Evaluation of cationic channel TRPV2 as a novel biomarker and therapeutic target in Leukemia-Implications concerning the resolution of pulmonary inflammation

Identification of Prognostic and Immune Characteristics of Two Lung Adenocarcinoma Subtypes Based on TRPV Channel Family Genes

Lung adenocarcinoma (LUAD) is one of the deadliest malignant tumors worldwide. Transient receptor potential vanilloid (TRPV) channels take pivotal parts in many cancers, but their impact on LUAD remains unexplored. In this study, LUAD samples were classified into two subtypes according to the expression characteristics of TRPV1-6 genes, with LUAD subtype cluster2 exhibiting significantly higher survival rates than cluster1. Subsequently, analysis of differentially expressed genes (DEGs) was performed between cluster1 and cluster2, revealing enrichment of DEGs in channel activity and Ca2+ signaling pathways. We established a protein-protein interaction network based on DEGs and constructed a LUAD prognostic model by using Cox regression analysis based on genes corresponding to 170 protein nodes. The prognostic model demonstrated good predictive ability for patient prognosis, with higher survival rates observed in the low-risk (LR) group. The risk score was validated as an independent prognostic indicator, according to Cox regression analysis. A clinically applicable nomogram was plotted. Immunological analysis indicated that the LR and high-risk (HR) groups had varied proportions of immune cell infiltration. The immunotherapy prediction indicated that LUAD patients in LR group had a greater likelihood to benefit from immune checkpoint blockade therapy. Furthermore, we hypothesized that the expression patterns of feature genes in the LUAD model were related to the sensitivity to lung cancer therapeutic drugs TAS-6417 and Erlotinib. To sum up, our LUAD prognostic model possessed clinical applicability for prognosis and immunotherapy response prediction.

Mechanism of anti-hyperuricemia of isobavachin based on network pharmacology and molecular docking

BACKGROUND

Hyperuricemia is a more popular metabolic disease caused by a disorder of purine metabolism. Our previous study firstly screened out a natural product Isobavachin as anti-hyperuricemia targeted hURAT1 from a Chinese medicine Haitongpi (Cortex Erythrinae). In view of Isobavachin's diverse pharmacological activities, similar to the Tranilast (as another hURAT1 inhibitor), our study focused on its potential targets and molecular mechanisms of Isobavachin anti-hyperuricemia based on network pharmacology and molecular docking.

METHODS

First of all, the putative target genes of compounds were screen out based on the public databases with different methods, such as SwissTargetPerdiction, PharmMapper and TargetNet,etc. Then the compound-pathways were obtained by the compounds' targets gene from David database for Gene Ontology (GO) function enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enrichment analysis. The cross pathways of compound-pathways and the diseases pathways of hyperuricemia from Comparative Toxicogenomics Database were be considered as the compound-disease pathways. Next, based on the compound-disease pathways and the PPI network, the core targets were identified based on the retrieved disease-genes. Finally, the compound-target-pathway-disease network was constructed by Cytoscape and the mechanism of isobavachin anti-hyperuricemia was discussed based on the network analysis.

RESULTS

Our study demonstrated that there were five pathways involved in Isobavachin against hyperuricemia, including Drug metabolism-other enzymes, Metabolic pathways, Bile secretion, Renin-angiotensin system and Renin secretion. Among the proteins involved in these pathways, HPRT1, REN and ABCG2 were identified as the core targets associated with hyperuricemia, which regulated the five pathways mentioned above. It is quite different from that of Tranilast, which involved in the same pathways except Bile secretion instead of purine metabolism.

CONCLUSION

This study revealed Isobavachin could regulate the pathways including Drug metabolism-other enzymes, Metabolic pathways, Bile secretion, Renin-angiotensin system, Renin secretion by core targets HPRT1, REN and ABCG2, in the treatment of hyperuricemia effect. Among them, the Bile secretion regulated by ABCG2 probably would be a novel pathway. Our work provided a theoretical basis for the pharmacological study of Isobavachin in lowering uric acid and further basic research.

