The Requirement of Reactive Oxygen Species Generation in the Apoptosis of Leukemia Cells Induced by 2-Methoxyestradiol.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4370-4370
Author(s):  
Guo Kunyuan ◽  
Miaorong She ◽  
Haiyan Hu ◽  
Xinqing Niu ◽  
Sanfang Tu ◽  
...  

Abstract 2-Methoxyestradiol (2-ME) is a new anticancer agent currently under investigation for treatment of leukemia. We evaluated the effects of 2-ME-induced apoptosis in two myeloid leukemia cell lines (U937 and HL-60) in association with reactive oxygen species (ROS) generation. We found that 2-ME resulted in viability decrease in a dose-dependent manner, generated ROS: nitric oxide and superoxide anions, and mitochondria damage. 2-ME-induced apoptosis correlated with increase in ROS. Quenching of ROS with N-acetyl-L-cysteine protected leukemia cells from the cytotoxicity of 2-ME and prevented apoptosis induction by 2-ME. Furthermore, addition of manumycin, a farnesyltransferase inhibitor, demonstrated by our previous studies that induced apoptosis of leukemic cells and induced ROS, significantly enhanced the apoptosis-induced by 2-ME. In conclusion, cellular ROS generation play an important role in the cytotoxic effect of 2-ME. It is possible to use ROS-generation agents such as manumycin to enhance the antileukemic effect. Such a combination strategy need the further in vivo justify and may have potential clinical application.

1996 ◽  
Vol 15 (5) ◽  
pp. 422-427 ◽  
Author(s):  
Y. Shen ◽  
H-M. Shen ◽  
C-Y. Shi ◽  
C-N. Ong

Benzene is myelotoxic and leukemogenic in humans. The mechanisms leading to these effects, however have not been fully elucidated. One of the underlying mechanisms is believed to be the oxidative damage caused by its metabolites. A comparative study was undertaken to examine the relationships between reactive oxygen species (ROS) production, lipid peroxidation and subse quent cytotoxicity induced by five major benzene meta bolites. The generation of ROS by benzene metabolites was demonstrated by the significant and dose-dependent increase of intracellular ROS formation in HL60 human promyelocytic leukemia cells in vitro. 1,4-Benzoquinone (BQ) was found to be the most potent metabolite in induction of ROS formation, followed by 1,2,4-benzene triol (BT) and to a lesser extent, phenol (PH) and trans, trans-muconaldehyde (MD). No significant effect was observed when the cells were treated with trans, trans-muconic acid (MA). The enhancement of ROS production by BQ was effectively inhibited by the addition of catalase, deferoxamine (DFO) and dimethyl sulfoxide (DMSO), but unchanged by superoxide dismutase (SOD), suggest that hydrogen peroxide (H2O2) and hydroxyl radicals (OH.) are the two major forms of ROS involved. The results also demonstrate that the ability of benzene metabolites in enhancing ROS generation is closely correlated to their capacity in causing lipid peroxidation and subsequent cytotoxicity. These findings together with earlier parallel observations on DNA damage suggest that ROS play an important role in the mechanism of carcinogenesis induced by benzene metabolites.


2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Mohammad Jalili-Nik ◽  
Mohammad Montazami Sadeghi ◽  
Elmira Mohtashami ◽  
Hamid Mollazadeh ◽  
Amir R. Afshari ◽  
...  

