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The Journal of Pharmacy and Pharmacology Nov 2015Obatoclax is a pan-Bcl-2 inhibitor with promising efficacy, especially when combined with other antineoplastic agents. Pharmacokinetic drug-drug interactions can occur...
OBJECTIVES
Obatoclax is a pan-Bcl-2 inhibitor with promising efficacy, especially when combined with other antineoplastic agents. Pharmacokinetic drug-drug interactions can occur systemically and at the level of the tumour cell. Thus, this study scrutinised the interaction potential of obatoclax in vitro.
METHODS
Obatoclax was screened for P-gp inhibition by calcein assay, for breast cancer resistance protein (BCRP) inhibition by pheophorbide A assay and for inhibition of cytochrome P450 isoenzymes (CYPs) by commercial kits. Induction of mRNA of drug-metabolising enzymes and drug transporters was quantified in LS180 cells via real-time polymerase chain reaction and involvement of nuclear receptors was assessed by reporter gene assays. Proliferation assays were used to assess whether obatoclax retains its efficacy in cell lines overexpressing BCRP, P-glycoprotein (P-gp) or multidrug resistance-associated protein 2 (MRP2).
KEY FINDINGS
Obatoclax induced the mRNA expression of several genes (e.g. CYP1A1, CYP1A2 and ABCG2 (five to seven-fold) through activation of the aryl hydrocarbon receptor in the nanomolar range. Obatoclax inhibits P-gp, BCRP and some CYPs at concentrations exceeding plasma levels. P-gp, MPR2 or BCRP overexpression did not influence the efficacy of obatoclax.
CONCLUSIONS
Obatoclax retains its efficacy in cells overexpressing P-gp, MRP2 or BCRP and might act as a perpetrator drug in interactions with drugs, for example being substrates of CYP1A2 or BCRP.
Topics: ATP Binding Cassette Transporter, Subfamily B, Member 1; ATP Binding Cassette Transporter, Subfamily G, Member 2; ATP-Binding Cassette Transporters; Animals; Cell Line; Cell Line, Tumor; Cytochrome P-450 Enzyme System; Drug Interactions; Drug Resistance, Multiple; Gene Expression Regulation; Humans; Indoles; LLC-PK1 Cells; Mice; Multidrug Resistance-Associated Protein 2; Multidrug Resistance-Associated Proteins; Neoplasm Proteins; Pyrroles; RNA, Messenger; Real-Time Polymerase Chain Reaction; Swine
PubMed: 26255619
DOI: 10.1111/jphp.12455 -
The FEBS Journal Jan 2017Influenza A viruses (IAVs) remain serious threats to public health because of the shortage of effective means of control. Developing more effective virus control...
Influenza A viruses (IAVs) remain serious threats to public health because of the shortage of effective means of control. Developing more effective virus control modalities requires better understanding of virus-host interactions. It has previously been shown that IAV induces the production of kynurenine, which suppresses T-cell responses, enhances pain hypersensitivity and disturbs behaviour in infected animals. However, the regulation of kynurenine biosynthesis during IAV infection remains elusive. Here we showed that IAV infection induced expression of interferons (IFNs), which upregulated production of indoleamine-2,3-dioxygenase (IDO1), which catalysed the kynurenine biosynthesis. Furthermore, IAV attenuated the IDO1 expression and the production of kynurenine through its NS1 protein. Interestingly, inhibition of viral replication prior to IFN induction limited IDO1 expression, while inhibition after did not. Finally, we showed that kynurenine biosynthesis was activated in macrophages in response to other stimuli, such as influenza B virus, herpes simplex virus 1 and 2 as well as bacterial lipopolysaccharides. Thus, the tight regulation of the kynurenine biosynthesis by host cell and, perhaps, pathogen might be a basic signature of a wide range of host-pathogen interactions, which should be taken into account during development of novel antiviral and antibacterial drugs.