Deregulated calcium signaling in blood cancer: Underlying mechanisms and therapeutic potential

Intracellular calcium signaling regulates diverse physiological and pathological processes. In solid tumors, changes to calcium channels and effectors via mutations or changes in expression affect all cancer hallmarks. Such changes often disrupt transport of calcium ions (Ca²⁺) in the endoplasmic reticulum (ER) or mitochondria, impacting apoptosis. Evidence rapidly accumulates that this is similar in blood cancer. Principles of intracellular Ca²⁺ signaling are outlined in the introduction. We describe different Ca²⁺-toolkit components and summarize the unique relationship between extracellular Ca²⁺ in the endosteal niche and hematopoietic stem cells. The foundational data on Ca²⁺ homeostasis in red blood cells is discussed, with the demonstration of changes in red blood cell disorders. This leads to the role of Ca²⁺ in neoplastic erythropoiesis. Then we expand onto the neoplastic impact of deregulated plasma membrane Ca²⁺ channels, ER Ca²⁺ channels, Ca²⁺ pumps and exchangers, as well as Ca²⁺ sensor and effector proteins across all types of hematologic neoplasms. This includes an overview of genetic variants in the Ca²⁺-toolkit encoding genes in lymphoid and myeloid cancers as recorded in publically available cancer databases. The data we compiled demonstrate that multiple Ca²⁺ homeostatic mechanisms and Ca²⁺ responsive pathways are altered in hematologic cancers. Some of these alterations may have genetic basis but this requires further investigation. Most changes in the Ca²⁺-toolkit do not appear to define/associate with specific disease entities but may influence disease grade, prognosis, treatment response, and certain complications. Further elucidation of the underlying mechanisms may lead to novel treatments, with the aim to tailor drugs to different patterns of deregulation. To our knowledge this is the first review of its type in the published literature. We hope that the evidence we compiled increases awareness of the calcium signaling deregulation in hematologic neoplasms and triggers more clinical studies to help advance this field.

The effects of cannabidiol via TRPV2 channel in chronic myeloid leukemia cells and its combination with imatinib

Chronic myeloid leukemia (CML) is a myeloproliferative disorder characterized by accumulation of immature cells in bone marrow and peripheral blood. Although successful results were obtained with tyrosine kinase inhibitors, several patients showed resistance. For this reason, the identification of new strategies and therapeutic biomarkers represents an attractive goal. The role of transient receptor potential (TRP) ion channels as possible drug targets has been elucidated in different types of cancer. Among natural compounds known to activate TRPs, cannabidiol (CBD) displays anticancer properties. By using FACS analysis, confocal microscopy, gene silencing, and cell growth assay, we demonstrated that CBD, through TRPV2, inhibits cell proliferation and cell cycle in CML cells. It promoted mitochondria dysfunction and mitophagy as shown by mitochondrial mass reduction and up‐regulation of several mitophagy markers. These effects were associated with changes in the expression of octamer‐binding transcription factor 4 and PU.1 markers regulated during cellular differentiation. Interestingly, a synergistic effect by combining CBD with the standard drug imatinib was found and imatinib‐resistant cells remain susceptible to CBD effects. Therefore, the targeting of TRPV2 by using CBD, through the activation of mitophagy and the reduction in stemness, could be a promising strategy to enhance conventional therapy and improve the prognosis of CML patients.

Transient receptor potential cation channel subfamily V (TRPV) and its importance in asthma

Transient receptor potential (TRP) ion channels play critical roles in physiological and pathological conditions. Increasing evidence has unveiled the contribution of TRP vanilloid (TRPV) family in the development of asthma. The TRPV family is a group (TRPV1-TRPV6) of polymodal channels capable of sensing thermal, acidic, mechanical stress, and osmotic stimuli. TRPVs can be activated by endogenous ligands including, arachidonic acid derivatives or endocannabinoids. While TRPV1-TRPV4 are non-selective cation channels showing a predominance for Ca²⁺ over Na ⁺ influx, TRPV5 and TRPV6 are only Ca²⁺ permeable selective channels. Asthma is a chronic inflammatory bronchopulmonary disorder involving airway hyperresponsiveness (AHR) and airway remodeling. Patients suffering from allergic asthma display an inflammatory pattern driven by cytokines produced in type-2 helper T cells (Th2) and type 2 innate lymphoid cells (ILC2s). Ion channels are essential regulators in airway smooth muscle (ASM) and immune cells physiology. In this review, we summarize the contribution of TRPV1, TRPV2, and TRPV4 to the pathogenesis of asthma. TRPV1 is associated with hypersensitivity to environmental pollutants and chronic cough, inflammation, AHR, and remodeling. TRPV2 is increased in peripheral lymphocytes of asthmatic patients. TRPV4 contributes to ASM cells proliferation, and its blockade leads to a reduced eosinophilia, neutrophilia, as well as an abolished AHR. In conclusion, TRPV2 may represent a novel biomarker for asthma in children; meanwhile, TRPV1 and TRPV4 seem to be essential contributors to the development and exacerbations of asthma. Moreover, these channels may serve as novel therapeutic targets for this ailment.

