Multiplexing High‐Content Flow (HCF) and Quantitative High‐Throughput Screening (qHTS) to Identify Compounds Capable of Decreasing Cell Viability, Activating Caspase 3/7, Expressing Annexin V, and Changing Mitochondrial Membrane Integrity

The geographical distribution of oesophageal cancer is linked to the exposure of fumonisin B1 (FB1), a mycotoxin produced by fungi that contaminates staple food worldwide. Non-genotoxic carcinogens like FB1 disturb homeostasis through increased cell proliferation or suppression of apoptosis. This study investigated the involvement of FB1 (0–20 μM) in spindle-shaped N-cadherin (+) CD45 (−) osteoblastic (SNO) cell death. Cell viability and death were assessed using the MTS and Annexin V-Fluos assays, respectively. Caspase activities were determined luminometrically and the comet assay assessed DNA damage. Induction of oxoguanine glycosylase 1 (OGG1) was measured using quantitative Polymerase Chain Reaction (qPCR), while cleaved poly (ADP-ribose) polymerase 1 (PARP-1) and Bax were determined by western blotting. Cell viability and PARP-1 cleavage were not affected by 1.25 μM FB1, but phosphatidylserine externalization, Bax protein expression, caspase activity, comet tail length and OGG1 transcripts were increased. The reduced cell viability in 10 μM FB1-treated cells was accompanied by corresponding increases in externalized phosphatidylserine, Bax, caspase-3/7 activity and cleaved PARP-1. The OGG1 transcripts were not significantly increased, but comet tails were increased. Bax, caspase-3/7 activities and cleaved PARP-1 were inhibited at 20 μM FB1. In addition, the OGG1 transcript levels were decreased ( p < 0.0001) along with comet lengths ( p < 0.0001). This study showed that FB1-induced apoptosis in SNO cells may be caspase-dependent or caspase-independent; the pathway used depends on the exposure concentration.

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A Novel High-Throughput Technique for Identifying Monoclonal Antibodies capable of Death Receptor Induced Apoptosis

Journal of Cell Death ◽

10.4137/jcd.s3660 ◽

2009 ◽

Vol 2 ◽

pp. JCD.S3660

Author(s):

Hang Fai Kwok ◽

Julie A. Gormley ◽

Christopher J. Scott ◽

James A. Johnston ◽

Shane A. Olwill

Keyword(s):

Cell Death ◽

High Throughput ◽

High Throughput Screening ◽

False Negative ◽

Death Receptor ◽

Annexin V ◽

Fas Receptor ◽

Induced Apoptosis

The study of death receptor family induced apoptosis has gained momentum in recent years with the knowledge that therapeutic antibodies targeting DR4 and DR5 (death receptor's 4 and 5) have proved efficacious in multiple clinical trials. The therapeutic rationale is based on targeting and amplifying a tumour tissues normal cell death programme (apoptosis). While advances in the targeting of DR4 and DR5 have been successful the search for an agonistic antibody to another family member, the Fas receptor, has proven more elusive. This is partly due to the differing in vitro and in vivo characteristics of individual antibodies. In order to induce Fas targeted cell death an antibody must be capable of binding to and trimerising the receptor. It has been shown that antibodies capable of performing this function in vivo, with the assistance of tumour associated cells, do not always induce apoptosis in vitro. As a result the use of current methodologies to detect functional antibodies in vitro may have dismissed potential therapeutic candidates ('false negative'). Here we report a novel high throughput screening technique which artificially cross-links antibodies bound to the Fas receptor. By combining this process with Annexin-V and Prodidium Iodide (PI) staining we can select for antibodies which have the potential to induce apoptosis in vivo.

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Development of a High Throughput Screening Assay for Mitochondrial Membrane Potential in Living Cells

CrossRef Listing of Deleted DOIs ◽

10.1177/108705710200700411 ◽

2002 ◽

Vol 7 (4) ◽

pp. 383-389 ◽

Cited By ~ 58

Author(s):

Shu-Gui Huang

Keyword(s):

Membrane Potential ◽

Mitochondrial Membrane Potential ◽

High Throughput ◽

High Throughput Screening ◽

Mitochondrial Membrane ◽

Living Cells ◽

Screening Assay ◽

Mitochondrial Inner Membrane ◽

Obesity And Diabetes ◽

High Throughput Screening Assay

The mitochondrion plays a pivotal role in energy metabolism in eukaryotic cells. The electrochemical potential across the mitochondrial inner membrane is regulated to cope with cellular energy needs and thus reflects the bioenergetic state of the cell. Traditional assays for mitochondrial membrane potential are not amenable to high-throughput drug screening. In this paper, I describe a high-throughput assay that measures the mitochondrial membrane potential of living cells in 96- or 384-well plates. Cells were first treated with test compounds and then with a fluorescent potentiometric probe, the cationic-lipophilic dye tetramethylrhodamine methyl ester (TMRM). The cells were then washed to remove free compounds and probe. The amount of TMRM retained in the mitochondria, which is proportional to the mitochondrial membrane potential, was measured on an LJL Analyst fluorescence reader. Under optimal conditions, the assay measured only the mitochondrial membrane potential. The chemical uncouplers carbonylcyanide m-chlorophenyl hydrazone and dinitrophenol decreased fluorescence intensity, with IC50 values (concentration at 50% inhibition) similar to those reported in the literature. A Z' factor of greater than 0.5 suggests that this cell-based assay can be adapted for high-throughput screening of chemical libraries. This assay may be used in screens for drugs to treat metabolic disorders such as obesity and diabetes, as well as cancer and neurodegenerative diseases.

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Iron-Overload Induces Apoptosis in Cardiomyocytes and Hepatocytes Via Mitochondrial/Caspase-3 Pathways.

Blood ◽

10.1182/blood.v112.11.1872.1872 ◽

2008 ◽

Vol 112 (11) ◽

pp. 1872-1872

Author(s):

Mo Yang ◽

Shing Chan ◽

Yiu Fai Cheung ◽

Shau Yin Ha ◽

Godfrey ChiFung Chan

Keyword(s):

Iron Overload ◽

Protective Effect ◽

Cell Viability ◽

Caspase 3 ◽

Annexin V ◽

Apoptotic Cells ◽

H9c2 Cells ◽

Plot Analysis ◽

Iron Treatment ◽

Induced Apoptosis

Abstract Cardiomyopathy and liver damage due to iron-overload are the major complications in patients with beta-thalassaemia major. Iron-overload may induce apoptosis in cardiomyocytes and hepatic cells, and that TPO may exert protective effect on apoptosis of cardiomyocytes (Circulation, 2006). In this study, we demonstrated firstly that iron induced apoptosis in cardiomyocytes. Using H9C2 cells, we have shown that iron reduced cell viability in a dose-dependent manner (0.003–3 mM) (n=6). By annexin V and PI staining, apoptotic cells were found to be significantly increased after iron treatment (0.3 mM, 72 hrs) (n=6). The expression of active caspase-3 was significantly increased in iron-treated cells. Furthermore, iron treatment increased the proportion of cells containing JC-1 monomers, indicating a trend in the drop of mitochondrial membrane potential (n=6). Secondly, we found that TPO exerted cardio-protective effect on iron-induced apoptosis. H9C2 cells were cultured in the presence of iron (0.3 mM) with or without TPO (5, 10, 20, 50, 100 ng/mL, 72 hrs). The cell viability was significantly increased with the treatment of TPO at 50 ng/mL and 100 ng/mL (n=4). Dot-plot analysis of annexin V/PI staining demonstrated that TPO (50 ng/mL) significantly reduced the population of apoptotic cells (n=6). Incubation with TPO also decreased the iron-induced caspase-3 expression (n=6). Flow cytometric dot-plot analysis of H9C2 cells also showed trends of amelioration of the increase in JC-1 monomers in the iron plus TPO group (n=6). The population of phospho-Akt and Erk1/2 were also significantly increased after treatment by TPO (P<0.05, n=4). Human liver cell line MIHA was also used as a cell model. We showed that iron-overload reduced cell viability in a dose-dependent manner (0.0375–0.6 mM) (n=7). By annexin V and PI staining, apoptotic cells were found to be significantly increased after iron treatment (0.15–0.6 mM) for 72 hrs (n=7). The expression of active caspase-3 was also significantly increased in iron-treated cells (n=5). We also found that TPO exerted proliferation effect on MIHA cell by activation of phospho-Akt. However, MIHA cells were cultured in the presence of iron (0.3 mM) with TPO (50 ng/mL, 72 hrs). The cell viability was not significantly increased with the treatment of TPO (n=5). Dot-plot analysis of annexin V/PI staining did not demonstrated that TPO reduced the population of apoptotic cells induced by iron-overload (n=5). Also, incubation with TPO did not decrease the iron-induced caspase-3 expression in these cells (n=5). Our findings suggest that iron-overload induces apoptosis in cardiomyocytes and hepatocytes via mitochondrial/caspase-3 pathways and that TPO might exert a protective effect on iron-overload induced apoptosis via the activation of Akt and Erk1/2 pathways in cardiomyocytes.

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The Diterpenoid Lactone Andrographolide Induces Reactive Oxygen Species (ROS) Dependent Apoptosis in ATRA Sensitive and Resistant APL Cell Lines.

Blood ◽

10.1182/blood.v120.21.2446.2446 ◽

2012 ◽

Vol 120 (21) ◽

pp. 2446-2446

Author(s):

Shuo Yang ◽

Jessica K. Altman ◽

Sheila Prachand ◽

Austin Tom ◽

Bo Ding ◽

...

Keyword(s):

Reactive Oxygen Species ◽

Cell Viability ◽

Cell Lines ◽

Mitochondrial Membrane ◽

Reactive Oxygen ◽

Annexin V ◽

Resistant Cell ◽

Oxygen Species ◽

Resistant Lines ◽

Sensitive Line

Abstract Abstract 2446 Andrographolide is a crystalline diterpenoid lactone. It consists of an α-alkylidene- g-butyrolactone moiety and three hydroxyls at C-3, C-14 and C-19, which are responsible for its biological activities. It is the major bioactive ingredient of the medicinal plant Andrographis paniculata and it has been used in Asia for a variety of non-malignant conditions. We previously reported that Andrographolide results in mitochondrial-mediated apoptosis in lymphoma cell lines and fresh malignant cells from patients with lymphoma (Yang et al. Clin Cancer Res 2010:16:4755). Based on the mechanism of action in lymphoma and a prior report in APL (Manikam et al. J Pharm Pharmacol 2009:61:9), we hypothesized that andrographolide may have biological activity in acute promyelocytic leukemia (APL) an that this may be related to reactive oxygen species (ROS). We therefore investigated the effects of andrographolide on cell viability, apoptosis induction, mitochondrial membrane poential and signaling pathways in 3 APL cell lines, the ATRA sensitive line NB4 and the ATRA-resistant lines NB4–007/6 and NB4–306 and 3 samples from patients with APL. Methods: NB4 (ATRA sensitive cell line), NB4–007/6 and NB4–306 (ATRA resistant cell lines) were cultured in RPMI-1640 under standard conditions. Cell viability was measured using the trypan blue or propidium iodide exclusion method. Fresh leukemic cells were obtained from 3 patients after informed consent according to an NU IRB approved protocol. One had ATRA-resistant APL and 2 had de-novo untreated APL. We measured apoptosis by Annexin V-FITC by FACS. We measured mitochondrial membrane potential and cell differentiation by standard techniques. Results: Incubation with increasing concentrations of andrographolide demonstrates loss of cell viability as measured by MTT assay. The IC50 at 48 hours was 6uM for NB4–306, 6.5uM for NB4–007/6 and 9uM for NB4. Apoptosis by Annexin V/FACS demonstrated that at 48 hours there was increasing apoptosis in all 3 cell lines and that the ATRA-resistant cell lines NB4–007/6 and NB4–306 were significantly more sensitive to andrographolide than the ATRA sensitive cell line NB4 (p< 0.025). This was accompanied by PARP and caspase 3-cleavage. There was evidence of decrease in mitochondrial membrane potential, but no effect on differentiation as measured by CD11b expression by flow. We next interrogated signaling pathways and found that in the ATRA resistant line NB4–007/6 there was an increase in phosphorylation of the Forkhead box O transcription factors p-FOXO1 at Thr24 and up-regulation of FasL (which peaked at 6 hours) and p27Kip1. We also demonstrated that andrographolide caused N-acetyl L- cysteine (NAC) reversible down regulation of c-MYC (in the ATRA resistant lines) and p-AKT (T308) (in the ATRA sensitive line) expression. In fresh patient specimens (n=3) there was dose dependent increase in apoptosis at 48 hours (>70% at 10uM, 85% at 20uM). From prior reports and our own data we suspected that the effects of andrographolide were dependent on reactive oxygen species (ROS), and indeed apoptosis was completely inhibited by NAC. Conclusion: Taken together, these data suggest that andrographolide, a novel natural diterpenoid lactone with significant biological activity in cancer, may have activity in patients with ATRA-resistant APL by a mechanism of action that is distinct from ATRA. We believe that these data provide a compelling rationale to add this natural diterpenoid lactone to the clinical trial agenda in APL. Disclosures: No relevant conflicts of interest to declare.

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Bone Marrow Stromal Cell-Derived Exosomes Facilitate Multiple Myeloma Cell Survival Through Inhibition Of The JNK Pathway

Blood ◽

10.1182/blood.v122.21.679.679 ◽

2013 ◽

Vol 122 (21) ◽

pp. 679-679

Author(s):

Jinheng Wang ◽

An Hendrix ◽

Elke De Bruyne ◽

Els Van Valckenborgh ◽

Eddy Himpe ◽

...

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

Cell Proliferation ◽

Western Blot ◽

Cell Viability ◽

Cell Survival ◽

Caspase 3 ◽

Annexin V ◽

Jnk Pathway ◽

Functional Components

Abstract Interplay between bone marrow stromal cells (BMSCs) and multiple myeloma (MM) cells plays a crucial role in MM pathogenesis by secreting growth factors, cytokines, and other functional components. Exosomes are 30-100nm diameter membranous vesicles constitutively released by several cell types including reticulocytes, cytotoxic T lymphocytes, B lymphocytes, epithelial and endothelial cells. Exosomes mediate local cell-cell communication by transferring mRNAs, miRNAs and proteins. Due to their ability to transfer functional components, exosomes play multiple roles by stimulating target cells, transferring membrane receptors, delivering proteins, and inducing epigenetic changes in recipient cells. Although the promotion of MM growth and survival induced by BMSCs has been studied, the role of BMSC-derived exosomes in this action remains unclear. Here, we investigated the effect and mechanisms of BMSC-derived exosomes on the proliferation and survival of MM cells using the murine 5T33MM model. This model mimics the human disease closely and of this model two lines exist: the 5T33MMvv model which is propagated in vivo and the 5T33MMvt line which is derived from 5T33MMvv cells but which can grow stroma-independently. Exosomes were isolated from conditioned medium using the ExoQuick-TC Exosome Precipitation Solution (System Biosciences) after culture of primary BMSCs obtained from naïve C57BL/KaLwRij mice or 5T33MM diseased mice. The size of exosomes derived from naïve BMSCs, 5T33 BMSCs and 5T33MMvt cells were confirmed using a NanoSight LM10. Several exosomal markers such as CD63, Flotillin-1, heat shock protein 90 (HSP90), and HSP70 were detected using Western blot. We co-cultured the BMSCs or MM cells with fluorescent dye-labeled exosomes to examine whether exosomes could be transferred into cells. The results showed that both naïve and 5T33 BMSC-derived exosomes could fuse with 5T33MMvt cells and that the uptake of 5T33MMvt cell-derived exosomes by BMSCs was also observed. As several cytokines were found to be present in BMSC- and MMvt cell-derived exosomes, this suggests that BMSCs and MM cells could exchange cytokines with each other through exosomes secretion and uptake. Furthermore, the cytokine composition of 5T33BMSC-derived exosomes compared to naïve BMSC-derived exosomes was different. We next performed luminescent cell viability assays, BrdU cell proliferation assays and 7-AAD/annexin-V stainings to examine the effects of BMSC-derived exosomes on MM cell viability, proliferation and survival, respectively. Both naïve and 5T33 BMSC-derived exosomes increased 5T33MMvt and MMvv cell viability in a dose- and time-dependently manner. BrdU uptake in 5T33MMvt and MMvv cells was also increased after treatment with BMSC-derived exosomes. Significantly reduced apoptosis of 5T33 MMvt and MMvv cells was observed when they were treated with BMSC-derived exosomes as judged by 7-AAD/annexin-V staining. 5T33MMvt and MMvv cells were treated with different amounts of BMSC-derived exosomes and apoptosis-related proteins Bcl-2, Bax, and caspase-3 were determined using western blot. Bcl-2 was increased slightly and activated (cleaved) caspase-3 was reduced after co-culture with exosomes, coinciding with the results of 7-AAD/annexin-V staining. To elucidate the mechanisms responsible for exosome-induced MM cell survival, we examined the activation of several proteins involved. Reduced phosphorylation of p53, p38MAPK and JNK were detected when 5T33MMvt were treated with naïve-BMSC-derived exosomes for 24h, whereas phosphorylated Erk1/2, Akt, and IGF1Rβ were not changed. Surprisingly, activation of p53 and p38MAPK were not changed after the treatment with 5T33 BMSC-derived exosomes. 5T33 BMSC-derived exosomes further decreased the activation of JNK, Bim expression and phosphorylated Bim compared to naïve BMSC-derived exosomes. As Bim is a pro-apoptosis protein, mainly regulated by the JNK pathway; promotion of MM cell survival likely results from the inhibition of the JNK pathway by BMSC-derived exosomes. In summary, our results demonstrate a positive role for BMSC-derived exosomes in induction of MM cell proliferation and survival. BMSC-derived exosomes could inhibit the JNK pathway, thereby reducing caspase-3 activation and protecting MM cells from apoptosis. Disclosures: No relevant conflicts of interest to declare.

