scholarly journals Simultaneous Treatment with P53 Overexpression and Interferon γ Exerts a Dramatic Increase in Apoptosis Induction of U87 Cells

2021 ◽  
Vol 10 ◽  
pp. e2270
Author(s):  
Zahra Abbasy ◽  
Hamid Zaferani Arani ◽  
Mahsa Ale-Ebrahim ◽  
Vihan Moodi ◽  
Javad Nematian ◽  
...  

Background: Gliomas possess low immunogenicity, which is an inevitable hinder in front of cancer immunotherapy. Different interferons (IFNs) may proceed apoptosis instead in p53-dependent or independent pathways. P53 induces the anti-inflammatory programmed cell death in cancer cells; on the other hand, IFN gamma (IFNγ) is a modulatory/pro-inflammatory cytokine. There are contradictory reports of whether this cytokine can possess an anti- or pro-cancerous impact on tumors. Hence, we aimed to investigate the possible cooperative apoptotic effect of the P53 and IFNγ over expressions on the U87 glioblastoma cell line. Materials and Methods: The P53 expressing vector was amplified by Escherichia coli BL21. This vector was confirmed by the aid of sequencing. At the next step, U87 cells were transfected using lipofectamine. Cells were treated with P53 vector and/or IFNγ. The type of cellular death investigated by flow cytometry and the expression level of cleaved caspase-3 protein was also precisely demonstrated by western blotting. Results: Sequencing results revealed that inserted P53 was identical with human P53. Western blot results revealed that both IFNγ and P53 overexpression could up-regulate cleaved caspase-3 protein expression in this cell line. Interestingly, flow cytometry data determined that concurrent treatment with P53 exogenous overexpression and IFNγ induces about 70% apoptosis in U87; more than the sum of cell death occurs after IFNγ or P53 overexpression alone (~18%+21%=39%). Conclusion: The present study results showed that p53-overexpression and IFNγ could ultimately induce up-regulation of the caspase-3 and ultimately significant apoptosis increasing in the U87 cell line. Although IFNγ is believed to be a pro-inflammatory cytokine and P53 is an anti-inflammatory agent, our results demonstrated that they could act synergistically to induce apoptosis in U87 cells. [GMJ.2021;10:e2270]

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1334.2-1335
Author(s):  
V. Can ◽  
I. Locke ◽  
P. Grieco ◽  
S. Getting

Background:Osteoarthritis (OA) is a degenerative joint disease that affects over 250 million people worldwide [1] with treatments focussing on the symptoms rather than the cause of the pathology [2, 3]. Thus, this degenerative joint disease requires novel treatment options [3, 4].Therefore, the melanocortin system [4] could provide a novel avenue to explore given its ability to exert anti-inflammatory effects and chondroprotection [5], although the receptor subtype involved is unclear.Objectives:This study aims to assess the chondroprotective and anti-inflammatory effects of the selective human melanocortin MC1 receptor agonist BMS-470539 dihydrochloride and the selective human MC3 receptor agonist PG-990 on S-Nitroso-N-acetyl-DL-penicillamine (SNAP) activated chondrocytes.Methods:The human chondrocytic cell-line C-20/A4 was seeded at 25.0 x 106viable cells/ml (5 μl droplet was transferred into individual wells of a 96-well plate). Micromass cultures [6] were stimulated with SNAP (1.0 mM) and after 2h treated with Dexamethasone (1.0 μM), selective human melanocortin MC1 receptor agonist BMS-470539 dihydrochloride (10.0 μg/ml) or selective human melanocortin MC3 receptor agonist PG-990 (10.0 μg/ml) for 6h. Cell viability was determined by MTT assay, Caspase -3 and -7 activity determined by Caspase-Glo 3/7 apoptosis assay. Glycosaminoglycan (GAG) content determined by alcian blue staining and anti-inflammatory heme-oxygenase-1 (HO-1) protein expression was determined by western blot. Data are expressed as Mean ±S.E.M ofn=4 samples repeated in triplicate. #p≤0.05vscontrol or *p≤0.05vsstimulus.Results:Cell viability analysis showed SNAP stimulation caused a maximal cell death of 23% (#p≤0.05), Dexamethasone, BMS-470539 dihydrochloride and PG-990 inhibited cell death by 2%, 98% and 129% respectively (*p≤0.05). SNAP stimulation caused a significant increase in Caspase -3 and -7 activity, which was inhibited by Dexamethasone, BMS-470539 dihydrochloride and PG-990 by 8%, 5% and 19% respectively (*p≤0.05). GAG content was significantly reduced by SNAP by 29% (#p≤0.05), which was inhibited by Dexamethasone, BMS-470539 dihydrochloride and PG-990 by 1%, 3% and 14% respectively (*p≤0.05). SNAP also caused a significant decrease in HO-1 protein expression, which was increased by Dexamethasone, BMS-470539 dihydrochloride and PG-990 by a 1.0-fold, 1.1-fold and 2.1-fold increase respectively (*p≤0.05).Conclusion:The selective human melanocortin MC3 receptor agonist PG-990 exhibited enhanced chondroprotection and modulation of inflammatory and tissue destructive mediators following SNAP activation compared to Dexamethasone and the selective human melanocortin MC1 receptor agonist BMS-470539 dihydrochloride. This suggests that melanocortin peptides display enhanced chondroprotective and anti-inflammatory effects at the MC3 receptor sub-type in this cell line.References:[1]Hunter DJ and Bierma-Zeinstra S. (2019).Lancet.393: 1745–59.[2]Can VCet al.(2020).Euro J Pharmacol. doi:https://doi.org/10.1016/j.ejphar.2020.172971.[3]Intekhab-Alam NYet al. (2013).Cell death & disease.4: 1-6.[4]Getting SJet al.(2006).Mol Pharmacol70: 1850-1855.[5]Kaneva MKet al.(2014).Biochem Pharmacol92: 336-47.[6]Greco KVet al.(2011).Biochem Pharmacol82: 1919-29.Disclosure of Interests:None declared


