Repurposing Cationic Amphiphilic Antihistamines for Cancer Treatment

LIN28-Targeting Chromenopyrazoles and Tetrahydroquinolines Induced Cellular Morphological Changes and Showed High Biosimilarity with BRD PROTACs

The probing of small molecules with heterocyclic scaffolds covering unexplored chemical space and the evaluation of their biological relevance are essential parts of forward chemical genetics approaches and for the development of potential small-molecule therapeutics. In this study, we profiled sets of chromenopyrazoles (CMPs) and tetrahydroquinolines (THQs), originally developed to target the protein-RNA interaction of LIN28-let-7, in a cell painting assay (CPA) measuring cellular morphological changes. Selected LIN28-inactive CMPs and THQs induced cellular morphological changes to different extents. The most CPA-active CMPs 2 and 3 exhibited high bio-similarity with the LCH and BET clusters, while the most CPA-active THQs 13 and 20 indicated a mechanism of action beyond the currently established biosimilarity clusters. Overall, this work demonstrated that CPA is useful in revealing "hidden" biological targets and mechanisms of action for biologically inactive small molecules, which are CMPs and THQs targeting the RNA-binding protein LIN28 in this case, evaluated in target-based strategies. When compared with annotated reference compounds, CMP 3 exhibited a high biosimilarity with the dual BRD7/9 degrading PROTAC VZ185, suggesting that CPA could potentially function as a new phenotypic approach to identify degrader molecules.

S6K1 is a Targetable Vulnerability in Tumors Exhibiting Plasticity and Therapy Resistance

Background: Most tumors initially respond to treatment, yet refractory clones subsequently develop owing to resistance mechanisms associated with cancer cell plasticity and heterogeneity. Methods: We used a chemical biology approach to identify protein targets in cancer cells exhibiting diverse driver mutations and representing models of tumor lineage plasticity and therapy resistance. An unbiased screen of a drug library was performed against cancer cells followed by synthesis of chemical analogs of the most effective drug. The cancer subtype target range of the leading drug was determined by PRISM analysis of over 900 cancer cell lines at the Broad Institute, MA. RNA-sequencing and enrichment analysis of differentially expressed genes, as well as computational molecular modeling and pull-down with biotinylated small molecules were used to identify and validate RPS6KB1 (p70S6K or S6K1) as an essential target. Genetic restoration was used to test the functional role of S6K1 in cell culture and xenograft models. Results: We identified a novel derivative of the antihistamine drug ebastine, designated Super-ebastine (Super-EBS), that inhibited the viability of cancer cells representing diverse KRAS and EGFR driver mutations and models of plasticity and treatment resistance. Interestingly, PRISM analysis indicated that over 95% of the diverse cancer cell lines tested were sensitive to Super-EBS and the predicted target was the serine/threonine kinase S6K1. S6K1 is upregulated in various cancers relative to counterpart normal/benign tissues and phosphorylated-S6K1 predicts poor prognosis for cancer patients. We noted that inhibition of S6K1 phosphorylation was necessary for tumor cell growth inhibition, and restoration of phospho-S6K1 rendered tumor cells resistant to Super-EBS. Inhibition of S6K1 phosphorylation by Super-EBS induced caspase-2 dependent apoptosis via inhibition of the Cdc42/Rac-1/p-PAK1 pathway that led to actin depolymerization and caspase-2 activation. The essential role of S6K1 in the action of Super-EBS was recapitulated in xenografts, and knockout of S6K1 abrogated tumor growth in mice. Conclusion: S6K1 is a therapeutic vulnerability in tumors exhibiting intrinsic and/or acquired resistance to treatment.

Underlying Mechanism of Lysosomal Membrane Permeabilization in CNS Injury: A Literature Review

Lysosomes play a crucial role in various intracellular pathways as their final destination. Various stressors, whether mild or severe, can induce lysosomal membrane permeabilization (LMP), resulting in the release of lysosomal enzymes into the cytoplasm. LMP not only plays a pivotal role in various cellular events but also significantly contributes to programmed cell death (PCD). Previous research has demonstrated the participation of LMP in central nervous system (CNS) injuries, including traumatic brain injury (TBI), spinal cord injury (SCI), subarachnoid hemorrhage (SAH), and hypoxic-ischemic encephalopathy (HIE). However, the mechanisms underlying LMP in CNS injuries are poorly understood. The occurrence of LMP leads to the activation of inflammatory pathways, increased levels of oxidative stress, and PCD. Herein, we present a comprehensive overview of the latest findings regarding LMP and highlight its functions in cellular events and PCDs (lysosome-dependent cell death, apoptosis, pyroptosis, ferroptosis, and autophagy). In addition, we consolidate the most recent insights into LMP in CNS injury by summarizing and exploring the latest advances. We also review potential therapeutic strategies that aim to preserve LMP or inhibit the release of enzymes from lysosomes to alleviate the consequences of LMP in CNS injury. A better understanding of the role that LMP plays in CNS injury may facilitate the development of strategic treatment options for CNS injury.

Glucosylceramide Synthase Inhibition in Combination with Aripiprazole Sensitizes Hepatocellular Cancer Cells to Sorafenib and Doxorubicin

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer deaths due to its late diagnosis and restricted therapeutic options. Therefore, the search for appropriate alternatives to commonly applied therapies remains an area of high clinical need. Here we investigated the therapeutic potential of the glucosylceramide synthase (GCS) inhibitor Genz-123346 and the cationic amphiphilic drug aripiprazole on the inhibition of Huh7 and Hepa 1-6 hepatocellular cancer cell and tumor microsphere growth. Single and combinatorial treatments with both drugs at 5 µM concentration led to efficient cell cycle arrest, reduced expression of cyclins A and E, increased lipid storage in lysosomal compartments, accompanied by increased uptake of lysotracker, and elevated expression of the autophagy marker Lc3 II. Both drugs affected mitochondrial function, indicated by altered mitotracker uptake and impaired mitochondrial respiration. Aripiprazole in monotherapy, or even more pronounced in combination with Genz, also potentiated the effect of the cytostatic drugs sorafenib and doxorubicin on tumor cell- and tumor spheroid-growth inhibition. Targeting GCS with Genz with the parallel application of cationic amphiphilic drugs such as aripiprazole in combination with cytostatic drugs may thus represent a potent therapeutic approach in the treatment of HCC and potentially other cancer types.

H1 Antihistamines-Promising Candidates for Repurposing in the Context of the Development of New Therapeutic Approaches to Cancer Treatment

Despite significant progress in the field of clinical oncology in terms of diagnostic and treatment methods, the results of anticancer therapy are still not fully satisfactory, especially due to limited response and high toxicity. This has forced the need for further research to finding alternative ways to improve success rates in oncological treatment. A good solution to this problem in the context of rapidly obtaining an effective drug that works on multiple levels of cancer and is also safe is the global strategy of repurposing an existing drug. Research into other applications of an existing drug enables a precise assessment of its possible mechanisms of action and, consequently, the broadening of therapeutic indications. This strategy is also supported by the fact that most non-oncological drugs have pleiotropic effects, and most of the diseases for which they were originally intended are multifactorial, which in turn is a very desirable phenomenon due to the heterogeneous and multifaceted biology of cancer. In this review, we will mainly focus on the anticancer potential of H1 antihistamines, especially the new generation that were not originally intended for cancer therapy, to highlight the relevant signaling pathways and discuss the properties of these agents for their judicious use based on the characteristic features of cancer.

Acidic sphingomyelinase interactions with lysosomal membranes and cation amphiphilic drugs: A molecular dynamics investigation

Lysosomes are pivotal in cellular functions and disease, influencing cancer progression and therapy resistance with Acid Sphingomyelinase (ASM) governing their membrane integrity. Moreover, cation amphiphilic drugs (CADs) are known as ASM inhibitors and have anti-cancer activity, but the structural mechanisms of their interactions with the lysosomal membrane and ASM are poorly explored. Our study, leveraging all-atom explicit solvent molecular dynamics simulations, delves into the interaction of glycosylated ASM with the lysosomal membrane and the effects of CAD representatives, i.e., ebastine, hydroxyebastine and loratadine, on the membrane and ASM. Our results confirm the ASM association to the membrane through the saposin domain, previously only shown with coarse-grained models. Furthermore, we elucidated the role of specific residues and ASM-induced membrane curvature in lipid recruitment and orientation. CADs also interfere with the association of ASM with the membrane at the level of a loop in the catalytic domain engaging in membrane interactions. Our computational approach, applicable to various CADs or membrane compositions, provides insights into ASM and CAD interaction with the membrane, offering a valuable tool for future studies.

