Antipsychotic Drugs Pimozide Research Articles

The antipsychotic drug pimozide promotes apoptosis through the RAF/ERK pathway and enhances autophagy in breast cancer cells

ABSTRACT The antipsychotic drug pimozide has been demonstrated to inhibit cancer. However, the precise anti-cancer mechanism of pimozide remains unclear. The purpose of this study was to investigate the effects of pimozide on human MCF-7 and MDA-MB-231 breast cancer cell lines, and the potential involvement in the RAF/ERK signaling. The effects of pimozide on cells were examined by 4,5-dimethylthiazol-2-yl-3,5-diphenylformazan, wound healing, colony formation, transwell assays, and caspase activity assay. Flow cytometry and acridine orange and ethidium bromide staining were performed to assess changes in cells. Transmission electron microscopy and monodansylcadaverine staining were used to observe autophagosomes. The cyclic adenosine monophosphate was evaluated using the FRET system. Immunohistochemistry, immunofluorescence, RNA interference, and western blot investigated the expression of proteins. Mechanistically, we focus on the RAF1/ERK signaling. We detected pimozide was docked to RAF1 by Schrodinger software. Pimozide down-regulated the phosphorylation of RAF1, ERK 1/2, Bcl-2, and Bcl-xl, up-regulated Bax, and cleaved caspase-9 to induce apoptosis. Pimozide might promote autophagy by up-regulating cAMP. The enhancement of autophagy increased the conversion of LC3-I to LC3-II and down-regulated p62 expression. But mTOR signaling was not involved in promoting autophagy. The knockdown of RAF1 expression induced autophagy and apoptosis in breast cancer cells, consistent with the results of pimozide or sorafenib alone. Blocked autophagy by chloroquine resulted in the impairment of pimozide-induced apoptosis. These data showed that pimozide inhibits breast cancer by regulating the RAF/ERK signaling pathway and might activate cAMP-induced autophagy to promote apoptosis and it may be a potential drug for breast cancer treatment.

Structure, gating, and pharmacology of human CaV3.3 channel

The low-voltage activated T-type calcium channels regulate cellular excitability and oscillatory behavior of resting membrane potential which trigger many physiological events and have been implicated with many diseases. Here, we determine structures of the human T-type CaV3.3 channel, in the absence and presence of antihypertensive drug mibefradil, antispasmodic drug otilonium bromide and antipsychotic drug pimozide. CaV3.3 contains a long bended S6 helix from domain III, with a positive charged region protruding into the cytosol, which is critical for T-type CaV channel activation at low voltage. The drug-bound structures clearly illustrate how these structurally different compounds bind to the same central cavity inside the CaV3.3 channel, but are mediated by significantly distinct interactions between drugs and their surrounding residues. Phospholipid molecules penetrate into the central cavity in various extent to shape the binding pocket and play important roles in stabilizing the inhibitor. These structures elucidate mechanisms of channel gating, drug recognition, and actions, thus pointing the way to developing potent and subtype-specific drug for therapeutic treatments of related disorders.

STAT3 Enhances Sensitivity of Glioblastoma to Drug-Induced Autophagy-Dependent Cell Death.