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Geniposide Prevents Hypoxia/Reoxygenation-Induced Apoptosis in H9c2 Cells: Improvement of Mitochondrial Dysfunction and Activation of GLP-1R and the PI3K/AKT Signaling Pathway

Cellular Physiology and Biochemistry ◽

10.1159/000445634 ◽

2016 ◽

Vol 39 (1) ◽

pp. 407-421 ◽

Cited By ~ 50

Author(s):

You-Qin Jiang ◽

Guang-lei Chang ◽

Ying Wang ◽

Dong-Ying Zhang ◽

Li Cao ◽

...

Keyword(s):

Cytochrome C ◽

Cell Viability ◽

Mitochondrial Dysfunction ◽

Mitochondrial Membrane ◽

Caspase 3 ◽

Akt Signaling ◽

Mitochondrial Morphology ◽

Mitochondrial Calcium ◽

H9c2 Cells ◽

Akt Signaling Pathway

Background/Aims: Myocardial ischemia/reperfusion injury is a major cause of morbidity and mortality associated with coronary heart disease. Many studies have demonstrated that natural products are promising chemotherapeutic drugs counteracting the loss of cardiomyocytes. Thus, the purpose of the present study was to investigate the effects of geniposide, a traditional Chinese herb extract from Gardenia jasminoides J. Ellis, on cardiomyocyte apoptosis induced by hypoxia/reoxygenation (H/R) in H9c2 cells, and their underlying mechanisms. Methods: Cell viability and apoptosis ratio were assessed using the cell counting kit-8 assay and Annexin V/propidium iodide (PI) staining. The concentrations of lactate dehydrogenase (LDH), intracellular total superoxide dismutase (T-SOD), and malondialdehyde (MDA) were detected by microplate reader. The production of reactive oxygen species/reactive nitrogen species (ROS/RNS), the level of mitochondrial calcium, and mitochondrial membrane potential depolarization were measured by confocal laser scanning microscopy. Mitochondrial morphology was visualized using transmission electron microscopy. The expressions of Bcl-2 mRNA and Caspase-3 mRNA were measured by reverse transcription-polymerase chain reaction (RT-PCR). The protein levels of cleaved caspase-3, Bcl-2, Bax, AKT, p-AKTserine473, cytochrome-c were detected by western bloting. Results: Geniposide pretreatment increased cell viability, decreased LDH levels in the supernatant, and inhibited cardiomyocyte apoptosis caused by H/R. Furthermore, geniposide reversed mitochondrial dysfunction by decreasing oxidative stress products (ROS/RNS and MDA), increasing anti-oxidative enzyme (T-SOD) level, improving mitochondrial morphology, attenuating mitochondrial calcium overload and blunting depolarization of mitochondrial membrane. Moreover, geniposide pretreatment increased Bcl-2 level and decreased Bax level, thus enhancing the Bcl-2/Bax ratio. Consistent with the above result, Bcl-2 mRNA expression was upregulated and caspase-3 mRNA expression was downregulated by geniposide. In addition, geniposide decreased the protein expression of cleaved caspase-3 and cytochrome-c and increased the level p-AKTserine473. The protective effects of geniposide were partially reversed by glucagon-like pepitide-1 receptor antagonist exendin-(9-39) and the phosphatidylinositol 3 kinase (PI3K) inhibitor LY294002. Conclusions: Our results suggest that geniposide pretreatment inhibits H/R-induced myocardial apoptosis by reversing mitochondrial dysfunction, an effect in part due to activation of GLP-1R and PI3K/AKT signaling pathway.

