scholarly journals Esculetin Neutralises Cytotoxicity oft-BHP but Not of H2O2on Human Leukaemia NB4 Cells

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Virginia Rubio ◽  
Ana I. García-Pérez ◽  
M. Cristina Tejedor ◽  
Angel Herráez ◽  
José C. Diez

The coumarin esculetin shows antioxidant action on some cell types, both by scavenging ROS and by decreasing ROS production. We have previously demonstrated the induction of apoptosis by esculetin on NB4 human leukaemia cells by an ill-defined mechanism related to ROS levels. In this work, we analyze the effect of the simultaneous treatment with esculetin and two oxidants to observe the early events in the mechanism of esculetin-induced apoptosis. Our results show that, from the early time of 15 min, esculetin acts synergistically with H2O2to decrease cell viability and metabolic activity and to increase apoptosis in NB4 cells. In contrast, the early oxidative effects oft-BHP are neutralised by esculetin, protecting human leukaemia NB4 cells from apoptosis. Esculetin seems to restrict the increase in peroxides caused by H2O2ort-BHP in the time interval analyzed. These results contribute to a better understanding of the cytotoxic effect caused by esculetin on NB4 cells. At the same time, the early neutralisation of exogenous oxidants could be of interest to prevent diseases related to oxidative stress imbalance.

2004 ◽  
Vol 32 (03) ◽  
pp. 377-387 ◽  
Author(s):  
Hyung-Jin Kim ◽  
Seon Il Jang ◽  
Young-Jun Kim ◽  
Hyun-Ock Pae ◽  
Hae-Young Won ◽  
...  

We studied the effect of 4-acetyl-12,13-epoxyl-9-trichothecene-3,15-diol (AETD) isolated from Isaria japonica, one of the most popular Chinese fungal medicines, on the induction of apoptosis in rat bladder carcinoma NBT-II cells. AETD was cytotoxic to NBT-II cells, and this cytotoxic effect appears to be attributed to its induction of apoptotic cell death, as AETD induced nuclear morphological changes and internucleosomal DNA fragmentation, and increased the proportion of hypodiploid cells and activity of caspase-3. AETD treatment also decreased the expression of the anti-apoptotic protein Bcl-2 and increased the expression of the pro-apoptotic protein Bax. These results provide important information in understanding the mechanism(s) of AETD-induced apoptosis.


PPAR Research ◽  
2008 ◽  
Vol 2008 ◽  
pp. 1-12 ◽  
Author(s):  
Heath A. Elrod ◽  
Shi-Yong Sun

Peroxisome proliferator-activated receptors (PPARs) are ligand binding transcription factors which function in many physiological roles including lipid metabolism, cell growth, differentiation, and apoptosis. PPARs and their ligands have been shown to play a role in cancer. In particular, PPARγligands including endogenous prostaglandins and the synthetic thiazolidinediones (TZDs) can induce apoptosis of cancer cells with antitumor activity. Thus, PPARγligands have a potential in both chemoprevention and therapy of several types of cancer either as single agents or in combination with other antitumor agents. Accordingly, the involvement of PPARγand its ligands in regulation of apoptosis of cancer cells have been extensively studied. Depending on cell types or ligands, induction of apoptosis in cancer cells by PPARγligands can be either PPARγ-dependent or -independent. Through increasing our understanding of the mechanisms of PPARγligand-induced apoptosis, we can develop better strategies which may include combining other antitumor agents for PPARγ-targeted cancer chemoprevention and therapy. This review will highlight recent research advances on PPARγand apoptosis in cancer.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4802-4802
Author(s):  
Priscila S. Scheucher ◽  
Guilherme Augusto Silva dos Santos ◽  
Hamilton Luiz G Teixeira ◽  
Roberto P. Falcao ◽  
Eduardo Magalhaes Rego

