Novel Therapeutic Approaches of Ion Channels and Transporters in Cancer

In silico pan-cancer analysis of VRAC subunits and their prognostic roles in human cancers

The study focuses on the VRAC channel and its significant roles in cancer development. It addresses a research gap by conducting a pan-cancer analysis with multi-omics bioinformatics tools, integrating data from the Human Protein Atlas (HPA) and Genotype-Tissue Expression (GTEx) datasets to examine mRNA expression patterns of its Leucine Rich Repeat Containing 8 (LRRC8) subunits in various tissues and cancers. The study links variations in LRRC8s expression with patient outcomes and includes analyses of DNA and RNA methylation. The study reveals significant correlations between LRRC8s expression and immune cell infiltration, as well as a positive association with cancer-associated fibroblasts and key immune regulators such as major histocompatibility complex (MHCs) and chemokines. Furthermore, the research suggests that LRRC8s are involved in cancer-signalling pathways, which may offer new therapeutic targets. Additionally, a drug sensitivity analysis shows that LRRC8 subunits affect drug responses differently, supporting the use of personalized therapeutic strategies. In conclusion, the study emphasizes the significance of VRAC subunits in cancer biology and suggests their potential as biomarkers and targets in cancer immunotherapy and personalized medicine.

Investigating the anti-lung cancer properties of Zhuang medicine Cycas revoluta Thunb. leaves targeting ion channels and transporters through a comprehensive strategy

BACKGROUND

Cycas revoluta Thunb., known for its ornamental, economic, and medicinal value, has leaves often discarded as waste. However, in ethnic regions of China, the leaves (CRL) are used in folk medicine for anti-tumor properties, particularly for regulating pathways related to cancer. Recent studies on ion channels and transporters (ICTs) highlight their therapeutic potential against cancer, making it vital to identify CRL's active constituents targeting ICTs in lung cancer.

PURPOSE

This study aims to uncover bioactive substances in CRL and their mechanisms in regulating ICTs for lung cancer treatment using network pharmacology, bioinformatics, molecular docking, molecular dynamics (MD) simulations, in vitro cell assays and HPLC.

METHODS

We analyzed 62 CRL compounds, predicted targets using PubChem and SwissTargetPrediction, identified lung cancer and ICT targets via GeneCards, and visualized overlaps with R software. Interaction networks were constructed using Cytoscape and STRING. Gene expression, GO, and KEGG analyses were performed using R software. TCGA data provided insights into differential, correlation, survival, and immune analyses. Key interactions were validated through molecular docking and MD simulations. Main biflavonoids were quantified using HPLC, and in vitro cell viability assays were conducted for key biflavonoids.

RESULTS

Venn diagram analysis identified 52 intersecting targets and ten active CRL compounds. The PPI network highlighted seven key targets. GO and KEGG analysis showed CRL-targeted ICTs involved in synaptic transmission, GABAergic synapse, and proteoglycans in cancer. Differential expression and correlation analysis revealed significant differences in five core targets in lung cancer tissues. Survival analysis linked EGFR and GABRG2 with overall survival, and immune infiltration analysis associated the core targets with most immune cell types. Molecular docking indicated strong binding of CRL ingredients to core targets. HPLC revealed amentoflavone as the most abundant biflavonoid, followed by hinokiflavone, sciadopitysin, and podocarpusflavone A. MD simulations showed that podocarpusflavone A and amentoflavone had better binding stability with GABRG2, and the cell viability assay also proved that they had better anti-lung cancer potential.

CONCLUSIONS

This study identified potential active components, targets, and pathways of CRL-targeted ICTs for lung cancer treatment, suggesting CRL's utility in drug development and its potential beyond industrial waste.