2010 ◽  
Vol 26 (5) ◽  
pp. 297-308 ◽  
Author(s):  
RM Satpute ◽  
J. Hariharakrishnan ◽  
R. Bhattacharya

Cyanide is a mitochondrial poison, which is ubiquitously present in the environment. Cyanide-induced oxidative stress is known to play a key role in mediating the neurotoxicity and cell death in rat pheochromocytoma (PC12) cells. PC12 cells are widely used as a model for neurotoxicity assays in vitro. In the present study, we investigated the protective effects of alpha-ketoglutarate (A-KG), a potential cyanide antidote, and N-acetyl cysteine (NAC), an antioxidant against toxicity of cyanide in PC12 cells. Cells were treated with various concentrations (0.625—1.25 mM) of potassium cyanide (KCN) for 4 hours, in the presence or absence of simultaneous treatment of A-KG (0.5 mM) and NAC (0.25 mM). Cyanide caused marked decrease in the levels of cellular antioxidants like superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR). Lipid peroxidation indicated by elevated levels of malondialdehyde (MDA) was found to be accompanied by decreased levels of reduced glutathione (GSH) and total antioxidant status (TAS) of the cells. Cyanide-treated cells showed notable increase in caspase-3 activity and induction of apoptotic type of cell death after 24 hours. A-KG and NAC alone were very effective in restoring the levels of GSH and TAS, but together they significantly resolved the effects of cyanide on antioxidant enzymes, MDA levels, and caspase-3 activity. The present study reveals that combination of A-KG and NAC has critical role in abbrogating the oxidative stress-mediated toxicity of cyanide in PC12 cells. The results suggest potential role of A-KG and NAC in cyanide antagonism.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3737-3737
Author(s):  
Feda Azab ◽  
Abdel Kareem Azab ◽  
Aldo M. Roccaro ◽  
Antonio Sacco ◽  
Phong Quang ◽  
...  