Enhancing immuno-oncology efficacy with H1-antihistamine in cancer therapy: a review of current research and findings

Cancer remains a major global cause of death, posing significant treatment challenges. The interactions between tumor cells and the tumor microenvironment (TME) are crucial in influencing tumor initiation, progression, metastasis, and treatment response. There has been significant research and clinical interest in targeting the TME as a therapeutic approach in cancer, with advancements being made through drug development. Histamine binds to HRH1 receptors on the TME, which inhibit CD8+ T cell activity, promote tumor growth, and contribute to resistance against immunotherapy. By inhibiting CD8+ T cells, the effectiveness of immunotherapies targeting these cells is reduced. By blocking the HRH1 pathway, H1-antihistamines can mitigate this suppression and enhance the response to immunotherapies that target CD8+ T cells. Therefore, understanding the role of histamine and its potential impact on T cells and the role of H1-antihistamines in improving immune-oncology (I/O) agents' efficacy ultimately could lead to more effective cancer therapies. The objective of this review is to examine the current literature to investigate the potential role of H1-antihistamines on the effectiveness of I/O drugs and their role in enhancing treatment against cancer. We conducted a comprehensive literature search, which included multiple databases including PubMed, Google Scholar, and EMBASE, as well as a search of oncology congresses. Our literature review initially identified thirty studies. Twenty-three of these were excluded for failing to meet inclusion criteria, which varied from study design to the type of antihistamines and patient populations involved. The clinical studies investigated the effect of different generations of H1-antihistamines in combination with I/O treatments on patients' outcomes. The findings from these studies indicated that patients using H1-antihistamines concomitantly with I/O agents experienced longer median overall survival (mOS), progression-free survival (mPFS), or improved survival compared to those who did not use antihistamines. Additionally, these trials differentiated between cationic and non-cationic H1-antihistamines, revealing that users of cationic antihistamines had overall better outcomes in terms of longer mOS and mPFS. The assessed trials were consistent in their comparisons of quantitative and qualitative, efficacy, and safety outcomes.

Loratadine Loaded Chitosan Tannic Acid Nanoparticles as Anti-Proliferative Agent Against Breast Cancer: In-silico, in-vitro and Cell Studies

Purpose

This study aims to prepare Loratadine-loaded chitosan/tannic acid nanoparticles (LOR-CS/TAN NPs) through ionic gelation to be used as an anti-proliferative agent to aid in overcoming breast cancer propagation.

Methods

First, in-silico virtual screening was carried out to select the most appropriate anti-histaminic drug based on its inhibitory effect on the H1-histamine receptor, resulting in the selection of Loratadine (LOR). Molecular interaction between LOR with chitosan (CS), a positively charged polymer, and hyaluronan, a negatively charged polymer, was investigated separately through molecular docking, leading to the selection of CS. Optimization was carried out using Box Behnken Design, with concentrations of CS, LOR, and tannic acid (TAN) as independent variables. The optimized nanoparticles were then examined through morphological and physicochemical studies. Cell studies against the MCF-7 breast cancer cell line were conducted to assess cytotoxicity, cell cycle, apoptosis, and necrosis.

Results

The optimum formulation was determined to be CS (0.2% w/v), LOR (1:2 weight ratio to CS), and TAN (1:30.6 weight ratio to CS). The optimized LOR-CS/TAN NPs exhibited a size of 283 nm, a polydispersity index (PDI) of 0.102, and an entrapment efficiency of 78%, along with sustained drug release for 24 hours. The results demonstrated that LOR-CS/TAN NPs possess higher anti-cancer activity compared to free LOR. This enhanced activity is attributed to the synergistic effect of the drug and the designed nanoparticle, particularly due to the presence of tannic acid.

Conclusion

In conclusion, Loratadine-loaded chitosan/tannic acid nanoparticles (LOR-CS/TAN NPs) demonstrated enhanced anti-cancer activity against the MCF-7 breast cancer cell line. The synergistic effect of Loratadine and the nanoparticle system, particularly due to the presence of tannic acid, resulted in higher cytotoxicity compared to free Loratadine. These findings suggest that LOR-CS/TAN NPs have significant potential as a novel anti-proliferative agent for breast cancer therapy.

The Effects of Nebivolol-Gefitinib-Loratadine Against Lung Cancer Cell Lines

BACKGROUND/AIM

Non-small-cell lung cancer (NSCLC) is the most frequently diagnosed malignancy and the first cause of cancer-related death. Thus, finding alternative therapeutic options is crucial. Drug repurposing offers therapeutic options in a simplified and affordable manner, especially to cancer patients in developing countries. Several drugs including antihistamines and beta-adrenergic receptor blockers (beta-blockers) display antiproliferative properties on cancer cells. Interestingly, NSCLC patients who had used either antihistamines or beta-blockers showed improved response to chemotherapy or reduced mortality in comparison to non-users of any of these drugs. However, combination therapy is gaining substantial interest in many cancers including non-EGFR mutated NSCLC. Here, we investigated the antineoplastic effect of the combination of the antihistamine loratadine, the beta-blocker nebivolol, and the tyrosine-kinase inhibitor gefitinib on NSCLC cell lines.

MATERIALS AND METHODS

A-549 and NCI-H1975 cell lines were used. The effect of nebivolol, gefitinib, and loratadine on the metabolic activity was studied using the MTT assay. The inhibitory concentrations (IC20 and IC50) were calculated and used in the drug-combination experiments. Apoptosis was investigated using flow cytometry; and cell survival using the colony formation assay.

RESULTS

The combination nebivolol-loratadine-gefitinib produced a significant synergistic effect on inhibiting the metabolic activity and colony formation, as well as on promoting apoptosis in both cell lines. Noteworthy, the effect on the cell line carrying the EGFR mutation (NCI-H1975) was very similar to the cell line that does not exhibit such mutation (A-549 cells).

CONCLUSION

The nebivolol-gefitinib-loratadine combination may be a promising alternative for lung cancer treatment.

Vitamin C-Dependent Uptake of Non-Heme Iron by Enterocytes, Its Impact on Erythropoiesis and Redox Capacity of Human Erythrocytes

In the small intestine, nutrients from ingested food are absorbed and broken down by enterocytes, which constitute over 95% of the intestinal epithelium. Enterocytes demonstrate diet- and segment-dependent metabolic flexibility, enabling them to take up large amounts of glutamine and glucose to meet their energy needs and transfer these nutrients into the bloodstream. During glycolysis, ATP, lactate, and H+ ions are produced within the enterocytes. Based on extensive but incomplete glutamine oxidation large amounts of alanine or lactate are produced. Lactate, in turn, promotes hypoxia-inducible factor-1α (Hif-1α) activation and Hif-1α-dependent transcription of various proton channels and exchangers, which extrude cytoplasmic H+-ions into the intestinal lumen. In parallel, the vitamin C-dependent and duodenal cytochrome b-mediated conversion of ferric iron into ferrous iron progresses. Finally, the generated electrochemical gradient is utilized by the divalent metal transporter 1 for H+-coupled uptake of non-heme Fe2+-ions. Iron efflux from enterocytes, subsequent binding to the plasma protein transferrin, and systemic distribution supply a wide range of cells with iron, including erythroid precursors essential for erythropoiesis. In this review, we discuss the impact of vitamin C on the redox capacity of human erythrocytes and connect enterocyte function with iron metabolism, highlighting its effects on erythropoiesis.

Repurposing the antihistamine drug bilastine as an anti-cancer metallic drug entity: synthesis and single-crystal X-ray structure analysis of metal-based bilastine and phen [Co(II), Cu(II) and Zn(II)] tailored anticancer chemotherapeutic agents against resistant cancer cells

Bilastine (BLA), 2-(4-(2-(4-(1-(2-ethoxyethyl)-1H-benzo[d]imidazole-2-yl)-piperidin-1-yl)-ethyl)-phenyl)-2-methylpropanoic acid, is an active antihistamine drug. With the idea of repurposing drugs from the existing pool of 'active' pharmaceutical ingredients, the therapeutic potency of bilastine as an anticancer agent was investigated via the tailored synthesis of a metal-based anticancer drug formulation of the type [BLA(phen)2M(II)]+·X-, where M = Co, Cu, and Zn and X- = NO3 and ClO4. The synthesized metal-based chemotherapeutics derived from the bilastine drug that acts as a ligand were thoroughly characterized using spectroscopic techniques, namely, UV-vis, FT-IR, and EPR (in the case of 1 and 2); 1H-NMR and 13C-NMR (in the case of 3); ESI-MS and single-crystal X-ray diffraction studies. Comprehensive biological studies (DNA binding, cleavage, and cytotoxic activity) using various biophysical and gel electrophoretic methods were carried out to validate their potential as anticancer agents. The cytotoxic activity of 'therapeutically promising' copper(II)-based drug candidate 2 was evaluated against MCF-7, MBA-MD-231, HeLa, HepG2, and Mia-PaCa-2 cancer cells via an SRB assay, and the results demonstrated 2 as a potent anticancer agent at low nanomolar concentrations against all tested cancer cells, preferably with a much superior anticancer efficacy against human pancreatic cancer cells.