Targeting Heme Oxygenase 2 (HO2) with TiNIR, a Theragnostic Approach for Managing Metastatic Non-Small Cell Lung Cancer

Despite notable advancements in cancer therapeutics, metastasis remains a primary obstacle impeding a successful prognosis. Our prior study has identified heme oxygenase 2 (HO2) as a promising therapeutic biomarker for the aggressive subsets within tumor. This study aims to systematically evaluate HO2 as a therapeutic target of cancer, with a specific emphasis on its efficacy in addressing cancer metastasis. Through targeted inhibition of HO2 by TiNIR (tumor-initiating cell probe with near infrared), we observed a marked increase in reactive oxygen species. This, in turn, orchestrated the modulation of AKT and cJUN activation, culminating in a substantial attenuation of both proliferation and migration within a metastatic cancer cell model. Furthermore, in a mouse model, clear inhibition of cancer metastasis was unequivocally demonstrated with an HO2 inhibitor administration. These findings underscore the therapeutic promise of targeting HO2 as a strategic intervention to impede cancer metastasis, enhancing the effectiveness of cancer treatments.

LRRC8A Is a Promising Prognostic Biomarker and Therapeutic Target for Pancreatic Adenocarcinoma

Pancreatic adenocarcinoma (PAAD) is a highly malignant tumor of the digestive system with increasing morbidity and mortality. The lack of sensitive and reliable biomarkers is one of the main reasons for the poor prognosis. Volume-regulated anion channels (VRAC), which are ubiquitously expressed in the vertebrate cell membrane, are composed of leucine-rich repeat-containing 8A (LRRC8A) and four other homologous family members (LRRC8B-E). VRAC heterogeneous complex is implicated in each of the six "hallmarks of cancer" and represents a novel therapeutic target for cancer. In this study, LRRC8A was speculated to be a promising prognostic biomarker and therapeutic target for PAAD based on a series of bioinformatics analyses. Additional cell experiments and immunohistochemical assays demonstrated that LRRC8A can affect the prognosis of PAAD and is correlated to cell proliferation, cell migration, drug resistance, and immune infiltration. Functional analysis indicated that LRRC8A influences the progression and prognosis of patients with PAAD by the regulation of CD8⁺ T cells immune infiltration. Taken together, these results can help in the design of new therapeutic drugs for patients with PAAD.

Ion Channels in Endometrial Cancer

Simple Summary

Uterine or endometrial cancer is one of the most common types of cancer among the female population. Different alterations of molecules are related to many types of cancer. Some molecules called ion channels have been described as involved in the development of cancer, including endometrial cancer. We review the scientific evidence about the involvement of the ion channels in endometrial cancer and how some treatments can be developed with these molecules as a target. Even though they are involved in the progression of endometrial cancer, since they are present throughout the whole body, some possible treatments based on these could be studied.

Abstract

Uterine or endometrial cancer (EC) is the sixth most common neoplasia among women worldwide. Cancer can originate from a myriad of causes, and increasing evidence suggests that ion channels (IC) play an important role in the process of carcinogenesis, taking part in many pathways such as self-sufficiency in growth signals, proliferation, evasion of programmed cell death (apoptosis), angiogenesis, cell differentiation, migration, adhesion, and metastasis. Hormones and growth factors are well-known to be involved in the development and/or progression of many cancers and can also regulate some ion channels and pumps. Since the endometrium is responsive and regulated by these factors, the ICs could make an important contribution to the development and progression of endometrial cancer. In this review, we explore what is beyond (ion) flow regulation by investigating the role of the main families of ICs in EC, including as possible targets for EC treatment.

KCa1.1 K+ Channel Inhibition Overcomes Resistance to Antiandrogens and Doxorubicin in a Human Prostate Cancer LNCaP Spheroid Model

Several types of K+ channels play crucial roles in tumorigenicity, stemness, invasiveness, and drug resistance in cancer. Spheroid formation of human prostate cancer (PC) LNCaP cells with ultra-low attachment surface cultureware induced the up-regulation of cancer stem cell markers, such as NANOG, and decreased the protein degradation of the Ca2+-activated K+ channel KCa1.1 by down-regulating the E3 ubiquitin ligase, FBXW7, compared with LNCaP monolayers. Accordingly, KCa1.1 activator-induced hyperpolarizing responses were larger in isolated cells from LNCaP spheroids. The pharmacological inhibition of KCa1.1 overcame the resistance of LNCaP spheroids to antiandrogens and doxorubicin (DOX). The protein expression of androgen receptors (AR) was significantly decreased by LNCaP spheroid formation and reversed by KCa1.1 inhibition. The pharmacological and genetic inhibition of MDM2, which may be related to AR protein degradation in PC stem cells, revealed that MDM2 was responsible for the acquisition of antiandrogen resistance in LNCaP spheroids, which was overcome by KCa1.1 inhibition. Furthermore, a member of the multidrug resistance-associated protein subfamily of ABC transporters, MRP5 was responsible for the acquisition of DOX resistance in LNCaP spheroids, which was also overcome by KCa1.1 inhibition. Collectively, the present results suggest the potential of KCa1.1 in LNCaP spheroids, which mimic PC stem cells, as a therapeutic target for overcoming antiandrogen- and DOX-resistance in PC cells.

Combinations of Calcitriol with Anticancer Treatments for Breast Cancer: An Update

Preclinical, clinical, and epidemiological studies indicate that vitamin D3 (VD) deficiency is a risk factor for the development of breast cancer. Underlying mechanisms include the ability of calcitriol to induce cell differentiation, inhibit oncogenes expression, and modify different signaling pathways involved in the control of cell proliferation. In addition, calcitriol combined with different kinds of antineoplastic drugs has been demonstrated to enhance their beneficial effects in an additive or synergistic fashion. However, a recognized adjuvant regimen based on calcitriol for treating patients with breast cancer has not yet been fully established. Accordingly, in the present work, we review and discuss the preclinical and clinical studies about the combination of calcitriol with different oncological drugs, aiming to emphasize its main therapeutic benefits and opportunities for the treatment of this pathology.

Inhibition of NHE-1 Increases Smoke-Induced Proliferative Activity of Barrett's Esophageal Cell Line

Several clinical studies indicate that smoking predisposes its consumers to esophageal inflammatory and malignant diseases, but the cellular mechanism is not clear. Ion transporters protect esophageal epithelial cells by maintaining intracellular pH at normal levels. In this study, we hypothesized that smoking affects the function of ion transporters, thus playing a role in the development of smoking-induced esophageal diseases. Esophageal cell lines were treated with cigarettesmoke extract (CSE), and the viability and proliferation of the cells, as well as the activity, mRNA and protein expression of the Na+/H+ exchanger-1 (NHE-1), were studied. NHE-1 expression was also investigated in human samples. For chronic treatment, guinea pigs were exposed to tobacco smoke, and NHE-1 activity was measured. Silencing of NHE-1 was performed by using specific siRNA. CSE treatment increased the activity and protein expression of NHE-1 in the metaplastic cells and decreased the rate of proliferation in a NHE-1-dependent manner. In contrast, CSE increased the proliferation of dysplastic cells independently of NHE-1. In the normal cells, the expression and activity of NHE-1 decreased due to in vitro and in vivo smoke exposure. Smoking enhances the function of NHE-1 in Barrett's esophagus, and this is presumably a compensatory mechanism against this toxic agent.

Ion Channels and Transporters in Autophagy

Ion exchange between intracellular and extracellular spaces is the basic mechanism for controlling cell metabolism and signal transduction. This process is mediated by ion channels and transporters on the plasma membrane, or intracellular membranes that surround various organelles, in response to environmental stimuli. Macroautophagy (hereafter referred to as autophagy) is one of the lysosomal-dependent degradation pathways that maintains homeostasis through the degradation and recycling of cellular components (e.g., dysfunctional proteins and damaged organelles). Although autophagy-related (ATG) proteins play a central role in regulating the formation of autophagy-related member structures (e.g., phagophores, autophagosomes, and autolysosomes), the autophagic process also involves changes in expression and function of ion channels and transporters. Here we discuss current knowledge of the mechanisms that regulate autophagy in mammalian cells, with special attention to the ion channels and transporters. We also highlight prospects for the development of drugs targeting ion channels and transporters in autophagy.