scholarly journals BAK activation is necessary and sufficient to drive ceramide synthase-dependent ceramide accumulation following inhibition of BCL2-like proteins

2013 ◽  
Vol 452 (1) ◽  
pp. 111-119 ◽  
Author(s):  
Levi J. Beverly ◽  
Lauren A. Howell ◽  
Maria Hernandez-Corbacho ◽  
Lavona Casson ◽  
Jerry E. Chipuk ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Apoptotic Cell ◽  
Chemotherapeutic Drugs ◽  
Ceramide Synthase ◽  
Bcl2 Family ◽  
Ceramide Synthesis ◽  
Multiple Cell ◽  
Necessary And Sufficient ◽  
In Cells

Determining mechanistic details about how drugs kill cancer cells is critical for predicting which cancers will respond to given therapeutic regimens and for identifying effective combinations of drugs that more potently kill cancer cells while sparing normal cells. The BCL2 family of proteins and bioactive sphingolipids are intricately linked during apoptotic cell death. In fact, many chemotherapeutic drugs are known to cause accumulation of the pro-apoptotic sphingolipid ceramide; however, the mechanism by which this occurs is not completely understood. In the present study we demonstrate that direct inhibition of anti-apoptotic BCL2 proteins with ABT-263 is sufficient to induce C16-ceramide synthesis in multiple cell lines, including human leukaemia and myeloma cells. ABT-263 activates CerS (ceramide synthase) activity only in cells expressing BAK or in cells capable of activating BAK. Importantly, recombinant BAK is sufficient to increase in vitro CerS activity in microsomes purified from Bak-KO (knockout) cells and activated BAK more potently activates CerS than inactive BAK. Likewise, ABT-263 addition to wild-type, but not Bak-deficient, microsomes increases CerS in vitro activity. Furthermore, we present a feed-forward model by which BAK activation of CerS by chemotherapeutic drugs leads to elevated ceramide levels that result in synergistic channel formation by ceramide (or one of its metabolites) and BAX/BAK.

scholarly journals SYNERGISTIC GROWTH INHIBITORY EFFECT OF FLAVONOL–KAEMPFEROL AND CONVENTIONAL CHEMOTHERAPEUTIC DRUGS ON CANCER CELLS

2017 ◽  
Vol 9 (2) ◽  
pp. 123 ◽  
Author(s):  
Chepuri Kalyani ◽  
Mangamoori Lakshmi Narasu ◽  
Yumnum Priyadarshini Devi
Keyword(s):  
Growth Inhibition ◽  
Cancer Cells ◽  
Cell Line ◽  
Cell Lines ◽  
Apoptotic Cell ◽  
Inhibitory Effect ◽  
Chemotherapeutic Drugs ◽  
Growth Inhibitory Effect ◽  
Growth Inhibitory

<p><strong>Objective: </strong>The objective of the present study was to evaluate synergistic growth inhibitory effect of a flavonol, kaempferol in combination with chemotherapeutic drugs doxorubicin or cisplatin.</p><p><strong>Methods: </strong>The anti-proliferative activities of kaempferol, doxorubicin and cisplatin on human colorectal cancer cells (HCT-15) and human breast cancer (MDA MB 231) were analyzed by 3-(4,5-dimehylthiaol-2-yl)-2,5-diphenyltetraolium bromide (MTT) assay. Further, combinational studies were performed in both the cell lines to evaluate the interaction of drugs with kaempferol. The combination index (CI) method was used to assess the synergism of kaempferol with doxorubicin or cisplatin. Finally, morphological alterations associated with apoptosis were examined under fluorescent microscope.</p><h1>Results: All compounds showed dose-dependent growth inhibition in both HCT-15 and MDA MB 231 cells. The phytochemical kaempferol showed fifty percent inhibitory concentrations (IC<sub>50</sub>) at 120±3.2 µg/ml and 64±1.2 µg/ml on HCT-15 and MDA MB 231 respectively. IC<sub>50 </sub>concentrations of doxorubicin and cisplatin on both the cell lines were achieved at 49.6±0.5 µg/ml, 25.4±2.9 µg/ml and 44±1.8 µg/ml, 40.6±0.8 µg/ml respectively. Further, <em>in vitro </em>therapeutic effect (IC<sub>50</sub>) of doxorubicin and cisplatin in terms of cell growth inhibition on HCT-15 cells were achieved at their one-fifth (10±0.83 µg/ml) and half (10±1.34 µg/ml) concentrations respectively when they were combined with 30 µg/ml of kaempferol individually. Simultaneously, on MDA-MB 231 cell line, the IC<sub>50</sub> concentrations were reduced to 18±1.22 µg/ml and 15±1.87 µg/ml respectively in combination with 32 µg/ml of kaempferol. The combinational index studies revealed the synergistic association of kaempferol with doxorubicin and cisplatin individually in each cell line. The fluorescence imaging studies strongly supported the synergistic association between kaempferol and doxorubicin or cisplatin by confirming significant apoptotic cell death in both the cell lines which was ~3 fold higher than each agent alone.</h1><p><strong>Conclusion: </strong>The study reveals<strong> </strong>the prominent synergism between the phytochemical, kaempferol and chemotherapeutic drugs doxorubicin or cisplatin which helps in elevating the therapeutic efficacy of drugs.</p>