Abstract Abstract 3737 Poster Board III-673 INTRODUCTION Waldenström macroglobulinemia (WM) is a low grade non-Hodgkin lymphoma, characterized by the presence of abnormal lymphoplasmacytic cells producing high levels of IgM. Although indolent, WM remains incurable, and therefore, there is an urgent need for rationally designed therapy in WM. Receptor tyrosine kinases (RTKs) are cell surface receptors for growth factors, cytokines and hormones which have a critical role in the development and progression of many types of cancer. However, their role in WM was not identified. TKI-258 (Novartis, Basel, Switzerland) is an ATP-competitive inhibitor with activity against (multiple) receptor tyrosine kinases including FGFR and other RTKs. We hypothesized that FGFR is up-regulated in WM and plays a major role in its progression; and that TKI-258 would reduce tumor progression in WM. METHODS AND RESULTS We tested the expression of FGFR3 on WM cells and found overexpression of this RTK compared to CD19+ cells from healthy donors. The activation of FGFR3 by recombinant FGF induced MAPK signaling pathway in WM cells including phosphorylation of RAF, ERK and STAT3. Also it induced PI3K signaling including phosphorylation of AKT, S6R and GSK3. TKI-258 inhibited the FGF induced activation of the MAPK and PI3K signaling pathways in a dose- response manner. Using MTT assay we tested the effect of TKI-258 ( 0 to 2.5 uM) on the survival of WM cell line BCWM-1, on IgM secreting cell line MEC-1, and on CD19+ cells selected from WM patient sample. We found that the TKI-258 induced cell death in all sample tested with an IC50 ranging 0.8-1 uM. Testing the effect of TKI-258 on the survival of CD19+ cells selected from peripheral blood or mononuclear cell from healthy donors showed a minimal effect of less than 10% cell death. These results provide a wide therapeutic window for the use of TKI-258 in WM. Moreover, we tested the effect of TKI-258 on the apoptosis of WM cells by flow cytometry using the apoptosis marker APO-2.7, and found that TKI-258 induced apoptosis of WM cells in a dose-response manner at both 24 and 48 treatment. Moreover these results were confirmed by testing changes in the expression of apoptosis related proteins in response to TKI-258 by immunoblotting, including induction of PARP, and caspase-3 and caspase-9 cleavage. In correlation with these results, cell cycle analysis by PI staining and analysis by flow cytometry of WM cells treated with TKI-258 for 24 hrs showed induction of sub-G1 increase in a dose response manner with an IC50 about 1uM. To test the effect of TKI-258 on the interaction of WM cells with the microenvironment we examined the effect of TKI-258 on adhesion of WM cells to fibronectin and bone marrow stromal cells (BMSCs), and found that TKI-258 induced a 50% decrease of adhesion. Moreover, we found no effect on the chemotaxis of WM induce by stroma derived factor-1 (SDF1). To test the direct effect of TKI-258 on the interaction with the microenvironment, we examined the proliferation of WM when cultured alone of in co-culture with BMSCs by 3H-thymidine uptake assay. We showed that TKI-258 inhibited the proliferation of WM cells with an IC50 of 0.8 uM, in the presence or absence of BMSCs. CONCLUSION In conclusion, we found an overexpression of FGFR3 in WM cells compared to CD19+ cells from healthy donors, and that TKI-258 inhibited the activation of proliferative pathways induced by activation of FGFR3 and led to inhibition of proliferation and apoptosis of WM cells. Disclosures: Ghobrial: Millennium: Honoraria, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1367-1367
Author(s):  
Adam J Bryant ◽  
Catalina A Palma ◽  
Mark Lutherborrow ◽  
Vivek Jayaswal ◽  
Yee Hwa Yang ◽  
...  

Abstract Abstract 1367 Acute Myeloid Leukaemia (AML) with a mutation in the Nucleophosmin1 gene (NPM1c+) accounts for one of the largest subtypes of AML, with an unknown etiology. MicroRNA dysregulation has now been implicated in the oncogenesis of many cancers including AML. We sought to investigate the role of microRNAs in the initiation and development of AML with the NPM1c+ mutation. MicroRNA profiling of bone marrow samples from 28 AML patients and confirmation by qRT-PCR demonstrated a unique microRNA signature in AML-NPM1c+ samples dominated by miR-10a over-expression of 19.6-fold compared to Nucleophosmin1 wild type (NPM1) samples. Functional assessments were performed in the human OCI-AML3 cell line, which is the only cell line to harbour NPM1c+. miR-10a repression was induced by transfection with miRCURY LNA microRNA knockdown probes (Exiqon). Cell growth (MTS) assay demonstrated a significant decrease of 19% in miR-10a knockdown cells compared to the Scrambled control. AnnexinV and Caspase 3 assays assessed the effect of miR-10a knockdown on apoptosis. miR-10a knockdown increased the proportion of AnnexinV positive events when compared to control treated cells by 34.9% and 39.3% at 24 and 48 hours respectively, but had no effect on Caspase 3 expression. Proliferation (BrdU uptake) assays did not show a change, however, clonogenic assays demonstrated a 26.1% decrease in colony number in miR-10a knockdown cells compared to the control. Potential mechanisms were elucidated by determining miR-10a mRNA targets in silico and confirmed by luciferase reporter assays. These included ARNT, GTFH1, ID4, KLF4, MAPRE1, NR4A3, RB1CC1 and TFAP2C. In this study, we have demonstrated that miR-10a was highly differentially expressed between AML-NPM1c+ cells compared to leukaemic cells bearing wild type NPM1. Knockdown of miR-10a in OCI-AML3 cells resulted in increased cell death as detected by AnnexinV binding (but not Caspase 3, indicating an effect independent of the classical apoptotic pathways) and reduced clonogenic capacity. These effects are thought to occur through miR-10a mediated modulation of ARNT, GTFH1, ID4, KLF4, MAPRE1, NR4A3, RB1CC1 and TFAP2C, all of which are associated with neoplastic transformation. Taken together, our results suggest that aberrant miR-10a over-expression in AML-NPM1c+ patients promotes cell survival. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2476-2476
Author(s):  
Krishan K. Sharma ◽  
Juan Felipe Rico ◽  
Michael W. Becker ◽  
Gail J. Roboz ◽  
Gabriela Chiosis ◽  
...  