Abstract Abstract 4802 Caffeic acid phenethyl ester (CAPE) is an active phenolic compound present in propolis obtained from honeybee hives. It is reported to present a spectrum of biological activities including antioxidant, anti-inflammatory and antitumoral. The antitumoral activity of CAPE as evaluated by several studies in vitro and in vivo seems to be related to distinct effects like inhibition of angiogenesis, invasion and metastasis and induction of apoptosis or differentiation of cancer cells. In the scenario of AML the demonstration of CAPE-induced apoptosis or cellular differentiation is restricted to the HL-60 cell line. Our aim was to evaluate the effects of CAPE treatment on primary AML samples as well as APL cell lines NB4 and NB4-R2 (a cell resistant to ATRA-induced differentiation) and on AML cell line Kasumi-1 (representative of core binding factor leukemia with AML1-ETO rearrangement). Proliferation and viability was evaluated by cell count with tripan blue in Neubauer chamber at fixed time intervals. Differentiation was evaluated by flow cytometer determination of CD11b expression. Apoptotic cells were defined as sub-G0 fraction and were evaluated by flow cytometer determination of propidium iodide- DNA fluorescence. Also apoptosis was detected by the annexin-V method. Leishman stained cytospins were used to confirm apoptosis or differentiation. CAPE did not induce differentiation in the cell lines NB4, NB4-R2 or Kasumi-1 and did not alter the differentiation induced by ATRA in NB4 cells. CAPE inhibited the proliferation of AML cell lines in a time and dose dependent fashion. The ED50 in 24h treatment for NB4 cell line (tripan blue) was 32.1 mcg/ml. ED50 (at 24h) for induction of apoptosis in the more sensitive assay using annexin-V in NB4 cells after 24h was 7.5mcg/ml and for Kasumi-1 was 10.2mcg/ml. CAPE (32 mcg/ml) significantly induced apoptosis after 24h in cells from AML patients (n=10), mean (IC95%) of 40.5% (29.26 – 51.76) versus control treated cells 18.16% (12.27 – 24.05); p=0.0004 In order to evaluate the mechanisms of CAPE-induced apoptosis in NB4 cells we performed a microarray analysis after 12 hours treatment (32mcg/ml). The majority of downregulated genes fall into two categories: positive cell cycle regulators and ribosomal genesis / protein traduction. In the other hand, upregulated genes fall into several categories, we point out chemokines and G- protein signalization genes. (Table 1 and 2) The role of IL-8 and Gro chemokines, that signaling by G-protein coupled receptors, has been determined in tumor progression and invasiveness. We are currently investigating the possibility that CAPE exerts an inhibitory effect in chemokine signaling in APL. In conclusion, CAPE-induced apoptosis in AML is associated with the regulation of specific genes. These properties are interesting and need further investigation. Disclosures: No relevant conflicts of interest to declare.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kazunori Watanabe ◽  
Tomoko Nawachi ◽  
Ruriko Okutani ◽  
Takashi Ohtsuki

AbstractMethods to spatially induce apoptosis are useful for cancer therapy. To control the induction of apoptosis, methods using light, such as photochemical internalization (PCI), have been developed. We hypothesized that photoinduced delivery of microRNAs (miRNAs) that regulate apoptosis could spatially induce apoptosis. In this study, we identified pre-miR-664a as a novel apoptosis-inducing miRNA via mitochondrial apoptotic pathway. Further, we demonstrated the utility of photoinduced cytosolic dispersion of RNA (PCDR), which is an intracellular RNA delivery method based on PCI. Indeed, apoptosis is spatially regulated by pre-miR-664a and PCDR. In addition, we found that apoptosis induced by pre-miR-664a delivered by PCDR was more rapid than that by lipofection. These results suggest that pre-miR-664a is a nucleic acid drug candidate for cancer therapy and PCDR and pre-miR-664a-based strategies have potential therapeutic uses for diseases affecting various cell types.


2021 ◽  
Vol 22 (7) ◽  
pp. 3649
Author(s):  
Patricia Ramos-Ramírez ◽  
Omar Tliba

Glucocorticoids (GCs) act via the GC receptor (GR), a receptor ubiquitously expressed in the body where it drives a broad spectrum of responses within distinct cell types and tissues, which vary in strength and specificity. The variability of GR-mediated cell responses is further extended by the existence of GR isoforms, such as GRα and GRβ, generated through alternative splicing mechanisms. While GRα is the classic receptor responsible for GC actions, GRβ has been implicated in the impairment of GRα-mediated activities. Interestingly, in contrast to the popular belief that GRβ actions are restricted to its dominant-negative effects on GRα-mediated responses, GRβ has been shown to have intrinsic activities and “directly” regulates a plethora of genes related to inflammatory process, cell communication, migration, and malignancy, each in a GRα-independent manner. Furthermore, GRβ has been associated with increased cell migration, growth, and reduced sensitivity to GC-induced apoptosis. We will summarize the current knowledge of GRβ-mediated responses, with a focus on the GRα-independent/intrinsic effects of GRβ and the associated non-canonical signaling pathways. Where appropriate, potential links to airway inflammatory diseases will be highlighted.


Blood ◽  
1999 ◽  
Vol 94 (12) ◽  
pp. 4060-4066 ◽  
Author(s):  
Maria Fiammetta Romano ◽  
Annalisa Lamberti ◽  
Rita Bisogni ◽  
Corrado Garbi ◽  
Antonio M. Pagnano ◽  
...  

