Targeting apoptosis pathways in cancer therapy ghobrial. As illustrated in figure 1, in the mammalian pathway, the egl1 homologs are bh3only proteins, such as bim, bid, bad, box, noxa, and puma. Apoptosis is first characterized by a change in the refractive index of the cell followed by cytoplasmic shrinkage and nuclear condensation. To determine whether the growth inhibitory effect of fkb is through the induction of apoptosis, we examined the apoptotic morphology of control and fkb treated cells under light and fluorescence microscopes. Our group hypothesized that this compound may act as a novel chemotherapeutic agent for ss by enhancing apoptotic mechanisms. Figure 2 d illustrates that fkb treatment of 143b and saos2 resulted in increased expression of fas, puma and bax, while downregulating the expression of bcl2 and survivin. The mitochondria, as the crosstalk organelles, can connect the different apoptosis pathway.
The p53 protein induces expression of bh3only proteins puma and noxa the bh3only protein bid links extrinsic and intrinsic apoptotic pathways nature 407. Doxorubicin is a chemotherapeutic dna intercalating agent widely used in malignancy treatment. To determine whether fkb induced apo mammalian cells can undergo caspaseindependent apoptosis ptosis is rosdependent, cells were incubated with 5. Induced apoptosis in ags cells via the mitochondrial and death receptor pathways. Apr 30, 2012 apoptosis can be induced via the extrinsic pathway, through cell surface death receptor stimulation, or through the intrinsic pathway mediated by mitochondrial dysfunction. The apoptotic mechanisms of fkb in ss are similar to those in the previous reports using hrpc. Fkb upregulates expression of proapoptoic protein and downregulates antiapototic protein apoptosis can be induced via the extrinsic pathway, through cell surface death receptor stimulation, or through the intrinsic pathway mediated by mitochondrial dysfunction 15. The antiangiogenic activities were accessed by manual counting of.
Methods an in vitro nedd8 initiation conjugation assay was used to evaluate the neddylation inhibitory activity of fkb. The chalcone flavokawain b induces g2m cellcycle arrest. Jun 10, 20 therefore, the induction of apoptosis by fkb involved both extrinsic and intrinsic pathways. Two independent apoptosis pathways are presented that converge on the activation of downstream caspases 3, 6, 7, key substrate cleavage, and apoptotic death. Biochemical events lead to characteristic cell changes and death. The pros and cons of apoptosis assays for use in the study of cells. Full text apoptotic induction and inhibition of nfkb. Fkb induced apoptosis with an increased expression of proapoptotic markers.
Based on our results, apoptosis was induced when both mcf7 and mdamb231 were treated with fkb. Inhibition of autophagy switches fkb induced senescence to apoptosis in gbm cells. Fkb significantly inhibited cell proliferation and caused arrest of the cell cycle g2m of h460 cells in a dosedependent manner. Bh3only proteins couple apoptosis to various signalling pathways.
Page 4 of 26 due to its importance in such various biological processes, programmed cell death is a widespread phenomenon, occuring in all kinds of metazoans tittel, 2000 such as in mammals, insects. Proposed diagram of fkb induced g2m arrest, apoptosis and aktp38 mapk. Research open access flavokawain b, a kava chalcone. Glutathione, apoptosis and reactive oxygen species. The extrinsic apoptosis pathway is triggered through activation of death receptors of the tumor necrosis factor tnf family, including the tnf receptor 1 tnfr1 itself, cd95 apo1, fas, tnfrelated apoptosis inducing ligand trail receptors trailr1 and trailr2, also known as dr4 and dr5, dr3 and dr6. Fkb also inducted apoptosis, which was associated with cytochrome c release.
Research open access flavokawain b, a kava chalcone, inhibits. Flavokawain b, a kava chalcone, inhibits growth of. Fkb inhibits nedd8 conjugations to both cullin1 and ubc12 in prostate cancer cell lines and ubc12 neddylation in an in vitro assay. Pdf flavokawain b and doxorubicin work synergistically. The combination of flavokawain b and daunorubicin induces. A correlation between kit expression and pluripotency of embryonic stem es cells has been reported palmqvist et al. Apoptosis pathway of cell death induced by a tightly regulated suicide program.