Cationic Channel TRPV2 Overexpression Promotes Resistance to Cisplatin-Induced Apoptosis in Gastric Cancer Cells

Gastric cancer (GC) is characterized by poor efficacy and modest clinical impact of current therapies, in which apoptosis evasion is relevant. Intracellular calcium homeostasis dysregulation is associated with apoptosis escaping, and aberrant expression of calcium regulator genes could promote GC drug resistance. Since we previously found a prognostic value for TRPV2 calcium channel expression in GC, we aimed to characterize the role of TRPV2 in cisplatin resistance. Using the TCGA-STAD dataset, we performed a differential gene expression analysis between GC samples in upper and lower tertiles of TRPV2 expression, and then through a gene set analysis, we highlighted the enriched ontology and canonical pathways. We used qRT-PCR to assess TRPV2 expression in three GC cell lines and flow cytometry to evaluate cisplatin-induced cell death rates. Calcium green-1-AM assay was used to estimate differences in intracellular Ca²⁺ concentrations after inhibition of TRPV2. We engineered AGS cell line to overexpress TRPV2 and used confocal microscopy to quantify its overexpression and localization and flow cytometry to evaluate their sensitivity to cisplatin. Consistent with our hypothesis, among enriched gene sets, we found a significant number of those involved in the regulation of apoptosis. Subsequently, we found an inverse correlation between TRPV2 expression and sensitivity to cisplatin in GC cell lines. Moreover, we demonstrated that inhibition of TRPV2 activity by tranilast blocks the efflux of Ca²⁺ ions and, in combination with cisplatin, induced a significant increase of apoptotic cells (p = 0.004). We also demonstrated that TRPV2 exogenous expression confers a drug-resistant phenotype, and that tranilast is able to revert this phenotype, restoring cisplatin sensitivity. Our findings consistently suggested that TRPV2 could be a potential target for overcoming cisplatin resistance by promoting apoptosis. Notably, our data are a prerequisite for the potential reposition of tranilast to the treatment of GC patients and anticipate the in vivo evaluation.

Tranilast, a Transient Receptor Potential Vanilloid 2 Channel (TRPV2) Inhibitor Attenuates Amyloid β-Induced Cognitive Impairment: Possible Mechanisms

Alzheimer's disease (AD) is associated with the accumulation of β-amyloid and leads to cognitive impairment. Numerous studies have established that neuronal calcium homeostasis is perturbed in AD. Recently, transient receptor potential vanilloid 2 (TRPV2) channels, a non-selective calcium-permeable channel, have been investigated in several diseases. However, the role of the TRPV2 channel has not been investigated in AD yet. In this study, intracerebroventricular administration of β-amyloid (10 μg) to Sprague Dawley rats resulted in cognitive impairment which was evident from the assessment of cognitive tests. Also, TRPV2 mRNA and protein expression were found to be upregulated, while the expression of Ca^2+/calmodulin-dependent protein kinase II (p-CaMKII-Thr-286), glycogen synthase kinase 3β (p-GSK-3β-Ser-9), cAMP response element-binding protein (p-CREB-Ser-133), and postsynaptic density protein 95 (PSD-95) were downregulated in the hippocampus of β-amyloid-treated animals. Even, β-amyloid-treated animals showed upregulation of mRNA level of calcium buffering proteins (parvalbumin and calsequestrin) and calcineurin A (PPP3CA) in the hippocampus. Acetylcholinesterase activity was also increased in the cortex of β-amyloid-treated animals. Three-week treatment with tranilast showed improvement in the cognitive parameters which was associated with a decrease in TRPV2 expression and AChE activity. Additionally, an increase in the protein expression of p-CaMKII, p-GSK-3β, p-CREB and PSD-95 in the hippocampus was found. Downregulation in the mRNA level of calcium buffering proteins (parvalbumin and calsequestrin) and calcineurin A in the hippocampus was also seen. These results reveal the importance of TRPV2 channels in the β-amyloid-induced cognitive deficits and suggest TRPV2 as a potential target for AD.