Targeting autophagy by antipsychotic phenothiazines: potential drug repurposing for cancer therapy

Cancer is recognized as the major cause of death worldwide and the most challenging public health issues. Tumor cells exhibit molecular adaptations and metabolic reprograming to sustain their high proliferative rate and autophagy plays a pivotal role to supply the high demand for metabolic substrates and for recycling cellular components, which has attracted the attention of the researchers. The modulation of the autophagic process sensitizes tumor cells to chemotherapy-induced cell death and reverts drug resistance. In this regard, many in vitro and in vivo studies having shown the anticancer activity of phenothiazine (PTZ) derivatives due to their potent cytotoxicity in tumor cells. Interestingly, PTZ have been used as antiemetics in antitumor chemotherapy-induced vomiting, maybe exerting a combined antitumor effect. Among the mechanisms of cytotoxicity, the modulation of autophagy by these drugs has been highlighted. Therefore, the use of PTZ derivatives can be considered as a repurposing strategy in antitumor chemotherapy. Here, we provided an overview of the effects of antipsychotic PTZ on autophagy in tumor cells, evidencing the molecular targets and discussing the underlying mechanisms. The modulation of autophagy by PTZ in tumor cells have been consistently related to their cytotoxic action. These effects depend on the derivative, their concentration, and also the type of cancer. Most data have shown the impairment of autophagic flux by PTZ, probably due to the blockade of lysosome-autophagosome fusion, but some studies have also suggested the induction of autophagy. These data highlight the therapeutic potential of targeting autophagy by PTZ in cancer chemotherapy.

Lysosomes in Cancer-At the Crossroad of Good and Evil

Although it has been known for decades that lysosomes are central for degradation and recycling in the cell, their pivotal role as nutrient sensing signaling hubs has recently become of central interest. Since lysosomes are highly dynamic and in constant change regarding content and intracellular position, fusion/fission events allow communication between organelles in the cell, as well as cell-to-cell communication via exocytosis of lysosomal content and release of extracellular vesicles. Lysosomes also mediate different forms of regulated cell death by permeabilization of the lysosomal membrane and release of their content to the cytosol. In cancer cells, lysosomal biogenesis and autophagy are increased to support the increased metabolism and allow growth even under nutrient- and oxygen-poor conditions. Tumor cells also induce exocytosis of lysosomal content to the extracellular space to promote invasion and metastasis. However, due to the enhanced lysosomal function, cancer cells are often more susceptible to lysosomal membrane permeabilization, providing an alternative strategy to induce cell death. This review summarizes the current knowledge of cancer-associated alterations in lysosomal structure and function and illustrates how lysosomal exocytosis and release of extracellular vesicles affect disease progression. We focus on functional differences depending on lysosomal localization and the regulation of intracellular transport, and lastly provide insight how new therapeutic strategies can exploit the power of the lysosome and improve cancer treatment.

The Efficacy of Cationic Amphiphilic Antihistamines on Outcomes of Patients with Pancreatic Ductal Adenocarcinoma

BACKGROUND

Cationic amphiphilic H1-antihistamines have demonstrated antitumor effects in preclinical studies. We conducted a retrospective cohort study to investigate their impact on patients with pancreatic adenocarcinoma (PDAC).

METHODS

We performed a matched cohort study involving PDAC patients from two tertiary centers in Taiwan using criteria including age, sex, and cancer stage. The primary outcome was overall survival (OS), and the secondary outcomes were progression-free survival (PFS) and objective response rates (ORR).

RESULTS

We matched 28 cationic amphiphilic antihistamine users with 56 non-cationic amphiphilic antihistamine users. Cationic amphiphilic antihistamine users showed significantly longer OS (median 16.4 [IQR, 2.8 - 89.0] vs.5.8 [IQR, 2.0 - 9.8] months; p<0.001) and PFS (median 12.2 [IQR, 2.2 - 83.3] vs. 5.2 [IQR, 1.7 - 8.4] months; p=0.002) compared to non-users. In the Cox proportional hazard models, the use of cationic amphiphilic antihistamines was associated with approximately 60% lower risk of all-cause mortality and disease progression. Additionally, cationic amphiphilic antihistamine users exhibited a significantly greater ORR than non-users (39% vs. 7%, p=0.004).

CONCLUSION

Our study suggests that cationic amphiphilic antihistamines are associated with improved survival outcomes in PDAC patients.

Emerging roles of lysosome homeostasis (repair, lysophagy and biogenesis) in cancer progression and therapy

In the era of personalized therapy, precise targeting of subcellular organelles holds great promise for cancer modality. Taking into consideration that lysosome represents the intersection site in numerous endosomal trafficking pathways and their modulation in cancer growth, progression, and resistance against cancer therapies, the lysosome is proposed as an attractive therapeutic target for cancer treatment. Based on the recent advances, the current review provides a comprehensive understanding of molecular mechanisms of lysosome homeostasis under 3R responses: Repair, Removal (lysophagy) and Regeneration of lysosomes. These arms of 3R responses have distinct role in lysosome homeostasis although their interdependency along with switching between the pathways still remain elusive. Recent advances underpinning the crucial role of (1) ESCRT complex dependent/independent repair of lysosome, (2) various Galectins-based sensing and ubiquitination in lysophagy and (3) TFEB/TFE proteins in lysosome regeneration/biogenesis of lysosome are outlined. Later, we also emphasised how these recent advancements may aid in development of phytochemicals and pharmacological agents for targeting lysosomes for efficient cancer therapy. Some of these lysosome targeting agents, which are now at various stages of clinical trials and patents, are also highlighted in this review.

Cationic amphiphilic drugs induce accumulation of cytolytic lysoglycerophospholipids in the lysosomes of cancer cells and block their recycling into common membrane glycerophospholipids

Lysosomes are acidic organelles responsible for lipid catabolism, and their functions can be disrupted by cationic amphiphilic drugs that neutralize lumenal pH and thereby inhibit most lysosomal hydrolases. These drugs can also induce lysosomal membrane permeabilization and cancer cell death, but the underlying mechanism remains elusive. Here, we uncover that the cationic amphiphilic drugs induce a substantial accumulation of cytolytic lysoglycerophospholipids within the lysosomes of cancer cells, and thereby prevent the recycling of lysoglycerophospholipids to produce common membrane glycerophospholipids. Using quantitative mass spectrometry-based shotgun lipidomics, we demonstrate that structurally diverse cationic amphiphilic drugs, along with other types of lysosomal pH-neutralizing reagents, elevate the amounts of lysoglycerophospholipids in MCF7 breast carcinoma cells. Lysoglycerophospholipids constitute ∼11 mol% of total glycerophospholipids in lysosomes purified from MCF7 cells, compared with ∼1 mol% in the cell lysates. Treatment with cationic amphiphilic drug siramesine further elevates the lysosomal lysoglycerophospholipid content to ∼24 mol% of total glycerophospholipids. Exogenously added traceable lysophosphatidylcholine is rapidly acylated to form diacylphosphatidylcholine, but siramesine treatment sequesters the lysophosphatidylcholine in the lysosomes and prevents it from undergoing acylation. These findings shed light on the unexplored role of lysosomes in the recycling of lysoglycerophospholipids and uncover the mechanism of action of promising anticancer agents.

The HN protein of Newcastle disease virus induces cell apoptosis through the induction of lysosomal membrane permeabilization

Lysosomes are acidic organelles that mediate the degradation and recycling of cellular waste materials. Damage to lysosomes can cause lysosomal membrane permeabilization (LMP) and trigger different types of cell death, including apoptosis. Newcastle disease virus (NDV) can naturally infect most birds. Additionally, it serves as a promising oncolytic virus known for its effective infection of tumor cells and induction of intensive apoptotic responses. However, the involvement of lysosomes in NDV-induced apoptosis remains poorly understood. Here, we demonstrate that NDV infection profoundly triggers LMP, leading to the translocation of cathepsin B and D and subsequent mitochondria-dependent apoptosis in various tumor and avian cells. Notably, the released cathepsin B and D exacerbate NDV-induced LMP by inducing the generation of reactive oxygen species. Additionally, we uncover that the viral Hemagglutinin neuraminidase (HN) protein induces the deglycosylation and degradation of lysosome-associated membrane protein 1 (LAMP1) and LAMP2 dependent on its sialidase activity, which finally contributes to NDV-induced LMP and cellular apoptosis. Overall, our findings elucidate the role of LMP in NDV-induced cell apoptosis and provide novel insights into the function of HN during NDV-induced LMP, which provide innovative approaches for the development of NDV-based oncolytic agents.

