Cílem tohoto projektu je nalézt přímé a jednoznačné důkazy, že zvýšená expese "death" receptorů TRAIL-R2 a CD95 zprostředkovaná transkripční aktivitou p53 signifikantně zvýší buněčný zánik indukovaný TRAIL a CD178. Navrhujeme užití jednoznačného modelu geneticky modifikovaných nádorových buněk, které mají buď "wild-type" nebo suprimovanou aktivitu p53.; This project aims to provide direct and unambiguous evidence that the upregulation of expression of death receptors TRAIL-R2 and CD95 mediated by p53 transcriptional activity significantly increases the amount of death induced by TRAIL and CD178. We propose to use an unambiguous model of genetically modified tumor cells that have either wild-type or suppressed p53 activity.

• MeSH
• antigeny CD95 MeSH
• apoptóza genetika   MeSH
• buněčná smrt MeSH
• nádorový supresorový protein p53 MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• onkologie
• hematologie a transfuzní lékařství
• biologie
• NLK Publikační typ
• závěrečné zprávy o řešení grantu IGA MZ ČR

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a cytokine that can trigger apoptosis in many types of human cancer cells via engagement of its two pro-apoptotic receptors TRAIL-R1 (DR4) and TRAIL-R2 (DR5). TRAIL can also activate several other signaling pathways such as activation of stress kinases, canonical NF-κB signaling and necroptosis. Though both receptors are ubiquitously expressed, their relative participation in TRAIL-induced signaling is still largely unknown. To analyze TRAIL receptor-specific signaling, we prepared Strep-tagged, trimerized variants of recombinant human TRAIL with high affinity for either DR4 or DR5 receptor. Using these receptor-specific ligands, we examined the contribution of individual pro-apoptotic receptors to TRAIL-induced signaling pathways. We found that in TRAIL-resistant colorectal HT-29 cells but not in pancreatic PANC-1 cancer cells, DISC formation and initial caspase-8 processing proceeds comparably via both DR4- and DR5-activated signaling. TRAIL-induced apoptosis, enhanced by the inhibitor of the Bcl-2 family ABT-737, or by the translation inhibitor homoharringtonine, proceeded in both cell lines predominantly via the DR5 receptor. ShRNA-mediated downregulation of DR4 or DR5 receptors in HT-29 cells also pointed to a stronger contribution of DR5 in TRAIL-induced apoptosis. In contrast to apoptosis, necroptotic signaling was activated similarly by both DR4- or DR5-specific ligands. Activation of auxiliary signaling pathways involving NF-κB or stress kinases proceeded under apoptotic conditions mainly in a DR5-dependent manner, while these signaling pathways were during necroptosis similarly activated by either of these ligands. Our study provides the first systematic insight into DR4-/DR5-specific signaling in colorectal and pancreatic cancer cells.

• MeSH
• apoptóza genetika   MeSH
• buňky HT-29 MeSH
• kaspasa 8 genetika   MeSH
• kolorektální nádory genetika   patologie   MeSH
• lidé MeSH
• malá interferující RNA MeSH
• nádory slinivky břišní genetika   patologie   MeSH
• nekróza genetika   patologie   MeSH
• NF-kappa B genetika   MeSH
• pankreas metabolismus   patologie   MeSH
• proliferace buněk genetika   MeSH
• protein TRAIL genetika   MeSH
• regulace genové exprese u nádorů MeSH
• signální transdukce genetika   MeSH
• TRAIL receptory genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

TRAIL (tumor-necrosis factor related apoptosis-inducing ligand, CD253) and its death receptors TRAIL-R1 and TRAIL-R2 selectively trigger the apoptotic cell death in tumor cells. For that reason, TRAIL has been extensively studied as a target of cancer therapy. In spite of the promising preclinical observations, the TRAIL-based therapies in humans have certain limitations. The two main therapeutic approaches are based on either an administration of TRAIL-receptor (TRAIL-R) agonists or a recombinant TRAIL. These approaches, however, seem to elicit a limited therapeutic efficacy, and only a few drugs have entered the phase II clinical trials. To deliver TRAIL-based therapies with higher anti-tumor potential several novel TRAIL-derivates and modifications have been designed. These novel drugs are, however, mostly preclinical, and many problems continue to be unraveled. We have reviewed the current status of all TRAIL-based monotherapies and combination therapies that have reached phase II and phase III clinical trials in humans. We have also aimed to introduce all novel approaches of TRAIL utilization in cancer treatment and discussed the most promising drugs which are likely to enter clinical trials in humans. To date, different strategies were introduced in order to activate anti-tumor immune responses with the aim of achieving the highest efficacy and minimal toxicity.In this review, we discuss the most promising TRAIL-based clinical trials and their therapeutic strategies.

• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

TRAIL, a ligand of the TNFalpha family, induces upon binding to its pro-death receptors TRAIL-R1/DR4 and TRAIL-R2/DR5 the apoptosis of cancer cells. Activated receptors incite the formation of the Death-Inducing Signaling Complex followed by the activation of the downstream apoptotic signaling. TRAIL-induced apoptosis is regulated at multiple levels, one of them being the presence and relative number of TRAIL pro- and anti-apoptotic receptors on the cytoplasmic membrane. In a yeast two-hybrid search for proteins that interact with the intracellular part (ICP) of DR4, we picked ARAP1, an adapter protein with ArfGAP and RhoGAP activities. In yeast, DR4(ICP) interacts with the alternatively spliced ARAP1 lacking 11 amino acids from the PH5 domain. Transfected ARAP1 co-precipitates with DR4 and co-localizes with it in the endoplasmic reticulum/Golgi, at the cytoplasmic membrane and in early endosomes of TRAIL-treated cells. ARAP1 knockdown significantly compromises the localization of DR4 at the cell surface of several tumor cell lines and slows down their TRAIL-induced death. ARAP1 overexpressed in HEL cells does not affect their TRAIL-induced apoptosis or the membrane localization of DR4, but it enhances the cell-surface presentation of phosphatidyl serine. Our data indicate that ARAP1 is likely involved in the regulation of the cell-specific trafficking of DR4 and might thus affect the efficacy of TRAIL-induced apoptosis.

• MeSH
• apoptóza účinky léků   MeSH
• buněčná membrána metabolismus   MeSH
• buněčné linie MeSH
• down regulace MeSH
• financování organizované MeSH
• lidé MeSH
• malá interferující RNA farmakologie   MeSH
• mapování interakce mezi proteiny MeSH
• nádorové buněčné linie MeSH
• protein TRAIL metabolismus   MeSH
• proteiny aktivující GTPasu fyziologie   MeSH
• receptory TNF metabolismus   MeSH
• techniky dvojhybridového systému MeSH
• transport proteinů fyziologie   MeSH
• transportní proteiny fyziologie   MeSH
• Check Tag
• lidé MeSH

PURPOSE: DNA repair defects due to detrimental BRCA2-mutations confer increased susceptibility towards DNA interstrand-crosslinking (ICL) agents and define patient subpopulations for individualized genotype-based cancer therapy. However, due to the side effects of these drugs, there is a need to identify additional agents, which could be used alone or in combination with ICL-agents. Therefore, we investigated whether BRCA2-mutations might also increase the sensitivity towards TRAIL-receptors (TRAIL-R)-targeting compounds. EXPERIMENTAL DESIGN: Two independent model systems were applied: a BRCA2 gene knockout and a BRCA2 gene complementation model. The effects of TRAIL-R-targeting compounds and ICL-agents on cell viability, apoptosis and cell cycle distribution were compared in BRCA2-proficient versus-deficient cancer cells in vitro. In addition, the effects of the TRAIL-R2-targeting antibody LBY135 were assessed in vivo using a murine tumor xenograft model. RESULTS: BRCA2-deficient cancer cells displayed an increased sensitivity towards TRAIL-R-targeting agents. These effects exceeded and were mechanistically distinguishable from the well-established effects of ICL-agents. In vitro, ICL-agents expectedly induced an early cell cycle arrest followed by delayed apoptosis, whereas TRAIL-R-targeting compounds caused early apoptosis without prior cell cycle arrest. In vivo, treatment with LBY135 significantly reduced the tumor growth of BRCA2-deficient cancer cells in a xenograft model. CONCLUSIONS: BRCA2 mutations strongly increase the in vitro- and in vivo-sensitivity of cancer cells towards TRAIL-R-mediated apoptosis. This effect is mechanistically distinguishable from the well-established ICL-hypersensitivity of BRCA2-deficient cells. Our study thus defines a new genetic subpopulation of cancers susceptible towards TRAIL-R-targeting compounds, which could facilitate novel therapeutic approaches for patients with BRCA2-deficient tumors.

