scholarly journals c-FLIP Mediates Resistance of Hodgkin/Reed-Sternberg Cells to Death Receptor–induced Apoptosis

2004 ◽  
Vol 199 (8) ◽  
pp. 1041-1052 ◽  
Author(s):  
Stephan Mathas ◽  
Andreas Lietz ◽  
Ioannis Anagnostopoulos ◽  
Franziska Hummel ◽  
Burkhard Wiesner ◽  
...  
Keyword(s):  
Death Receptor ◽  
B Cell Lymphoma ◽  
Immunohistochemical Analysis ◽  
Death Domain ◽  
Inhibitory Protein ◽  
Antiapoptotic Proteins ◽  
Signaling Complex ◽  
Induced Apoptosis ◽  
High Level ◽  
Interfering Rna

Resistance to death receptor–mediated apoptosis is supposed to be important for the deregulated growth of B cell lymphoma. Hodgkin/Reed-Sternberg (HRS) cells, the malignant cells of classical Hodgkin's lymphoma (cHL), resist CD95-induced apoptosis. Therefore, we analyzed death receptor signaling, in particular the CD95 pathway, in these cells. High level CD95 expression allowed a rapid formation of the death-inducing signaling complex (DISC) containing Fas-associated death domain–containing protein (FADD), caspase-8, caspase-10, and most importantly, cellular FADD-like interleukin 1β–converting enzyme-inhibitory protein (c-FLIP). The immunohistochemical analysis of the DISC members revealed a strong expression of CD95 and c-FLIP overexpression in 55 out of 59 cases of cHL. FADD overexpression was detectable in several cases. Triggering of the CD95 pathway in HRS cells is indicated by the presence of CD95L in cells surrounding them as well as confocal microscopy showing c-FLIP predominantly localized at the cell membrane. Elevated c-FLIP expression in HRS cells depends on nuclear factor (NF)-κB. Despite expression of other NF-κB–dependent antiapoptotic proteins, the selective down-regulation of c-FLIP by small interfering RNA oligoribonucleotides was sufficient to sensitize HRS cells to CD95 and tumor necrosis factor–related apoptosis-inducing ligand–induced apoptosis. Therefore, c-FLIP is a key regulator of death receptor resistance in HRS cells.

scholarly journals C5, A Cassaine Diterpenoid Amine, Induces Apoptosis via the Extrinsic Pathways in Human Lung Cancer Cells and Human Lymphoma Cells

2020 ◽  
Vol 21 (4) ◽  
pp. 1298 ◽  
Author(s):  
Hyo-Jin Kim ◽  
Bo-Gyeong Seo ◽  
Kwang Dong Kim ◽  
Jiyun Yoo ◽  
Joon-Hee Lee ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Death Receptor ◽  
B Cell Lymphoma ◽  
Human Lung Cancer ◽  
Caspase 8 ◽  
Death Domain ◽  
Extrinsic Pathway ◽  
Inhibitory Protein ◽  
Apoptosis Pathways ◽  
Induced Apoptosis

Apoptosis pathways in cells are classified into two pathways: the extrinsic pathway, mediated by binding of the ligand to a death receptor and the intrinsic pathway, mediated by mitochondria. Apoptosis is regulated by various proteins such as Bcl-2 (B-cell lymphoma 2) family and cellular FLICE (Fas-associated Death Domain Protein Interleukin-1β-converting enzyme)-inhibitory protein (c-FLIP), which have been reported to inhibit caspase-8 activity. In this study, it was found that C5 (3β-Acetyl-nor-erythrophlamide), a compound of cassaine diterpene amine from Erythrophleum fordii, induced cell apoptosis in a variety of types of cancer cells. Induction of apoptosis in cancer cells by C5 was inversely related to the level of Bcl-2 expression. Overexpression of Bcl-2 into cancer cells significantly decreased C5-induced apoptosis. It was also found that treatment of cancer cells with a caspase-8 inhibitor significantly suppressed C5-induced apoptosis; however, treatment with caspase-9 inhibitors did not affect C5-induced apoptosis, suggesting that C5 may induce apoptosis via the extrinsic pathway by activating caspase-8. It was confirmed that treatment with C5 alone induced an association of FADD with procaspase-8; however, overexpression of c-FLIP decreased C5-induced caspase-8 activation. In conclusion, C5 could be utilized as a new useful lead compound for the development of an anti-cancer agent that has the goal of apoptosis.