Loratidine is associated with improved prognosis and exerts antineoplastic effects via apoptotic and pyroptotic crosstalk in lung cancer

BACKGROUND

Tumor-associated inflammation suggests that anti-inflammatory medication could be beneficial in cancer therapy. Loratadine, an antihistamine, has demonstrated improved survival in certain cancers. However, the anticancer mechanisms of loratadine in lung cancer remain unclear.

OBJECTIVE

This study investigates the anticancer mechanisms of loratadine in lung cancer.

METHODS

A retrospective cohort of 4,522 lung cancer patients from 2006 to 2018 was analyzed to identify noncancer drug exposures associated with prognosis. Cellular experiments, animal models, and RNA-seq data analysis were employed to validate the findings and explore the antitumor effects of loratadine.

RESULTS

This retrospective study revealed a positive association between loratadine administration and ameliorated survival outcomes in lung cancer patients, exhibiting dose dependency. Rigorous in vitro and in vivo assays demonstrated that apoptosis induction and epithelial-mesenchymal transition (EMT) reduction were stimulated by moderate loratadine concentrations, whereas pyroptosis was triggered by elevated dosages. Intriguingly, loratadine was found to augment PPARγ levels, which acted as a gasdermin D transcription promoter and caspase-8 activation enhancer. Consequently, loratadine might incite a sophisticated interplay between apoptosis and pyroptosis, facilitated by the pivotal role of caspase-8.

CONCLUSION

Loratadine use is linked to enhanced survival in lung cancer patients, potentially due to its role in modulating the interplay between apoptosis and pyroptosis via caspase-8.

Molecular mechanism of antihistamines recognition and regulation of the histamine H1 receptor

Histamine receptors are a group of G protein-coupled receptors (GPCRs) that play important roles in various physiological and pathophysiological conditions. Antihistamines that target the histamine H1 receptor (H1R) have been widely used to relieve the symptoms of allergy and inflammation. Here, to uncover the details of the regulation of H1R by the known second-generation antihistamines, thereby providing clues for the rational design of newer antihistamines, we determine the cryo-EM structure of H1R in the apo form and bound to different antihistamines. In addition to the deep hydrophobic cavity, we identify a secondary ligand-binding site in H1R, which potentially may support the introduction of new derivative groups to generate newer antihistamines. Furthermore, these structures show that antihistamines exert inverse regulation by utilizing a shared phenyl group that inserts into the deep cavity and block the movement of the toggle switch residue W4286.48. Together, these results enrich our understanding of GPCR modulation and facilitate the structure-based design of novel antihistamines.

Immunogenic cell death (ICD) enhancers-Drugs that enhance the perception of ICD by dendritic cells

The search for immunostimulatory drugs applicable to cancer immunotherapy may profit from target-agnostic methods in which agents are screened for their functional impact on immune cells cultured in vitro without any preconceived idea on their mode of action. We have built a synthetic mini-immune system in which stressed and dying cancer cells (derived from standardized cell lines) are confronted with dendritic cells (DCs, derived from immortalized precursors) and CD8+ T-cell hybridoma cells expressing a defined T-cell receptor. Using this system, we can identify three types of immunostimulatory drugs: (i) pharmacological agents that stimulate immunogenic cell death (ICD) of malignant cells; (ii) drugs that act on DCs to enhance their response to ICD; and (iii) drugs that act on T cells to increase their effector function. Here, we focus on strategies to develop drugs that enhance the perception of ICD by DCs and to which we refer as "ICD enhancers." We discuss examples of ICD enhancers, including ligands of pattern recognition receptors (exemplified by TLR3 ligands that correct the deficient function of DCs lacking FPR1) and immunometabolic modifiers (exemplified by hexokinase-2 inhibitors), as well as methods for target deconvolution applicable to the mechanistic characterization of ICD enhancers.

Repositioning the antihistamine ebastine as an intracellular siRNA delivery enhancer

Small interfering RNAs (siRNAs) are promising therapeutics for the treatment of human diseases via the induction of sequence-specific gene silencing. To be functional, siRNAs require cytosolic delivery into target cells. However, state-of-the-art delivery systems mediate cellular entry through endocytosis and suffer from ineffective endosomal escape, routing a substantial fraction of the siRNA towards the lysosomal compartment. Cationic amphiphilic drugs (CADs) have been described to improve cytosolic siRNA delivery by the transient induction of lysosomal membrane permeabilization. In this work, we evaluated ebastine, an antihistamine CAD, for its ability to enhance cytosolic release of siRNA in a non-small cell lung cancer model. In particular, we demonstrated that ebastine can improve the siRNA-mediated gene silencing efficiency of a polymeric nanogel by 40-fold, outperforming other CAD compounds. Additionally, ebastine substantially enhanced gene knockdown of a cholesterol-conjugated siRNA, in two-dimensional (2D) cell culture as well as in three-dimensional (3D) tumor spheroids. Finally, ebastine could strongly promote siRNA delivery of lipid nanoparticles (LNPs) composed of a pH-dependent switchable ionizable lipid and with stable PEGylation, in contrast to state-of-the-art LNP formulations. Altogether, we identified ebastine as a potent and versatile siRNA delivery enhancer in cancer cells, which offers opportunities for drug combination therapy in oncology.

Desipramine induces eryptosis in human erythrocytes, an effect blunted by nitric oxide donor sodium nitroprusside and N-acetyl-L-cysteine but enhanced by Calcium depletion

Background: Desipramine a representative of tricyclic antidepressants (TCAs) promotes recovery of depressed patients by inhibition of reuptake of neurotransmitters serotonin (SER) and norepinephrine (NE) in the presynaptic membrane by directly blocking their respective transporters SERT and NET.Aims: To study the effect of desipramine on programmed erythrocyte death (eryptosis) and explore the underlying mechanisms.Methods: Phosphatidylserine (PS) exposure on the cell surface as marker of cell death was estimated from annexin-V-binding, cell volume from forward scatter in flow cytometry. Hemolysis was determined photometrically, and intracellular glutathione [GSH]i from high performance liquid chromatography.Results: Desipramine dose-dependently significantly enhanced the percentage of annexin-V-binding cells and didn´t impact glutathione (GSH) synthesis. Desipramine-induced eryptosis was significantly reversed by pre-treatment of erythrocytes with either nitric oxide (NO) donor sodium nitroprusside (SNP) or N-acetyl-L-cysteine (NAC). The highest inhibitory effect was obtained by using both inhibitors together. Calcium (Ca2+) depletion aggravated desipramine-induced eryptosis. Changing the order of treatment, i.e. desipramine first followed by inhibitors, could not influence the inhibitory effect of SNP or NAC.Conclusion: Antidepressants-caused intoxication can be treated by SNP and NAC, respectively. B) Patients with chronic hypocalcemia should not be treated with tricyclic anti-depressants or their dose should be noticeably reduced.

Real-Time Monitoring of Lysosomal Membrane Permeabilization Using Acridine Orange

Loss of lysosomal membrane integrity results in leakage of lysosomal hydrolases to the cytosol which might harm cell function and induce cell death. Destabilization of lysosomes often precede apoptotic or necrotic cell death and occur during both physiological and pathological conditions. The weak base acridine orange readily enters cells and accumulates in the acidic environment of lysosomes. Vital staining with acridine orange is a well-proven technique to observe lysosomal destabilization using fluorescence microscopy and flow cytometry. These analyses are, however, time consuming and only adapted for discrete time points, which make them unsuitable for large-scale approaches. Therefore, we have developed a time-saving, high-throughput microplate reader-based method to follow destabilization of the lysosomal membrane in real-time using acridine orange. This protocol can easily be adopted for patient samples since the number of cells per sample is low and the time for analysis is short.

Proapoptotic and proautophagy effect of H1-receptor antagonist desloratadine in human glioblastoma cell lines

Glioblastomas are aggressive and usually incurable high-grade gliomas without adequate treatment. In this study, we aimed to investigate the potential of desloratadine to induce apoptosis/autophagy as genetically regulated processes that can seal cancer cell fates. All experiments were performed on U251 human glioblastoma cell line and primary human glioblastoma cell culture. Cytotoxic effect of desloratadine was investigated using MTT and CV assays, while oxidative stress, apoptosis, and autophagy were detected by flow cytometry and immunoblot. Desloratadine treatment decreased cell viability of U251 human glioblastoma cell line and primary human glioblastoma cell culture (IC50 value 50 µM) by an increase of intracellular reactive oxygen species and caspase activity. Also, desloratadine decreased the expression of main autophagy repressor mTOR and its upstream activator Akt and increased the expression of AMPK. Desloratadine exerted dual cytotoxic effect inducing both apoptosis- and mTOR/AMPK-dependent cytotoxic autophagy in glioblastoma cells and primary glioblastoma cell culture.