Abstract We investigated the involvement of NF-κB/Rel transcription factors that reportedly can inhibit apoptosis in various cell types in the antiapoptotic mechanism of the cytoprotectant amifostine. In the nontumorigenic murine myeloid progenitor 32D cells incubated with amifostine, we detected a reduction of the IκB cytoplasmic levels by Western blotting and a raising of nuclear NF-κB/Rel complexes by electrophoretic mobility shift assay. Amifostine inhibited by more than 30% the growth factor deprivation-induced apoptosis, whereas its effect failed when we blocked the NF-κB/Rel activity with an NF-κB/Rel-binding phosphorothioate decoy oligodeoxynucleotide. In human cord blood CD34+ cells, the NF-κB/Rel p65 subunit was detectable (using immunofluorescence analysis) mainly in the cytoplasm in the absence of amifostine, whereas its presence was appreciable in the nuclei of cells incubated with the cytoprotectant. In 4 CD34+ samples incubated for 3 days in cytokine-deficient conditions, cell apoptosis was reduced by more than 30% in the presence of amifostine (or amifostine plus a control oligo); the effect of amifostine was abolished in cultures with the decoy oligo. These findings indicate that the inhibition of hematopoietic progenitor cell apoptosis by amifostine requires the induction of NF-κB/Rel factors and that the latter can therefore exert an antiapoptotic activity in the hematopoietic progenitor cell compartment. Furthermore, the identification of this specific mechanism underlying the survival-promoting activity of amifostine lends support to the possible use of this agent in apoptosis-related pathologies, such as myelodysplasias.


1999 ◽  
Vol 163 (3) ◽  
pp. 487-494 ◽  
Author(s):  
R Rajah ◽  
A Khare ◽  
PD Lee ◽  
P Cohen

Cells are known to undergo apoptosis when cultured in high serum concentrations. However, the serum factors responsible for this induction of apoptosis have not been identified. The IGF-binding protein-3 (IGFBP-3), a negative growth regulator, is found at concentrations of 5 microgram/ml in serum. We have recently demonstrated that IGFBP-3 induces apoptosis in PC-3 cells, a prostate cancer cell line, at a concentration of 500 ng/ml. In this communication, we demonstrate the role of IGFBP-3 as one of the apoptosis-inducing agents in high serum concentrations. Treatment of PC-3 cells with increasing concentrations (40% to 90%) of intact human serum (HS) resulted in a dose-dependent decrease in cell growth. Valinomycin, an ionophore, was used as a positive control to measure the induction of apoptosis by serum treatment in PC-3 cells. Treatment with 90% serum showed significant suppression of growth (P<0.001) compared with the effect of 10% serum. Treatment with increasing concentrations of HS (40% to 90%) resulted in a dose-dependent increase in apoptosis. Treatment with 90% HS showed a 10-fold increase in apoptotic index compared with cells treated with 10% HS. Treatment of PC-3 cells with IGFs and IGFBP-3-depleted 90% human sera (depleted serum=DS) demonstrated significantly lower levels of apoptosis (50% reduction in the effect of 90% HS) suggesting a role of IGFBP-3 in inducing apoptosis in high serum concentration. Furthermore, treatment with DS supplemented with recombinant IGFBP-3 (500 ng/ml) brought the apoptotic index down close to the level of apoptosis induced by 90% intact serum treatment (P<0.001). However, DS supplemented with physiological concentrations of IGFs (500 ng/ml) showed only partial recovery of cell survival demonstrated by 90% DS. This data indicates that IGFBP-3 is one of the factors in serum that is responsible for high-serum-induced apoptosis.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Sung Min Ju ◽  
Jun Gue Kang ◽  
Jun Sang Bae ◽  
Hyun Ock Pae ◽  
Yeoung Su Lyu ◽  
...  

Apigenin is a member of the flavone subclass of flavonoids present in fruits and vegetables. Apigenin has long been considered to have various biological activities, such as antioxidant, anti-inflammatory, and antitumorigenic properties, in various cell types. Cisplatin was known to exhibit cytotoxic effect to renal cells by inducing apoptosis through activation of p53. The present study investigated the antiapoptotic effects of apigenin on the cisplatin-treated human renal proximal tubular epithelial (HK-2) cells. HK-2 cells were pretreated with apigenin (5, 10, 20 μM) for 1 h and then treated with 40 μM cisplatin for various times. Apigenin inhibited the cisplatin-induced apoptosis of HK-2 cells. Interestingly, apigenin itself exerted cytostatic activity because of its ability to induce cell cycle arrest. Apigenin inhibited caspase-3 activity and PARP cleavage in cisplatin-treated cells. Apigenin reduced cisplatin-induced phosphorylation and expression of p53, with no significant influence on production of ROS that is known to induce p53 activation. Furthermore, apigenin promoted cisplatin-induced Akt phosphorylation, suggesting that enhanced Akt activation may be involved in cytoprotection. Taken together, these results suggest that apigenin ameliorates cisplatin-induced apoptosis through reduction of p53 activation and promotion of PI3K/Akt pathway in HK-2 cells.