Topics: Animals; Antiviral Agents; Female; Gene Expression Regulation; Host-Pathogen Interactions; Humans; Immunologic Factors; Indoleamine-Pyrrole 2,3,-Dioxygenase; Indoles; Influenza A Virus, H1N1 Subtype; Interferons; Kynurenine; Lung; Macrophages; Metabolic Networks and Pathways; Mice; Mice, Inbred BALB C; Orthomyxoviridae Infections; Oxazoles; Oximes; Primary Cell Culture; Pyrroles; Sulfonamides; Thiazoles; Transcriptome; Tryptophan; Viral Nonstructural Proteins; Virus Replication
PubMed: 27860276
DOI: 10.1111/febs.13966 -
Clinical Cancer Research : An Official... Jan 2009Prosurvival Bcl-2 proteins inhibit the mitochondrial and death receptor-mediated apoptotic pathways. Obatoclax is a small-molecule antagonist of the BH3-binding groove...
PURPOSE
Prosurvival Bcl-2 proteins inhibit the mitochondrial and death receptor-mediated apoptotic pathways. Obatoclax is a small-molecule antagonist of the BH3-binding groove of Bcl-2 proteins that may enhance tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) sensitivity and efficacy.
EXPERIMENTAL DESIGN
Human pancreatic cancer cell lines were incubated with obatoclax and/or TRAIL and cell viability, Annexin V labeling, caspase cleavage, and cytochrome c release were measured. In drug-treated cell lines, protein-protein interactions were studied by immunoprecipitation. Bax/Bak activation was analyzed using conformation-specific antibodies. Lentiviral short hairpin RNA was used to knockdown Bim, Bid, and apoptosis-inducing factor (AIF) expression.
RESULTS
Obatoclax reduced the viability of PANC-1 and BxPC-3 cell lines and synergistically enhanced TRAIL-mediated cytotoxicity. Obatoclax enhanced TRAIL-mediated apoptosis, as shown by Annexin V labeling, which was accompanied by caspase activation (caspase-8, -9, and -3) and cleavage of Bid. Obatoclax potentiated TRAIL-mediated Bax/Bak activation and the release of mitochondrial cytochrome c, Smac, and AIF. Mechanisms underlying the apoptotic effect of obatoclax include displacement of Bak from its sequestration by Bcl-x(L) or Mcl-1 and release of Bim from Bcl-2 or Mcl-1. Bid knockdown by short hairpin RNA attenuated caspase cleavage and cytotoxicity of obatoclax plus TRAIL. Bim knockdown failed to inhibit the cytotoxic effect of obatoclax alone or combined with TRAIL yet attenuated TRAIL-mediated cytotoxicity. AIF knockdown attenuated cytotoxicity of the drug combination.
CONCLUSIONS
Obatoclax potentiates TRAIL-mediated apoptosis by unsequestering Bak and Bim from Bcl-2/Bcl-x(L) or Mcl-1 proteins. This drug combination enhances Bid-mediated cross-talk between the mitochondrial and death receptor-mediated apoptotic pathways and may represent a novel therapeutic strategy against pancreatic cancer.
Topics: Apoptosis; BH3 Interacting Domain Death Agonist Protein; Caspases; Cell Line, Tumor; Cytochromes c; Humans; Indoles; Myeloid Cell Leukemia Sequence 1 Protein; Pancreatic Neoplasms; Proto-Oncogene Proteins c-bcl-2; Pyrroles; TNF-Related Apoptosis-Inducing Ligand; bcl-2 Homologous Antagonist-Killer Protein; bcl-2-Associated X Protein
PubMed: 19118042
DOI: 10.1158/1078-0432.CCR-08-1575 -
Viruses Oct 2019Viruses are the major causes of acute and chronic infectious diseases in the world. According to the World Health Organization, there is an urgent need for better...