Anticancer effects of ikarugamycin and astemizole identified in a screen for stimulators of cellular immune responses

BACKGROUND

Most immunotherapies approved for clinical use rely on the use of recombinant proteins and cell-based approaches, rendering their manufacturing expensive and logistics onerous. The identification of novel small molecule immunotherapeutic agents might overcome such limitations.

METHOD

For immunopharmacological screening campaigns, we built an artificial miniature immune system in which dendritic cells (DCs) derived from immature precursors present MHC (major histocompatibility complex) class I-restricted antigen to a T-cell hybridoma that then secretes interleukin-2 (IL-2).

RESULTS

The screening of three drug libraries relevant to known signaling pathways, FDA (Food and Drug Administration)-approved drugs and neuroendocrine factors yielded two major hits, astemizole and ikarugamycin. Mechanistically, ikarugamycin turned out to act on DCs to inhibit hexokinase 2, hence stimulating their antigen presenting potential. In contrast, astemizole acts as a histamine H1 receptor (H1R1) antagonist to activate T cells in a non-specific, DC-independent fashion. Astemizole induced the production of IL-2 and interferon-γ (IFN-γ) by CD4+ and CD8+ T cells both in vitro and in vivo. Both ikarugamycin and astemizole improved the anticancer activity of the immunogenic chemotherapeutic agent oxaliplatin in a T cell-dependent fashion. Of note, astemizole enhanced the CD8+/Foxp3+ ratio in the tumor immune infiltrate as well as IFN-γ production by local CD8+ T lymphocytes. In patients with cancer, high H1R1 expression correlated with low infiltration by TH1 cells, as well as with signs of T-cell exhaustion. The combination of astemizole and oxaliplatin was able to cure the majority of mice bearing orthotopic non-small cell lung cancers (NSCLC), then inducing a state of protective long-term immune memory. The NSCLC-eradicating effect of astemizole plus oxaliplatin was lost on depletion of either CD4+ or CD8+ T cells, as well as on neutralization of IFN-γ.

CONCLUSIONS

These findings underscore the potential utility of this screening system for the identification of immunostimulatory drugs with anticancer effects.

Current and novel approaches in the pharmacological treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most lethal malignant tumours worldwide. The mortality-to-incidence ratio is up to 91.6% in many countries, representing the third leading cause of cancer-related deaths. Systemic drugs, including the multikinase inhibitors sorafenib and lenvatinib, are first-line drugs used in HCC treatment. Unfortunately, these therapies are ineffective in most cases due to late diagnosis and the development of tumour resistance. Thus, novel pharmacological alternatives are urgently needed. For instance, immune checkpoint inhibitors have provided new approaches targeting cells of the immune system. Furthermore, monoclonal antibodies against programmed cell death-1 have shown benefits in HCC patients. In addition, drug combinations, including first-line treatment and immunotherapy, as well as drug repurposing, are promising novel therapeutic alternatives. Here, we review the current and novel pharmacological approaches to fight HCC. Preclinical studies, as well as approved and ongoing clinical trials for liver cancer treatment, are discussed. The pharmacological opportunities analysed here should lead to significant improvement in HCC therapy.

Ebastine impairs metastatic spread in triple-negative breast cancer by targeting focal adhesion kinase

We sought to investigate the utility of ebastine (EBA), a second-generation antihistamine with potent anti-metastatic properties, in the context of breast cancer stem cell (BCSC)-suppression in triple-negative breast cancer (TNBC). EBA binds to the tyrosine kinase domain of focal adhesion kinase (FAK), blocking phosphorylation at the Y397 and Y576/577 residues. FAK-mediated JAK2/STAT3 and MEK/ERK signaling was attenuated after EBA challenge in vitro and in vivo. EBA treatment induced apoptosis and a sharp decline in the expression of the BCSC markers ALDH1, CD44 and CD49f, suggesting that EBA targets BCSC-like cell populations while reducing tumor bulk. EBA administration significantly impeded BCSC-enriched tumor burden, angiogenesis and distant metastasis while reducing MMP-2/-9 levels in circulating blood in vivo. Our findings suggest that EBA may represent an effective therapeutic for the simultaneous targeting of JAK2/STAT3 and MEK/ERK for the treatment of molecularly heterogeneous TNBC with divergent profiles. Further investigation of EBA as an anti-metastatic agent for the treatment of TNBC is warranted.

Cationic amphiphilic antihistamines inhibit STAT3 via Ca2+-dependent lysosomal H+ efflux

Commonly used antihistamines and other cationic amphiphilic drugs (CADs) are emerging as putative cancer drugs. Their unique chemical structure enables CADs to accumulate rapidly inside lysosomes, where they increase lysosomal pH, alter lysosomal lipid metabolism, and eventually cause lysosomal membrane permeabilization. Here, we show that CAD-induced rapid elevation in lysosomal pH is caused by a lysosomal H+ efflux that requires P2RX4-mediated lysosomal Ca2+ release and precedes the lysosomal membrane permeabilization. The subsequent cytosolic acidification triggers the dephosphorylation, lysosomal translocation, and inactivation of the oncogenic signal transducer and activator of transcription 3 (STAT3) transcription factor. Moreover, CAD-induced lysosomal H+ efflux sensitizes cancer cells to apoptosis induced by STAT3 inhibition and acts synergistically with STAT3 inhibition in restricting the tumor growth of A549 non-small cell lung carcinoma xenografts. These findings identify lysosomal H+ efflux and STAT3 inhibition as anticancer mechanisms of CADs and reinforce the repurposing of safe and inexpensive CADs as cancer drugs with a drug combination strategy.

Macrophage and monocyte subsets as new therapeutic targets in cancer immunotherapy

The introduction of immune checkpoint inhibitors (ICIs) for the treatment of solid cancers dramatically turned the tables in clinical routine. However, therapy success is still limited with up to 70% of non-responders in patients with ICI treatment. Traditionally, most immunotherapy approaches aim at directly stimulating anti-tumor T cell responses. More recently, tumor-associated macrophages have come into focus due to their predominance in solid tumors. Intensive cross-talk with tumor cells and immune as well as stromal cells within the tumor microenvironment can drive either pro- or anti-tumorigenic macrophage phenotypes. In turn, tumor-associated macrophages strongly shape cytokine and metabolite levels in the tumor microenvironment and thus are central players in anti-tumor immunity. Thus, ambivalent macrophage populations exist which raises therapeutic possibilities to either enhance or diminish their functionality. However, molecular signals controlling tumor-associated macrophage polarization are incompletely understood. Gaining in-depth understanding of monocyte/macrophage properties both in circulation and within distinct tumor microenvironments would (i) allow the development of new therapeutic approaches, and (ii) could additionally aid our understanding of underlying mechanisms limiting current therapy with the option of combinatorial therapies to increase efficacy. In this review, we summarize recent data addressing heterogeneity of tumor-associated macrophage populations and we discuss strategies to target macrophages using known molecular pathways with the potential for straight-forward clinical application.

Lysosomes as a Target of Anticancer Therapy

Lysosomes are organelles containing acidic hydrolases that are responsible for lysosomal degradation and the maintenance of cellular homeostasis. They play an important role in autophagy, as well as in various cell death pathways, such as lysosomal and apoptotic death. Various agents, including drugs, can induce lysosomal membrane permeability, resulting in the translocation of acidic hydrolases into the cytoplasm, which promotes lysosomal-mediated death. This type of death may be of great importance in anti-cancer therapy, as both cancer cells with disturbed pathways leading to apoptosis and drug-resistant cells can undergo it. Important compounds that damage the lysosomal membrane include lysosomotropic compounds, antihistamines, immunosuppressants, DNA-damaging drugs, chemotherapeutics, photosensitizers and various plant compounds. An interesting approach in the treatment of cancer and the search for ways to overcome the chemoresistance of cancer cells may also be combining lysosomotropic compounds with targeted modulators of autophagy to induce cell death. These compounds may be an alternative in oncological treatment, and lysosomes may become a promising therapeutic target for many diseases, including cancer. Understanding the functional relationships between autophagy and apoptosis and the possibilities of their regulation, both in relation to normal and cancer cells, can be used to develop new and more effective anticancer therapies.