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Benzo(a)pyrene, an Active Product of Cigarette Smoke, Role in PLA2 Isoforms Activation in Colon Cancer

Journal of Global Oncology ◽

10.1200/jgo.18.79801 ◽

2018 ◽

Vol 4 (Supplement 2) ◽

pp. 193s-193s

Author(s):

S. Sharma ◽

S. Yadav ◽

S. Rana ◽

P. Avti ◽

K.L. Khanduja

Keyword(s):

Colon Cancer ◽

Cell Viability ◽

Cigarette Smoke ◽

Membrane Integrity ◽

Annexin V ◽

Cell Types ◽

Ros Generation ◽

Dependent Manner ◽

Colon Cells ◽

Ht 29

Background and aim: One of the active combustion product of cigarette smoke, Benzo[a]pyrenes, role in pulmonary cancer is clearly understood. However, its role in gastrointestinal cancer including colon cancer is not clearly understood. Methods: In this study, benzo(a)pyrenes was treated to colon cells to evaluate its role in cell viability, cellular ROS, and gene expression of various PLA2 isoforms was evaluated by FACS and PCR. The identified PLA2 was silenced at the gene level to evaluate its role in cell viability and ROS generation. Results: B(a)P treatment at 1 µg/mL for 48 h to HCT-15 male colon cells significantly reduced the cell viability without affecting HT-29 female colon cells. Higher doses and longer treatment duration with B(a)P showed that female colon cells were highly sensitive than male colon cells. Annexin-V/PI staining for preapoptotic detection showed that B(a)P treatment increased the apoptosis in both the cell types in a concentration and time-dependent manner. The cytosolic ROS (cROS) and superoxide radical (SOR) formation in the female colon cells was significantly higher than male colon cells unlike the mitochondrial ROS (mtROS) production which was significantly higher in male colon cells. Treatment with B(a)P significantly upregulated the IID and IVA PLA2 isoform groups in HCT-15 male colon cells, whereas IB was upregulated in HT-29 female colon cells among the various PLA2 isozyme gene studied (IB, IID, III, IVA, IVB, IVC, VI, X, aiPLA2 and iPLA2). Gene silencing experiments targeting PLA2 IID and IVA in the HCT-15 male colon cells and IB in HT-29 female colon cells showed no effect with B(a)P treatment on the cell proliferation, apoptosis, membrane integrity and free radicals (ROS, mtROS, and SOR) generation. Conclusion: Targeting specific PLA2 isozymes in a cell-specific manner abolished the B(a)P-induced PLA2-mediated oxidative damage–related signaling pathways.

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Licochalcone A-Induced Apoptosis Through the Activation of p38MAPK Pathway Mediated Mitochondrial Pathways of Apoptosis in Human Osteosarcoma Cells In Vitro and In Vivo

Cells ◽

10.3390/cells8111441 ◽

2019 ◽

Vol 8 (11) ◽

pp. 1441 ◽

Cited By ~ 7

Author(s):

Lin ◽

Yang ◽

Chiou ◽

Hsieh ◽

Wen ◽

...