Simple SummaryGlioblastoma is the most common primary brain cancer in adults. One reason for the development and malignancy of this tumor is the misregulation of certain cellular proteins. The oncoprotein STAT3 that is frequently overactive in glioblastoma cells is associated with more aggressive disease and decreased patient survival. Autophagy is a form of cellular self digestion that normally maintains cell integrity and provides nutrients and basic building blocks required for growth. While glioblastoma is known to be particularly resistant to conventional therapies, recent research has suggested that these tumors are more sensitive to excessive overactivation of autophagy, leading to autophagy-dependent tumor cell death. Here, we show a hitherto unknown role of STAT3 in sensitizing glioblastoma cells to excessive autophagy induced with the repurposed drug pimozide. These findings provide the basis for future research aimed at determining whether STAT3 can serve as a predictor for autophagy-proficient tumors and further support the notion of overactivating autophagy for cancer therapy.Glioblastoma (GBM) is a devastating disease and the most common primary brain malignancy of adults with a median survival barely exceeding one year. Recent findings suggest that the antipsychotic drug pimozide triggers an autophagy-dependent, lysosomal type of cell death in GBM cells with possible implications for GBM therapy. One oncoprotein that is often overactivated in these tumors and associated with a particularly dismal prognosis is Signal Transducer and Activator of Transcription 3 (STAT3). Here, we used isogenic human and murine GBM knockout cell lines, advanced fluorescence microscopy, transcriptomic analysis and FACS-based assessment of cell viability to show that STAT3 has an underappreciated, context-dependent role in drug-induced cell death. Specifically, we demonstrate that depletion of STAT3 significantly enhances cell survival after treatment with Pimozide, suggesting that STAT3 confers a particular vulnerability to GBM. Furthermore, we show that active STAT3 has no major influence on the early steps of the autophagy pathway, but exacerbates drug-induced lysosomal membrane permeabilization (LMP) and release of cathepsins into the cytosol. Collectively, our findings support the concept of exploiting the pro-death functions of autophagy and LMP for GBM therapy and to further determine whether STAT3 can be employed as a treatment predictor for highly apoptosis-resistant, but autophagy-proficient cancers.

The antipsychotic drug pimozide is effective against human T-cell leukemia virus type 1-infected T cells

Patients with adult T-cell leukemia (ATL), caused by the human T-cell leukemia virus type 1 (HTLV-1), exhibit poor prognosis owing to drug resistance. Pimozide is a dopamine D2 receptor antagonist and antipsychotic shown to exhibit anticancer activity. Herein, we investigated whether pimozide exerts anti-ATL effects and explored the mechanisms underlying these effects. Pimozide inhibited cell growth and survival in HTLV-1-infected T cells but not in the uninfected T cells. The dopamine D2 receptor subfamily mRNA expression levels in HTLV-1-infected T cells were high. Pimozide induced G1 cell cycle arrest concomitant with the upregulation of p21/p27/p53, and suppression of cyclin D2/E, cyclin-dependent kinase 2/4/6 and c-Myc expression, and pRb phosphorylation. Pimozide also induced apoptosis by activating caspases, upregulating pro-apoptotic proteins and downregulating anti-apoptotic proteins. Additionally, it promoted reactive oxygen species (ROS) generation and increased the expression of the endoplasmic reticulum stress marker activating transcription factor 4 and the DNA damage-inducible protein GADD45α and the phosphorylation of the DNA damage marker H2AX. Furthermore, pimozide-induced cytotoxicity was partially inhibited by a ROS scavenger, and pan-caspase and necroptosis inhibitors, indicating the involvement of caspase-dependent and -independent lethal pathways. The activities of the nuclear factor-κB, Akt, STAT3/5 and AP-1 signaling pathways were inhibited via the dephosphorylation of IκBα, IκB kinase α/β, Akt and STAT3/5, in addition to reduced JunB and JunD expression in HTLV-1-infected T cells. Pimozide also exhibited potent anti-ATL activity in the xenograft mouse model. These findings demonstrated the efficacy of pimozide as a potential therapeutic agent for ATL.