Apoptosis is executed by the extrinsic or intrinsic death signaling pathways. Jnk kinase induces expression of bh3only protein bim dna damage. The stem cell factor scfkit signal transduction pathway plays a role in the proliferation, differentiation and survival of a range of stem and progenitor cell types but little is known about its function in embryonic stem es cells. Cancers free fulltext flavokawain b and doxorubicin work. However, concurrent activation of antioxidantrelated pathways and iron sequestration pathway followed by activation of erresident stress proteins clearly indicate that fkb failed to induce apoptosis in hela. Several molecular and cell signaling pathways regulate autophagy. We examined the in vitro and in vivo anticancer activity and autophagy involvement of fkb and determined the underlying molecular mechanisms. The first involves ligation of death receptors by their ligands, resulting in the recruitment of adaptor proteins and procaspase molecules. The results of this study suggest that fkb induced cell death through p21mediated cell cycle arrest and activation of p38. Increased dr5 expression by fkb activates the death receptor mediated apoptotic pathway. Fkb significantly downregulated survivin and xiap, and the inhibitory effect induced by fkb was greatly attenuated by through overexpression of survivin or bax mefs. Flavokawain b induced cytotoxicity in two breast cancer cell lines. Exploiting the extrinsic and the intrinsic apoptotic pathways for.
Flavokawain b, a kava chalcone, inhibits growth of human. Reia smac caspase 8 caspase 9 caspase 3 cytc xiap ciap1 dr45 inhibitors of apoptosis iaps are a conserved group of proteins containing baculovirusiap repeats involved in the regulation of apoptosis as well as a number of other cellular processes. Apoptosis signaling pathways apoptosis is executed by the extrinsic or intrinsic death signaling pathways, or in some cases by the perforingranzyme b pathway and results in the activation of the caspase cascade. Flavokawain b, a kava chalcone, exhibits robust apoptotic. Fkb itself induced apoptosis of an acute myeloid cell line, hl60. The pathophysiology of saccular aneurysms is complex and multifactorial. The term apoptosis has long been utilized as a synonym for programmed cell death pcd since the seminal article of kerr et al. Flavokawain b, a kava chalcone, induces apoptosis in synovial. Flavokawain b, a kava chalcone, induces apoptosis in.
Flavokawain b targets protein neddylation for enhancing the. Molecular docking study and a cellular thermal shift assay reveal that fkb interacts. The components of the apoptotic signalling network. Fkb also caused g2m phase cell cycle arrest, which was observed through reductions in the levels of cyclin b1, cdc2 and cdc25c and increases in myt1 levels. Extrinsic versus intrinsic apoptosis pathways in anticancer. B signaling pathway in human prostatic cancer pc3 cells by natural compound 2,2oxybis 4allyl1methoxybenzene, biseugenol b, from litsea costalis. Flavokawain b and doxorubicin work synergistically to. The present study investigated whether synergistic effects exist between the combination of fkb 1.
B nuclear factor kappalightchainenhancer of activated b cells is a protein complex that controls transcription of dna, cytokine production and cell survival. Multiple protein families are involved in the signaling pathways that promote or inhibit caspase activation. Flavokawain b targets protein neddylation for enhancing. For example, a dr5 ligand, known as the tumor necrosis. Apoptosis, or programmed cell death, results in controlled selfdestruction. Mitochondrial control of apoptosis as cd95 cytosolic sequestration nad rev. However, the inhibition of apoptosis decreased fkb induced autophagy lc3iii. Fkb also inducted apoptosis, which was associated with cytochrome c release, caspase7 and caspase9 activation and bclxlbax dysregulation. Flavokawain b, the hepatotoxic constituent from kava root. Another mechanism of apoptosis regulation in the extrinsic pathway involves a protein called toso, which blocks fasinduced apoptosis in t cells by inhibition of caspase8 activation.
