Tolcapone induces oxidative stress leading to apoptosis and inhibition of tumor growth in Neuroblastoma

High content imaging of relative ATP levels for mitochondrial toxicity prediction in human induced pluripotent stem cell derived cardiomyocytes

Human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) are increasingly being evaluated in assays aimed at better understanding potential cardiotoxic liability of newly developed therapeutic compounds. Disruption of mitochondria has been implicated in the mechanism of drug-induced cardiotoxicity of some compounds. Therefore, we have developed a high content imaging assay for the investigation of mitochondrial toxicity in hiPSC-CMs using ATP-Red, a fluorescent dye capable of detecting subcellular localization of relative ATP levels in living cells. We demonstrated time-dependent decreases in ATP-Red signal over 6 h treatment with known mitochondrial toxicants antimycin (0.03, 0.1 µM) or oligomycin (3, 10 µM). Concentration-dependent decreases in ATP-Red signal with antimycin (0.001-0.3 µM) and oligomycin (0.003-1 µM) were rescued by restoring glycolysis through glucose supplementation. Decreased ATP levels were also identified in a selection of clinically available drugs with reported association with mitochondrial toxicity but absent in compounds with no known association with mitochondrial dysfunction. ATP measurements using the ATP-Red imaging assay were consistent with orthogonal measurements of whole cell ATP levels in lysed hiPSC-CMs following compound treatment. Similar findings were also obtained with measurement of mitochondrial membrane potential, except amiodarone which had no change despite decreased ATP levels. The developed high throughput imaging assay, assessing subcellular ATP dynamics, could provide mechanistic insights for tested compounds.

Characterization of the Biochemical Recurrence Prediction Ability and Progression Correlation of Peroxiredoxins Family in Prostate Cancer Based on Integrating Single-Cell RNA-Seq and Bulk RNA-Seq Cohorts

INTRODUCTION

The peroxiredoxins (PRDXs) family plays a crucial role in balancing reactive oxygen species (ROS) levels in tumor cells. However, its potential role in prognosis and therapy response of prostate cancer (PCa) remains unknown.

METHODS

In this study, we utilized 2 public single-cell RNA datasets and 8 bulk-RNA datasets to investigate the clinical value of six PRDXs family members in PCa. Expression comparison, biochemical recurrence analysis, and therapy response analysis were measured. Pathway enrichments were utilized to predict the potential down-stream pathway it may involve. In vitro experiments were used to validate the function of PRDX5 in the progression of castration-resistant prostate cancer (CRPC) cell lines.

RESULT

Among the PRDXs family, PRDX5 was most related to the advancement of prostate cancer. A nomogram integrating the expression of PRDX5 with clinical features was developed to better predict clinical outcomes in PCa patients compared to 30 published signatures. Immunohistochemistry was used to verify that PRDX5 expression was higher in advanced levels of PCa tissue. Gene Set Enrichment Analysis (GSEA) and pathway predictive analysis revealed that the PRDX5 related genes were mainly relevant to ROS Pathway, Mitochondria-related functions, cellular respiration, and oxidative phosphorylation. In vitro cell proliferation assays, ROS determination assay, and apoptosis assay together revealed that depletion of PRDX5 induces apoptosis via ROS accumulation in CRPC cells. Moreover, the expression of PRDX5 in CRPC cells also affects the sensitivity to the ARSI therapy.

CONCLUSION

This study offers new evidence for determining that the expression of PRDX5 is associated with advanced tumor grade, poor prognosis, and suboptimal response to multiple therapies in PCa within the PRDXs family. Last but not least, our study provides new insights into precision medicine in PCa and provides a reference for further research on PRDX5.