Comprehensive analysis of genomic alterations, clinical outcomes, putative functions and potential therapeutic value of MMP11 in human breast cancer

The aim of the current study is to comprehend the prognostic and therapeutic value of matrix metalloproteinase (MMP11) in breast cancer using computational analyses. Gene expression-based Outcome for Breast cancer Online (GOBO) analysis revealed that MMP11 expression was increased in tumor when compared to normal. Among the subtypes, human epidermal growth factor receptor 2 (HER2) enriched and estrogen receptor (ER) positive showed higher expression of MMP11. The results were independently validated with cBioPortal and Oncomine databases. Tumors with high MMP11 expression showed poor overall survival and distant metastasis free survival. Further, protein-protein interactome network was constructed and molecular pathway analysis using Reactome database identified its putative role in diverse cellular processes. In addition, UALCAN web portal revealed hypomethylation in the promoter region of MMP11 in breast tumors. Molecular docking using iGEMDOCK and Autodock Vina were performed to identify natural compounds and repurposed drugs interaction with MMP11. Our study confirms the prognostic significance of MMP11 in breast cancer and their intrinsic subtypes. Twelve bio-compounds which were predominantly flavonoids and anti-psychotic drug pimozide showed significant docking scores with MMP11. Further, potential of these compounds in inhibiting MMP11 related molecular pathways and in targeting breast cancer cells are yet to be studied.

The antipsychotic drug pimozide inhibits IgE-mediated mast cell degranulation and migration

BackgroundMast cells (MCs) mediate a key role in allergic diseases. Detailed studies of how the neuroleptic drug pimozide affects MC activity are lacking. The aim of this study was to investigate pimozide inhibition of immunoglobulin E (IgE)-mediated MC activation and MC-mediated allergic responses. MethodMCs were stimulated with anti-dinitrophenyl (DNP) IgE antibodies and DNP-horse serum albumin (HSA) antigen (Ag), and anti-allergic pimozide effects were detected by measuring β-hexosaminidase levels. Morphological changes were observed histologically. In vivo pimozide effects were assessed in passive cutaneous anaphylaxis (PCA) and ovalbumin (OVA)-sensitized active systemic anaphylaxis mouse (ASA) model experiments. Levels of phosphorylated (p-) SYK (spleen tyrosine kinase) and MAPKs (mitogen-activated protein kinases) were detected in western blots. ResultsWe found that pimozide inhibited MC degranulation, reduced MC release of β-hexosaminidase dose-dependently in activated RBL-2H3 (IC50: 13.52 μM) and bone marrow derived MC (BMMC) (IC50: 42.42 μM), and reduced MC morphological changes. The IgE/Ag-induced migration effect was suppressed by pimozide treatment dose-dependently. Pimozide down-regulated IgE/Ag-induced phosphorylation of SYK and MAPKs in activated MCs. Moreover, pimozide attenuated allergic reactions in PCA and ASA model mice, and decreased MC populations among splenic cells. ConclusionsThe antipsychotic drug pimozide can suppress IgE-mediated MC activation in vitro and in vivo and should be considered for repurposing to suppress MC-mediated diseases.

In silico Selection and Experimental Validation of FDA-Approved Drugs as Anti-quorum Sensing Agents.

The emergence of antibiotic resistant bacterial pathogens is increasing at an unprecedented pace, calling for the development of new therapeutic options. Small molecules interfering with virulence processes rather than growth hold promise as an alternative to conventional antibiotics. Anti-virulence agents are expected to decrease bacterial virulence and to pose reduced selective pressure for the emergence of resistance. In the opportunistic pathogen Pseudomonas aeruginosa the expression of key virulence traits is controlled by quorum sensing (QS), an intercellular communication process that coordinates gene expression at the population level. Hence, QS inhibitors represent promising anti-virulence agents against P. aeruginosa. Virtual screenings allow fast and cost-effective selection of target ligands among vast libraries of molecules, thus accelerating the time and limiting the cost of conventional drug-discovery processes, while the drug-repurposing approach is based on the identification of off-target activity of FDA-approved drugs, likely endowed with low cytotoxicity and favorable pharmacological properties. This study aims at combining the advantages of virtual screening and drug-repurposing approaches to identify new QS inhibitors targeting the pqs QS system of P. aeruginosa. An in silico library of 1,467 FDA-approved drugs has been screened by molecular docking, and 5 hits showing the highest predicted binding affinity for the pqs QS receptor PqsR (also known as MvfR) have been selected. In vitro experiments have been performed by engineering ad hoc biosensor strains, which were used to verify the ability of hit compounds to decrease PqsR activity in P. aeruginosa. Phenotypic analyses confirmed the impact of the most promising hit, the antipsychotic drug pimozide, on the expression of P. aeruginosa PqsR-controlled virulence traits. Overall, this study highlights the potential of virtual screening campaigns of FDA-approved drugs to rapidly select new inhibitors of important bacterial functions.

