scholarly journals EXTH-62. PRECLINICAL EFFICACY OF THE IMIPRIDONE ONC-206 AGAINST MEDULLOBLASTOMA

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii100-ii101
Author(s):  
Tobey MacDonald ◽  
Anshu Malhotra ◽  
Jingbo Liu ◽  
Hongying Zhang ◽  
Matthew Schneiderjan ◽  
...  
Keyword(s):  
Cell Death ◽  
Malignant Glioma ◽  
Ex Vivo ◽  
Clinical Results ◽  
Normal Brain ◽  
Dependent Manner ◽  
Group 3 ◽  
Dose Dependent

Abstract Treatment for medulloblastoma (MB) is typically ineffective for MYC amplified or metastatic SHH, Group 3 and 4 subgroups. Promising preclinical and clinical results have been obtained for adult and pediatric malignant glioma treated with ONC-201, a selective antagonist of DRD2, a G-protein coupled receptor that regulates prosurvival pathways. Herein, we report the activity of ONC-201 and ONC-206, which has increased non-competitive antagonism of DRD2, against MB. We treated three different MB cell types representative of SHH- and Group 3-like cells, with varied levels of DRD2 expression, and consistently observed increased cell death in a dose-dependent manner at lower doses of ONC-206 compared to ONC-201. We also evaluated ClpP as an additional drug target in MB. ClpP is a mitochondrial protease that has been shown to directly bind and be activated by ONC 201, and is highly expressed at the protein level across pediatric MB, malignant glioma and ATRT, but not normal brain. We observed that similar to ONC-201, ONC-206 treatment of MB cells induces the restoration of mitochondrial membrane potential to the non-proliferative state, degradation of the mitochondrial substrate SDHB, reduction in survivin and elevation in ATF4 (integrated stress response). Importantly, ONC-206 treatment induced significant cell death of patient-derived SHH, WNT, and Group 3 tumors ex vivo and Group 4 cells in vitro, while having no observable toxicity in normal brain. ONC-206 treatment of a transgenic mouse model of Shh MB in vivo significantly reduces tumor growth and doubles survival time in a dose-dependent manner following 2 weeks of therapy. Additional in vivo data will be reported in preparation for a planned Phase I study of ONC-206 in children with malignant brain tumors.

scholarly journals MODL-06. PRECLINICAL EFFICACY OF THE IMIPRIDONE ONC-206 AGAINST MEDULLOBLASTOMA

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii412-iii412
Author(s):  
Anshu Malhotra ◽  
Jingbo Liu ◽  
Hongying Zhang ◽  
Minhui Ma ◽  
Jose Velazquez Vega ◽  
...  
Keyword(s):  
Cell Death ◽  
Ex Vivo ◽  
Cell Types ◽  
Clinical Results ◽  
Normal Brain ◽  
Dependent Manner ◽  
Competitive Antagonism ◽  
Group 3

Abstract Treatment for medulloblastoma (MB) is typically ineffective for MYC amplified or metastatic SHH, Group 3 and 4 subgroups. Promising preclinical and clinical results have been obtained in brain cancers treated with ONC-201, a selective antagonist of DRD2, a G-protein coupled receptor that regulates prosurvival pathways. Herein, we report the activity of ONC-201 and ONC-206, which has increased non-competitive antagonism of DRD2, against MB. We treated three different MB cell types representative of SHH- and Group 3-like cells, with varied levels of DRD2 expression, and consistently observed increased cell death in a dose-dependent manner at lower doses of ONC-206 compared to ONC-201. We also evaluated ClpP as an additional drug target in MB. ClpP is a mitochondrial protease that has been shown to directly bind and be activated by ONC 201, and is highly expressed at the protein level across pediatric MB, malignant glioma and ATRT, but not normal brain. We observed that similar to ONC-201, ONC-206 treatment of MB cells induces the restoration of mitochondrial membrane potential to the non-proliferative state, degradation of the mitochondrial substrate SDHB, reduction in survivin and elevation in ATF4 (integrated stress response). Importantly, ONC-206 treatment induced significant cell death of patient-derived SHH, WNT, and Group 3 tumors ex vivo and Group 4 cells in vitro, while having no observable toxicity in normal brain. Efficacy studies of ONC-206 against MB in vivo will be reported in preparation for a planned Phase I study of ONC-206 in children with malignant brain tumors.

scholarly journals TB-4 Antitumor effects of a novel curcumin derivative curcumin monoglucuronide on glioblastoma cells in vitro and in vivo

2021 ◽  
Vol 3 (Supplement_6) ◽  
pp. vi6-vi6
Author(s):  
Takashi Fujii ◽  
Shun Yamamuro ◽  
Masamichi Takahashi ◽  
Akihide Kondo ◽  
Yoshitaka Narita ◽  
...  
Keyword(s):  
Cell Death ◽  
Water Soluble ◽  
Dependent Manner ◽  
Antitumor Effects ◽  
Multiple Cell ◽  
Human Gbm ◽  
Dose Dependent ◽  
Novel Therapeutic

Abstract The therapeutic outcome of glioblastomas (GBMs) is still very poor. Therefore, invention of novel therapeutic methods against GBM cases is considered urgent. The antitumor effects of naturally-derived compounds are attracting attention recently, and therapeutic efficacy of curcumin, a plant-derived compound previously used for multiple purpose, has been indicated in many cancer systems; however, clinical application of curcumin is considered difficult because of its poor bioavailability (under 1 %). Curcumin monoglucuronide (CMG), a water-soluble prodrug of curcumin recently developed for overcoming this weakness, has been demonstrated excellent antitumor effects for several malignancies in vitro and in vivo; therefore, we investigated the effects of CMG against GBM cells. CMG induced cell death of human GBM cells lines (T98G, U251MG, and U87MG) by dose dependent manner by triggering multiple forms of cell death such as apoptosis and perthanatos. Immunoblotting of CMG-treated GBM cell lysates demonstrated activation of multiple cell death signaling. Furthermore, immunodeficiency mice harboring intracerebral U87MG cell xenografts systemically treated by CMG showed significantly prolonged survival compared with control mice. These results suggest CMG would be a novel therapeutic agent against GBM cases.

In Vitro Activity of a Novel Fully Human Anti-CD40 Antibody CHIR-12.12 in Chronic Lymphocytic Leukemia: Blockade of CD40 Activation and Induction of ADCC.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2504-2504 ◽  
Author(s):  
Xia Tong ◽  
Georgios V. Georgakis ◽  
Long Li ◽  
O’Brien Susan ◽  
Younes Anas ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Cell Death ◽  
Chronic Lymphocytic Leukemia ◽  
Cell Line ◽  
Blood Donors ◽  
Lymphocytic Leukemia ◽  
Dependent Manner ◽  
Dose Dependent

Abstract B-cell chronic lymphocytic leukemia (CLL) is characterized by in vivo accumulation of long-lived CD5+ B cells. However when cultured in vitro CLL cells die quickly by apoptosis. Protection from apoptosis in vivo is believed to result from supply of survival signals provided by cells in the microenvironment. We and others have previously reported that CLL cells express CD40 receptor, and that CD40 stimulation of CLL cells may rescue CLL cells from spontaneous and drug-induced apoptosis in vitro. These observations suggested that blocking CD40-CD40L pathway might deprive CLL cells from survival signals and induce apoptosis. To test this hypothesis, we have generated a fully human anti-CD40 blocking monoclonal antibody in XenoMousemice (Abgenix, Inc.). The antibody CHIR-12.12 was first evaluated for its effect on normal human lymphocytes. Lymphocytes from all 10 healthy blood donors did not proliferate in response to CHIR-12.12 at any concentration tested (0.0001 mg/ml to 10 mg/ml range). In contrast, activating CD40 on normal B-lymphocytes by CD40L induced their proliferation in vitro. Importantly, CHIR-12.12 inhibited CD40L- induced proliferation in a dose dependent manner with an average IC50 of 51 ± 26 pM (n=10 blood donors). The antagonistic activity of CHIR-12.12 was then tested in primary CLL samples from 9 patients. CHIR-12.12 alone did not induce CLL cell proliferation. In contrast, primary CLL cells incubated with CD40L, either resisted spontaneous cell death or proliferated. This effect was reversed by co-incubation with CHIR-12.12 antibody, restoring CLL cell death (n=9). CHIR-12.12 was then examined for its ability to lyse CLL cell line EHEB by antibody dependent cell mediated cytotoxicity (ADCC). Freshly isolated human NK cells from normal volunteer blood donors were used as effector cells. CHIR-12.12 showed lysis activity in a dose dependent manner and produced maximum lysis levels at 0.1 mg/ml. When compared with rituximab, CHIR-12.12 mediated greater maximum specific lysis (27.2 % Vs 16.2 %, p= 0.007). The greater ADCC by CHIR-12.12 was not due to higher density of CD40 molecules on CLL cell line compared to CD20 molecules. The CLL target cells expressed 509053 ±13560 CD20 molecules compared to 48416 ± 584 CD40 molecules. Collectively, these preclinical data suggest that CHIR-12.12 monoclonal antibody may have a therapeutic role in patients with CLL.