Role of transient receptor potential vanilloid subtype 2 in lower oesophageal sphincter in rat acid reflux oesophagitis

Gastroesophageal reflux disease (GERD) is a common gastrointestinal disorder. In the present study, we investigated TRP vanilloid subfamily member 2 (TRPV2) expression in lower oesophageal sphincter (LES) and its involvement in acid reflux oesophagitis in rats. Expression of TRPV2 and nerve growth factor mRNAs was significantly enhanced in LES of rats with reflux oesophagitis compared with normal rats. TRPV2 was mainly expressed in inhibitory motor neurons, and partly in intrinsic and extrinsic primary afferent neurons, and macrophages in LES of normal and reflux oesophagitis rats. Number of TRPV2-immunopositive nerve fibres was significantly increased, but that of nNOS-, CGRP-, and PGP9.5-nerve fibres was not changed in reflux oesophagitis compared with normal group. Probenecid produced nitric oxide production and relaxation in LES and this response was significantly enhanced in oesophagitis compared with normal group. Probenecid-induced relaxant effect was blocked by a TRPV2 inhibitor, tranilast, and a NOS inhibitor, NG-nitro-l-arginine methyl ester, in reflux oesophagitis rats. Oral administration of tranilast significantly improved body weight loss, oesophageal lesions, and epithelial thickness in oesophagitis model. These results suggest that up-regulation of TRPV2 in inhibitory motor neurons is involved in LES relaxation in oesophagitis model. TRPV2 inhibition might be beneficial for treatment of GERD.

Anti-cancer effects of Tranilast: An update

Tranilast (TRN) or (N-3,4 -dimethoxy cinnamoyl]-anthranilic acid) is an analog of a tryptophan metabolite and is identified mainly as an anti-allergic agent with limited side effects. The anti-cancer effects of tranilast either alone or in combination with chemotherapeutic drugs have been evidenced in several pre-clinical studies. The main mechanism of action of tranilast includes targeting and modulation of various signaling and immune regulatory pathways including Transforming growth factor-beta (TGF-β), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), phosphatidylinositol 3-kinase (PI3K), MAP-Kinase (MAPK), Protein kinase B (‎Akt/PKB), c-Jun N-terminal kinase, modulation of cancer stem cells, etc. Most of these pathways are involved in tumor proliferation, invasion, and metastasis and it is postulated that tranilast, with its low toxicity profile and high anti-carcinogenic abilities, can serve as a potential anti-tumorigenic agent. The main aim of this review is to provide updated information on the anti-cancer effects of tranilast and its significance as a therapeutic agent.

Transient Receptor Potential (TRP) Channels in Haematological Malignancies: An Update

Transient receptor potential (TRP) channels are improving their importance in different cancers, becoming suitable as promising candidates for precision medicine. Their important contribution in calcium trafficking inside and outside cells is coming to light from many papers published so far. Encouraging results on the correlation between TRP and overall survival (OS) and progression-free survival (PFS) in cancer patients are available, and there are as many promising data from in vitro studies. For what concerns haematological malignancy, the role of TRPs is still not elucidated, and data regarding TRP channel expression have demonstrated great variability throughout blood cancer so far. Thus, the aim of this review is to highlight the most recent findings on TRP channels in leukaemia and lymphoma, demonstrating their important contribution in the perspective of personalised therapies.