Ursolic Acid Impairs Cellular Lipid Homeostasis and Lysosomal Membrane Integrity in Breast Carcinoma Cells

Cancer is one of the leading causes of death worldwide, thus the search for new cancer therapies is of utmost importance. Ursolic acid is a naturally occurring pentacyclic triterpene with a wide range of pharmacological activities including anti-inflammatory and anti-neoplastic effects. The latter has been assigned to its ability to promote apoptosis and inhibit cancer cell proliferation by poorly defined mechanisms. In this report, we identify lysosomes as the essential targets of the anti-cancer activity of ursolic acid. The treatment of MCF7 breast cancer cells with ursolic acid elevates lysosomal pH, alters the cellular lipid profile, and causes lysosomal membrane permeabilization and leakage of lysosomal enzymes into the cytosol. Lysosomal membrane permeabilization precedes the essential hallmarks of apoptosis placing it as an initial event in the cascade of effects induced by ursolic acid. The disruption of the lysosomal function impairs the autophagic pathway and likely partakes in the mechanism by which ursolic acid kills cancer cells. Furthermore, we find that combining treatment with ursolic acid and cationic amphiphilic drugs can significantly enhance the degree of lysosomal membrane permeabilization and cell death in breast cancer cells.

Galactosyl- and glucosylsphingosine induce lysosomal membrane permeabilization and cell death in cancer cells

Isomeric lysosphingolipids, galactosylsphingosine (GalSph) and glucosylsphingosine (GlcSph), are present in only minute levels in healthy cells. Due to defects in their lysosomal hydrolysis, they accumulate at high levels and cause cytotoxicity in patients with Krabbe and Gaucher diseases, respectively. Here, we show that GalSph and GlcSph induce lysosomal membrane permeabilization, a hallmark of lysosome-dependent cell death, in human breast cancer cells (MCF7) and primary fibroblasts. Supporting lysosomal leakage as a causative event in lysosphingolipid-induced cytotoxicity, treatment of MCF7 cells with lysosome-stabilizing cholesterol prevented GalSph- and GlcSph-induced cell death almost completely. In line with this, fibroblasts from a patient with Niemann-Pick type C disease, which is caused by defective lysosomal cholesterol efflux, were significantly less sensitive to lysosphingolipid-induced lysosomal leakage and cell death. Prompted by the data showing that MCF7 cells with acquired resistance to lysosome-destabilizing cationic amphiphilic drugs (CADs) were partially resistant to the cell death induced by GalSph and GlcSph, we compared these cell death pathways with each other. Like CADs, GalSph and GlcSph activated the cyclic AMP (cAMP) signalling pathway, and cAMP-inducing forskolin sensitized cells to cell death induced by low concentrations of lysosphingolipids. Contrary to CADs, lysosphingolipid-induced cell death was independent of lysosomal Ca2+ efflux through P2X purinerigic receptor 4. These data reveal GalSph and GlcSph as lysosome-destabilizing lipids, whose putative use in cancer therapy should be further investigated. Furthermore, the data supports the development of lysosome stabilizing drugs for the treatment of Krabbe and Gaucher diseases and possibly other sphingolipidoses.

Prostate Cancer Cells Are Sensitive to Lysosomotropic Agent Siramesine through Generation Reactive Oxygen Species and in Combination with Tyrosine Kinase Inhibitors

BACKGROUND

Prostate cancer is the most common cancer affecting men often resulting in aggressive tumors with poor prognosis. Even with new treatment strategies, drug resistance often occurs in advanced prostate cancers. The use of lysosomotropic agents offers a new treatment possibility since they disrupt lysosomal membranes and can trigger a series of events leading to cell death. In addition, combining lysosomotropic agents with targeted inhibitors can induce increased cell death in different cancer types, but prostate cancer cells have not been investigated.

METHODS

We treated prostate cancer cells with lysosomotropic agents and determine their cytotoxicity, lysosome membrane permeabilization (LMP), reactive oxygen species (ROS) levels, and mitochondrial dysfunction. In addition, we treated cells with lysosomotropic agent in combination with tyrosine kinase inhibitor, lapatinib, and determined cell death, and the role of ROS in this cell death.

RESULTS

Herein, we found that siramesine was the most effective lysosomotropic agent at inducing LMP, increasing ROS, and inducing cell death in three different prostate cancer cell lines. Siramesine was also effective at increasing cell death in combination with the tyrosine kinase inhibitor, lapatinib. This increase in cell death was mediated by lysosome membrane permeabilization, an increased in ROS levels, loss of mitochondrial membrane potential and increase in mitochondrial ROS levels. The combination of siramesine and lapatinib induced apoptosis, cleavage of PARP and decreased expression of Bcl-2 family member Mcl-1. Furthermore, lipid peroxidation occurred with siramesine treatment alone or in combination with lapatinib. Treating cells with the lipid peroxidation inhibitor alpha-tocopherol resulted in reduced siramesine induced cell death alone or in combination with lapatinib. The combination of siramesine and lapatinib failed to increase cell death responses in normal prostate epithelial cells.

CONCLUSIONS

This suggests that lysomotropic agents such as siramesine in combination with tyrosine kinase inhibitors induces cell death mediated by ROS and could be an effective treatment strategy in advanced prostate cancer.

Efficacy of cationic amphiphilic antihistamines on outcomes of patients treated with immune checkpoint inhibitors

BACKGROUND

Cationic amphiphilic antihistamines have been shown to improve patient outcomes in immunogenic tumours, but whether they can augment and improve response to immunotherapy is unknown. We aim to evaluate the effect of cationic amphiphilic antihistamines in patients receiving immune checkpoint inhibitors (ICIs).

METHODS

We conducted a retrospective propensity score-matched cohort study at two tertiary referral centres in Taiwan between January 2015 and December 2021. Patients who received desloratadine, cyproheptadine, and ebastine were classified as cationic amphiphilic antihistamine users. The primary outcome was overall survival, and the secondary outcomes were progression-free survival and clinical benefit rate. Patients treated with cationic amphiphilic antihistamines were matched to patients who received non-cationic amphiphilic antihistamines based on variables including age, cancer type, stage, and history of allergic diseases.

RESULTS

A total of 734 ICI-treated patients were included. After matching, 68 cationic amphiphilic antihistamine and non-cationic amphiphilic antihistamine users remained for analysis. Compared with non-cationic amphiphilic antihistamine users, patients who received cationic amphiphilic antihistamines had a significantly longer median overall survival (24.8 versus 10.4 months; Log-rank, p = 0.018) and progression-free survival (10.6 versus 4.93 months; Log-rank, p = 0.004). The use of cationic amphiphilic antihistamines was associated with an approximately 50% lower risk of all-cause mortality (HR, 0.55 [95% CI: 0.34-0.91]). Survival benefits were not seen in patients who received cationic amphiphilic antihistamines before immune checkpoint blockade. These survival benefits were observed regardless of the generation of cationic amphiphilic antihistamines.

CONCLUSION

The use of cationic amphiphilic antihistamines was associated with improved survival among patients treated with immunotherapy.

Loratadine, an antihistaminic drug, suppresses the proliferation of endometrial stromal cells by inhibition of TRPV2

The transient receptor potential (TRP) channel TRPV2 is widely expressed in a variety of different cell types and tissues. However, elucidating the exact biological functions of TRPV2 is significantly hampered by the lack of selective pharmacological tools to modulate channel activity in vitro and in vivo. This study aimed to identify new compounds that modify TRPV2 activity via the use of a plate-based calcium imaging approach to screen a drug repurposing library. Three antihistaminic drugs, loratadine, astemizole and clemizole were identified to reduce calcium-influx evoked by the TRPV2 agonist tetrahydrocannabivarin in HEK293 cells expressing murine TRPV2. Using single-cell calcium-microfluorimetry and whole-cell patch clamp recordings, we further confirmed that all three compounds induced a concentration-dependent block of TRPV2-mediated Ca²⁺ influx and whole-cell currents, with loratadine being the most potent antagonist of TRPV2. Moreover, this study demonstrated that loratadine was able to block both the human and mouse TRPV2 orthologs, without inhibiting the activity of other closely related members of the TRPV superfamily. Finally, loratadine inhibited TRPV2-dependent responses in a primary culture of mouse endometrial stromal cells and attenuated cell proliferation and migration in in vitro cell proliferation and wound healing assays. Taken together, our study revealed that the antihistaminic drugs loratadine, astemizole and clemizole target TRPV2 in a concentration-dependent manner. The identification of these antihistaminic drugs as blockers of TRPV2 may form a new starting point for the synthesis of more potent and selective TRPV2 antagonists, which could further lead to the unravelling of the physiological role of the channel.

