23 research outputs found
TRAIL-receptor preferences in pancreatic cancer cells revisited: Both TRAIL-R1 and TRAIL-R2 have a licence to kill
Background
TRAIL is a potent and specific inducer of apoptosis in tumour cells and therefore is a possible new cancer treatment. It triggers apoptosis by binding to its cognate, death-inducing receptors, TRAIL-R1 and TRAIL-R2. In order to increase its activity, receptor-specific ligands and agonistic antibodies have been developed and some cancer types, including pancreatic cancer, have been reported to respond preferentially to TRAIL-R1 triggering. The aim of the present study was to examine an array of TRAIL-receptor specific variants on a number of pancreatic cancer cells and test the generality of the concept of TRAIL-R1 preference in these cells.
Methods
TRAIL-R1 and TRAIL-R2 specific sTRAIL variants were designed and tested on a number of pancreatic cancer cells for their TRAIL-receptor preference. These sTRAIL variants were produced in HEK293 cells and were secreted into the medium. After having measured and normalised the different sTRAIL variant concentrations, they were applied to pancreatic and control cancer cells. Twenty-four hours later apoptosis was measured by DNA hypodiploidy assays. Furthermore, the specificities of the sTRAIL variants were validated in HCT116 cells that were silenced either for TRAIL-R1 or TRAIL-R2.
Results
Our results show that some pancreatic cancer cells use TRAIL-R1 to induce cell death, whereas other pancreatic carcinoma cells such as AsPC-1 and BxPC-3 cells trigger apoptosis via TRAIL-R2. This observation extended to cells that were naturally TRAIL-resistant and had to be sensitised by silencing of XIAP (Panc1 cells). The measurement of TRAIL-receptor expression by FACS revealed no correlation between receptor preferences and the relative levels of TRAIL-R1 and TRAIL-R2 on the cellular surface.
Conclusions
These results demonstrate that TRAIL-receptor preferences in pancreatic cancer cells are variable and that predictions according to cancer type are difficult and that determining factors to inform the optimal TRAIL-based treatments still have to be identified
Sodium butyrate sensitises human pancreatic cancer cells to both the intrinsic and the extrinsic apoptotic pathways.
Pancreatic cancer is characterised by a highly malignant phenotype with a marked resistance to conventional therapies and to apoptotic activators. Here, we demonstrate that sodium butyrate (NaBt), an inhibitor of histone deacetylases, sensitises human pancreatic cancer cell lines to both mitochondria- and Fas-mediated apoptosis. The analysis of anti-apoptotic and pro-apoptotic members of the Bcl-2 family in untreated pancreatic cancer cell lines shows a generalised low expression of Bcl-2 and a strong expression of Bcl-xL. NaBt treatment results in a marked down-regulation of Bcl-xL expression, mitochondrial membrane depolarization, cytochrome c release from mitochondria, activation of caspase-9 and -3 and apoptosis induction. Furthermore, NaBt sensitises pancreatic cancer cells to Fas-mediated apoptosis as well. In fact, the combined treatment with NaBt and the agonistic antibody anti-Fas (CH11) is able to induce apoptosis at an early time, in which neither NaBt nor CH11 alone induce apoptosis. Down-regulation of FLIP and activation of caspase-8 allow apoptosis to occur. These findings suggest that sodium butyrate could represent a good candidate for the development of new therapeutic strategies aimed at improving chemotherapy and immunotherapy in pancreatic cancer
Prediction of Structure-Born Vibrations Induced Into Large Structures by Train Transit
The paper presents an approach for the evaluation of train induced structural noise in large civil structures. The procedure is based on time domain Simulation of train-track interaction. The calculation is split into two stages, in order to manage also structure representations with a high number of degrees of freedom
Inhibition of E-Selectin (GMI-1271) or E-selectin together with CXCR4 (GMI-1359) re-sensitizes multiple myeloma to therapy
Rapid and efficient cancer cell killing mediated by high-affinity death receptor homotrimerizing trail variants