scholarly journals Sesamol Induces Apoptosis-Like Cell Death in Leishmania donovani

2021 ◽  
Vol 11 ◽  
Author(s):  
Rahat Ali ◽  
Shams Tabrez ◽  
Sajjadul Kadir Akand ◽  
Fazlur Rahman ◽  
Atahar Husein ◽  
...  
Keyword(s):  
Cell Death ◽  
Dna Fragmentation ◽  
Leishmania Donovani ◽  
Ex Vivo ◽  
Annexin V ◽  
Parasite Load ◽  
Ultrastructural Changes ◽  
Dependent Manner

BackgroundVisceral leishmaniasis (VL), caused by the protozoan parasite Leishmania donovani (L. donovani), is the most severe form of leishmaniasis. It is largely responsible for significant morbidity and mortality in tropical and subtropical countries. Currently, available therapeutics have lots of limitations including high-cost, adverse side-effects, painful route of administration, less efficacy, and resistance. Therefore, it is time to search for cheap and effective antileishmanial agents. In the present work, we evaluated the antileishmanial potential of sesamol against promastigotes as well as intracellular amastigotes. Further, we tried to work out its mechanism of antileishmanial action on parasites through different assays.MethodologyIn vitro and ex vivo antileishmanial assays were performed to evaluate the antileishmanial potential of sesamol on L. donovani. Cytotoxicity was determined by MTT assay on human THP-1-derived macrophages. Sesamol-induced morphological and ultrastructural changes were determined by electron microscopy. H2DCFDA staining, JC-1dye staining, and MitoSOX red staining were performed for reactive oxygen assay (ROS), mitochondrial membrane potential, and mitochondrial superoxide, respectively. Annexin V/PI staining for apoptosis, TUNEL assay, and DNA laddering for studying sesamol-induced DNA fragmentation were performed.ConclusionsSesamol inhibited the growth and proliferation of L. donovani promastigotes in a dose-dependent manner. It also reduced the intracellular parasite load without causing significant toxicity on host-macrophages. Overall, it showed antileishmanial effects through induction of ROS, mitochondrial dysfunction, DNA fragmentation, cell cycle arrest, and apoptosis-like cell death to parasites. Our results suggested the possible use of sesamol for the treatment of leishmaniasis after further in vivo validations.

scholarly journals The effect of chlorin e6 drug on platelet aggregation activity

2019 ◽  
Vol 8 (3) ◽  
pp. 4-10 ◽  
Author(s):  
N. N. Petrishchev ◽  
M. A. Galkin ◽  
T. G. Grishacheva ◽  
I. N. Dementjeva ◽  
S. G. Chefu
Keyword(s):  
Platelet Aggregation ◽  
Laser Irradiation ◽  
Ex Vivo ◽  
Platelet Rich Plasma ◽  
Dependent Manner ◽  
Functional Changes ◽  
Aggregation Activity ◽  
Dose Dependent