scholarly journals Hypo-Expression of Flice-Inhibitory Protein and Activation of the Caspase-8 Apoptotic Pathways in the Death-Inducing Signaling Complex Due to Ischemia Induced by the Compression of the Asphyxiogenic Tool on the Skin in Hanging Cases

Diagnostics ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 938
Author(s):  
Aniello Maiese ◽  
Alessandra De Matteis ◽  
Giorgio Bolino ◽  
Emanuela Turillazzi ◽  
Paola Frati ◽  
...  
Keyword(s):  
Tertiary Structure ◽  
Active Form ◽  
Three Dimensional ◽  
Death Receptor ◽  
Cell Receptor ◽  
Control Group ◽  
Caspase 8 ◽  
Inhibitory Protein ◽  
Signaling Complex ◽  
Induced Apoptosis

The FLICE-inhibitory protein (c-FLIPL) (55 kDa) is expressed in numerous tissues and most abundantly in the kidney, skeletal muscles and heart. The c-FLIPL has a region of homology with caspase-8 at the carboxy-terminal end which allows the molecule to assume a tertiary structure similar to that of caspases-8 and -10. Consequently, c-FLIPL acts as a negative inhibitor of caspase-8, preventing the processing and subsequent release of the pro-apoptotic molecule active form. The c-FLIP plays as an inhibitor of apoptosis induced by a variety of agents, such as tumor necrosis factor (TNF), T cell receptor (TCR), TNF-related apoptosis inducing ligand (TRAIL), Fas and death receptor (DR). Increased expression of c-FLIP has been found in many human malignancies and shown to be involved in resistance to CD95/Fas and TRAIL receptor-induced apoptosis. We wanted to verify an investigative protocol using FLIP to make a differential diagnosis between skin sulcus with vitality or non-vital skin sulcus in hanged subjects and those undergoing simulated hanging (suspension of the victim after murder). The study group consisted of 21 cases who died from suicidal hanging. The control group consisted of traumatic or natural deaths, while a third group consisted of simulated hanging cases. The reactions to the Anti-FLIP Antibody (Abcam clone-8421) was scored for each section with a semi-quantitative method by means of microscopic observation carried out with confocal microscopy and three-dimensional reconstruction. The results obtained allow us to state that the skin reaction to the FLIP is extremely clear and precise, allowing a diagnosis of unequivocal vitality and a very objective differentiation with the post-mortal skin sulcus.

scholarly journals Differential Inhibition of TRAIL-Mediated DR5-DISC Formation by Decoy Receptors 1 and 2

2006 ◽  
Vol 26 (19) ◽  
pp. 7046-7055 ◽  
Author(s):  
Delphine Mérino ◽  
Najoua Lalaoui ◽  
Alexandre Morizot ◽  
Pascal Schneider ◽  
Eric Solary ◽  
...  
Keyword(s):  
Death Receptor ◽  
Death Domain ◽  
Transmembrane Receptors ◽  
Signaling Complex ◽  
Cancer Cell Death ◽  
Decoy Receptors ◽  
Additional Level ◽  
Induced Apoptosis ◽  
Death Receptor 4 ◽  
Trail Signaling

ABSTRACT Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a member of the TNF family that induces cancer cell death by apoptosis with some selectivity. TRAIL-induced apoptosis is mediated by the transmembrane receptors death receptor 4 (DR4) (also known as TRAIL-R1) and DR5 (TRAIL-R2). TRAIL can also bind decoy receptor 1 (DcR1) (TRAIL-R3) and DcR2 (TRAIL-R4) that fail to induce apoptosis since they lack and have a truncated cytoplasmic death domain, respectively. In addition, DcR1 and DcR2 inhibit DR4- and DR5-mediated, TRAIL-induced apoptosis and we demonstrate here that this occurs through distinct mechanisms. While DcR1 prevents the assembly of the death-inducing signaling complex (DISC) by titrating TRAIL within lipid rafts, DcR2 is corecruited with DR5 within the DISC, where it inhibits initiator caspase activation. In addition, DcR2 prevents DR4 recruitment within the DR5 DISC. The specificity of DcR1- and DcR2-mediated TRAIL inhibition reveals an additional level of complexity for the regulation of TRAIL signaling.