scholarly journals RasOncogene-Mediated Progressive Silencing of Extracellular Superoxide Dismutase in Tumorigenesis

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Francesca Cammarota ◽  
Gabriella de Vita ◽  
Marco Salvatore ◽  
Mikko O. Laukkanen
Keyword(s):  
Superoxide Dismutase ◽  
Cancer Cells ◽  
Self Regulation ◽  
Thyroid Cell ◽  
Extracellular Superoxide Dismutase ◽  
Mrna Synthesis ◽  
Ras Activation ◽  
Degree Of Differentiation ◽  
In Cells

Extracellular superoxide dismutase (SOD3) is a secreted enzyme that uses superoxide anion as a substrate in a dismutase reaction that results in the formation of hydrogen peroxide. Both of these reactive oxygen species affect growth signaling in cells. Although SOD3 has growth-supporting characteristics, the expression ofSOD3is downregulated in epithelial cancer cells. In the current work, we studied the mechanisms regulatingSOD3expressionin vitrousing thyroid cell models representing different stages of thyroid cancer. We demonstrate that a low level of RAS activation increasesSOD3mRNA synthesis that then gradually decreases with increasing levels of RAS activation and the decreasing degree of differentiation of the cancer cells. Our data indicate thatSOD3regulation can be divided into two classes. The first class involves RAS–driven reversible regulation ofSOD3expression that can be mediated by the following mechanisms: RAS GTPase regulatory genes that are responsible forSOD3self-regulation; RAS-stimulated p38 MAPK activation; and RAS-activated increased expression of themir21microRNA, which inversely correlates withsod3mRNA expression. The second class involves permanent silencing ofSOD3mediated by epigenetic DNA methylation in cells that represent more advanced cancers. Therefore, the work suggests thatSOD3belongs to the group ofrasoncogene-silenced genes.

Blueberry flavonoids inhibit matrix metalloproteinase activity in DU145 human prostate cancer cells

2005 ◽  
Vol 83 (5) ◽  
pp. 637-643 ◽  
Author(s):  
Michael D Matchett ◽  
Shawna L MacKinnon ◽  
Marva I Sweeney ◽  
Katherine T Gottschall-Pass ◽  
Robert A.R Hurta
Keyword(s):  
Prostate Cancer ◽  
Cancer Cells ◽  
Apoptotic Cell ◽  
Human Prostate ◽  
Response To Treatment ◽  
Human Prostate Cancer ◽  
Prostate Cancer Cells ◽  
The Matrix ◽  
Ecm Degradation