The goal of the study is to evaluate the effect of Radachlorin (OOO “RADA-PHARMA”, Russia) (RC) on platelet aggregation in ex vivo and in vivo experiments. The experiments were conducted on male Wistar rats. Platelet aggregation activity was determined in platelet-rich plasma (PRP) using a turbidimetric method and the aggregation inducer was ADP at a final concentration of 1.25 μM. PRP samples containing RC were irradiated with ALOD-Granat laser device (OOO “Alkom Medika”, Russia) at 662 nm wavelength with 0.05 W/cm2 power density. After a 5-minute incubation of PRP with RC in the dark, dose-dependent inhibition of platelet aggregation was observed. Laser irradiation (12.5 J/cm2 and, especially, 25 J/cm2) increased the inhibitory effect of RC. 3 hours after intravenous administration of RC, the rate and intensity of platelets aggregation did not change, while disaggregation slowed down significantly. Irradiation at a dose of 5 J/cm2 did not affect the platelets aggregation kinetics, and disaggregation slowed down even more at 10 J/cm2, and at 20 J/cm2 the rate and intensity of platelets aggregation decreased, and no disaggregation occurred.In vitro, RC inhibited the ADP-induced platelet aggregation in rats in a dose-dependent manner; after laser irradiation, this effect was enhanced significantly. The effect of RC on circulating platelets leads to a change in their functional state, which manifests in slowing down the disaggregation after exposure to ADP. After laser irradiation (10 J/cm2 and, especially, 20 J/cm2), the severity of the functional changes increases. The role of decreasing the disaggregation activity of platelets in the mechanism of vascular thrombosis in the affected area of photodynamic therapy (PDT) is discussed.

Limiting Carryover Events Resulting from Cell Surface Retention of VSV-G Pseudotyped HIV-Lentivector Particles on Hematopoietic Targets

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3735-3735
Author(s):  
Lee O’Neill ◽  
Yung-Wei Pan ◽  
Amy M. Skinner ◽  
Peter Kurre
Keyword(s):  
Gene Transfer ◽  
Cell Surface ◽  
Ex Vivo ◽  
Target Cells ◽  
Vector Particle ◽  
Dependent Manner ◽  
Dose Dependent ◽  
Vector Particles

Abstract Preclinical evidence and clinical trials speak to the therapeutic potential of retrovirus vectors for the heritable genetic modification of cells. Careful evaluation of the antecedent risks is critical to move these applications forward. Others previously demonstrated the persistence of intact vector particles on the surface of target cells. Inadvertent particle transfer after in vivo applications could lead to the transduction of bystander tissues, or provoke immunological responses. We recently demonstrated prolonged adherence of VSV-G pseudotyped, HIV-1 derived lentivirus particles after ex vivo transduction culture of murine hematopoietic target cells (1°) with subsequent transduction of secondary (2°) targets in vitro and in vivo. Extended particle adherence is independent of Env pseudotype and routine wash procedures (Pan et al., J Virol. Jan 2007). We hypothesized that unwanted carryover could be minimized by disrupting the vector particle attachment to 2° cells while maintaining uptake to 1° targets. Initial studies indicated that the transduction of 1° targets at 4°C (to prevent uptake) for up to 6 hours followed by serial PBS washes and subsequent direct co-culture with fibroblasts resulted in undiminished 2° gene transfer compared to transduction at 37°C. Conversely, post-transduction exposure to escalating concentrations of citric acid resulted in a systematic decrease in both 1° and 2° gene transfer rates. This is consistent with separable mechanisms for pH sensitive VSV-G mediated uptake of particles in 1° targets and the receptor independent attachment responsible for carryover and 2° transduction, respectively. Glycosaminoglycans, including heparin, quantitatively bind to pseudotyped vector particles. We found that exposure of particles to heparin effectively abrogated subsequent transduction of cells by disrupting attachment. Remarkably, serial heparin washes at the conclusion of transduction had only minimal effects on gene transfer to 1° targets, but resulted in a two-log reduction in 2° gene transfer. Increases in the concentration of protamine sulfate (a polycation) during transduction partly reversed the effect of heparin (a polyanion), demonstrating the residual impact of electrostatic interactions on attachment of retrovirus particles from the 1° cell. In further studies we showed that trypsin washes following vector exposure incompletely cleaved 1° cell surface bound particles while pronase effectively degraded cell surface bound particles in a dose dependent manner, abrogating carryover. Because pronase at high concentrations also compromised cell surface epitope integrity we studied the expression of chemokine receptor (CXCR) 4, both a critical mediator of progenitor cell homing to the bone marrow and a representative protease-sensitive surface molecule. These experiments revealed a dose dependent degradation of CXCR4 on the cell surface of 1° target cells and rapid regeneration within three hours, critical for applications involving the injection of ex vivo modified hematopoietic cells. In conclusion, our results demonstrate that select wash procedures can disrupt the ability of virus particles to bind secondary targets, degrade residual surface bound particles and reduce gene transfer to inadvertent 2° targets in vitro by up to 99%. These studies are important first steps in understanding and limiting inadvertent carryover in the context of gene therapy while maximizing target cell transduction.