scholarly journals Edelfosine and perifosine induce selective apoptosis in multiple myeloma by recruitment of death receptors and downstream signaling molecules into lipid rafts

Blood ◽  
2006 ◽  
Vol 109 (2) ◽  
pp. 711-719 ◽  
Author(s):  
Consuelo Gajate ◽  
Faustino Mollinedo
Keyword(s):  
Multiple Myeloma ◽  
Cytochrome C ◽  
Lipid Rafts ◽  
Lipid Raft ◽  
Death Receptor ◽  
Death Receptors ◽  
Death Domain ◽  
Cytochrome C Release ◽  
Signaling Complex ◽  
Induced Apoptosis

Abstract Multiple myeloma (MM) is an incurable B-cell malignancy, requiring new therapeutic strategies. We have found that synthetic alkyl-lysophospholipids (ALPs) edelfosine and perifosine induced apoptosis in MM cell lines and patient MM cells, whereas normal B and T lymphocytes were spared. ALPs induced recruitment of Fas/CD95 death receptor, Fas-associated death domain–containing protein, and procaspase-8 into lipid rafts, leading to the formation of the death-inducing signaling complex (DISC) and apoptosis. TNF-related apoptosis-inducing ligand receptor-1/death receptor 4 (TRAIL-R1/DR4) and TRAIL-R2/DR5, as well as Bid, were also recruited into lipid rafts, linking death receptor and mitochondrial signaling pathways. ALPs induced mitochondrial cytochrome c release. Bcl-XL overexpression prevented cytochrome c release and apoptosis. A Fas/CD95-deficient MM subline expressing DR4 and DR5 was resistant to edelfosine. Fas/CD95 retrovirus transduction bestowed edelfosine sensitivity in these cells. A Fas/CD95 mutant lacking part of the intracellular domain was ineffective. Lipid raft disruption prevented ALP-induced Fas/CD95 clustering, DISC formation, and apoptosis. ALP-induced apoptosis was Fas/CD95 ligand (FasL/CD95L) independent. ALP-induced recruitment of death receptors in lipid rafts potentiated MM cell killing by FasL/CD95L and TRAIL. These data uncover a novel lipid raft–mediated therapy in MM involving concentration of death receptors in membrane rafts, with Fas/CD95 playing a major role in ALP-mediated apoptosis.

scholarly journals Hepatitis B Spliced Protein (HBSP) Suppresses Fas-Mediated Hepatocyte Apoptosis via Activation of PI3K/Akt Signaling

2018 ◽  
Vol 92 (23) ◽  
Author(s):  
Shu-Xiang Wu ◽  
Wan-Nan Chen ◽  
Zhen-Tang Jing ◽  
Wei Liu ◽  
Xin-Jian Lin ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Acquired Resistance ◽  
Death Domain ◽  
Hepatocyte Apoptosis ◽  
Inhibitory Protein ◽  
Signaling Complex ◽  
B Virus ◽  
Phosphoinositide 3 Kinase ◽  
Induced Apoptosis

ABSTRACTHepatitis B spliced protein (HBSP) is known to associate with viral persistence and pathogenesis; however, its biological and clinical significance remains poorly defined. Acquired resistance to Fas-mediated apoptosis is thought to be one of the major promotors for hepatitis B virus (HBV) chronicity and malignancy. The purpose of this study was to investigate whether HBSP could protect hepatocytes against Fas-initiated apoptosis. We showed here that HBSP mediated resistance of hepatoma cells or primary human hepatocytes (PHH) to agonistic anti-Fas antibody (CH11)- or FasL-induced apoptosis. Under Fas signaling stimulation, expression of HBSP inhibited Fas aggregation and prevented recruitment of the adaptor molecule Fas-associated death domain (FADD) and procaspase-8 (or FADD-like interleukin-1β-converting enzyme [FLICE]) into the death-inducing signaling complex (DISC) while increasing recruitment of cellular FLICE-inhibitory protein L (FLIPL) into the DISC. Those effects may be mediated through activation of the phosphoinositide 3-kinase (PI3K)/Akt pathway as evidenced by increased cellular phosphatidylinositol (3,4,5)-trisphosphate (PIP3) content and PI3K activity and enhanced phosphorylation of mTORC2 and PDPK1 as well as Akt itself. Confirmedly, inhibition of PI3K by LY294002 reversed the effect of HBSP on Fas aggregation, FLIPLexpression, and cellular apoptosis. These results indicate that HBSP functions to prevent hepatocytes from Fas-induced apoptosis by enhancing PI3K/Akt activity, which may contribute to the survival and persistence of infected hepatocytes during chronic infection.IMPORTANCEOur study revealed a previously unappreciated role of HBSP in Fas-mediated apoptosis. The antiapoptotic activity of HBSP is important for understanding hepatitis B virus pathogenesis. In particular, HBV variants associated with hepatoma carcinoma may downregulate apoptosis of hepatocytes through enhanced HBSP expression. Our study also found that Akt is centrally involved in Fas-induced hepatocyte apoptosis and revealed that interventions directed at inhibiting the activation or functional activity of Akt may be of therapeutic value in this process.

