Caspases activation in hyperthermia-induced stimulation of TRAIL apoptosis (original) (raw)
Related papers
Nature cell …, 2005
Activation of 'initiator' (or 'apical') caspases-2, -8 or -9 (refs 1-3) is crucial for induction of apoptosis. These caspases function to activate executioner caspapses that, in turn, orchestrate apoptotic cell death. Here, we show that a cell-permeable, biotinylated pan-caspase inhibitor (bVAD-fmk) both inhibited and 'trapped' the apical caspase activated when apoptosis was triggered. As expected, only caspase-8 was trapped in response to ligation of death receptors, whereas only caspase-9 was trapped in response to a variety of other apoptosis-inducing agents. Caspase-2 was exclusively activated in heat shock-induced apoptosis. This activation of caspase-2 was also observed in cells protected from heat-shock-induced apoptosis by Bcl-2 or Bcl-xL. Reduced sensitivity to heat-shock-induced death was observed in caspase-2(-/-) cells. Furthermore, cells lacking the adapter molecule RAIDD failed to activate caspase-2 after heat shock treatment and showed resistance to apoptosis in this setting. This approach unambiguously identifies the apical caspase activated in response to apoptotic stimuli, and establishes caspase-2 as a proximal mediator of heat shock-induced apoptosis.
Sensitization of chronic lymphocytic leukemia cells to TRAIL-induced apoptosis by hyperthermia
Cancer Letters, 2007
We recently reported that, in cultured leukemic T lymphocytes and promyelocytic cells, a mild heat shock treatment (1 h at 42°C) induced a long lasting stimulation of the apoptosis induced by TNF-related apoptosis inducing ligand (TRAIL). On the opposite, no effects were recorded toward normal human T lymphocytes. The apoptogenic efficiency of TRAIL in leukemic lymphocytes is linked to the long lasting increased ability of TRAIL to recognize and bind DR4 and DR5 receptors during hyperthermia. Here, we have analyzed whether this new apoptotic co-treatment could be relevant toward primary cells from patients suffering of chronic lymphocytic leukemia. Analysis of samples from 24 patients with different ages, sex and disease stages revealed that half of them had lymphocytes that, once isolated and analyzed in vitro, positively responded (increase of cell death) to the heat shock plus TRAIL co-treatment. Analysis of the level of expression of various anti-apoptotic proteins in the cell samples revealed a great heterogeneity between patients and no clear relationships could be drawn. Nevertheless, most cell samples that were sensitive to TRAIL plus heat shock induced apoptosis displayed a higher level of cell surface DR4 and DR5 receptors than the non-sensitive counterparts. Hence, analysis of the level of TRAIL surface receptors is a prerequisite for future clinical applications based on this protocol.
Heat shock proteins: essential proteins for apoptosis regulation
Journal of Cellular and Molecular Medicine, 2008
Many different external and intrinsic apoptotic stimuli induce the accumulation in the cells of a set of proteins known as stress or heat shock proteins (HSPs). HSPs are conserved proteins present in both prokaryotes and eukaryotes. These proteins play an essential role as molecular chaperones by assisting the correct folding of nascent and stress-accumulated misfolded proteins, and by preventing their aggregation. HSPs have a protective function, that is they allow the cells to survive to otherwise lethal conditions. Various mechanisms have been proposed to account for the cytoprotective functions of HSPs. Several of these proteins have demonstrated to directly interact with components of the cell signalling pathways, for example those of the tightly regulated caspase-dependent programmed cell death machinery, upstream, downstream and at the mitochondrial level. HSPs can also affect caspase-independent apoptosis-like process by interacting with apoptogenic factors such as apoptosis-inducing factor (AIF) or by acting at the lysosome level. This review will describe the different key apoptotic proteins interacting with HSPs and the consequences of these interactions in cell survival, proliferation and apoptotic processes. Our purpose will be illustrated by emerging strategies in targeting these protective proteins to treat haematological malignancies.