Synergistic Effects of a Novel Water-Soluble Small Molecule, ON 013105, and Rituximab on Mantle Cell Lymphoma In Vitro and In Vivo

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 771-771
Author(s):  
Anil Prasad ◽  
Ashutosh Shrivastava ◽  
Ramana Reddy ◽  
Amanda M. Gillum ◽  
E. Premkumar Reddy ◽  
...  
Keyword(s):  
Cell Death ◽  
Tumor Volume ◽  
Cell Lymphoma ◽  
Single Agent ◽  
Dependent Manner ◽  
Mantle Cell ◽  
Dose Dependent ◽  
Efficacy Studies

Abstract Abstract 771 Mantle cell lymphoma (MCL) is a well-defined subtype of B-cell non-Hodgkin's lymphoma characterized by a t(11;14)(q13;q32) chromosomal translocation, and associated with constitutive over-expression of cyclin D1. MCL generally has poor clinical outcome marked by relapse. There is considerable need for novel and more effective agents against MCL. ON 013105 belongs to the styryl benzylsulfones, a novel family of non-ATP competitive kinase inhibitors with potent antitumor activity. Here, we report that ON 013105 induced cell death in a dose-dependent manner in two well-characterized MCL cell lines, Granta 519 and Z138C. In vitro cell death was preceded by the activation of caspases 3 and 9 and cleavage of PARP, indicating induction of apoptosis. In addition, ON 013105-treated cells exhibited reduced expression of cyclin D1 and c-myc. These effects on expression and apoptosis were not evident in cells treated with ON 013101, an inactive (non-cytotoxic) isomer of ON 013105. Since it is common clinical practice to combine Rituximab (RTX) with chemotherapy regimens in treating CD20+ B cell-lymphoma, we studied ON 013105 combined with rituximab, and found ON 013105-induced apoptosis more efficiently than when employed as a single agent. The combination effect on cell death was synergistic in nature. To further study this activity, we focused on Mcl-1, a member of the anti-apoptotic Bcl-2 family known to inhibit apoptosis induced by cytotoxic stimuli through antagonizing pro-apoptotic Bcl-2 family members. We observed a dramatic decrease in Mcl-1 expression in cells treated with ON 013105 (but not with ON 013101) in combination with RTX, compared to ON 013105 alone. We also evaluated the effects of ON 013105 in combination with Doxorubicin or Vincristine and found that both these compounds also significantly enhanced the cytotoxic effects of ON 013105. In vivo pharmacokinetics studies in a mouse model system revealed that plasma concentrations up to 50 μM could be safely achieved by administering ON 013105 at 100 mg/kg via i.v or i.p routes. Significant levels of ON 013100 (30-40% of the peak levels of ON 013105), an active metabolite, were also detected in the circulation, presumably due to the in vivo dephosphorylation of ON 013105 by phosphatase action. ON 013105 was well tolerated in mice, both as a single agent and when used in combination with rituximab, and there were no systemic toxic effects to the host and no loss in body weight. In vivo efficacy studies in mouse xenograft models employing transplanted MCL cells demonstrated that ON 013105 effectively inhibited tumor growth in a dose-dependent manner. ON 013015 at 25 mg/kg (Q2D) and 75mg/kg (Q7D) induced 46% and 80 % reduction of tumor volume, respectively, compared to controls, over 4 weeks of treatment. Moreover, ON 013105 at 25 mg/kg (Q2D) in a combination regimen with RTX (2.5 mg/kg, Q3D) induced over 85% reduction of tumor volume. Though in vivo efficacy studies of ON013015 (25 mg/kg, Q2D) in combination with Doxorubicin (3.5mg/kg, Q7D) or Vincristine (0.3mg/kg, Q2D) showed drastic decrease in tumor growth in mouse models, this effect was accompanied by severe side effects to the host, including mortality. In sum, ON 013105, alone and in combination with RTX may be a potent therapeutic agent against MCL. A Phase I dose escalation trial of ON 013105 as a single agent is underway in patients with relapsed/refractory lymphoma including MCL. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Estrogen receptor coregulator binding modulator (ERX-11) enhances the activity of CDK4/6 inhibitors against estrogen receptor-positive breast cancers