Targeting Catechol-O-Methyltransferase Induces Mitochondrial Dysfunction and Enhances the Efficacy of Radiotherapy in Glioma

Radiotherapy (RT) is commonly used to try to eliminate any remaining tumor cells following surgical resection of glioma. However, tumor recurrence is prevalent, highlighting the unmet medical need to develop therapeutic strategies to enhance the efficacy of RT in glioma. Focusing on the radiosensitizing potential of the currently approved drugs known to cross the blood-brain barrier can facilitate rapid clinical translation. Here, we assessed the role of catechol-O-methyltransferase (COMT), a key enzyme to degrade catecholamines and a drug target for Parkinson's disease, in glioma treatment. Analysis of The Cancer Genome Atlas data showed significantly higher COMT expression levels in both low-grade glioma and glioblastoma compared to normal brain tissues. Inhibition of COMT by genetic knockout or FDA-approved COMT inhibitors significantly sensitized glioma cells to RT in vitro and in vivo. Mechanistically, COMT inhibition in glioma cells led to mitochondria dysfunction and increased mitochondrial RNA release into the cytoplasm, activating the cellular antiviral double-stranded RNA sensing pathway and type I interferon (IFN) response. Elevated type I IFNs stimulated the phagocytic capacity of microglial cells, enhancing RT efficacy. Given the long-established safety record of the COMT inhibitors, these findings provide a solid rationale to evaluate them in combination with RT in patients with glioma. Significance: Inhibition of catechol-O-methyltransferase, a well-established drug target in Parkinson's disease, interferes with mitochondrial electron transport and induces mitochondrial double-stranded RNA leakage, activating type I interferon signaling and sensitizing glioma to radiotherapy.

3-O-Methyltolcapone and Its Lipophilic Analogues Are Potent Inhibitors of Transthyretin Amyloidogenesis with High Permeability and Low Toxicity

Transthyretin (TTR) is an amyloidogenic homotetramer involved in the transport of thyroxine in blood and cerebrospinal fluid. To date, more than 130 TTR point mutations are known to destabilise the TTR tetramer, leading to its extracellular pathological aggregation accumulating in several organs, such as heart, peripheral and autonomic nerves, and leptomeninges. Tolcapone is an FDA-approved drug for Parkinson's disease that has been repurposed as a TTR stabiliser. We characterised 3-O-methyltolcapone and two newly synthesized lipophilic analogues, which are expected to be protected from the metabolic glucuronidation that is responsible for the lability of tolcapone in the organism. Immunoblotting assays indicated the high degree of TTR stabilisation, coupled with binding selectivity towards TTR in diluted plasma of 3-O-methyltolcapone and its lipophilic analogues. Furthermore, in vitro toxicity data showed their several-fold improved neuronal and hepatic safety compared to tolcapone. Calorimetric and structural data showed that both T4 binding sites of TTR are occupied by 3-O-methyltolcapone and its lipophilic analogs, consistent with an effective TTR tetramer stabilisation. Moreover, in vitro permeability studies showed that the three compounds can effectively cross the blood-brain barrier, which is a prerequisite for the inhibition of TTR amyloidogenesis in the cerebrospinal fluid. Our data demonstrate the relevance of 3-O-methyltolcapone and its lipophilic analogs as potent inhibitors of TTR amyloidogenesis.

DESI-MSI-based technique to unravel spatial distribution of COMT inhibitor Tolcapone

Ascertaining compound exposure and its spatial distribution are essential steps in the drug development process. Desorption electrospray ionization mass spectrometry (DESI-MSI) is a label-free imaging technique capable of simultaneously identify and visualize the distribution of a diverse range of biomolecules. In this study, DESI-MSI was employed to investigate spatial distribution of tolcapone in rat liver and brain coronal - frontal and striatal -sections after a single oral administration of 100 mg/Kg of tolcapone, brain-penetrant compound. Tolcapone was evenly distributed in liver tissue sections whereas in the brain it showed differential distribution across brain regions analyzed, being mainly located in the olfactory bulb, basal forebrain region, striatum, and pre-frontal cortex (PFC; cingulate, prelimbic and infralimbic area). Tolcapone concentration in tissues was compared using DESI-MSI and liquid-chromatography mass spectrometry (LC-MS/MS). DESI-MSI technique showed a higher specificity on detecting tolcapone in liver sections while in the brain samples DESI-MSI did not allow a feasible quantification. Indeed, DESI-MSI is a qualitative technique that allows to observe heterogeneity on distribution but more challenging regarding accurate measurements. Overall, tolcapone was successfully localized in liver and brain tissue sections using DESI-MSI, highlighting the added value that this technique could provide in assisting tissue-specific drug distribution studies.