1997 ◽  
Vol 110 (3) ◽  
pp. 379-387 ◽  
Author(s):  
Q. Chen ◽  
R.S. Benson ◽  
A.D. Whetton ◽  
S.R. Brant ◽  
M. Donowitz ◽  
...  

Removal of interleukin-3 from murine IC.DP pre-mast cells results in irreversible commitment to apoptosis within 18 hours. To identify early events necessary for the engagement of apoptosis we examined the regulation of intracellular pH (pH(i)). IC.DP cells acidified 2 hours after removal of interleukin-3 (before discernible signs of apoptosis) and by 18 hours pH(i) had decreased by 0.15 units. The acidification was due to both an increase in an acid-loading process which only occurs when intracellular pH is above 6.8 and a slight reduction in H+ efflux via NA+/H+ exchange. Activation of a temperature sensitive mutant of v-Abl protein tyrosine kinase suppressed apoptosis of IC.DP cells in the absence of interleukin-3 but did not stimulate proliferation, and moreover prevented cellular acidification. Acidification of the cells by 0.2 units to pH 6.86 by complete inhibition of Na+/H+ exchange by 10 microM 5′-(N-methyl-N-isobutyl)-amiloride prevented the suppression of apoptosis by v-abl protein tyrosine kinase following IL 3 withdrawal. However in the presence of interleukin-3, addition of 10 microM 5′-(N-methyl-N-isobutyl)-amiloride only resulted in a fall of pH(i) to 7.17. Apoptosis did not occur and the cells continued to proliferate. Thus, in this model intracellular pH must fall below a critical value for apoptosis to occur. Together these data point to a step in cytokine deprivation induced apoptosis (at least in some haemopoietic cell types) which is either enhanced by or dependent upon an acidic intracellular environment which is the result of an increase in acid loading and inhibition of Na+/H+ exchange activity. One of the mechanisms by which activation of v-Abl protein tyrosine kinase suppresses apoptosis is by prevention of intracellular acidification.


1994 ◽  
Vol 345 (1313) ◽  
pp. 269-275 ◽  

Regulation of multicellular architecture involves a dynamic equilibrium between cell proliferation, differentiation with consequent growth arrest, and cell death. Apoptosis is one particular form of active cell death that is extremely rapid and characterized by auto-destruction of chromatin, cellular blebbing and condensation, and vesicularization of internal components. The c- myc proto-oncogene encodes an essential component of the cell’s proliferative machinery and its deregulated expression is implicated in most neoplasms. Intriguingly, c- myc can also act as a potent inducer of apoptosis. Myc-induced apoptosis occurs only in cells deprived of growth factors or forcibly arrested with cytostatic drugs. Myc-induced apoptosis is dependent upon the level at which it is expressed and deletion mapping shows that regions of c-Myc required for apoptosis overlap with regions necessary for co-transformation, autoregulation, inhibition of differentiation, transcriptional activation and sequence-specific DNA binding. Moreover, induction of apoptosis by c-Myc requires association with c-Myc’s heterologous partner, Max. All of this strongly implies that c-Myc drives apoptosis through a transcriptional mechanism: presumably by modulation of target genes. Two simple models can be invoked to explain the induction of apoptosis by c-Myc. One holds that death arises from a conflict in growth signals which is generated by the inappropriate or unscheduled expression of c-Myc under conditions that would normally promote growth arrest. In this ‘Conflict’ model, induction of apoptosis is not a normal function of c-Myc but a pathological manifestation of its deregulation. It thus has significance only for models of carcinogenic progression in which myc genes are invariably disrupted. The other model holds that induction of apoptosis is a normal obligate function of c-Myc which is modulated by specific survival factors. Thus, every cell that enters the cycle invokes an obligate abort suicide pathway which must be continuously suppressed by signals from the immediate cellular environment for the proliferating cell to survive. Evidence will be presented supporting this second ‘Dual Signal’ model for cell growth and survival, and its widespread implications will be discussed.


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