2019 ◽  
Vol 21 (1) ◽  
Author(s):  
Suryavathi Viswanadhapalli ◽  
Shihong Ma ◽  
Gangadhara Reddy Sareddy ◽  
Tae-Kyung Lee ◽  
Mengxing Li ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Estrogen Receptor ◽  
Combination Therapy ◽  
Endocrine Therapy ◽  
Tumor Regression ◽  
Ex Vivo ◽  
Dependent Manner ◽  
Dose Dependent

Abstract Background CDK4/6 inhibitors in combination with endocrine therapy (AE/AI/SERDs) are approved for the treatment of ER+ advanced breast cancer (BCa). However, not all patients benefit from CDK4/6 inhibitors therapy. We previously reported a novel therapeutic agent, ERX-11, that binds to the estrogen receptor (ER) and modulates ER-coregulator interactions. Here, we tested if the combination of ERX-11 with agents approved for ER+ BCa would be more potent. Methods We tested the effect of combination therapy using BCa cell line models, including those that have acquired resistance to tamoxifen, letrozole, or CDK4/6 inhibitors or have been engineered to express mutant forms of the ER. In vitro activity was tested using Cell Titer-Glo, MTT, and apoptosis assays. Mechanistic studies were conducted using western blot, reporter gene assays, RT-qPCR, and mass spectrometry approaches. Xenograft, patient-derived explants (PDEs), and xenograft-derived explants (XDE) were used for preclinical evaluation and toxicity. Results ERX-11 inhibited the proliferation of therapy-resistant BCa cells in a dose-dependent manner, including ribociclib resistance. The combination of ERX-11 and CDK4/6 inhibitor was synergistic in decreasing the proliferation of both endocrine therapy-sensitive and endocrine therapy-resistant BCa cells, in vitro, in xenograft models in vivo, xenograft-derived explants ex vivo, and in primary patient-derived explants ex vivo. Importantly, the combination caused xenograft tumor regression in vivo. Unbiased global mass spectrometry studies demonstrated profound decreases in proliferation markers with combination therapy and indicated global proteomic changes in E2F1, ER, and ER coregulators. Mechanistically, the combination of ERX-11 and CDK4/6 inhibitor decreased the interaction between ER and its coregulators, as evidenced by immunoprecipitation followed by mass spectrometry studies. Biochemical studies confirmed that the combination therapy significantly altered the expression of proteins involved in E2F1 and ER signaling, and this is primarily driven by a transcriptional shift, as noted in gene expression studies. Conclusions Our results suggest that ERX-11 inhibited the proliferation of BCa cells resistant to both endocrine therapy and CDK4/6 inhibitors in a dose-dependent manner and that the combination of ERX-11 with a CDK4/6 inhibitor may represent a viable therapeutic approach.

Tetraarsenic oxide–induced inhibition of malignant glioma cell invasion in vitro via a decrease in matrix metalloproteinase secretion and protein kinase B phosphorylation

2014 ◽  
Vol 121 (6) ◽  
pp. 1483-1491 ◽  
Author(s):  
Ho-Shin Gwak ◽  
Myung-Jin Park ◽  
In-Chul Park ◽  
Sang Hyeok Woo ◽  
Hyeon-Ok Jin ◽  
...  
Keyword(s):  
Malignant Glioma ◽  
Cell Lines ◽  
Glioma Cell ◽  
Dependent Manner ◽  
Akt Phosphorylation ◽  
Glioma Cell Lines ◽  
Gsk 3Β ◽  
Dose Dependent