Regulation of the matrix metalloproteinases (MMPs), the major mediators of extracellular matrix (ECM) degradation, is crucial to regulate ECM proteolysis, which is important in metastasis. This study examined the effects of 3 flavonoid-enriched fractions (a crude fraction, an anthocyanin-enriched fraction, and a proanthocyanidin-enriched fraction), which were prepared from lowbush blueberries (Vaccinium angustifolium), on MMP activity in DU145 human prostate cancer cells in vitro. Using gelatin gel electrophoresis, MMP activity was evaluated from cells after 24-hr exposure to blueberry fractions. All fractions elicited an ability to decrease the activity of MMP-2 and MMP-9. Of the fractions tested, the proanthocyanidin-enriched fraction was found to be the most effective at inhibiting MMP activity in these cells. No induction of either necrotic or apoptotic cell death was noted in these cells in response to treatment with the blueberry fractions. These findings indicate that flavonoids from blueberry possess the ability to effectively decrease MMP activity, which may decrease overall ECM degradation. This ability may be important in controlling tumor metastasis formation.Key words: blueberry flavonoids, MMP activity, prostate cancer cells.

scholarly journals Cytoplasmic Dynein Nucleates Microtubules to Organize Them into Radial Arrays In Vivo

2004 ◽  
Vol 15 (6) ◽  
pp. 2742-2749 ◽  
Author(s):  
Viacheslav Malikov ◽  
Anna Kashina ◽  
Vladimir Rodionov
Keyword(s):  
Cytoplasmic Dynein ◽  
Exact Function ◽  
Necessary And Sufficient ◽  
Stimulation Of ◽  
In Cells

Numerous evidence demonstrates that dynein is crucial for organization of microtubules (MTs) into radial arrays, but its exact function in this process is unclear. Here, we studied the role of cytoplasmic dynein in MT radial array formation in the absence of the centrosome. We found that dynein is a potent MT nucleator in vitro and that stimulation of dynein activity in cytoplasmic fragments of melanophores induces nucleation-dependent formation of MT radial array in the absence of the centrosome. This new property of dynein, in combination with its known role as an MT motor that is essential for MT array organization in the absence and presence of the centrosome, makes it a unique molecule whose activity is necessary and sufficient for the formation and maintenance of MT radial arrays in cells.

scholarly journals α5β1 integrin recycling promotes Arp2/3-independent cancer cell invasion via the formin FHOD3

2015 ◽  
Vol 210 (6) ◽  
pp. 1013-1031 ◽  
Author(s):  
Nikki R. Paul ◽  
Jennifer L. Allen ◽  
Anna Chapman ◽  
Maria Morlan-Mairal ◽  
Egor Zindy ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Cell Invasion ◽  
Molecular Mechanisms ◽  
Cancer Metastasis ◽  
Cancer Cell Invasion ◽  
Coupling Protein ◽  
Α5β1 Integrin ◽  
In Cells

Invasive migration in 3D extracellular matrix (ECM) is crucial to cancer metastasis, yet little is known of the molecular mechanisms that drive reorganization of the cytoskeleton as cancer cells disseminate in vivo. 2D Rac-driven lamellipodial migration is well understood, but how these features apply to 3D migration is not clear. We find that lamellipodia-like protrusions and retrograde actin flow are indeed observed in cells moving in 3D ECM. However, Rab-coupling protein (RCP)-driven endocytic recycling of α5β1 integrin enhances invasive migration of cancer cells into fibronectin-rich 3D ECM, driven by RhoA and filopodial spike-based protrusions, not lamellipodia. Furthermore, we show that actin spike protrusions are Arp2/3-independent. Dynamic actin spike assembly in cells invading in vitro and in vivo is regulated by Formin homology-2 domain containing 3 (FHOD3), which is activated by RhoA/ROCK, establishing a novel mechanism through which the RCP–α5β1 pathway reprograms the actin cytoskeleton to promote invasive migration and local invasion in vivo.