The tumour necrosis factor family member TNF-related apoptosis-inducing ligand (TRAIL) selectively induces apoptosis in a variety of cancer cells through the activation of death receptors 4 (DR4) and 5 (DR5) and is considered a promising anticancer therapeutic agent. As apoptosis seems to occur primarily via only one of the two death receptors in many cancer cells, the introduction of DR selectivity is thought to create more potent TRAIL agonists with superior therapeutic properties. By use of a computer-aided structure-based design followed by rational combination of mutations, we obtained variants that signal exclusively via DR4. Besides an enhanced selectivity, these TRAIL-DR4 agonists show superior affinity to DR4, and a high apoptosis-inducing activity against several TRAIL-sensitive and -resistant cancer cell lines in vitro. Intriguingly, combined treatment of the DR4-selective variant and a DR5-selective TRAIL variant in cancer cell lines signalling by both death receptors leads to a significant increase in activity when compared with wild-type rhTRAIL or each single rhTRAIL variant. Our results suggest that TRAIL induced apoptosis via high-affinity and rapid-selective homotrimerization of each DR represent an important step towards an efficient cancer treatment. Cell Death and Disease (2010) 1, e83; doi: 10.1038/cddis.2010.61; published online 21 October 201
3R gene expression in chronic lymphocytic leukemia reveals insight into disease evolution
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Hepatocyte growth factor favors monocyte differentiation into regulatory interleukin (IL)-10++IL-12low/neg accessory cells with dendritic-cell features
Several hematopoietic growth factors, including interleukin-10 (IL-10) and transforming growth factor-beta1 (TGF-beta1), promote the differentiation of tolerogenic dendritic cells (DCs). Hepatocyte growth factor (HGF) is a pleiotropic cytokine whose effects on human DC differentiation and function have not been investigated. Monocytes cultured with HGF (HGFMo) differentiated into accessory cells with DC-like morphology, released low amounts of IL-12p70 and up-regulated IL-10 both at the mRNA and at the protein level. Upon activation with HGFMo, allogeneic CD4+CD25- T cells expressed the T regulatory (Treg)-associated transcription factor FoxP3, proliferated poorly, and released high levels of IL-10. Interestingly, blockade of surface immunoglobulin-like transcript 3 (ILT3) on HGFMo or neutralization of secreted IL-10 translated into partial restoration of T-cell proliferation. Secondary stimulation of HGFMo-primed CD4+ T cells with immunogenic DCs differentiated with granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-4 from monocytes of the same donor resulted in measurable T-cell proliferation. HGFMo-primed CD4+ T cells significantly inhibited the proliferation of naive CD4+CD25- T cells in a cell-contact-dependent manner. Finally, DNA microarray analysis revealed a unique gene-expression profile of HGF-activated monocytes. Collectively, our findings point to a novel role for HGF in the regulation of monocyte/DC functions that might be exploited therapeutically
Aggressive systemic mastocytosis with the co-occurrence of PRKG2::PDGFRB, KAT6A::NCOA2, and RXRA::NOTCH1 fusion transcripts and a heterozygous RUNX1 frameshift mutation
: Systemic mastocytosis (SM) is a myeloproliferative neoplasm displaying abnormal mast cell proliferation. It is subdivided into different forms, including aggressive systemic mastocytosis (ASM) and systemic mastocytosis with an associated hematologic neoplasm (SM-AHN). Oncogenic genetic alterations include point mutations, mainly the KIT D816V, conferring poor prognosis and therapy resistance, and fusion genes, with those involving PDGFRA/PDGFRB as the most recurrent events. We here describe an ASM case negative to the KIT D816V and JAK2 V617F alterations but showing a RUNX1 frameshift heterozygous mutation and the co-occurrence of three fusion transcripts. The first one, PRKG2::PDGFRB, was generated by a balanced t(4;5)(q24;q32) translocation as the sole abnormality. Other two novel chimeras, KAT6A::NCOA2 and RXRA::NOTCH1, originated from cryptic intra-chromosomal abnormalities. The patient rapidly evolved towards SM-AHN, characterized by the persistence of the PRKG2::PDGFRB chimera, due to the presence of an extra copy of the der(5)t(4;5)(q24;q34) chromosome and an increase in the RUNX1 mutation allelic frequency. The results indicated that the transcriptional landscape and the mutational profile of SM deserve attention to predict the evolution and prognosis of this complex disease, whose classification criteria are still a matter of debate