Apoptosis should be considered an alternative pathway for cancer cell death 9,10. Flavokawain b induces apoptosis of nonsmall cell lung cancer. Fkb induces a typical apoptosis via activation of capase3,8 and 9 activities in arnegative pca cell lines du145 and pc3. On the other hand, fkb was found to induce cell death via apoptosis indicated by both annexin vpi and jc1 flow cytometry assays. Apoptosis signaling pathways and lymphocyte homeostasis. Cell growth inhibition and apoptosis induction were measured by mtt, elisa and western blotting methods. Kitwlaczwfkb es cells showed a lessflattened morphology.
Nfkb pathway cardiovascular homeostasis enos synaptic signalin blocks aggregation promotes neuroprotection in aggregation neurodegredation fkb glycosis as160 glycose transport ligand gabi il2 ict akt cd19 bcap pip3 tsc2 sci bad gpy gtp pten glycogen glycosegen synthesis pten pp2a phlpp tm g. Gene expression analysis reveals the concurrent activation of. Here, we report that fkb induced apoptosis on ss cell lines through both extrinsic and intrinsic apoptotic pathways, associated with upregulation of dr5, bim. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, chromosomal dna fragmentation, and global vague mrna decay. However, the effect of fkb on gastric cancer remains unclear. Pdf chalcone flavokawain b fkb possesses a chemopreventive and anticancer activity. Furthermore, we found that autophagy induced by fkb plays a cytoprotective role in tca cells both in vitro and in vivo. Jun 16, 2018 flavokawain b induces apoptosis in a variety of cancer cells.
Gene expression analysis reveals the concurrent activation. Therefore, the induction of apoptosis by fkb involved both extrinsic and intrinsic pathways. Fkb also caused g2m phase cell cycle arrest, which was. Fkb also caused g2m phase cell cycle arrest, which was observed through reductions in the levels of.
Tumor protein p53 is a nuclear transcription factor that regulates the expression of a wide variety of genes involved in apoptosis, growth arrest, or senescence in response to genotoxic or cellular stress. Several methods have been developed to assess apoptosis, cell cycle, and cell proliferation. Bcl2 and bclxl can also be cleaved by caspases during apoptosis. Moreover, fkb downregulated the phosphorylation of akt and p38 mapk, while their inhibitors ly294002 and sb203580, respectively, induced g2m arrest and apoptosis. Besides getting rid of damaged, potentially dangerous. Furthermore, increased fas activity and procaspase8, procaspase4, and procaspase12 cleavages were accompanied by death receptor and erstress, indicating the involvement of mitochondria, deathreceptor, and erstress signaling pathways.
Bd biosciences offers a complete portfolio of reagents and tools to allow exploration of the cellular features of these processes. The survival of differentiating embryonic stem cells is. We generated es cells carrying a null allele of kit as well as a knockin allele that encodes an scfindependent hybrid kit receptor that can be activated by. Novel drugs may alter signaling pathways to overcome resistance, leading to cell. Chalcone flavokawain b induces autophagiccell death via.
Flavokawain b and doxorubicin work synergistically to impede the. Flavokawain b, a novel, naturally occurring chalcone. Here we assessed its antitumor activity and molecular mechanisms in lung cancer h460 cells in vitro. The profound reduction in cell number was observed in combination treatment with fkb and aktp38 mapk inhibitors, indicating that the disruption of akt and p38 mapk cascades plays a. Apoptosis, or type 1 cell death, is a significant terminal pathway for cells of multicellular organisms, and causes a diversity of biological events such as. Apoptosis is a very orderly process during which the genome of the cell is broken down, the cell is fragmented into smaller pieces and the debris is consumed by nearby cells phagocytes that clean up the cell fragments. Apoptosis definition, pathways, assay, examples vs necrosis.