Keyword(s):

Cell Viability ◽

Mitochondrial Membrane ◽

Annexin V ◽

Osteosarcoma Cells ◽

Antitumor Effects ◽

Licochalcone A ◽

Human Osteosarcoma ◽

Human Osteosarcoma Cells

Background: Licochalcone A (LicA) is isolated from the roots of Glycyrrhiza glabra and possesses antitumor and anti-invasive activities against several tumor cells. However, the antitumor effects of LicA on human osteosarcoma cells have yet to be demonstrated either in vitro or in vivo. Methods: Cell viability was measured by MTT assay. Apoptosis and mitochondrial dysfunction were detected with Annexin V/PI staining and JC-1 staining by flow cytometry. The expressions of caspase- or mitochondrial-related proteins were demonstrated by western blotting. Antitumor effect of LicA on 143B xenograft mice in vivo. Results: LicA could inhibit cell proliferation and induce apoptosis in human osteosarcoma cells, as evidenced by a decrease in cell viability, loss of mitochondrial membrane potentials, and activation of caspases. LicA treatment substantially reduced the expression of Bcl-2 and Mcl-1 and increased the expression of cleaved-caspase-3, cleaved-caspase-9, cleaved-PARP, and Bax in HOS and U2OS cells. Moreover, mitochondrial membrane potential and apoptosis suppression mediated by Z-VAD or tauroursodeoxycholic acid significantly reduced LicA-induced mitochondria-dependent apoptosis. The study also determined that LicA treatment induced p38MAPK phosphorylation, but siRNA-p38 or BIRB796 substantially reversed cell viability through the inhibition of mitochondria-dependent apoptosis pathways. Finally, an in vivo study revealed that LicA significantly inhibited 143B xenograft tumor growth. Conclusions: These findings demonstrate that LicA has antitumor activities against human osteosarcoma cells through p38MAPK regulation of mitochondria-mediated intrinsic apoptotic pathways in vitro and in vivo.

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Inhibition of human head and neck squamous cell cancer growth by modulation of heat shock proteins and induction of the mitochondrial apoptotic pathway with withaferin A

Journal of Clinical Oncology ◽

10.1200/jco.2009.27.15_suppl.e17003 ◽

2009 ◽

Vol 27 (15_suppl) ◽

pp. e17003-e17003

Author(s):

M. S. Cohen ◽

B. N. Timmermann ◽

G. O'Donnell ◽

A. K. Samadi

Keyword(s):

Flow Cytometry ◽

Membrane Potential ◽

Heat Shock ◽

Heat Shock Proteins ◽

Cell Viability ◽

Mitochondrial Membrane ◽

Annexin V ◽

Withaferin A ◽

Shock Proteins ◽

Mts Assay

e17003 Background: Epithelial cancers, particularly lung cancer and head and neck squamous cell carcinoma (HNSCC), continue to pose formidable challenges in clinical practice. Novel chemotherapeutic agents have been developed, but even those have limited long-term benefits in the treatment of these tumors, illustrating the need to continue to improve systemic therapy for affected patients. The objective of the present study was to investigate the effect of withaferin A (WA), a plant-derived small molecule, on cancer cell growth, heat shock protein expression and induction of apoptosis in human HNSCCs. Methods: MDA1986 and JMAR HNSCC cells were used in all experiments. The effect of WA on cell viability was determined by MTS assay. Apoptosis and mitochondrial membrane potential changes were assessed by annexin V/propidium iodide and JC-1 staining respectively using standard flow cytometry methods. Effect of WA on modulation of heat shock proteins was determined by Western blot analysis. Results: Withaferin A reduces cell viability in both MDA1986 and JMAR cells with IC50 levels of 265 ± 5 nM by MTS assay, which is 5 fold higher than its reported activity in breast cancer cells. WA completely down-regulates HSP90beta, GRP94, and TRAP-1 expression at 250 nM concentration in HNSCC cells at 24 hours treatment. In addition, WA markedly increased HSP70 levels and mildly increased HSP27 levels in a dose-dependent manner at 24 hours treatment. Flow cytometry with Annexin V/PI staining shows that 5 μM WA treatment for 24 hours induced apoptosis in 63% of MDA1986 and 60% of JMAR cells. WA at 5 μM also reduced mitochondrial membrane potential by JC-1 staining with flow cytometry to less than 10% of controls in both JMAR and MDA1986 cells at 24 hours treatment. Conclusions: Withaferin A is a potent novel inhibitor of HSP90 in human HNSCCs. In addition to HSP modulation, its anticancer mechanistic effects involve apoptotic cell death through the mitochondrial pathway. This molecule shows promise for further in vivo studies to establish preclinical proof of concept as a novel anticancer therapy in this disease. No significant financial relationships to disclose.

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