Differential Interactome Based Drug Repositioning Unraveled Abacavir, Exemestane, Nortriptyline Hydrochloride, and Tolcapone as Potential Therapeutics for Colorectal Cancers

There is a critical requirement for alternative strategies to provide the better treatment in colorectal cancer (CRC). Hence, our goal was to propose novel biomarkers as well as drug candidates for its treatment through differential interactome based drug repositioning. Differentially interacting proteins and their modules were identified, and their prognostic power were estimated through survival analyses. Drug repositioning was carried out for significant target proteins, and candidate drugs were analyzed via in silico molecular docking prior to in vitro cell viability assays in CRC cell lines. Six modules (mAPEX1, mCCT7, mHSD17B10, mMYC, mPSMB5, mRAN) were highlighted considering their prognostic performance. Drug repositioning resulted in eight drugs (abacavir, ribociclib, exemestane, voriconazole, nortriptyline hydrochloride, theophylline, bromocriptine mesylate, and tolcapone). Moreover, significant in vitro inhibition profiles were obtained in abacavir, nortriptyline hydrochloride, exemestane, tolcapone, and theophylline (positive control). Our findings may provide new and complementary strategies for the treatment of CRC.

Tolcapone Treatment for Cognitive and Behavioral Symptoms in Behavioral Variant Frontotemporal Dementia: A Placebo-Controlled Crossover Study

BACKGROUND

There are currently no disease-targeted treatments for cognitive or behavioral symptoms in patients with behavioral variant frontotemporal dementia (bvFTD).

OBJECTIVE

To determine the effect of tolcapone, a specific inhibitor of Catechol-O-Methyltransferase (COMT), in patients with bvFTD.

METHODS

In this randomized, double-blind, placebo-controlled, cross-over study at two study sites, we examined the effect of tolcapone on 28 adult outpatients with bvFTD. The primary outcome was reaction time on the N-back cognitive test. As an imaging outcome, we examined differences in the resting blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) signal intensity between subjects on placebo versus tolcapone performing the N-back test. Secondary outcomes included measures of cognitive performance and behavioral disturbance using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), Neuropsychiatric Inventory-Questionnaire (NPI-Q), and Clinical Global Impressions scale (CGI).

RESULTS

Tolcapone was well tolerated and no patients dropped out. The most frequent treatment-related adverse event during tolcapone treatment was elevated liver enzymes (21%). There were no significant differences between tolcapone treatment and placebo in the primary or imaging outcomes. However, there were significant differences between RBANS total scores (p < 0.01), NPI-Q total scores (p = 0.04), and CGI total scores (p = 0.035) between treatment conditions which were driven by differences between baseline and tolcapone conditions. Further, there was a trend toward significance between tolcapone and placebo on the CGI (p = 0.078).

CONCLUSIONS

Further study of COMT inhibition and related approaches with longer duration of treatment and larger sample sizes in frontotemporal lobar degeneration-spectrum disorders may be warranted.