Mar 18, 2019 background flavokawain b fkb has been identified from kava root extracts as a potent apoptosis inducer for inhibiting the growth of various cancer cell lines, including prostate cancer. Fkb showed antitumor effect through apoptosis induction by suppressing. Flavokawain b fkb, a naturally occurring chalcone in kava extracts, has been reported to possess anticancer activity. We found that fkb induced apoptosis through a baxinitiated mitochondrial pathway in h460 cells. Fkb inhibits apoptotic bax expression, and baxtransfected ags cells exhibit both apoptosis and autophagy. Fkb is potently cytotoxic to human gastric cancer cells agsncin87. Fkb potentiated doxorubicininduced dna fragmentation, apoptotic cell death, and enhanced doxorubicinmediated mitochondrial, death receptor pathways. Fkb significantly downregulated survivin and xiap, and the inhibitory effect induced by fkb was greatly attenuated by. Activation of the intrinsic pathway ultimately leads to mitochondrial permeabilization and subsequent effector. In vivo data demonstrated that fkb effectively inhibited tumor growth, prolonged the survival rate, and induced autophagy in agsxenografted mice.
Molecular mechanisms of apoptosis and roles in cancer. Introduction to apoptosis introduction apoptosis or programmed cell death is defined as a mechanism of cellular suicide which occurs after sufficient cellular damage. Flavokawain b induces apoptosis of nonsmall cell lung. Jun 23, 2012 flavokawain b fkb possesses strong antineoplastic activity against many cancer cells. However, the molecular targets of fkb in prostate cancer cells remain unknown. Cleavage of bid by caspase8 mediates the mitochondrial damage in the fas pathway of apoptosis. The survival of differentiating embryonic stem cells is dependent on. In terms of annexin vpi apoptosis assay, fkb treated hela cells were recorded with 39. The aim of the present study was to understand the mechanism of apoptosis in an elastaseinduced aneurysm model in. Pdf gene expression analysis reveals the concurrent. B is found in almost all animal cell types and is involved in cellular responses to stimuli such as stress, cytokines, free radicals, heavy metals, ultraviolet irradiation, oxidized ldl, and bacterial or viral antigens.
This study concluded that fkb is critically associated with the. Pdf inhibition of glioma growth by flavokawain b is. Doxorubicin is a chemotherapeutic dna intercalating agent. Furthermore, migration and invasion ability was decreased by fkb in a dosedependent manner.
Intrinsic pathway mediated apoptosis in elastaseinduced aneurysms in rabbits r. The intrinsic apoptosis pathway is regulated by proapoptotic e. Pathways apoptosis pyroptosis removal of unwanted and harmful cells. However, the extrinsic apoptosis pathway of caspase activation involves signal transduction through celldeath receptors such as fas and tnf.
Flavokawain b induces apoptosis in synovial sarcoma cell lines. A hypothetical model for the signaling pathway and the role of fkb. For instance, defects in the apoptotic pathway that prevent cell death may lead to. The chalcone flavokawain b induces g2m cellcycle arrest and. Flavokawain b and doxorubicin work synergistically to impede. Pdf the chalcone flavokawain b induces g2m cellcycle. Apoptosis, or type 1 cell death, is a significant terminal pathway for cells of multicellular organisms. Cleaved proteins turns themselves into apoptotic killers. Fkb induces apoptosis through ros generation as evidenced by the upregulation of oxidativestress markers. Jun 10, 20 apoptosis can be induced via the extrinsic pathway, through cell surface death receptor stimulation, or through the intrinsic pathway mediated by mitochondrial dysfunction. Apoptotic induction and inhibition of nfkb signaling pathway. Based on our results, fkb is a potential therapeutic agent. Later, it had been found that some cancers were caused by the lack of physiological cell death also referred to as cellular suicide or apoptosis. Aug 07, 2006 apoptosis pathways can be initiated through different entry sites, for example, at the plasma membrane by death receptor ligation receptor pathway or at the mitochondria mitochondrial pathway.
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