Abstract Abstract 2476 Stress-inducible heat shock protein 70 (HSP70) is a major cytoprotective factor and a molecular chaperone that interacts with HSP90 to form a multi-chaperone complex. Cancer cells are highly dependent on this complex due to their increased demand for protein synthesis. HSP70 overexpression inhibits apoptosis and has been associated with drug resistance and poor prognosis. YK5, a novel inhibitor of tumor-HSP70, has been shown to induce potent cell death in AML blast, progenitor, and stem cell populations with minimal effects in normal hematopoietic cells. Due to the role of HSP70 in drug resistance, we examined the effect of combining YK5 with other chemotherapeutic agents, including arsenic trioxide, cytarabine, suberoylanilide hydroxamic acid (SAHA) and PU-H71, a novel tumor-specific HSP90 inhibitor. We tested the ability of YK5 to synergize with either AsO3, AraC, SAHA, or PU-H71 in primary AML samples. Using multiparameter flow cytometry to measure viability after 48 hours of treatment, we found that combining 1μM YK5 with either 500nM AsO3 or PU-H71 resulted in a significant increase in cell death when compared to either agent alone (n=9, mean viability: 51.8, 67.2, and 13.4% for AsO3, YK5, and AsO3/YK5, respectively, P = 0.0018; mean viability: 57.1 and 20.8% for PU-H71 and PU-H71/YK5, respectively, P = 0.0029). A synergistic relationship between YK5 and both AsO3 and PU-H71 was found in all nine primary samples (combination indexes 0.29 – 0.76 with YK5/AsO3, 0.33 – 0.83 with YK5/PU-H71). In contrast, the combination of YK5 with either AsO3 or PU-H71 in CD34+ cord blood mononuclear cells did not result in a significant increase in cell death when compared to either agent alone (mean viability: 42.4, 72.4, and 37.2% for AsO3, YK5, and AsO3/YK5, respectively; mean viability: 61.1 and 51.1% for PU-H71 and PU-H71/YK5, respectively). YK5 in combination with either AraC or SAHA, however, did not result in a significant increase in cell death when compared to either drug alone, with an additive effect being demonstrated with a 1:1 YK5 to AraC/SAHA drug ratio (Mean CI = 0.9918). To determine the mechanism of the observed synergistic activity, intracellular HSP70 and active caspase-3, a client of HSP70, were measured using flow cytometry. Both AsO3 and PU-H71 significantly increased intracellular HSP70 and caspase-3 (Mean fold change = 18.3, 21.0 of HSP70 and 9.9, 8.3 of Caspase-3 for AsO3 and PU-H71 treatment, respectively), while treatment with AraC or SAHA resulted in no change in HSP70 levels. Furthermore, quantitative PCR revealed that treatment with either AsO3 or PU-H71 strongly upregulated HSPA1A and HSPA6, the main stress-inducible isoforms of HSP70 (Mean fold change = 15.9, 14.1 of HSPA1A, and 20.8, 23.4 of HSPA6 for AsO3 and PU-H71 treatment, respectively). AraC and SAHA had no significant upregulation of these genes. We have previously shown that increased levels of HSPA1A correlate with sensitivity to HSP70 inhibition via YK5. To further explore the mechanism of this observed synergy, flow cytometry was used to measure the levels of reactive oxygen species (ROS). Treatment with AsO3, PU-H71, AraC, or SAHA resulted in a significant increase in ROS (Mean fold change = 2.75, 1.92, 2.89, 1.67, respectively). Quantitative PCR also confirmed the activation of the oxidative stress response by the upregulation of heme oxygenase 1 (HMOX1) by treatment with these drugs (Mean fold change = 10.9, 8.7, 11.2, 7.7, respectively). YK5, however, did not induce ROS or upregulate HMOX1. Interestingly, pretreatment with NAC in primary AML samples (n=4) resulted in no protection from YK5 synergistic effect when combined with either AsO3 or PU-H71. These results suggest that YK5 synergizes with AsO3 and PU-H71 due to the increase in intracellular HSP70 caused by these drugs. This synergy is most likely due to the activation of the heat shock response and independent of the production of ROS due to drug treatment. In summary, we have found that the novel tumor-HSP70 inhibitor YK5 can synergize with AsO3 and PU-H71 in primary human AML, and that the basis of this synergism is due to the increase in intracellular HSP70 caused by these chemotherapeutic agents. HSP70 inhibition represents a novel approach in AML treatment and can be particularly significant to drug-resistant patients when combined with other chemotherapy. Disclosures: Roboz: Astex Pharmaceuticals: Research Funding.


2014 ◽  
Vol 21 (2) ◽  
pp. 122
Author(s):  
Suryani Hutomo ◽  
Yanti Ivana Suryanto ◽  
Heni Susilowati ◽  
Agustinus Rudolf Phym ◽  
Devi Chretella Maheswara

Kopi adalah minuman yang biasa dikonsumsi oleh masyarakat sehari-hari. Telah diketahui bahwa kopi mengandung kafein seperti yang terdapat juga pada teh dan coklat. Kandungan terbanyak kafein terdapat pada kopi. Kafein mempunyai struktur kimia 1, 3, 7- trimethylxanthine dan merupakan derivat xanthine. Senyawa ini dapat menginduksi kematian sel yang mengarah pada apoptosis, namun mekanisme yang terlibat belum diketahui dengan jelas. Tingginyakonsumsi kopi di dunia yang selalu meningkat mengindikasikan perlunya dilakukan penelitian untuk mengetahui efek kafein pada epitel rongga mulut yang berkontak langsung dengan kafein. Penelitian terdahulu melaporkan bahwaekstrak kopi menyebabkan kerusakan sel yang sebagian besar mengarah pada apoptosis, tetapi mekanismenya belum jelas. Tujuan penelitian ini adalah untuk menganalisis mekanisme kematian sel KB yang diinduksi oleh kafein melaluiaktivasi caspase-3. Sel KB sebagai model epitel oral (5x10⁴ sel) dikultur dalam DMEM menggunakan 24 wells microplate selama 24 jam sebelum perlakuan. Sel selanjutnya dipapar dengan kafein dengan konsentrasi 100 μg/ml, 200 μg/ml, 400 μg/ml dan diinkubasi selama 24 dan 48 jam dalam DMEM. Doxorubicin (0,5625 μg/ml) digunakan sebagai kontrol positif induksi apoptosis. Teknik imunositokimia terhadap caspase-3 dilakukan pada sel setelah dipapar kafeinuntuk mengamati adanya ekspresi caspase-3 sebagai ciri apoptosis. Identifikasi caspase-3 dilakukan menggunakan mikroskop fase kontras. Ekspresi protein caspase-3 terdeteksi pada sitoplasma sel KB. Hasil penelitian ini menunjukkanadanya ekspresi caspase-3 aktif yang ditandai dengan warna cokelat dengan intensitas kuat pada sitoplasma sebagian besar sel setelah dipapar kafein dengan konsentrasi 100 μg/ml dan 200 μg/ml selama 24 jam. Disimpulkan bahwa ekstrak kopi menyebabkan apoptosis sel KB melalui jalur aktivasi caspase-3. ABSTRACT: The Expression of Caspase-3 in Oral Cavity (Kb Cell Line) after Exposure to Coffee Extract. People widely consume coffee in daily meals. It is known there is caffeine found in coffee like it is found in tea and chocolate.Caffeine is found in the greatest amount of coffee. This 1, 3, 7- trimethyl xanthine substance is a derivate of xanthine that is consumed by almost all people in the world. This substance could induce cell death that mainly is apoptosis, but how the mechanism has not been clearly understood. Considering that coffee is widely consumed in the whole world, it is necessary to conduct an experiment to find any possible effect of caffeine to oral epitel that make direct exposure to caffeine. This experiment is targeted to analyze the mechanism of cell death which caused by caffeine through activation of caspase-3. KB cells as oral epithelial model (5x10⁴ sel) were cultured in DMEM using 24 well microplate for 24 hours before treatment. Then caffeine was given with concentration of 100 μg/ml, 200 μg/ml and 400 μg/ml. Cells were then incubated for 24 and 48 hours period in DMEM. Doxorubicin (0,5625 μg/ml) was used as a positive control of apoptosis induction. Immunocytochemistry technique was then done to observe any caspase three expression as amarker for apoptosis. Identification of active caspase-3 was then done using contrast phase microscope. The results showed expression of caspase-3 in KB cells cytoplasm which observed as high intensity of brown colored molecules incell cytoplasm after 100 μg/ml and 200 μg/ml caffeine exposure in 24 hours. It was concluded that coffee extract induce KB cells apoptosis through caspase-3 activation mechanism.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 5090-5090
Author(s):  
Angeliki Xagorari ◽  
Sarantis Tsetsakos ◽  
Zoi Katana ◽  
Konstantinos Krikonis ◽  
Anastasia Kouvatsi ◽  
...  

Abstract Introduction Microparticles (MPs) are small vesicles 100nm-1μm derived from the apoptotic or stimulated cells. The mechanism of their production is distinctive from exosomes or apoptotic bodies. MPs have been detected in the blood in many pathological conditions associated mainly with endothelial injury, thrombosis and inflammation. Our previous study showed that MPs originated also from CD34+ cells of umbilical cord blood, which is an alternative source for hemopoeitic stem cell transplantation. MPs considered as markers of cell activation, as well as apoptosis. Apoptosis is a complex interaction network regulated either through death receptor like FAS or through the internal pathway of Bcl2, Bax. The two pathways activate the executor of cell death program, caspases. The aim of this study is to elucidate the role of MPs in apoptosis of hemopoietic cells. Methods Umbilical cord blood units (UCB) were collected after informed consent. The units that were used in this study, were rejected as not appropriate for transplantation due to low volume. The HL60 promyelocytic leukemia cell line was cultured in RPMI (Life Technologies) supplemented with 10% fetal calf serum (FCS) and 1% penicillin-strepromycin. CD34+ MPs were isolated from the plasma of UCBs after centrifugation and magnetic bead MACS purification (Miltenyi Biotec). The number of CD34+ MPs was estimated by flow cytometry using CD34-PE and Annexin V-FITC Abs. Mononuclear cells (MNC) were collected after density gradient centrifugation on lymphoprep (Fresenius) and were cultured for 3 and 6 days in the presence of CD34+ MPs. Viability assays were performed using 7-AAD in flow cytometry. In another set of experiments different numbers of CD34+ MPs were used in MNC cultures. RNA was extracted from MNC using Qiagen RNA extraction kit and reverse transcribed into cDNA using Superscript II reverse transcriptase (Invitrogen) with random primers (Promega). RT-PCR was performed using Platinum Pfx polymerase (Invitrogen). The primers for FAS, BCL2, BAX, caspase 3, survivin and GAPDH genes were used. The PCR products were analysed in an agarose gel electrophoresis. Results Cell viability increased in UCB derived MNC (UCB-MNC) incubated with CD34+ MPs (800 /ml) after 3 day vs. 6 days of culture. The UCB-MNC viability was higher using 800/ml CD34+ MPs vs. 400/ml. In contrast, CD34+ MPs (800 /ml vs. 400/ml) did not affect the viability in one day MNC culture. Purified CD34+ MPs were applied to UCB-MNC cultures and by RT-PCR was shown increased expression of BCL2 gene as well as FAS and caspase-3 genes. The promyelocytc cell line HL60 has been used in order to analyze the effect of CD34+ MPs in leukemic cells. The expression of Bcl2 was decreased in HL60 cells co-incubated with CD34+ MPs. This result shows an opposite effect of CD34+ MPs in the apoptotic gene Bcl2 for the HL60 cells indicating that there are different mechanisms of MP function in various cell types. Conclusions In this study we have identified and monitored the time- and dose-dependent effect of CD34-derived microparticles in the viability of UCB mononuclear cells. Additionally, CD34+ MPs function is accosiated with the high expression of the pro- and anti-apoptotic Bcl2 and apoptotic FAS. In contrast CD34+ MPs decreases the expression of Bcl2 in the promyelocytic leukemia cell line HL60. Therefore the stem cell derived microparticles might serve as a potential regulator of apoptosis in normal and malignant hematopoietic cells. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3471-3471
Author(s):  
Amy Johnson ◽  
Lisa Smith ◽  
Jiuxiang Zhu ◽  
Nyla Heerema ◽  
Sara Guster ◽  
...  