Glioblastoma multiforme (GBM) is the most hostile tumor in the central nervous system. Unfortunately, the prognosis of GBM patients is poor following surgical interventions, chemotherapy, and radiotherapy. Consequently, more efficient and effective treatment options for the treatment of GBM need to be explored. Zerumbone, as a sesquiterpene derived from Zingiber zerumbet Smith, has substantial cytotoxic and antiproliferative activities in some types of cancer. Here, we show that exposure of GBM cells (U-87 MG) to Zerumbone demonstrated significant growth inhibition in a concentration-dependent manner. Zerumbone also induced apoptosis and caused cell cycle arrest of human GBM U-87 MG cells in the G2/M phase of the cell cycle. In detail, the apoptotic process triggered by Zerumbone involved the upregulation of proapoptotic Bax and the suppression of antiapoptotic Bcl-2 genes expression as determined by qRT-PCR. Moreover, Zerumbone enhanced the generation of reactive oxygen species (ROS), and N-acetyl cysteine (NAC), as an antioxidant, reversed the ROS-induced cytotoxicity of U-87 MG cells. The Western blot analysis suggested that Zerumbone activated the NF-κB p65, which was partly inhibited by NAC treatment. Collectively, our results confirmed that Zerumbone induces cytotoxicity by ROS generation. Thus, the study raises the possibility of Zerumbone as a potential natural agent for treating GBM due to its ability to induce cytotoxicity.


Blood ◽  
2010 ◽  
Vol 116 (18) ◽  
pp. 3593-3603 ◽  
Author(s):  
Sumaiya Sharmeen ◽  
Marko Skrtic ◽  
Mahadeo A. Sukhai ◽  
Rose Hurren ◽  
Marcela Gronda ◽  
...  

Abstract To identify known drugs with previously unrecognized anticancer activity, we compiled and screened a library of such compounds to identify agents cytotoxic to leukemia cells. From these screens, we identified ivermectin, a derivative of avermectin B1 that is licensed for the treatment of the parasitic infections, strongyloidiasis and onchocerciasis, but is also effective against other worm infestations. As a potential antileukemic agent, ivermectin induced cell death at low micromolar concentrations in acute myeloid leukemia cell lines and primary patient samples preferentially over normal hematopoietic cells. Ivermectin also delayed tumor growth in 3 independent mouse models of leukemia at concentrations that appear pharmacologically achievable. As an antiparasitic, ivermectin binds and activates chloride ion channels in nematodes, so we tested the effects of ivermectin on chloride flux in leukemia cells. Ivermectin increased intracellular chloride ion concentrations and cell size in leukemia cells. Chloride influx was accompanied by plasma membrane hyperpolarization, but did not change mitochondrial membrane potential. Ivermectin also increased reactive oxygen species generation that was functionally important for ivermectin-induced cell death. Finally, ivermectin synergized with cytarabine and daunorubicin that also increase reactive oxygen species production. Thus, given its known toxicology and pharmacology, ivermectin could be rapidly advanced into clinical trial for leukemia.


Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3372 ◽  
Author(s):  
Yan-Hui Shen ◽  
Li-Ying Wang ◽  
Bao-Bao Zhang ◽  
Qi-Ming Hu ◽  
Pu Wang ◽  
...  

Ethyl rosmarinate (RAE) is one of the active constituents from Clinopodium chinense (Benth.) O. Kuntze, which is used for diabetic treatment in Chinese folk medicine. In this study, we investigated the protective effect of RAE on high glucose-induced injury in endothelial cells and explored its underlying mechanisms. Our results showed that both RAE and rosmarinic acid (RA) increased cell viability, decreased the production of reactive oxygen species (ROS), and attenuated high glucose-induced endothelial cells apoptosis in a dose-dependent manner, as evidenced by Hochest staining, Annexin V–FITC/PI double staining, and caspase-3 activity. RAE and RA both elevated Bcl-2 expression and reduced Bax expression, according to Western blot. We also found that LY294002 (phosphatidylinositol 3-kinase, or PI3K inhibitor) weakened the protective effect of RAE. In addition, PDTC (nuclear factor-κB, or NF-κB inhibitor) and SP600125 (c-Jun N-terminal kinase, or JNK inhibitor) could inhibit the apoptosis in endothelial cells caused by high glucose. Further, we demonstrated that RAE activated Akt, and the molecular docking analysis predicted that RAE showed more affinity with Akt than RA. Moreover, we found that RAE inhibited the activation of NF-κB and JNK. These results suggested that RAE protected endothelial cells from high glucose-induced apoptosis by alleviating reactive oxygen species (ROS) generation, and regulating the PI3K/Akt/Bcl-2 pathway, the NF-κB pathway, and the JNK pathway. In general, RAE showed greater potency than RA equivalent.