Antipsychotic agent pimozide promotes reversible proliferative suppression by inducing cellular quiescence in liver cancer.

The antipsychotic drug pimozide has been found to exhibit anticancer effects. Previously, it was demonstrated that pimozide inhibits hepatocellular carcinoma (HCC) cell growth, but its pharmacodynamic characteristics remain unclear. The aim of the present study was to investigate the reversibility and mechanism of the ability of pimozide to inhibit cell proliferation in liver cancer. Cell viability was determined by Cell Counting Kit-8 and colony formation assay. The cell cycle distribution was analyzed by flow cytometry with Ki-67 and PI staining. ROS production of HCC cells was detected with DCFH-DA and inhibited with NAC treatment. Western blot assay was performed to detect the expression of related signaling molecules in HCC cells. Our results showed that pimozide promoted G0/G1 phase arrest in HCC cell lines without significant cell death. Its anti-proliferative effects on HCC cells were reversible, consistent with involvement of cell quiescence and reactive oxygen species (ROS) production. Pimozide enhanced inhibition of HCC cell proliferation by sorafenib. In conclusion, elucidation of pimozide's reversible proliferation inhibition in liver cancer and additive activity with a well-established anticancer drug warrants further exploration of the potential of pimozide as an adjuvant anticancer therapy.

NH2‐Functionalized Multi Walled Carbon Nanotubes Decorated with ZnO Nanoparticles and Graphene Quantum Dots for Sensitive Assay of Pimozide

AbstractIn this study, a novel and sensitive electrochemical nanosensor for the determination of antipsychotic drug Pimozide (PZ) is proposed using NH2 functionalized multi walled carbon nanotubes (NH2fMWCNT) decorated with and ZnO nanoparticles (ZnONPs) co‐catalyzed by graphene quantum dots (GQDs). Prior to electrochemical analyses of PZ, the designed nanosensor was well characterized in terms of surface morphology by scanning electron microscopy (SEM) and SEM armed with EDX analysis. Electrochemical impedance spectroscopy (EIS) employed to investigate the electron transfer capability and cyclic voltammetry (CV) technique was used to successfully compare the redox response of PZ on the surface of modified and unmodified electrode. The designed nanosensor response was linear between 6.25×10−11–1.20×10−7 M concentration range of PZ with a limit of detection value as 1.02×10−11 M. The influence of interfering agents was further studied to examine the selectivity of the designed sensor. A rapid screening of PZ as is required in pharmaceutical and biological samples underscores the paramount importance of nano based electrochemical sensor for its sensitive and selective detection.

The anti-psychotic drug pimozide is a novel chemotherapeutic for breast cancer.

Pimozide, an antipsychotic drug of the diphenylbutylpiperidine class, has been shown to suppress cell growth of breast cancer cells in vitro. In this study we further explore the inhibitory effects of this molecule in cancer cells. We found that Pimozide inhibited cell proliferation in a dose- and time-dependent manner in MDA-MB-231 breast cancer cells and A549 lung cancer cells. Furthermore, we found that Pimozide also promoted apoptosis as demonstrated by cell cycle arrest and induction of double-strand DNA breaks but did not result in any effect in the non-transformed MCF10A breast cell line. In order to shed new lights into the molecular pathways affected by Pimozide, we show that Pimozide downregulated RAN GTPase and AKT at both protein and mRNA levels and inhibited the AKT signaling pathway in MDA-MB-231 breast cancer cells. Pimozide also inhibited the epithelial mesenchymal transition and cell migration and downregulated the expression of MMPs. Administration of Pimozide showed a potent in vivo antitumor activity in MDA-MB-231 xenograft animal model and reduced the number of lung metastases by blocking vascular endothelial growth factor receptor 2. Furthermore, Pimozide inhibited myofibroblast formation as evaluated by the reduction in α-smooth muscle actin containing cells. Thus, Pimozide might inhibit tumor development by suppressing angiogenesis and by paracrine stimulation provided by host reactive stromal cells. These results demonstrate a novel in vitro and in vivo antitumor activity of Pimozide against breast and lung cancer cells and provide the proof of concept for a putative Pimozide as a novel approach for cancer therapy.