The Multidirectional Effect of Azelastine Hydrochloride on Cervical Cancer Cells

A major cause of cancer cell resistance to chemotherapeutics is the blocking of apoptosis and induction of autophagy in the context of cell adaptation and survival. Therefore, new compounds are being sought, also among drugs that are commonly used in other therapies. Due to the involvement of histamine in the regulation of processes occurring during the development of many types of cancer, antihistamines are now receiving special attention. Our study concerned the identification of new mechanisms of action of azelastine hydrochloride, used in antiallergic treatment. The study was performed on HeLa cells treated with different concentrations of azelastine (15-90 µM). Cell cycle, level of autophagy (LC3 protein activity) and apoptosis (annexin V assay), activity of caspase 3/7, anti-apoptotic protein of Bcl-2 family, ROS concentration, measurement of mitochondrial membrane potential (Δψm), and level of phosphorylated H2A.X in response to DSB were evaluated by cytometric method. Cellular changes were also demonstrated at the level of transmission electron microscopy and optical and fluorescence microscopy. Lysosomal enzyme activities-cathepsin D and L and cell viability (MTT assay) were assessed spectrophotometrically. Results: Azelastine in concentrations of 15-25 µM induced degradation processes, vacuolization, increase in cathepsin D and L activity, and LC3 protein activation. By increasing ROS, it also caused DNA damage and blocked cells in the S phase of the cell cycle. At the concentrations of 45-90 µM, azelastine clearly promoted apoptosis by activation of caspase 3/7 and inactivation of Bcl-2 protein. Fragmentation of cell nucleus was confirmed by DAPI staining. Changes were also found in the endoplasmic reticulum and mitochondria, whose damage was confirmed by staining with rhodamine 123 and in the MTT test. Azelastine decreased the mitotic index and induced mitotic catastrophe. Studies demonstrated the multidirectional effects of azelastine on HeLa cells, including anti-proliferative, cytotoxic, autophagic, and apoptotic properties, which were the predominant mechanism of death. The revealed novel properties of azelastine may be practically used in anti-cancer therapy in the future.

Chemical Interrogation of Nuclear Size Identifies Compounds with Cancer Cell Line-Specific Effects on Migration and Invasion

Background: Lower survival rates for many cancer types correlate with changes in nuclear size/scaling in a tumor-type/tissue-specific manner. Hypothesizing that such changes might confer an advantage to tumor cells, we aimed at the identification of commercially available compounds to guide further mechanistic studies. We therefore screened for Food and Drug Administration (FDA)/European Medicines Agency (EMA)-approved compounds that reverse the direction of characteristic tumor nuclear size changes in PC3, HCT116, and H1299 cell lines reflecting, respectively, prostate adenocarcinoma, colonic adenocarcinoma, and small-cell squamous lung cancer. Results: We found distinct, largely nonoverlapping sets of compounds that rectify nuclear size changes for each tumor cell line. Several classes of compounds including, e.g., serotonin uptake inhibitors, cyclo-oxygenase inhibitors, β-adrenergic receptor agonists, and Na⁺/K⁺ ATPase inhibitors, displayed coherent nuclear size phenotypes focused on a particular cell line or across cell lines and treatment conditions. Several compounds from classes far afield from current chemotherapy regimens were also identified. Seven nuclear size-rectifying compounds selected for further investigation all inhibited cell migration and/or invasion. Conclusions: Our study provides (a) proof of concept that nuclear size might be a valuable target to reduce cell migration/invasion in cancer treatment and (b) the most thorough collection of tool compounds to date reversing nuclear size changes specific to individual cancer-type cell lines. Although these compounds still need to be tested in primary cancer cells, the cell line-specific nuclear size and migration/invasion responses to particular drug classes suggest that cancer type-specific nuclear size rectifiers may help reduce metastatic spread.

Repurposing non-oncology small-molecule drugs to improve cancer therapy: Current situation and future directions

Drug repurposing or repositioning has been well-known to refer to the therapeutic applications of a drug for another indication other than it was originally approved for. Repurposing non-oncology small-molecule drugs has been increasingly becoming an attractive approach to improve cancer therapy, with potentially lower overall costs and shorter timelines. Several non-oncology drugs approved by FDA have been recently reported to treat different types of human cancers, with the aid of some new emerging technologies, such as omics sequencing and artificial intelligence to overcome the bottleneck of drug repurposing. Therefore, in this review, we focus on summarizing the therapeutic potential of non-oncology drugs, including cardiovascular drugs, microbiological drugs, small-molecule antibiotics, anti-viral drugs, anti-inflammatory drugs, anti-neurodegenerative drugs, antipsychotic drugs, antidepressants, and other drugs in human cancers. We also discuss their novel potential targets and relevant signaling pathways of these old non-oncology drugs in cancer therapies. Taken together, these inspiring findings will shed new light on repurposing more non-oncology small-molecule drugs with their intricate molecular mechanisms for future cancer drug discovery.

H1-Antihistamines Reduce the Risk of Hepatocellular Carcinoma in Patients With Hepatitis B Virus, Hepatitis C Virus, or Dual Hepatitis B Virus-Hepatitis C Virus Infection

H1-antihistamines (AHs) may exert protective effects against cancer. This study investigated the association of AH use with the risk of hepatocellular carcinoma (HCC) in patients with hepatitis B virus (HBV), hepatitis C virus (HCV), or dual HBV-HCV virus infection.

Glioblastoma cytotoxicity conferred through dual disruption of endolysosomal homeostasis by Vacquinol-1

Background

Increased membrane trafficking is observed in numerous cancer types, including glioblastoma. Targeting the oncogenic driven acquired alterations in membrane trafficking by synthetic cationic amphiphilic small molecules has recently been shown to induce death of glioblastoma cells, although the molecular targets are unknown.

Methods

The mechanism of action of the cationic amphiphilic drug Vacquinol-1 (Vacq1)-induced cytotoxicity was investigated using cell biology, biochemistry, functional experiments, chemical biology, unbiased antibody-based post-translation modification profiling, and mass spectrometry-based chemical proteomic analysis on patient-derived glioblastoma cells.

Results

Vacq1 induced two types of abnormal endolysosomal vesicles, enlarged vacuoles and acidic vesicle organelles (AVOs). Mechanistically, enlarged vacuoles were formed by the impairment of lysosome reformation through the direct interaction and inhibition of calmodulin (CaM) by Vacq1, while AVO formation was induced by Vacq1 accumulation and acidification in the endosomal compartments through its activation of the v-ATPase. As a consequence of v-ATPase activation, cellular ATP consumption markedly increased, causing cellular energy shortage and cytotoxicity. This effect of Vacq1 was exacerbated by its inhibitory effects on calmodulin, causing lysosomal depletion and a failure of acidic vesicle organelle clearance.

Conclusion

Our study identifies the targets of Vacq1 and the mechanisms underlying its selective cytotoxicity in glioblastoma cells. The dual function of Vacq1 sets in motion a glioblastoma-specific vicious cycle of ATP consumption resulting in cellular energy crisis and cell death.

Lipid Cubic Systems for Sustained and Controlled Delivery of Antihistamine Drugs

Antihistamines are capable of blocking mediator responses in allergic reactions including allergic rhinitis and dermatological reactions. By incorporating various H1 receptor antagonists into a lipid cubic phase network, these active ingredients can be delivered locally over an extended period of time owing to the mucoadhesive nature of the system. Local delivery can avoid inducing unwanted side effects, often observed after systematic delivery. Lipid-based antihistamine delivery systems are shown here to exhibit prolonged release capabilities. In vitro drug dissolution studies investigated the extent and release rate of two model first-generation and two model second-generation H1 antagonist antihistamine drugs from two monoacyglycerol-derived lipid models. To optimize the formulation approach, the systems were characterized macroscopically and microscopically by small-angle X-ray scattering and polarized light to ascertain the mesophase accessed upon an incorporation of antihistamines of varying solubilities and size. The impact of encapsulating the antihistamine molecules on the degree of mucoadhesivity of the lipid cubic systems was investigated using multiparametric surface plasmon resonance. With the ultimate goal of developing therapies for the treatment of allergic reactions, the ability of the formulations to inhibit mediator release utilizing RBL-2H3 mast cells with the propensity to release histamine upon induction was explored, demonstrating no interference from the lipid excipient on the effectiveness of the antihistamine molecules.

Blockade of Glycosphingolipid Synthesis Inhibits Cell Cycle and Spheroid Growth of Colon Cancer Cells In Vitro and Experimental Colon Cancer Incidence In Vivo

Colorectal cancer (CRC) is one of the most frequently diagnosed cancers in humans. At early stages CRC is treated by surgery and at advanced stages combined with chemotherapy. We examined here the potential effect of glucosylceramide synthase (GCS)-inhibition on CRC biology. GCS is the rate-limiting enzyme in the glycosphingolipid (GSL)-biosynthesis pathway and overexpressed in many human tumors. We suppressed GSL-biosynthesis using the GCS inhibitor Genz-123346 (Genz), NB-DNJ (Miglustat) or by genetic targeting of the GCS-encoding gene UDP-glucose-ceramide-glucosyltransferase- (UGCG). GCS-inhibition or GSL-depletion led to a marked arrest of the cell cycle in Lovo cells. UGCG silencing strongly also inhibited tumor spheroid growth in Lovo cells and moderately in HCT116 cells. MS/MS analysis demonstrated markedly elevated levels of sphingomyelin (SM) and phosphatidylcholine (PC) that occurred in a Genz-concentration dependent manner. Ultrastructural analysis of Genz-treated cells indicated multi-lamellar lipid storage in vesicular compartments. In mice, Genz lowered the incidence of experimentally induced colorectal tumors and in particular the growth of colorectal adenomas. These results highlight the potential for GCS-based inhibition in the treatment of CRC.