2007 ◽  
Vol 97 (01) ◽  
pp. 88-98 ◽  
Author(s):  
Christina Barja-Fidalgo ◽  
Vany Nascimento-Silva ◽  
Maria Arruda ◽  
Iolanda Fierro

SummaryLipoxins and their aspirin-triggered carbon-15 epimers have emerged as mediators of key events in endogenous anti-inflammation and resolution. However, the implication of these novel lipid mediators on cardiovascular diseases such as hypertension, atherosclerosis, and heart failure has not been investigated. One of the major features shared by these pathological conditions is the increased production of reactive oxygen species (ROS) generated by vascular NAD(P)H oxidase activation. In this study, we have examined whether an aspirin-triggered lipoxin A4 analog (ATL-1) modulates ROS generation in endothelial cells (EC). Pre-treatment of EC with ATL-1 (1–100 nM) completely blocked ROS production triggered by different agents, as assessed by dihydrorhodamine 123 and hydroethidine. Furthermore, ATL-1 inhibited the phosphorylation and translocation of the cytosplamic NAD(P)H oxidase subunit p47phox to the cell membrane as well as NAD(P)H oxidase activity. Western blot and immunofluorescence microscopy analyses showed that ATL-1 (100 nM) impaired the redox-sensitive activation of the transcriptional factor NF-κB, a critical step in several events associated to vascular pathologies. These results demonstrate that ATL-1 suppresses NAD(P)H oxidase-mediated ROS generation in EC, strongly indicating that lipoxins may play a protective role against the development and progression of cardiovascular diseases.


2020 ◽  
Vol 8 ◽  
Author(s):  
Elisa Carrasco ◽  
Juan Carlos Stockert ◽  
Ángeles Juarranz ◽  
Alfonso Blázquez-Castro

For decades, the possibility to generate Reactive Oxygen Species (ROS) in biological systems through the use of light was mainly restricted to the photodynamic effect: the photoexcitation of molecules which then engage in charge- or energy-transfer to molecular oxygen (O2) to initiate ROS production. However, the classical photodynamic approach presents drawbacks, like per se chemical reactivity of the photosensitizing agent or fast molecular photobleaching due to in situ ROS generation, to name a few. Recently, a new approach, which promises many advantages, has entered the scene: plasmon-driven hot-electron chemistry. The effect takes advantage of the photoexcitation of plasmonic resonances in metal nanoparticles to induce a new cohort of photochemical and redox reactions. These metal photo-transducers are considered chemically inert and can undergo billions of photoexcitation rounds without bleaching or suffering significant oxidative alterations. Also, their optimal absorption band can be shape- and size-tailored in order to match any of the near infrared (NIR) biological windows, where undesired absorption/scattering are minimal. In this mini review, the basic mechanisms and principal benefits of this light-driven approach to generate ROS will be discussed. Additionally, some significant experiments in vitro and in vivo will be presented, and tentative new avenues for further research will be advanced.


2008 ◽  
Vol 19 (7) ◽  
pp. 2984-2994 ◽  
Author(s):  
Davide Gianni ◽  
Ben Bohl ◽  
Sara A. Courtneidge ◽  
Gary M. Bokoch

NADPH oxidase (Nox) family enzymes are one of the main sources of cellular reactive oxygen species (ROS), which have been shown to function as second messenger molecules. To date, seven members of this family have been reported, including Nox1-5 and Duox1 and -2. With the exception of Nox2, the regulation of the Nox enzymes is still poorly understood. Nox1 is highly expressed in the colon, and it requires two cytosolic regulators, NoxO1 and NoxA1, as well as the binding of Rac1 GTPase, for its activity. In this study, we investigate the role of the tyrosine kinase c-Src in the regulation of ROS formation by Nox1. We show that c-Src induces Nox1-mediated ROS generation in the HT29 human colon carcinoma cell line through a Rac-dependent mechanism. Treatment of HT29 cells with the Src inhibitor PP2, expression of a kinase-inactive form of c-Src, and c-Src depletion by small interfering RNA (siRNA) reduce both ROS generation and the levels of active Rac1. This is associated with decreased Src-mediated phosphorylation and activation of the Rac1-guanine nucleotide exchange factor Vav2. Consistent with this, Vav2 siRNA that specifically reduces endogenous Vav2 protein is able to dramatically decrease Nox1-dependent ROS generation and abolish c-Src-induced Nox1 activity. Together, these results establish c-Src as an important regulator of Nox1 activity, and they may provide insight into the mechanisms of tumor formation in colon cancers.