Extract from the Leaves of Toona sinensis Roemor Exerts Potent Antiproliferative Effect on Human Lung Cancer Cells

2002 ◽  
Vol 30 (02n03) ◽  
pp. 307-314 ◽  
Author(s):  
Hui-Chiu Chang ◽  
Wen-Chun Hung ◽  
Ming-Shyan Huang ◽  
Hseng-Kuang Hsu
Keyword(s):  
Lung Cancer ◽  
Cancer Cells ◽  
Human Lung ◽  
Apoptotic Cell ◽  
A549 Cells ◽  
Lung Cancer Cells ◽  
Lung Fibroblasts ◽  
Human Lung Cancer ◽  
Toona Sinensis

Recent study indicated that the components of Toona sinensis Roemor have potent anti-inflammatory and analgesic effects. These components have also been reported to inhibit the growth of boils in vivo. In this study, we investigated the effect of crude extract from the leaves of Toona sinensis Roemor on the proliferation of A549 lung cancer cells. We found that the extract effectively blocked cell cycle progression by inhibiting the expression of cyclin D1 and E in A549 cells. Additionally, incubation of the extract led to activation of caspase-3-like proteases and apoptotic cell death. Conversely, the extract did not show any significant cytotoxic effect on primarily cultured human foreskin fibroblasts or MRC-5 human lung fibroblasts. Therefore, antiproliferative action of the extract is specific for tumor cells. Our results suggest that the components of Toona sinensis Roemor have potent anticancer effects in vitro and identification of the useful components in the extract may lead to the development of a novel class of anticancer drugs.

scholarly journals Acidification induces Bax translocation to the mitochondria and promotes ultraviolet light-induced apoptosis

2008 ◽  
Vol 13 (1) ◽  
Author(s):  
Lin Yang ◽  
Yongyu Mei ◽  
Qifeng Xie ◽  
Xiaoyan Han ◽  
Fucheng Zhang ◽  
...  
Keyword(s):  
Cell Death ◽  
Uv Light ◽  
Apoptotic Cell ◽  
Apoptotic Cell Death ◽  
Chemotherapeutic Drugs ◽  
Normal Medium ◽  
Sds Page ◽  
Translocation Assay ◽  
Induced Apoptosis

AbstractIt has been suggested that Bax translocation to the mitochondria is related to apoptosis, and that cytosol acidification contributes to apoptosis events. However, the mechanisms remain obscure. We investigated the effect of acidification on Bax translocation and on ultraviolet (UV) light-induced apoptosis. The Bax translocation assay in vitro showed that Bax translocated to the mitochondria at pH 6.5, whereas no Bax translocation was observed at pH 7.4. VHDBB cells expressing the GFP-Bax fusion protein were treated for 12 h with a pH 6.5 DMEM medium, nigericin (5 μg/ml) and UV light (50 J/cm2), separately or in combination, and Bax translocation to the mitochondria was determined by SDS-PAGE and Western blot, and apoptotic cell death was detected by flow cytometry. The results showed that some of the Bax translocated to the mitochondria in the cells treated with the normal medium, nigericin and UV in combination, whereas all of the Bax translocated to the mitochondria in the cells treated with the pH 6.5 medium, nigericin and UV in combination. In VHDBB cells treated for 12 h with nigericin, UV alone, and UV and nigericin in combination, the respective rates of apoptotic cell death were 25.08%, 33.25% and 52.88%. In cells treated with pH 6.5 medium and nigericin, pH 6.5 medium and UV, and pH 6.5 medium, nigericin and UV in combination, the respective rates of apoptotic cell death increased to 37.19%, 41.42% and 89.44%. Our results indicated that acidification induces Bax translocation from the cytosol to the mitochondria, and promotes UV lightmediated apoptosis. This suggests that there is a possibility of improving cancer treatment by combining acidification with irradiation or chemotherapeutic drugs.

Fisetin mediated apoptotic cell death in parental and Oxaliplatin/irinotecan resistant colorectal cancer cells in vitro and in vivo

2018 ◽  
Vol 233 (9) ◽  
pp. 7134-7142 ◽  
Author(s):  
Long-Bin Jeng ◽  
Bharath Kumar Velmurugan ◽  
Ming-Cheng Chen ◽  
Hsi-Hsien Hsu ◽  
Tsung-Jung Ho ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cell Death ◽  
Cancer Cells ◽  
Apoptotic Cell ◽  
Apoptotic Cell Death ◽  
Colorectal Cancer Cells
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