Viruses are the major causes of acute and chronic infectious diseases in the world. According to the World Health Organization, there is an urgent need for better control of viral diseases. Repurposing existing antiviral agents from one viral disease to another could play a pivotal role in this process. Here, we identified novel activities of obatoclax and emetine against herpes simplex virus type 2 (HSV-2), echovirus 1 (EV1), human metapneumovirus (HMPV) and Rift Valley fever virus (RVFV) in cell cultures. Moreover, we demonstrated novel activities of emetine against influenza A virus (FLUAV), niclosamide against HSV-2, brequinar against human immunodeficiency virus 1 (HIV-1), and homoharringtonine against EV1. Our findings may expand the spectrum of indications of these safe-in-man agents and reinforce the arsenal of available antiviral therapeutics pending the results of further in vitro and in vivo tests.
Topics: Animals; Antiviral Agents; Biphenyl Compounds; Cell Culture Techniques; Chlorocebus aethiops; Dogs; Emetine; Enterovirus B, Human; HIV-1; Herpesvirus 2, Human; Homoharringtonine; Humans; Indoles; Madin Darby Canine Kidney Cells; Niclosamide; Pyrroles; Vero Cells; Virus Diseases; Viruses
PubMed: 31635418
DOI: 10.3390/v11100964 -
Neuro-oncology Advances 2023IDH-wildtype glioblastoma (GBM) is a highly malignant primary brain tumor with a median survival of 15 months after standard of care, which highlights the need for...
BACKGROUND
IDH-wildtype glioblastoma (GBM) is a highly malignant primary brain tumor with a median survival of 15 months after standard of care, which highlights the need for improved therapy. Personalized combination therapy has shown to be successful in many other tumor types and could be beneficial for GBM patients.
METHODS
We performed the largest drug combination screen to date in GBM, using a high-throughput effort where we selected 90 drug combinations for their activity onto 25 patient-derived GBM cultures. 43 drug combinations were selected for interaction analysis based on their monotherapy efficacy and were tested in a short-term (3 days) as well as long-term (18 days) assay. Synergy was assessed using dose-equivalence and multiplicative survival metrics.
RESULTS
We observed a consistent synergistic interaction for 15 out of 43 drug combinations on patient-derived GBM cultures. From these combinations, 11 out of 15 drug combinations showed a longitudinal synergistic effect on GBM cultures. The highest synergies were observed in the drug combinations Lapatinib with Thapsigargin and Lapatinib with Obatoclax Mesylate, both targeting epidermal growth factor receptor and affecting the apoptosis pathway. To further elaborate on the apoptosis cascade, we investigated other, more clinically relevant, apoptosis inducers and observed a strong synergistic effect while combining Venetoclax (BCL targeting) and AZD5991 (MCL1 targeting).
CONCLUSIONS
Overall, we have identified via a high-throughput drug screening several new treatment strategies for GBM. Moreover, an exceptionally strong synergistic interaction was discovered between kinase targeting and apoptosis induction which is suitable for further clinical evaluation as multi-targeted combination therapy.
PubMed: 37455945
DOI: 10.1093/noajnl/vdad073 -
Oral Oncology Feb 2014More than half of head and neck squamous cell carcinoma (HNSCC) patients are initially treated with curative intent, but will relapse over the course of their disease...
OBJECTIVES
More than half of head and neck squamous cell carcinoma (HNSCC) patients are initially treated with curative intent, but will relapse over the course of their disease and have poor prognosis with a median survival of approximately 6months. Novel therapeutic approaches are in desperate need for this patient population. The anti-apoptotic BCL-2 family proteins such as BCL-2, BCL-XL, and MCL-1 are involved in oncogenesis and chemoresistance and are overexpressed in HNSCC. Obatoclax is a small-molecule antagonist of the BH3-binding groove of anti-apoptotic BCL-2 family. We evaluated the activity of obatoclax against 4 HNSCC cell lines (UMSCC-1, Cal33, 1483, UMSCC-22A).
METHODS
Cell viability was determined by MTT assay, cell cycle status by propidium iodide staining, and apoptosis by Annexin-V staining and immunoblotting. Autophagy was assessed by immunofluorescence and immunoblotting.