Cell Death & Disease
TRAIL is involved in immune tumor surveillance and is considered a promising anti-cancer agent owing to its limited side effects on healthy cells. However, some cancer cells display resistance, or become resistant to TRAIL-induced cell death. Hyperthermia can enhance sensitivity to TRAIL-induced cell death in various resistant cancer cell lines, including lung, breast, colon or prostate carcinomas. Mild heat shock treatment has been proposed to restore Fas ligand or TRAIL-induced apoptosis through c-FLIP degradation or the mitochondrial pathway. We demonstrate here that neither the mitochondria nor c-FLIP degradation are required for TRAIL-induced cell death restoration during hyperthermia. Our data provide evidence that insolubilization of c-FLIP, alone, is sufficient to enhance apoptosis induced by death receptors. Hyperthermia induced c-FLIP depletion from the cytosolic fraction, without apparent degradation, thereby preventing c-FLIP recruitment to the TRAIL DISC and allowing ef...
2013
ABT-737 Abott laboratories inhibitor of Bcl-2, Bcl-xL, Bcl-w AIF Apoptosis-inducing factor APAF-1 Apoptotic protease-activating factor-1 AP20187 FKBP ligand (homodimerizer) ASK1 Apoptosis signal-regulating kinase 1 ATP Adenosine triphosphate BAD Bcl-2 associated death promoter BAK Bcl-2 antagonist / killer BAX Bcl-2-associated X protein BCL-2 B-cell leukemia/lymphoma-2 BCL-x L B-cell lymphoma extra-large BFL1/A1 Bcl-2 related protein A1 BH Bcl-2 homology BH3 Bcl-2 homology domain 3 BID BH3 interacting domain death agonist BiFC Bi-molecular fluorescence complementation BIK Bcl-2-interacting killer BIM Bcl-2-interacting mediator of cell death BIR Baculovirus IAP repeat BMF Bcl-2-modifying factor BRAF v-raf murine sarcoma viral oncogene homolog B b-VAD-fmk Biotinylated-valine-alanine-aspartate-fluoromethylketone CARD Caspase activation and recruitment domain Caspases Cysteinyl aspartate-specific proteases CED Cell death abnormal c-FLIP Cellular-FLICE-like inhibitory protein CH11 Agonistic human CD95 antibody cIAP1/2 Cellular inhibitor of apoptosis-1/2 c-neu verb -B2 erythroblastic leukemia viral oncogene homolog 2, neuro/glioblastoma derived oncogene homolog cyt. c Cytochrome c dATP Deoxyadenosine triphosphate DD Death domain DDR DNA damage response DED Death effector domain DISC Death-inducing signaling complex DKO Double knockout xiv plasma membrane DD
Heat shock proteins – modulators of apoptosis in tumour cells
Leukemia, 2000
Apoptosis is a genetically programmed, physiological method of cell destruction. A variety of genes are now recognised as positive or negative regulators of this process. Expression of inducible heat shock proteins (hsp) is known to correlate with increased resistance to apoptosis induced by a range of diverse cytotoxic agents and has been implicated in chemotherapeutic resistance of tumours and carcinogenesis. Intensive research on apoptosis over the past number of years has provided significant insights into the mechanisms and molecular events that occur during this process. The modulatory effects of hsps on apoptosis are well documented, however, the mechanisms of hsp-mediated protection against apoptosis remain to be fully defined, although several hypotheses have been proposed. Elucidation of these mechanisms should reveal novel targets for manipulating the sensitivity of leukaemic cells to therapy. This review aims to explain the currently understood process of apoptosis and the effects of hsps on this process. Several proposed mechanisms for hsp protection against apoptosis and the therapeutic implications of hsps in leukaemia are also discussed. Leukemia (2000) 14,
The Indonesian Biomedical Journal, 2019
BACKGROUND: Hyperthermia is used as an adjuvant treatment to sensitize cancer cells to subsequent radiotheraphy or chemotherapy. The aim of this study was to study the effect of severe hyperthermia on osteosarcoma cells and its underlying causes.METHODS: Short-term (1 h) severe hyperthermia (45°C) was applied to osteoblast-like osteosarcoma cells (MG-63) and the heat shock response and cell death mechanisms were investigated after recovery at 37°C for 72 h.RESULTS: Cell viability was significantly reduced (p<0.05) and apoptosis was significantly induced by severe hyperthermia in MG-63 cells (p<0.001). Caspase 3/7, 4 and 12 activities were significantly increased after 72 h of recovery at 37°C, indicating that severe hyperthermia induced endoplasmic reticulum (ER) stress and apoptosis (p<0.05). Heat shock protein 90 alpha (Hsp90α) was significantly down regulated at the protein level after recovery, in association with apoptosis induction (p<0.01). Additionally, caspase 8...