P-gp Inhibition by the Anti-psychotic Drug Pimozide Increases Apoptosis, as well as Expression of pRb and pH2AX in Highly Drug-resistant KBV20C Cells.

The present study was designed to identify drugs that could sensitize P-glycoprotein (P-gp)-overexpressing resistant KBV20C cancer cells to treatment with Halaven (HAL) or vincristine (VIC). Using relatively low doses or IC50 concentrations of drugs to sensitize anti-mitotic drug-resistant KBV20C cells, pimozide (PIM) sensitized HAL-resistant KBV20C cancer cells, with higher P-gp inhibitory activity than another anti-psychotic drug, fluphenazine (FLU). The first-generation P-gp inhibitor verapamil required a dose that was similar to that of PIM for P-gp inhibition, suggesting that PIM has a similar specificity for binding P-gp to prevent efflux of anti-mitotic drugs. Furthermore, co-treatment with PIM and another anti-mitotic drug, VIC, also increased sensitization of KBV20C cells, suggesting that PIM can be combined with other anti-mitotic drugs to sensitize resistant cancer cells. PIM caused a reduction in cell viability and an increase in the number of cells arresting at the G2 phase of the cell cycle. PIM induced both early and late apoptosis in KBV20C cells in response to HAL treatment. Furthermore, the DNA damage marker pH2AX, the cell-cycle protein pRb, and the pro-apoptotic protein C-PARP levels increased after HAL-PIM co-treatment, indicative of a mechanism involving G2 phase arrest and an increase in the number of cells undergoing apoptosis. PIM may be a promising therapeutic agent for the treatment of cancers that are resistant to anti-mitotic drugs.

Electrocatalytic behavior of copper ferrite decorated carbon nanofibers towards oxidative determination of antipsychotic drug Pimozide

Pimozide (PMZ) is highly potent antipsychotic drug used worldwide against Tourette syndrome (TS) and schizophrenia. However, it has several chronic side effects on human body when consumed in excess. In this work, a carbon nanofiber/copper ferrite nanoparticles composite modified carbon paste electrode (CNF-CuFe2O4/CPE) based electrochemical sensor was developed to determine PMZ. The CNF-CuFe2O4 nanocomposite synthesized by a simple yet facile hydrothermal method. The formation and surface characteristics of nanocomposite were studied by using X-ray diffraction and electron microscopic techniques. When employed as a voltammetric sensor, the CNF-CuFe2O4/CPE showed excellent electrocatalytic activity towards electro-oxidation of PMZ in B.R. buffer solution of pH 2.0 as a supporting electrolyte. The oxidation peak current of PMZ was found to have a linear relationship with its concentration in the range of 9 × 10−9 to 5 × 10−4 M. The limit of detection and limit of quantification were calculated to be 2.3 × 10−10 M and 7.69 × 10−10 M using differential pulse voltammetric method. The practical applicability of constructed CNF-CuFe2O4/CPE sensor was examined in pharmaceutical formulations, human blood serum and urine samples for selective and precise analysis of PMZ. The results obtained demonstrate that the electrochemical response of PMZ is excellent on the surface of CNF-CuFe2O4/CPE which indicates that it holds a high efficiency as a voltammetric sensor for the trace analysis of PMZ.