TRPV2: A Cancer Biomarker and Potential Therapeutic Target

The Transient Receptor Potential Vanilloid type-2 (TRPV2) channel exhibits oncogenicity in different types of cancers. TRPV2 is implicated in signaling pathways that mediate cell survival, proliferation, and metastasis. In leukemia and bladder cancer, the oncogenic activity of TRPV2 was linked to alteration of its expression profile. In multiple myeloma patients, TRPV2 overexpression correlated with bone tissue damage and poor prognosis. In prostate cancer, TRPV2 overexpression was associated with the castration-resistant phenotype and metastasis. Loss or inactivation of TRPV2 promoted glioblastoma cell proliferation and increased resistance to CD95-induced apoptotic cell death. TRPV2 overexpression was associated with high relapse-free survival in triple-negative breast cancer, whereas the opposite was found in patients with esophageal squamous cell carcinoma or gastric cancer. Another link was found between TRPV2 expression and either drug-induced cytotoxicity or stemness of liver cancer. Overall, these findings validate TRPV2 as a prime candidate for cancer biomarker and future therapeutic target.

Investigational drugs in early phase clinical trials targeting thermotransient receptor potential (thermoTRP) channels

INTRODUCTION

Thermo transient receptor potential (thermoTRP) channels are some of the most intensely pursued therapeutic targets of the past decade. They are considered promising targets of numerous diseases including chronic pain and cancer. Modulators of these proteins, in particular TRPV1-4, TRPM8 and TRPA1, have reached clinical development, but none has been approved for clinical practice yet.

AREAS COVERED

The therapeutic potential of targeting thermoTRP channels is discussed. The discussion is centered on our experience and on available data found in SciFinder, PubMed, and ClinicalTrials.gov database from the past decade. This review focuses on the therapeutic progress concerning this family of channels, including strategies to improve their therapeutic index for overcoming adverse effects.

EXPERT OPINION

Although thermoTRPs are pivotal drug targets, translation to the clinic has faced two key problems, (i) unforeseen side effects in Phase I trials and, (ii) poor clinical efficacy in Phase II trials. Thus, there is a need for (i) an enhanced understanding of the physiological role of these channels in tissues and organs and (ii) the development of human-based pre-clinical models with higher clinical translation. Furthermore, progress in nanotechnology-based delivery strategies will positively impact thermoTRP human pharmacology.

Construction of prognostic predictor by comprehensive analyzing alternative splicing events for colon adenocarcinoma

Background

Colon adenocarcinoma (COAD) is one of the most common malignant tumors, with high incidence and mortality rates worldwide. Reliable prognostic biomarkers are needed to guide clinical practice.

Methods

Comprehensive gene expression with alternative splicing (AS) profiles for each patient was downloaded using the SpliceSeq database from The Cancer Genome Atlas. Cox regression analysis was conducted to screen for prognostic AS events. The R package limma was used to screen differentially expressed genes (DEGs) between normal and tumor samples in the COAD cohort. A Venn plot analysis was performed between DEGs and prognostic AS events, and the DEGs that co-occurred with prognostic AS events (DEGAS) were identified. The top 30 most-connected DEGAS in protein–protein interaction analysis were identified through Cox proportional hazards regression to establish prognostic models.

Results

In total, 350 patients were included in the study. A total of 22,451 AS events were detected, of which 2004 from 1439 genes were significantly associated with survival time. By overlapping these 1439 genes with 6455 DEGs, 211 DEGs with AS events were identified. After the construction of the protein–protein interaction network, the top 30 hub genes were included in a multivariate analysis. Finally, a risk score based on 12 genes associated with overall survival was established (P < 0.05). The area under the curve was 0.782. The risk score was an independent predictor (P < 0.001).

Conclusions

By exploring survival-associated AS events, a powerful prognostic predictor consisting of 12 DEGAS was built. This study aims to propose a novel method to provide treatment targets for COAD and guide clinical practice in the future.

The TRPV2 cation channels: from urothelial cancer invasiveness to glioblastoma multiforme interactome signature