Valosin-Containing Protein (VCP)/p97: A Prognostic Biomarker and Therapeutic Target in Cancer

Valosin-containing protein (VCP)/p97, a member of the AAA+ ATPase family, is a molecular chaperone recruited to the endoplasmic reticulum (ER) membrane by binding to membrane adapters (nuclear protein localization protein 4 (NPL4), p47 and ubiquitin regulatory X (UBX) domain-containing protein 1 (UBXD1)), where it is involved in ER-associated protein degradation (ERAD). However, VCP/p97 interacts with many cofactors to participate in different cellular processes that are critical for cancer cell survival and aggressiveness. Indeed, VCP/p97 is reported to be overexpressed in many cancer types and is considered a potential cancer biomarker and therapeutic target. This review summarizes the role of VCP/p97 in different cancers and the advances in the discovery of small-molecule inhibitors with therapeutic potential, focusing on the challenges associated with cancer-related VCP mutations in the mechanisms of resistance to inhibitors.

Pathophysiological Roles of Histamine Receptors in Cancer Progression: Implications and Perspectives as Potential Molecular Targets

High levels of histamine and histamine receptors (HRs), including H1R~H4R, are found in many different types of tumor cells and cells in the tumor microenvironment, suggesting their involvement in tumor progression. This review summarizes the latest evidence demonstrating the pathophysiological roles of histamine and its cognate receptors in cancer biology. We also discuss the novel therapeutic approaches of selective HR ligands and their potential prognostic values in cancer treatment. Briefly, histamine is highly implicated in cancer development, growth, and metastasis through interactions with distinct HRs. It also regulates the infiltration of immune cells into the tumor sites, exerting an immunomodulatory function. Moreover, the effects of various HR ligands, including H1R antagonists, H2R antagonists, and H4R agonists, on tumor progression in many different cancer types are described. Interestingly, the expression levels of HR subtypes may serve as prognostic biomarkers in several cancers. Taken together, HRs are promising targets for cancer treatment, and HR ligands may offer novel therapeutic potential, alone or in combination with conventional therapy. However, due to the complexity of the pathophysiological roles of histamine and HRs in cancer biology, further studies are warranted before HR ligands can be introduced into clinical settings.

Phenothiazines alter plasma membrane properties and sensitize cancer cells to injury by inhibiting annexin-mediated repair

Repair of damaged plasma membrane in eukaryotic cells is largely dependent on the binding of annexin repair proteins to phospholipids. Changing the biophysical properties of the plasma membrane may provide means to compromise annexin-mediated repair and sensitize cells to injury. Since, cancer cells experience heightened membrane stress and are more dependent on efficient plasma membrane repair, inhibiting repair may provide approaches to sensitize cancer cells to plasma membrane damage and cell death. Here, we show that derivatives of phenothiazines, which have widespread use in the fields of psychiatry and allergy treatment, strongly sensitize cancer cells to mechanical-, chemical-, and heat-induced injury by inhibiting annexin-mediated plasma membrane repair. Using a combination of cell biology, biophysics, and computer simulations, we show that trifluoperazine acts by thinning the membrane bilayer, making it more fragile and prone to ruptures. Secondly, it decreases annexin binding by compromising the lateral diffusion of phosphatidylserine, inhibiting the ability of annexins to curve and shape membranes, which is essential for their function in plasma membrane repair. Our results reveal a novel avenue to target cancer cells by compromising plasma membrane repair in combination with noninvasive approaches that induce membrane injuries.

OPALS: A New Osimertinib Adjunctive Treatment of Lung Adenocarcinoma or Glioblastoma Using Five Repurposed Drugs

Background: Pharmacological targeting aberrant activation of epidermal growth factor receptor tyrosine kinase signaling is an established approach to treating lung adenocarcinoma. Osimertinib is a tyrosine kinase approved and effective in treating lung adenocarcinomas that have one of several common activating mutations in epidermal growth factor receptor. The emergence of resistance to osimertinib after a year or two is the rule. We developed a five-drug adjuvant regimen designed to increase osimertinib’s growth inhibition and thereby delay the development of resistance. Areas of Uncertainty: Although the assembled preclinical data is strong, preclinical data and the following clinical trial results can be discrepant. The safety of OPALS drugs when used individually is excellent. We have no data from humans on their tolerability when used as an ensemble. That there is no data from the individual drugs to suspect problematic interaction does not exclude the possibility. Data Sources: All relevant PubMed.org articles on the OPALS drugs and corresponding pathophysiology of lung adenocarcinoma and glioblastoma were reviewed. Therapeutic Opinion: The five drugs of OPALS are in wide use in general medicine for non-oncology indications. OPALS uses the anti-protozoal drug pyrimethamine, the antihistamine cyproheptadine, the antibiotic azithromycin, the antihistamine loratadine, and the potassium sparing diuretic spironolactone. We show how these inexpensive and generically available drugs intersect with and inhibit lung adenocarcinoma growth drive. We also review data showing that both OPALS adjuvant drugs and osimertinib have data showing they may be active in suppressing glioblastoma growth.

The Contribution of Lysosomes to DNA Replication

Lysosomes, acidic, membrane-bound organelles, are not only the core of the cellular recycling machinery, but they also serve as signaling hubs regulating various metabolic pathways. Lysosomes maintain energy homeostasis and provide pivotal substrates for anabolic processes, such as DNA replication. Every time the cell divides, its genome needs to be correctly duplicated; therefore, DNA replication requires rigorous regulation. Challenges that negatively affect DNA synthesis, such as nucleotide imbalance, result in replication stress with severe consequences for genome integrity. The lysosomal complex mTORC1 is directly involved in the synthesis of purines and pyrimidines to support DNA replication. Numerous drugs have been shown to target lysosomal function, opening an attractive avenue for new treatment strategies against various pathologies, including cancer. In this review, we focus on the interplay between lysosomal function and DNA replication through nucleic acid degradation and nucleotide biosynthesis and how these could be exploited for therapeutic purposes.

Antihistamines and Ovarian Cancer Survival: Nationwide Cohort Study and in Vitro Cell Viability Assay

Antihistamines with cationic amphiphilic drug (CAD) characteristics induce cancer-specific cell death in experimental studies. Epidemiologic evidence is, however, limited. In a Danish nationwide cohort of ovarian cancer patients diagnosed during 2000-2015 (n = 5075), we evaluated the association between filled antihistamine prescriptions and cancer mortality. We used Cox regression models to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) for ovarian cancer mortality. In an in vitro cell viability assay, we evaluated cell death in three ovarian cancer cell lines after treatment with clinically relevant doses of eight antihistamines. In our cohort study, CAD antihistamine use (≥1 prescription; n = 133) was associated with a hazard ratio of 0.63 (95% CI = 0.40 to 0.99) compared to use of non-CAD antihistamines (n = 304), and we found a tendency toward a dose-response association. In our cell viability assay, we found consistent and dose-dependent cytotoxicity for all CAD but not non-CAD antihistamines. In this nationwide cohort study, use of antihistamines with CAD characteristics is associated with a prognostic benefit in ovarian cancer patients.

Lysosomes and Cancer Progression: A Malignant Liaison

During primary tumorigenesis isolated cancer cells may undergo genetic or epigenetic changes that render them responsive to additional intrinsic or extrinsic cues, so that they enter a transitional state and eventually acquire an aggressive, metastatic phenotype. Among these changes is the alteration of the cell metabolic/catabolic machinery that creates the most permissive conditions for invasion, dissemination, and survival. The lysosomal system has emerged as a crucial player in this malignant transformation, making this system a potential therapeutic target in cancer. By virtue of their ubiquitous distribution in mammalian cells, their multifaced activities that control catabolic and anabolic processes, and their interplay with other organelles and the plasma membrane (PM), lysosomes function as platforms for inter- and intracellular communication. This is due to their capacity to adapt and sense nutrient availability, to spatially segregate specific functions depending on their position, to fuse with other compartments and with the PM, and to engage in membrane contact sites (MCS) with other organelles. Here we review the latest advances in our understanding of the role of the lysosomal system in cancer progression. We focus on how changes in lysosomal nutrient sensing, as well as lysosomal positioning, exocytosis, and fusion perturb the communication between tumor cells themselves and between tumor cells and their microenvironment. Finally, we describe the potential impact of MCS between lysosomes and other organelles in propelling cancer growth and spread.