The antipsychotic drug pimozide inhibits cell growth in prostate cancer through suppression of STAT3 activation.

Currently, drug discovery and development for clinical treatment of prostate cancer has received increased attention, specifically the STAT3 inhibitor. Our previous study reported that the neuroleptic drug pimozide had antitumor activity against hepatocellular carcinoma cells or stem-like cells through suppressing the STAT3 activity. In the present study we demonstrate that pimozide inhibits cell growth and cellular STAT3 activation in prostate cancer cells. Our results showed that pimozide inhibited prostate cancer cell proliferation in a dose- and time-dependent manner by inducing G1 phase cell cycle arrest, downregulated the ability of colony formation and sphere forming, as well as suppressed cells migration in both DU145 and LNCaP cells. Surprisingly, pimozide reduced the basal expression of phosphorylation STAT3 at tyrosine 705 and reversed the expression of phosphorylation of STAT3 induced by IL-6 addition, suggesting that pimozide can suppress cellular STAT3 activation. Thus, the antipsychotic agent pimozide may be a potential and novel therapeutic for patients with advanced prostate cancer.

Delusional infestation: a case series from a university dermatology center in São Paulo, Brazil.

Monosymptomatic hypochondriac psychosis (MHP) patients present with a delusional ideation that revolves around one particular hypochondriac concern. Delusional infestation is the most common type of MHP seen by the dermatologist. This study was designed to retrospectively investigate a group of patients with delusions of infestation seen in an academic medical center in São Paulo, Brazil. A retrospective study of patients presenting with delusional infestation between 2007 and 2014 was conducted. Records were reviewed to study personal data, symptoms, and treatments. Thirty patients were studied (22 female, eight male). Their mean age was 58 years in men and 60 years in women. Twenty-four patients spent most of their time at home (i.e. they were housewives, retired, or unemployed). The duration of disease varied from 3 months to 20 years. Fifteen patients brought in fragments of material that they believed to be parasites ("specimen sign"). Treatment consisted of the antipsychotic drugs pimozide (1-6 mg/d) or olanzapine (5-10 mg/d). Three patients did not return for follow-up. Follow-up varying from 2 months to 7 years was recorded in 24 patients. Two patients were treated with other psychoactive drugs prescribed by psychiatrists for additional psychiatric diagnoses. Control of symptoms was achieved in the majority of patients who underwent adequate follow-up. Delusional infestation is an extremely chronic disease. Attempts to discontinue treatment in those patients in whom a lengthy follow-up was performed inevitably resulted in symptom relapses.

Tremorolytic effects of adenosine A2A antagonists: implications for parkinsonism

Drug-induced tremulous jaw movements in rats have been used as a model of parkinsonian tremor. Because adenosine A2A antagonists have antiparkinsonian effects, the present experiments were conducted to study the ability of adenosine A2A antagonism to reverse the tremulous jaw movements produced by the antipsychotic drugs pimozide, haloperidol and reserpine. In one group of studies, rats received daily injections of the dopamine antagonist pimozide, and on day 8 they received injections of pimozide plus various doses of the A2A antagonists KW 6002 or MSX-3. KW 6002 and MSX-3 suppressed pimozide-induced tremulous jaw movements, reduced catalepsy, and increased locomotion. MSX-3 also suppressed the jaw movements induced by haloperidol and reserpine. In addition, local injections of MSX-3 into the ventrolateral neostriatum suppressed pimozide-induced tremulous jaw movements. Thus, adenosine A2A antagonism can reverse the tremulous movements induced by antipsychotic drugs, which is consistent with the hypothesis that antagonism of adenosine A2A receptors can result in antiparkinsonian effects. Adenosine A2A antagonists may be useful for their tremorolytic effects, and may help in treating both idiopathic and antipsychotic-induced parkinsonian symptoms.