Abstract Chronic lymphocytic leukemia (CLL) is an incurable adult leukemia characterized by disrupted apoptosis. While the majority of patients with CLL are asymptomatic at diagnosis, most progress and require therapy. Identification of new targets and therapeutic agents is therefore a high priority for the treatment of CLL. Synthetic chemistry yielded derivatives of the COX-2 inhibitor, celecoxib, with increased ability to induce apoptosis in the 1–10 μ M range in prostate cancer cells, a similar proposed mechanism of action, and increased in vivo activity in a murine prostate cancer xenograft model. Based upon these data, a Rapid Access to Intervention Development (RAID) proposal is underway to generate OSU03012 for clinical studies in prostate cancer. In addition, we are examining the biologic effects of these new agents in primary CLL cells and lymphoblastic cell lines, showing a novel mechanism of cell killing independent of caspase activation and bcl-2 over-expression. To determine the in vitro activity against CLL cells, 11 CLL patient PBMCs were incubated in various concentrations of OSU03012. The LC50 at 24 hrs was 7.12μM and decreased to 5.45μM at 72 hrs. We show both early (annexin-V positive) and late (both annexin-V/PI positive) apoptosis concurrent with loss of mitochondrial membrane potential typical of apoptosis. These data suggest OSU03012 is highly cytotoxic toward CLL cells in vitro at doses well below those attainable without toxicity in a murine model. Additionally, we show that OSU03012 mediates apoptosis by activation of the intrinsic, mitochondrial pathway of apoptosis but also activates alternative caspase independent cell death pathways. CLL cells from 8 patients were incubated in 10μM OSU03012 for 24 hrs and assessed for caspase-3 and PARP. Immunoblots reveal a dose dependent increase in active caspase-3 concurrent with a decrease in the pro-form. This occurred concurrently with the appearance of the 85 kD cleaved product of PARP that is a known downstream target of caspase-3. In the same 8 patient lysates we saw no change in the inactive pro-form of caspase-8, but consistent processing of caspase-9. These data suggest that OSU03012 in part utilizes the intrinsic pathway of apoptosis to promote CLL cell death. Incubation of CLL cells with z-VAD-fmk and OSU03012 did not abrogate cell death, but eliminated processing of caspase-9, caspase-3 and PARP, suggesting that this agent also activates caspase independent mechanisms of cell death. Given the caspase dependent and independent pathways utilized by OSU03012, we assessed the dependence of cell death on bcl-2 expression. Here we show that bcl-2 over-expression in the 697 lymphoblastic cell line greatly diminishes the apoptosis observed with fludarabine, but potent apoptosis is equally observed with OSU03012 compared to the empty vector cell line. Furthermore, in the bcl-2 over-expressing cell line, caspase-3 and PARP cleavage was not observed despite equivalent apoptosis supporting further multiple mechanisms of cell killing induced by OSU03012. In summary, OSU03012 is an oral bioavailable therapeutic agent that has potent in vitro activity against primary CLL cells. This cytotoxicity is mediated by both caspase dependent and independent pathways and can overcome bcl-2 over-expression. These data provide support for further investigation of the mechanism of action of OSU03012 in CLL cells and performance of early Phase I studies in CLL as part of the RAID process.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3260-3260
Author(s):  
Craig T. Wallington-Beddoe ◽  
John Hewson ◽  
Kenneth Francis Bradstock ◽  
Linda J. Bendall