Lidocaine Induces Apoptosis via the Mitochondrial Pathway Independently of Death Receptor Signaling

2007 ◽  
Vol 107 (1) ◽  
pp. 136-143 ◽  
Author(s):  
Robert Werdehausen ◽  
Sebastian Braun ◽  
Frank Essmann ◽  
Klaus Schulze-Osthoff ◽  
Henning Walczak ◽  
...  
Keyword(s):  
B Cell ◽  
Cell Lymphoma ◽  
Neuroblastoma Cells ◽  
Death Receptor ◽  
B Cell Lymphoma ◽  
Death Domain ◽  
Protein Overexpression ◽  
Caspase Activation ◽  
Caspase 9 ◽  
Induced Apoptosis

Abstract Background: Local anesthetics, especially lidocaine, can lead to persistent cauda equina syndrome after spinal anesthesia. Recently, lidocaine has been reported to trigger apoptosis, although the underlying mechanisms remain unknown. To elucidate the pathway of lidocaine-induced apoptosis, the authors used genetically modified cells with overexpression or deficiencies of key regulators of apoptosis. Methods: Human Jurkat T-lymphoma cells overexpressing the antiapoptotic protein B-cell lymphoma 2 as well as cells deficient of caspase 9, caspase 8, or Fas-associated protein with death domain were exposed to lidocaine and compared with parental cells. The authors evaluated cell viability, mitochondrial alterations, cytochrome c release, caspase activation, and early apoptosis. Apoptosis was in addition investigated in neuroblastoma cells. Results: In Jurkat cells, lidocaine reduced viability, associated with a loss of the mitochondrial membrane potential. At low concentrations (3–6 mm) of lidocaine, caspase 3 was activated and release of cytochrome c was detected, whereas at higher concentrations (10 mm), no caspase activation was found. Apoptosis by lidocaine was strongly reduced by B-cell lymphoma-2 protein overexpression or caspase-9 deficiency, whereas cells lacking the death receptor pathway components caspase 8 and Fas-associated protein with death domain were not protected and displayed similar apoptotic alterations as the parental cells. Lidocaine also induced apoptotic caspase activation in neuroblastoma cells. Conclusions: Apoptosis is triggered by concentrations of lidocaine occurring intrathecally after spinal anesthesia, whereas higher concentrations induce necrosis. The data indicate that death receptors are not involved in lidocaine-induced apoptosis. In contrast, the observation that B-cell lymphoma-2 protein overexpression or the lack of caspase 9 abolished apoptosis clearly implicates the intrinsic mitochondrial death pathway in lidocaine-induced apoptosis.

scholarly journals Model-based dissection of CD95 signaling dynamics reveals both a pro- and antiapoptotic role of c-FLIPL

2010 ◽  
Vol 190 (3) ◽  
pp. 377-389 ◽  
Author(s):  
Nicolai Fricker ◽  
Joel Beaudouin ◽  
Petra Richter ◽  
Roland Eils ◽  
Peter H. Krammer ◽  
...  
Keyword(s):  
Death Receptor ◽  
Caspase 8 ◽  
Converting Enzyme ◽  
Receptor Stimulation ◽  
Western Blots ◽  
Antiapoptotic Protein ◽  
Signaling Complex ◽  
Signaling Dynamics ◽  
Induced Apoptosis