RESULTS
All four HNSCC cell lines were highly sensitive to single-agent obatoclax with IC50's ranging from 46 to 177nM. Obatoclax induced apoptosis in all four HNSCC cell lines as evidenced by increases in sub-G1 DNA content, Annexin-V staining, and PARP cleavage. In addition, obatoclax induced autophagy in all 4 cell lines, and the addition of the autophagy inhibitor chloroquine enhanced obatoclax cytotoxicity.
CONCLUSION
Our findings demonstrate potent monotherapeutic activity of obatoclax against HNSCC cells, and enhancement of this activity in the presence of chloroquine. This preclinical study suggests that obatoclax might have therapeutic value in the treatment of HNSCC, either alone or in combination with inhibitors of autophagy.
Topics: Apoptosis; Autophagy; Carcinoma, Squamous Cell; Cell Survival; Head and Neck Neoplasms; Humans; Indoles; Inhibitory Concentration 50; Proto-Oncogene Proteins c-bcl-2; Pyrroles
PubMed: 24216166
DOI: 10.1016/j.oraloncology.2013.10.013 -
Nan Fang Yi Ke Da Xue Xue Bao = Journal... Apr 2016To explore whether MG-132 could enhance the anti-tumor activity of obatoclax against esophageal cancer cell line CaES-17.
OBJECTIVE
To explore whether MG-132 could enhance the anti-tumor activity of obatoclax against esophageal cancer cell line CaES-17.
METHODS
MTT assay was used to determine the cytotoxicity of obatoclax and MG-132 in CaES-17 cells. The IC(50) of obatoclax and MG-132 were used to determine the molar ratio (1:2.4) of the two drugs for combined treatment of the cells. The concentrations of obatoclax and MG-132 ranged from 1/8 IC(50) to 4 IC(50) after serial dilution, and their combination index (CI) was calculated using CompuSyn software. The expression of ubiquitin and the cleavage of PARP, caspase-9, phospho-histone H3 and phospho-aurora A/B/C in the exposed cells were examined with Western blotting; the cell apoptosis was measured by flow cytometry with Annexin V staining, and the percentage of cells in each cell cycle phase was also determined by flow cytometry.
RESULTS
The CI of obatoclax and MG-132 was 0.296 for a 50% inhibition of Caes-17 cells and was 0.104 for a 95% inhibition. The cells treated with obatoclax or MG-132 alone showed increased expression of ubiquitin and cleavage of PARP and caspase-9. Compared with the cells treated with obatoclax or MG-132 alone, the cells with a combined treatment exhibited significantly increased expression of ubiquitin, cleavage of PARP and caspase-9, and expression of phospho-Histone H3 (P<0.05). The combined treatment of the cells also resulted in significantly increased expression of phospho-Aurora A/B/C compared with obatoclax treatment alone. The cells with the combined treatment showed significantly higher percentages of apoptotic cells and cells in sub-G(1) and G(2)/M phases compared with the cells treated with either of the drugs (P<0.05).
CONCLUSION
Obatoclax combined with MG-132 shows a significant synergistic anti-tumor effect against esophageal cancer CaES-17 cells by inducing apoptosis and cell cycle arrest.
Topics: Apoptosis; Caspase 9; Cell Cycle Checkpoints; Cell Line, Tumor; Esophageal Neoplasms; Histones; Humans; Indoles; Leupeptins; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerases; Pyrroles
PubMed: 27113178
DOI: No ID Found -
Nature Reviews. Drug Discovery Jun 2010Mitochondria are the cells' powerhouse, but also their suicidal weapon store. Dozens of lethal signal transduction pathways converge on mitochondria to cause the... (Review)
Review
Mitochondria are the cells' powerhouse, but also their suicidal weapon store. Dozens of lethal signal transduction pathways converge on mitochondria to cause the permeabilization of the mitochondrial outer membrane, leading to the cytosolic release of pro-apoptotic proteins and to the impairment of the bioenergetic functions of mitochondria. The mitochondrial metabolism of cancer cells is deregulated owing to the use of glycolytic intermediates, which are normally destined for oxidative phosphorylation, in anabolic reactions. Activation of the cell death machinery in cancer cells by inhibiting tumour-specific alterations of the mitochondrial metabolism or by stimulating mitochondrial membrane permeabilization could therefore be promising therapeutic approaches.