Abstract Abstract 3260 Introduction: Acute lymphoblastic leukemia (ALL) is the most common form of childhood cancer, which usually responds to chemotherapy. Long-term survival in adults is poor with most developing disease relapse, whilst Ph+ ALL has a particularly poor prognosis. FTY720 is an immunosuppressive drug that has recently demonstrated efficacy in phase 3 trials of relapsing/remitting multiple sclerosis. FTY720 also appears promising in a number of malignancies with the proposed mechanism being the reactivation of PP2A, a protein serine/threonine phosphatase whose activity may be reduced in malignant cells. Here we report findings of in vitro testing of FTY720 on Ph+ and negative ALL cell lines and primary patient samples, describing mechanisms of cell death. Methods: ALL cell lines and primary patient samples were treated with 1 nM - 100 μM FTY720 for 24 hours. Viability was measured by flow cytometry using propidium iodide and annexin V staining. Cellular proliferation was measured by 3H-thymidine incorporation. Flow cytometry and western blotting were used to measure caspase 3 activation whilst western blotting was used to assess caspase 3, PARP cleavage and LC3II formation. Electron microscopy permitted a detailed examination of cell ultra-structure and confocal microscopy with lysosensor blue staining enabled visualisation of acidic vacuoles. Reactive oxygen species generation was assessed by flow cytometry using the cell permeable dye carboxy-H2DCFDA. Results: FTY720 produced a profound reduction in proliferation and viability of Ph+ (ALL1 cells) and Ph− (REH, NALM6 and LK63 cells) cell lines and patient samples (n=7) in the low micromolar range. IC50 values for loss of viability at 24 hours ranged from 5.3 μM for ALL1 to 7.9 μM for LK63. The IC50 values for proliferation at 24 hours were 1.4 μM for ALL1 and 3.5 μM for REH. Caspase 3 activation was observed only at very low levels by flow cytometry whilst both caspase 3 and PARP cleavage were not detected by western blotting. Inhibition of caspases by ZVAD-FMK failed to rescue ALL cells from FTY720 induced cell death, demonstrating a caspase independent cell death mechanism. Light microscopy revealed prominent cytoplasmic vacuolation, and electron microscopy showed features consistent with autophagy and necrosis. Western blotting demonstrated strong LC3II bands and confocal microscopy, using lysosensor blue, revealed prominent acidic vacuolation, all confirming the induction of autophagy. Reactive oxygen species were generated in response to FTY720 treatment and partial reversal of this by N-acetyl-cysteine produced a concomitant increase in cell viability. PP2A inhibition with okadaic acid failed to rescue cells from FTY720-induced cell death. Conclusion: FTY720 is a highly active drug in vitro in ALL cell lines and patient samples. Evidence supports a caspase independent mechanism of cell death with the occurrence of autophagy and necrosis. PP2A activation is not solely responsible for leukemic cell death. Data on the in vivo effects of FTY720 on ALL cells in NOD-SCID mice will be presented. Disclosures: Bendall: Genzyme: Honoraria.


2016 ◽  
Vol 38 (2) ◽  
pp. 786-800 ◽  
Author(s):  
Mona Samy Guida ◽  
Ali Abd El-Aal ◽  
Yehya Kafafy ◽  
Safwat Farid Salama ◽  
Badr Mohamed Badr ◽  
...  

Background/Aims: Recent studies have shown that thymoquinone (TQ) exerts protective effects against ionizing radiation-induced cataracts in lens after total cranium irradiation of rats. Nevertheless, there is no published work investigated the effects of TQ on T cell development and biology in animal models exposed to gamma radiation. Therefore, in the present study we focused on determining the effects of TQ on radiation damage in the thymus, radiation-induced T cell imbalance, and on immune dysfunction induced by gamma-rays. Methods: Three groups of rats were used: a control group, a gamma-irradiated group, and a gamma-irradiated group that was orally supplemented with TQ. Serum lipid profiles, malondialdehyde (MDA) levels, and pro-inflammatory cytokine levels were measured to assess gamma irradiation-induced oxidative stress and inflammatory capacity. T cell apoptosis was evaluated by annexin V/propidium iodide staining followed by flow cytometry analysis. The expression of pro-apoptotic proteins such as Bax and caspase-3, the anti-apoptotic protein Bcl-2, and an exhaustion marker of T cells (PD-1) in CD4+ and CD8+ T cell populations was evaluated using flow cytometry analysis. The T cell architecture of the thymus gland was evaluated by histological analysis. Results: Exposure to gamma radiation increased triglyceride, cholesterol, LDL-C, MDA, TNF-α and IL-6 levels and decreased HDL-C levels. The altered lipid profile and MDA and pro-inflammatory cytokine (TNF-α and IL-6) levels induced by exposure to gamma radiation were significantly restored in TQ-treated gamma-irradiated rats. Rats exposed to gamma radiation exhibited increased exhaustion of T lymphocytes via down-regulation of Bcl-2 expression and upregulation of PD-1, Bax, and caspase-3 expression, which sensitized these cells to apoptosis. Interestingly, treatment of gamma-irradiated rats with TQ decreased T cell exhaustion and apoptosis by modulating the expression of Bcl-2, PD-1, Bax, and caspase-3. Conclusions: Our results provide evidence for the beneficial effects of TQ as an effective radioprotective candidate that enhances cellular immunity.


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