Cellular FADD-like interleukin-1β–converting enzyme inhibitory proteins (c-FLIPs; isoforms c-FLIP long [c-FLIPL], c-FLIP short [c-FLIPS], and c-FLIP Raji [c-FLIPR]) regulate caspase-8 activation and death receptor (DR)–induced apoptosis. In this study, using a combination of mathematical modeling, imaging, and quantitative Western blots, we present a new mathematical model describing caspase-8 activation in quantitative terms, which highlights the influence of c-FLIP proteins on this process directly at the CD95 death-inducing signaling complex. We quantitatively define how the stoichiometry of c-FLIP proteins determines sensitivity toward CD95-induced apoptosis. We show that c-FLIPL has a proapoptotic role only upon moderate expression in combination with strong receptor stimulation or in the presence of high amounts of one of the short c-FLIP isoforms, c-FLIPS or c-FLIPR. Our findings resolve the present controversial discussion on the function of c-FLIPL as a pro- or antiapoptotic protein in DR-mediated apoptosis and are important for understanding the regulation of CD95-induced apoptosis, where subtle differences in c-FLIP concentrations determine life or death of the cells.

scholarly journals UXT-V1 protects cells against TNF-induced apoptosis through modulating complex II formation

2011 ◽  
Vol 22 (8) ◽  
pp. 1389-1397 ◽  
Author(s):  
Yuefeng Huang ◽  
Liang Chen ◽  
Yi Zhou ◽  
Heng Liu ◽  
Jueqing Yang ◽  
...  
Keyword(s):  
Tumor Necrosis ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Receptor Complex ◽  
Tnf Receptor ◽  
Death Domain ◽  
Complex Ii ◽  
Signaling Complex ◽  
Induced Apoptosis ◽  
Necrosis Factor

Proteins that directly regulate tumor necrosis factor (TNF) signaling have critical roles in determining cell death and survival. Previously we characterized ubiquitously expressed transcript (UXT)-V2 as a novel transcriptional cofactor to regulate nuclear factor-κB in the nucleus. Here we report that another splicing isoform of UXT, UXT-V1, localizes in cytoplasm and regulates TNF-induced apoptosis. UXT-V1 knockdown cells are hypersensitive to TNF-induced apoptosis. We demonstrated that UXT-V1 is a new component of TNF receptor signaling complex. We found that UXT-V1 binds to TNF receptor-associated factor 2 and prevents TNF receptor–associated death domain protein from recruiting Fas-associated protein with death domain. More importantly, UXT-V1 is a short-half-life protein, the degradation of which facilitates the formation of the apoptotic receptor complex II in response to TNF treatment. This study demonstrates that UXT-V1 is a novel regulator of TNF-induced apoptosis and sheds new light on the underlying molecular mechanism of this process.

scholarly journals Daxx Silencing Sensitizes Cells to Multiple Apoptotic Pathways

2003 ◽  
Vol 23 (20) ◽  
pp. 7108-7121 ◽  
Author(s):  
Liuh-Yow Chen ◽  
J. Don Chen
Keyword(s):  
Gene Expression ◽  
Transcriptional Repression ◽  
Mammalian Cells ◽  
Death Receptor ◽  
Kinase Activation ◽  
Transient Overexpression ◽  
Apoptotic Pathways ◽  
Induced Apoptosis ◽  
Caspase Gene ◽  
Interfering Rna

ABSTRACT Daxx is a nuclear protein involved in apoptosis and transcriptional repression, and it interacts with the death receptor Fas, promyelocytic leukemia protein (PML), and several transcriptional repressors. The function of Daxx in apoptosis is controversial because opposite results were obtained in transient overexpression and genetic knockout studies. Furthermore, the roles of PML and transcriptional repression in Daxx-regulated apoptosis are currently unknown. In this study, we investigated the role of Daxx in Fas- and stress-induced apoptosis by small interfering RNA-mediated Daxx silencing in mammalian cells. Daxx silencing had no apparent cytotoxic effects on mammalian cells within 72 h. Intriguingly, Daxx silencing strongly sensitized cells to Fas- and stress-induced apoptosis, which was accompanied by caspase activation, cytochrome c release, and Jun N-terminal kinase activation. Consistently, endogenous Daxx was degraded rapidly upon induction of apoptosis by stress or anti-Fas antibody. Finally, PML silencing had no effect on Daxx silencing-mediated apoptotic events, while caspase gene expression was upregulated in the absence of Daxx. These data strongly suggest that Daxx may inhibit Fas and stress-mediated apoptosis by suppressing proapoptotic gene expression outside of PML domains.

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