Object Local invasiveness of malignant glioma is a major reason for the failure of current treatments including surgery and radiation therapy. Tetraarsenic oxide (As4O6 [TAO]) is a trivalent arsenic compound that has potential anticancer and antiangiogenic effects in selected cancer cell lines at a lower concentration than arsenic trioxide (As2O3 [ATO]), which has been more widely tested in vitro and in vivo. The authors tried to determine the cytotoxic concentration of TAO in malignant glioma cell lines and whether TAO would show anti-invasive effects under conditions independent of cell death or apoptosis. Methods The human phosphatase and tensin homolog (PTEN)-deficient malignant glioma cell lines U87MG, U251MG, and U373MG together with PTEN-functional LN428 were cultured with a range of micromolar concentrations of TAO. The invasiveness of the glioma cell lines was analyzed. The effect of TAO on matrix metalloproteinase (MMP) secretion and membrane type 1 (MT1)-MMP expression was measured using gelatin zymography and Western blot, respectively. Akt, or protein kinase B, activity, which is a downstream effector of PTEN, was assessed with a kinase assay using glycogen synthesis kinase-3β (GSK-3β) as a substrate and Western blotting of phosphorylated Akt. Results Tetraarsenic oxide inhibited 50% of glioma cell proliferation at 6.3–12.2 μM. Subsequent experiments were performed under the same TAO concentrations and exposure times, avoiding the direct tumoricidal effect of TAO, which was confirmed with apoptosis markers. An invasion assay revealed a dose-dependent decrease in invasiveness under the influence of TAO. Both the gelatinolytic activity of MMP-2 and MT1-MMP expression decreased in a dose-dependent manner in all cell lines, which was in accordance with the invasion assay results. The TAO decreased kinase activity of Akt on GSK-3β assay and inhibited Akt phosphorylation in a dose-dependent manner in all cell lines regardless of their PTEN status. Conclusions These results showed that TAO effectively inhibits proliferation of glioblastoma cell lines and also exerts an anti-invasive effect via decreased MMP-2 secretion, decreased MT1-MMP expression, and the inhibition of Akt phosphorylation under conditions devoid of cytotoxicity. Further investigations using an in vivo model are needed to evaluate the potential role of TAO as an anti-invasive agent.

Aprotinin Reduces Nitric Oxide Production in Vitro and in Vivo in a Dose-Dependent Manner

1998 ◽  
Vol 94 (5) ◽  
pp. 505-509 ◽  
Author(s):  
N. L. Bruda ◽  
B. J. Hurlbert ◽  
G. E. Hill
Keyword(s):  
Nitric Oxide ◽  
Cardiopulmonary Bypass ◽  
Interleukin 1 ◽  
Dependent Manner ◽  
Group 3 ◽  
Anti Inflammatory ◽  
Group 2 ◽  
Dose Dependent

1. Cardiopulmonary bypass is associated with an increase in nitric oxide concentrations, and plasma levels of tumour necrosis factor and interleukin-1. Aprotinin, a serine protease inhibitor, commonly used during cardiopulmonary bypass to reduce blood loss, has been demonstrated to exhibit significant anti-inflammatory effects during and after cardiopulmonary bypass. 2. Airway nitric oxide was measured during cardiopulmonary bypass in 10 controls (Group 1), 10 subjects receiving half-dose aprotinin (Group 2) and 10 patients receiving full-dose aprotinin (Group 3). In vitro, a murine bronchial epithelial cell line (LA-4) was cultured with cytomix (a combination of tumour necrosis factor, interleukin-1, and (γ-interferon) with and without aprotinin in increasing concentrations. Nitrite concentrations, the stable and measureable end-product of nitric oxide oxidative metabolism, were measured in the culture supernatant by chemiluminescence. 3. Airway nitric oxide concentrations were increased after 50 min cardiopulmonary bypass compared with that measured at 5 min in controls (53 ± 5 versus 29 ± 3 ppb, P < 0.05) but not in the aprotinin-treated groups (25 ± 4 versus 14 ± 5, Group 2; 21 ± 6 versus 15 ± 3 ppb, Group 3). 4. In a dose-dependent manner, nitrite levels (means ± S.E.M.) were significantly reduced by aprotinin at 500 and 1000 units/ml when compared with cells cultured in the presence of cytomix alone (P < 0.05). 5. These data demonstrate that aprotinin, in a dose-responsive manner, reduces nitric oxide production in vivo and reduces cytokine-induced nitrite production by murine bronchial epithelial cells in vitro. Since increased airway nitric oxide is found in inflammatory lung diseases, like asthma, and anti-inflammatory therapy reduces the concentration of airway nitric oxide, these data support the concept that aprotinin is anti-inflammatory during cardiopulmonary bypass.

Sign in / Sign up

Export Citation Format

Share Document