Association of high-risk neuroblastoma classification based on expression profiles with differentiation and metabolism

Neuroblastoma, the most common extracranial solid malignancy among children, originates from undifferentiated neural crest cells (NCC). Despite recent intensified treatment, high-risk patients still have a high mortality rate. To explore a new therapeutic strategy, we performed an integrated genomic and transcriptomic analysis of 30 high-risk neuroblastoma cases. Based on the expression profiling of RNA sequencing, neuroblastoma was classified into Mesenchymal (MES; n = 5) and Noradrenergic (ADRN; n = 25) clusters, as previously reported in the super-enhancer landscape. The expression patterns in MES-cluster cases were similar to normal adrenal glands, with enrichment in secretion-related pathways, suggesting chromaffin cell-like features built from NCC-derived Schwann cell precursors (SCPs). In contrast, neuron-related pathways were enriched in the ADRN-cluster, indicating sympathoblast features reported to originate from NCC but not via SCPs. Thus, MES- and ADRN-clusters were assumed to be corresponding to differentiation pathways through SCP and sympathoblast, respectively. ADRN-cluster cases were further classified into MYCN- and ATRX-clusters, characterized by genetic alterations, MYCN amplifications and ATRX alterations, respectively. MYCN-cluster cases showed high expression of ALDH18A1, encoding P5CS related to proline production. As reported in other cancers, this might cause reprogramming of proline metabolism leading to tumor specific proline vulnerability candidate for a target therapy of metabolic pathway. In ATRX-cluster, SLC18A2 (VMAT2), an enzyme known to prevent cell toxicity due to the oxidation of dopamine, was highly expressed and VMAT2 inhibitor (GZ-793A) represented significant attenuation of cell growth in NB-69 cell line (high SLC18A2 expression, no MYCN amplification) but not in IMR-32 cell line (MYCN amplification). In addition, the correlation of VMAT2 expression with metaiodobenzylguanidine (MIBG) avidity suggested a combination of VMAT2 inhibitor and MIBG radiation for a novel potential therapeutic strategy in ATRX-cluster cases. Thus, targeting the characteristics of unique neuroblastomas may prospectively improve prognosis.

Endothelial Colony-Forming Cell Function Is Reduced During HIV Infection

BACKGROUND

Human immunodeficiency virus (HIV) may be related to cardiovascular disease through monocyte activation-associated endothelial dysfunction.

METHODS

Blood samples from 15 HIV-negative participants (the uninfected group), 8 HIV-positive participants who were not receiving antiretroviral therapy (ART) (the infected, untreated group), and 15 HIV-positive participants who were receiving ART (the infected, treated group) underwent flow cytometry of endothelial colony-forming cells (ECFCs) and monocyte proportions. IncuCyte live cell imaging of 8 capillary proliferative capacity parameters were obtained from cord blood ECFCs treated with participant plasma.

RESULTS

The ECFC percentage determined by flow cytometry was not different between the study groups; however, values of the majority of capillary proliferative capacity parameters (ie, cell area, network length, network branch points, number of networks, and average tube width uniformity) were significantly lower in infected, untreated participants as compared to values for uninfected participants or infected, treated participants (P < .00625 for all comparisons). CD14+CD16+ intermediate monocytes and soluble CD163 were significantly and negatively correlated with several plasma-treated, cord blood ECFC proliferative capacity parameters in the combined HIV-positive groups but not in the uninfected group.

CONCLUSIONS

Cord blood ECFC proliferative capacity was significantly impaired by plasma from infected, untreated patients, compared with plasma from uninfected participants and from infected, treated participants. Several ECFC functional parameters were adversely associated with monocyte activation in the HIV-positive groups, thereby suggesting a mechanism by which HIV-related inflammation may impair vascular reparative potential and consequently increase the risk of cardiovascular disease during HIV infection.

Systems pharmacogenomics - gene, disease, drug and placebo interactions: a case study in COMT

Disease, drugs and the placebos used as comparators are inextricably linked in the methodology of the double-blind, randomized controlled trial. Nonetheless, pharmacogenomics, the study of how individuals respond to drugs based on genetic substrate, focuses primarily on the link between genes and drugs, while the link between genes and disease is often overlooked and the link between genes and placebos is largely ignored. Herein, we use the example of the enzyme catechol-O-methyltransferase to examine the hypothesis that genes can function as pharmacogenomic hubs across system-wide regulatory processes that, if perturbed in andomized controlled trials, can have primary and combinatorial effects on drug and placebo responses.