Topics: Animals; Antineoplastic Agents; Cell Membrane Permeability; HSP90 Heat-Shock Proteins; Humans; Indoles; Mitochondria; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Pyrroles; Reactive Oxygen Species; Resveratrol; Stilbenes
PubMed: 20467424
DOI: 10.1038/nrd3137 -
International Journal of Molecular... Aug 2019This Special Issue of (IJMS) covers one of the most intriguing and emerging fields in terms of molecular oncology and uro-oncologic research efforts over the recent...
This Special Issue of (IJMS) covers one of the most intriguing and emerging fields in terms of molecular oncology and uro-oncologic research efforts over the recent years, namely urothelial carcinoma of the bladder (UCB), as well as urothelial carcinoma of the upper urinary tract (UTUC). A total of 8 articles published in this Special Issue highlight the current progress in molecular oncology and cancer genetics in UCB, including a wide range of research topics, such as FGFR-inhibitors, sarcopenia in UCB, molecular predictors of response following neoadjuvant chemotherapy, exercise cardiac training impacts in the murine UCB model, Obatoclax, tropomyosins as potential biomarkers, immunotherapeutic approaches, as well as a transcriptional analysis of immunohistochemically defined UCB-subgroups. Find a brief summary of the respective articles below.
Topics: Animals; Exercise; Humans; Immunotherapy; Neoadjuvant Therapy; Urinary Bladder; Urinary Bladder Neoplasms; Urothelium
PubMed: 31382543
DOI: 10.3390/ijms20153790 -
Molecular Pharmacology Apr 2012Prior studies demonstrated that resistance to the ERBB1/2 inhibitor lapatinib could be overcome by the B cell CLL/lymphoma-2 (BCL-2) family antagonist obatoclax...
Prior studies demonstrated that resistance to the ERBB1/2 inhibitor lapatinib could be overcome by the B cell CLL/lymphoma-2 (BCL-2) family antagonist obatoclax (GX15-070). Coadministration of lapatinib with obatoclax caused synergistic cell killing by eliciting autophagic cell death that was dependent upstream on mitochondrial reactive oxygen species generation and increased p62 levels and downstream on activation of p38 mitogen-activated protein kinase and inactivation of mammalian target of rapamycin. By immunohistochemical analysis, in drug combination-treated cells, microtubule-associated protein light chain 3 (LC3) associated with mitochondrial (cytochrome c oxidase), autophagosome (p62), and autolysosome (lysosomal associated membrane protein 2) proteins. Treatment of cells with 3-methyladenine or knockdown of beclin 1 was protective, whereas chloroquine treatment had no protective effect. Expression of myeloid cell leukemia-1 (MCL-1), compared with that of BCL-2 or BCL-2-related gene long isoform, protected against drug combination lethality. Lapatinib and obatoclax-initiated autophagy depended on NOXA-mediated displacement of the prosurvival BCL-2 family member, MCL-1, from beclin 1, which was essential for the initiation of autophagy. Taken together, our data argue that lapatinib and obatoclax-induced toxic autophagy is due to impaired autophagic degradation, and this disturbance of autophagic flux leads to an accumulation of toxic proteins and loss of mitochondrial function.
Topics: Antineoplastic Agents; Autophagy; Cell Death; Cell Line, Tumor; Genes, erbB-2; Humans; Indoles; Lapatinib; Proto-Oncogene Proteins c-bcl-2; Pyrroles; Quinazolines
PubMed: 22219388
DOI: 10.1124/mol.111.076851