2012 ◽  
Vol 610-613 ◽  
pp. 794-797
Author(s):  
Yu Shang ◽  
Lan Lan Fan ◽  
Ling Zhang

Exposure to ambient particulate matter (PM) is found to be associated with adverse cardiopulmonary diseases. Endotoxin presented in PM is suggested to be one of the most important factors in triggering pro-inflammatory cytokine/chemokine release upon the exposure of PM. Pre-treated with endotoxin is found to enhance the inflammatory responses induced by PM in cultured cells. The aim of present study is to investigate the roles of endotoxin on the cytotoxicity and the generation of reactive oxygen species (ROS) induced by PM2.5 in a human lung epithelial cell line A549. The results find that PM2.5 induced a dose-dependent decrease in cell viability and pre-treated with endotoxin did not change the cytotoxicity of PM2.5 in A549 cells. Nevertheless the endotoxin significantly reduced the ROS generation in A549 induced by PM2.5 at the dose of 400 μg/mL. The results indicated that the combined effects of endotoxin and PM were complex and deserved further investigations.


2015 ◽  
Vol 35 (5) ◽  
pp. 1958-1974 ◽  
Author(s):  
Ayman M. Saleh ◽  
Ahmad Aljada ◽  
Mustafa M. El-Abadelah ◽  
Salim S. Sabri ◽  
Jalal A. Zahra ◽  
...  

Background/Aims: In our quest to develop an isoindigo with improved efficacy and bioavailability, we recently synthesized a series of novel substituted pyridone-annelated isoindigo and evaluated their antiproliferative effects. We identified the compound [(E)-1-(5'-Chloro-2'-oxoindolin-3'-ylidene)-6-ethyl-2,3,6,9-tetrahydro-2,9-dioxo-1H-pyrrolo[3,2-f] quinoline-8-carboxylic acid], abbreviated as 5'-Cl, which shows selective antiproliferative activities against various cancer cell lines mediated through apoptosis. Here we have investigated the molecular mechanisms underlying the apoptotic activity of 5'-Cl in the human promyelocytic leukemia HL-60 cells. Methods: We employed different methods to determine the apoptotic pathways triggered by 5'-Cl in HL-60 cells, using flow cytometry, nuclear staining, caspases activation, mitochondria functioning, generation of reactive oxygen species (ROS) and Western blotting techniques. Results: Low concentrations (1-8 µM) of 5'-Cl inhibited the growth of HL-60 cells in a dose and time-dependent manner. Cytotoxicity of this compound is found to be mediated by a caspase-dependent apoptosis. Also, there were indications of caspase independent apoptosis as z-VAD-FMK failed to fully rescue the cells from 5‘-Cl-induced apoptosis. In addition, the compound triggered generation of Reactive Oxygen Species (ROS), caused depolarization of the mitochondrial inner membrane, decreased the level of cellular ATP, modulated the expression and phosphorylation of Bcl-2 leading to loss of its association with Bax and increased the release of cytochrome c to the cytosol of treated cells. The effects of 5‘-Cl on mitochondria and apoptosis were substantially blocked in the presence of a combination between z-VAD-FMK and either of the ROS scavenger N-acetyl-L-cysteine (NAC) or pyrrolidine dithiocarbamate (PDTC). Conclusion: We demonstrated that the growth inhibitory effects of 5'-Cl in HL-60 cells involve multiple pathways of apoptosis and dysregulation of mitochondrial functions.


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