Changes in transient receptor potential (TRP) Ca²⁺ permeable channels are associated with development and progression of different types of cancer. Herein, we report data relative to the expression and function of TRP vanilloid 2 (TRPV2) channels in cancer. Overexpression of TRPV2 is observed in high-grade urothelial cancers and treatment with the TRPV2 agonist cannabidiol induces apoptosis. In prostate cancer, TRPV2 promotes migration and invasion, and TRPV2 overexpression characterizes the castration-resistant phenotype. In breast cancer cells, inhibition of TRPV2 by tranilast reduces the insulin-like growth factor-1 stimulated proliferation. TRPV2 overexpression in triple-negative breast cancer cells is associated with high recurrence-free survival. Increased TRPV2 overexpression is present in patients with esophageal squamous cell carcinoma associated with advanced disease, lymph node metastasis, and poor prognosis. Increased TRPV2 transcripts have been found both in benign hepatoma and in hepatocarcinomas, where TRPV2 expression is associated with portal vein invasion and reduction of cancer stem cell expression. TRPV2 expression and function has been also evaluated in gliomagenesis. This receptor negatively controls survival, proliferation, and resistance to CD95- or BCNU-induced apoptosis. In glioblastoma stem cells, TRPV2 activation promotes differentiation and inhibits the proliferation in vitro and in vivo. In glioblastoma, the TRPV2 is part of an interactome-based signature complex, which is negatively associated with survival, and it is expressed in high risk of recurrence and temozolomide-resistant patients. Finally, also in hematological malignancies, such as myeloma or acute myeloid leukemia, TRPV2 might represent a target for novel therapeutic approaches. Overall, these findings demonstrate that TRPV2 exhibits an oncogenic activity in different types of cancers, controlling survival, proliferation, migration, angiogenesis, and invasion signaling pathways. Thus, it prompts the pharmacological use of TRPV2 targeting in the control of cancer progression.

Potential roles in cardiac physiology and pathology of the cation channel TRPV2 expressed in cardiac cells and cardiac macrophages: a mini-review

TRPV2 is a well-conserved channel protein expressed in almost all tissues. Cardiomyocyte TRPV2 is expressed in the intercalated disks of the cardiac sarcomeres, where it is involved in maintaining the proper mechanoelectric coupling and structure. It is also abundantly expressed in the intracellular pools, mainly the endoplasmic reticulum. Under pathological conditions, TRPV2 is translocated to the sarcolemma, where it mediates an abnormal [Ca]²⁺ entry that may contribute to disease progression. In addition, an intracellularly diffused TRPV2 expression is present in resident cardiac macrophages. Upon infection or inflammation, TRPV2 is engaged in early phagosomes and is, therefore, potentially involved in protecting the cardiac tissue. Following acute myocardial infarction, a profound elevated expression of TRPV2 is observed on the cell membrane of the peri-infarct macrophages. The macrophage TRPV2 may harbor a detrimental effect in cardiac recovery by increasing unfavorable migration and phagocytosis processes in the injured heart. Most reports suggest that while cardiac TRPV2 activation may be beneficial under specific physiological conditions, both cardiac- and macrophage-related TRPV2 blocking can significantly ameliorate disease progression in various pathological states. To verify this possibility, the time frame of TRPV2 overexpression and its mediated signaling need to be fully characterized in both cardiomyocyte and cardiac macrophage populations.

Repurposing of Tranilast for Potential Neuropathic Pain Treatment by Inhibition of Sepiapterin Reductase in the BH4 Pathway

Tetrahydrobiopterin (BH₄) is a cofactor in the production of various signaling molecules including nitric oxide, dopamine, adrenaline, and noradrenaline. BH₄ levels are critical for processes associated with cardiovascular function, inflammation, mood, pain, and neurotransmission. Increasing pieces of evidence suggest that BH₄ is upregulated in chronic pain. Sepiapterin reductase (SPR) catalyzes both the reversible reduction of sepiapterin to dihydrobiopterin (BH₂) and 6-pyruvoyl-tetrahydrobiopterin to BH₄ within the BH₄ pathway. Therefore, inhibition of SPR by small molecules can be used to control BH₄ production and ultimately alleviate chronic pain. Here, we have used various in silico and in vitro experiments to show that tranilast, licensed for use in bronchial asthma, can inhibit sepiapterin reduction by SPR. Docking and molecular dynamics simulations suggest that tranilast can bind to human SPR (hSPR) at the same site as sepiapterin including S157, one of the catalytic triad residues of hSPR. Colorimetric assays revealed that tranilast was nearly twice as potent as the known hSPR inhibitor, N-acetyl serotonin. Tranilast was able to inhibit hSPR activity both intracellularly and extracellularly in live cells. Triple quad mass spectrophotometry of cell lysates showed a proportional decrease of BH₄ in cells treated with tranilast. Our results suggest that tranilast can act as a potent hSPR inhibitor and therefore is a valid candidate for drug repurposing in the treatment of chronic pain.