• MeSH
• apoptóza účinky léků   MeSH
• kontrolní body buněčného cyklu účinky léků   MeSH
• lidé MeSH
• malá interferující RNA genetika   MeSH
• myší monoklonální protilátky farmakologie   MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• oprava DNA genetika   MeSH
• proliferace buněk MeSH
• protein BRCA2 genetika   MeSH
• protinádorové látky farmakologie   MeSH
• reagencia zkříženě vázaná farmakologie   MeSH
• RNA interference MeSH
• TRAIL receptory antagonisté a inhibitory   MeSH
• viabilita buněk účinky léků   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: The genome of multiple myeloma (MM) clonal plasma cells is characterized by genetic changes of prognostic importance. Disease progression is accompanied by a number of secondary chromosomal aberrations including chromosome 8. We focused on the detection of chromosome 8 aberrations in patients with MM who were examined at 2 different phases: diagnosis and progression/relapse. PATIENTS AND METHODS: A total of 62 patients with MM were examined at the time of diagnosis and at relapse/progression. The median age was 64 years (range, 39-78 years); the study included 29 males and 33 females. We analyzed bone marrow samples for detecting aberrations on chromosome 8 by the fluorescence immunophenotyping and interphase cytogenetics as a tool for the investigation of neoplasms (FICTION) and fluorescence in situ hybridization methods with specific probes. RESULTS: Chromosome 8 aberrations were detected in 24 (38.7%) patients at diagnosis and in 29 (46.8%) patients at progression/relapse. Only 5 (8%) patients developed additional chromosome 8 changes at progression/relapse. The aberrations were heterogeneous, involving numerical and structural changes of the MYC gene. Aberrations of the short arm of chromosome 8, involving the genes TRAIL-R1/-R2, were less frequent (4 of 62 patients, 6.4%). All aberrations of chromosome 8 were accompanied with additional changes and with an advanced clinical phase of the disease. This finding significantly influenced the overall survival of patients. CONCLUSION: In the current study, chromosome 8 aberrations were highly heterogeneous, were presented at diagnosis in patients with advanced clinical stage, and were associated with worse overall survival. We have not confirmed the increase of frequency aberration of chromosome 8 in disease progression. The findings demonstrate the importance of fluorescence in situ hybridization examination of chromosome 8 in newly diagnosed patients with MM.

• MeSH
• chromozomální aberace * MeSH
• cytogenetické vyšetření MeSH
• dospělí MeSH
• geny myc MeSH
• hybridizace in situ fluorescenční MeSH
• imunofenotypizace MeSH
• Kaplanův-Meierův odhad MeSH
• klonální evoluce MeSH
• lidé středního věku MeSH
• lidé MeSH
• lidské chromozomy, pár 8 * MeSH
• mnohočetný myelom diagnóza   genetika   mortalita   terapie   MeSH
• nádorové biomarkery MeSH
• progrese nemoci MeSH
• recidiva MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• staging nádorů MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Balance and lower limb strength deficits are associated with a high incidence of falls in older adults. This study investigated the association between balance control during and after stair descent onto a compliant surface and lower limb strength. Thirty-five women and 14 men participated in this study. Stair descent time, mean center of pressure velocity in anteroposterior and mediolateral direction during stair descent (CoP VAP and CoP VML), and CoP velocity in the first 5 s of restabilization phase (CoP V5) were evaluated. Bilateral strength of the knee flexors and extensors, and ankle plantar and dorsal flexors was evaluated. Spearman correlation analysis with Bonferroni correction yielded a significant association between the strength of the knee flexors on the trailing limb and stair descent time in women (r = 0.502, p = 0.002, R2 = 0.246). The same analysis in men revealed a significant association between the strength of the knee flexors on the trailing limb and CoP VAP (r = -0.820, p < 0.001, R2 = 0.280) and CoP VML (r = -0.697, p = 0.006, R2 = 0.359). The strength of the ankle plantar flexors on the trailing limb was significantly associated with stair descent time (r = 0.684, p = 0.007, R2 = 0.429) and CoP VAP (r = -0.723, p = 0.003, R2 = 0.408) in men. Stair descent balance control is associated with knee flexion strength on trailing limb in women, and with ankle plantar flexion and knee flexion strength on the same limb in men.

• MeSH
• biomechanika MeSH
• hlezenní kloub * MeSH
• kolenní kloub MeSH
• koleno MeSH
• kosterní svaly MeSH
• kotník * MeSH
• lidé MeSH
• senioři MeSH
• svalová síla MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH