell pathologies (e.g., cardiac arrhythmias or epilepsy); however, their involvement in non-excitable cell pathologies is relatively recent. Among all ion channels, the voltage-gated potassium channels Kv10.1 have been established as a promising target in cancer treatment due to their high expression in tumoral tissues compared to low levels in healthy tissues.

Potassium Channels as a Target for Cancer Therapy: Current Perspectives

Potassium (K⁺) channels are highly regulated membrane proteins that control the potassium ion flux and respond to different cellular stimuli. These ion channels are grouped into three major families, Kv (voltage-gated K⁺ channel), Kir (inwardly rectifying K⁺ channel) and K2P (two-pore K⁺ channels), according to the structure, to mediate the K⁺ currents. In cancer, alterations in K⁺ channel function can promote the acquisition of the so-called hallmarks of cancer – cell proliferation, resistance to apoptosis, metabolic changes, angiogenesis, and migratory capabilities – emerging as targets for the development of new therapeutic drugs. In this review, we focus our attention on the different K⁺ channels associated with the most relevant and prevalent cancer types. We summarize our knowledge about the potassium channels structure and function, their cancer dysregulated expression and discuss the K⁺ channels modulator and the strategies for designing new drugs.

Overcoming challenges of HERG potassium channel liability through rational design: Eag1 inhibitors for cancer treatment

Two decades of research have proven the relevance of ion channel expression for tumor progression in virtually every indication, and it has become clear that inhibition of specific ion channels will eventually become part of the oncology therapeutic arsenal. However, ion channels play relevant roles in all aspects of physiology, and specificity for the tumor tissue remains a challenge to avoid undesired effects. Eag1 (K_V 10.1) is a voltage-gated potassium channel whose expression is very restricted in healthy tissues outside of the brain, while it is overexpressed in 70% of human tumors. Inhibition of Eag1 reduces tumor growth, but the search for potent inhibitors for tumor therapy suffers from the structural similarities with the cardiac HERG channel, a major off-target. Existing inhibitors show low specificity between the two channels, and screenings for Eag1 binders are prone to enrichment in compounds that also bind HERG. Rational drug design requires knowledge of the structure of the target and the understanding of structure-function relationships. Recent studies have shown subtle structural differences between Eag1 and HERG channels with profound functional impact. Thus, although both targets' structure is likely too similar to identify leads that exclusively bind to one of the channels, the structural information combined with the new knowledge of the functional relevance of particular residues or areas suggests the possibility of selective targeting of Eag1 in cancer therapies. Further development of selective Eag1 inhibitors can lead to first-in-class compounds for the treatment of different cancers.

Emerging Roles for Ion Channels in Ovarian Cancer: Pathomechanisms and Pharmacological Treatment

Ovarian cancer (OC) is the deadliest gynecologic cancer, due to late diagnosis, development of platinum resistance, and inadequate alternative therapy. It has been demonstrated that membrane ion channels play important roles in cancer processes, including cell proliferation, apoptosis, motility, and invasion. Here, we review the contribution of ion channels in the development and progression of OC, evaluating their potential in clinical management. Increased expression of voltage-gated and epithelial sodium channels has been detected in OC cells and tissues and shown to be involved in cancer proliferation and invasion. Potassium and calcium channels have been found to play a critical role in the control of cell cycle and in the resistance to apoptosis, promoting tumor growth and recurrence. Overexpression of chloride and transient receptor potential channels was found both in vitro and in vivo, supporting their contribution to OC. Furthermore, ion channels have been shown to influence the sensitivity of OC cells to neoplastic drugs, suggesting a critical role in chemotherapy resistance. The study of ion channels expression and function in OC can improve our understanding of pathophysiology and pave the way for identifying ion channels as potential targets for tumor diagnosis and treatment.

Potassium Channels as a Potential Target Spot for Drugs

Aberrant function or expression of potassium channels can be underlying in pathologies such as cardiac arrhythmia, diabetes mellitus, hypertension, preterm birth, and various types of cancer. The expression of potassium channels is altered in many types of diseases. Also, we have previously shown that natural polyphenols, such as resveratrol, and selective synthetic modulators of potassium channels, like pinacidil, can alter their function and lead to the desired outcome. Therefore, targeting potassium channels with substance, which has an influence on their function, is promising access to cancer, diabetes mellitus, preterm birth, or hypertension therapy. In this chapter, we could discuss strategies for targeting different types of potassium channels as potential targets for synthetic and natural molecules therapy.