Engineering the TGFβ Receptor to Enhance the Therapeutic Potential of Natural Killer Cells as an Immunotherapy for Neuroblastoma

PURPOSE

The ability of natural killer (NK) cells to lyse allogeneic targets, without the need for explicit matching or priming, makes them an attractive platform for cell-based immunotherapy. Umbilical cord blood is a practical source for generating banks of such third-party NK cells for "off-the-shelf" cell therapy applications. NK cells are highly cytolytic, and their potent antitumor effects can be rapidly triggered by a lack of HLA expression on interacting target cells, as is the case for a majority of solid tumors, including neuroblastoma. Neuroblastoma is a leading cause of pediatric cancer-related deaths and an ideal candidate for NK-cell therapy. However, the antitumor efficacy of NK cells is limited by immunosuppressive cytokines in the tumor microenvironment, such as TGFβ, which impair NK cell function and survival.

EXPERIMENTAL DESIGN

To overcome this, we genetically modified NK cells to express variant TGFβ receptors, which couple a mutant TGFβ dominant-negative receptor to NK-specific activating domains. We hypothesized that with these engineered receptors, inhibitory TGFβ signals are effectively converted to activating signals.

RESULTS

Modified NK cells exhibited higher cytotoxic activity against neuroblastoma in a TGFβ-rich environment in vitro and superior progression-free survival in vivo, as compared with their unmodified controls.

CONCLUSIONS

Our results support the development of "off-the-shelf" gene-modified NK cells, that overcome TGFβ-mediated immune evasion, in patients with neuroblastoma and other TGFβ-secreting malignancies.

Endometriosis Malignant Transformation: Epigenetics as a Probable Mechanism in Ovarian Tumorigenesis

Endometriosis, defined as the presence of ectopic endometrial glands and stroma outside the uterine cavity, is a chronic, hormone-dependent gynecologic disease affecting millions of women across the world, with symptoms including chronic pelvic pain, dysmenorrhea, dyspareunia, dysuria, and subfertility. In addition, there is well-established evidence that, although endometriosis is considered benign, it is associated with an increased risk of malignant transformation, with the involvement of various mechanisms of development. More and more evidence reveals an important contribution of epigenetic modification not only in endometriosis but also in mechanisms of endometriosis malignant transformation, including DNA methylation and demethylation, histone modifications, and miRNA aberrant expressions. In this present review, we mainly summarize the research progress about the current knowledge regarding the epigenetic modifications of the relations between endometriosis malignant transformation and ovarian cancer in an effort to identify some risk factors probably associated with ectopic endometrium transformation.

Tolcapone induces oxidative stress leading to apoptosis and inhibition of tumor growth in Neuroblastoma

Catechol‐O‐methyltransferase (COMT) is an enzyme that inactivates dopamine and other catecholamines by O‐methylation. Tolcapone, a drug commonly used in the treatment of Parkinson's disease, is a potent inhibitor of COMT and previous studies indicate that Tolcapone increases the bioavailability of dopamine in cells. In this study, we demonstrate that Tolcapone kills neuroblastoma (NB) cells in preclinical models by inhibition of COMT. Treating four established NB cells lines (SMS‐KCNR, SH‐SY5Y, BE(2)‐C, CHLA‐90) and two primary NB cell lines with Tolcapone for 48 h decreased cell viability in a dose‐dependent manner, with IncuCyte imaging and Western blotting indicating that cell death was due to caspase‐3‐mediated apoptosis. Tolcapone also increased ROS while simultaneously decreasing ATP‐per‐cell in NB cells. Additionally, COMT was inhibited by siRNA in NB cells and showed similar increases in apoptotic markers compared to Tolcapone. In vivo xenograft models displayed inhibition of tumor growth and a significant decrease in time‐to‐event in mice treated with Tolcapone compared to untreated mice. These results indicate that Tolcapone is cytotoxic to neuroblastoma cells and invite further studies into Tolcapone as a promising novel therapy for the treatment of neuroblastoma.