Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer fatalities in Western societies, characterized by high metastatic potential and resistance to chemotherapy. Critical molecular mechanisms of these phenotypical features still remain unknown, thus hampering the development of effective prognostic and therapeutic measures in PDAC. Here we show that transcriptional co-factor Transducin beta-like (TBL) 1 was over-expressed in both human and murine PDAC. Inactivation of TBL1 in human and mouse pancreatic cancer cells reduced cellular proliferation and enhanced chemosensitivity, correlating with diminished glucose uptake, glycolytic flux, and PI3kinase signaling. TBL1 deficiency both prevented and reversed pancreatic tumor growth in mice, triggering transcriptional PI3kinase inhibition also in vivo. As TBL1 mRNA levels were also found to correlate with overall and disease-free survival in a cohort of human PDAC patients and to predict therapy responsiveness in these subjects, TBL1 expression may serve both as a novel prognostic marker and molecular target in the treatment of human PDAC.
Transcriptional co-factor Transducin beta-like (TBL) 1 acts as a checkpoint in pancreatic cancer malignancy.
Cell line, TreatmentView Samples
Autophagy is a mechanism that regulates cellular metabolism and clearance of damaged macromolecules and organelles. Impaired degradation of modified macromolecules contributes to cellular dysfunction and is observed in aged tissue and senescent cells. We have inactivated Atg7, an essential autophagy gene, in murine keratinocytes and have found in an earlier study that this resulted in increased baseline oxidative stress and reduced capacity to degrade crosslinked proteins after oxidative ultraviolet stress. To investigate whether autophagy deficiency would promote cellular aging, we studied, how Atg7 deficient (KO) and Atg7 bearing cells (WT) would respond to stress induced by Paraquat (PQ), an oxidant drug commonly used to induce cellular senescence.
Autophagy deficient keratinocytes display increased DNA damage, senescence and aberrant lipid composition after oxidative stress in vitro and in vivo.
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Failures to produce neutralizing antibodies upon HIV-1 infection result in part from B cell dysfunction due to unspecific B cell activation. How HIV-1 affects antigen-specific B cell functions remains elusive. Using an adoptive transfer mouse model and ex vivo HIV infection of human tonsil tissue we found that expression of the HIV-1 pathogenesis factor NEF in CD4 T cells undermines their helper function and impairs cognate B cell functions including mounting of efficient specific IgG responses. NEF interfered with T cell help via a specific protein interaction motif that prevents polarized cytokine secretion at the T cell - B cell immune synapse. This interference reduced B cell activation and proliferation and thus disrupted germinal center formation and affinity maturation. These results identify NEF as a key component for HIV-mediated dysfunction of antigen-specific B cells. Therapeutic targeting of the identified molecular surface in NEF will facilitate host control of HIV infection.
HIV-1 infection of CD4 T cells impairs antigen-specific B cell function.
Specimen partView Samples
C5aR1, a receptor for the complement activation proinflammatory fragment, C5a, is primarily expressed on cells of the myeloid lineage, and to a lesser extent on endothelial cells and neurons in brain. Previous work demonstrated C5aR1 antagonist, PMX205, decreased amyloid pathology and suppressed cognitive deficits in Alzheimer Disease (AD) mouse models. In the Arctic AD mouse model, genetic deletion of C5aR1 prevented behavior deficits at 10 months. However, the molecular mechanisms of this protection has not been definitively demonstrated. To understand the role of microglial C5aR1 in the Arctic AD mouse model, we have taken advantage of the CX3CR1GFP and CCR2RFP reporter mice to distinguish microglia as GFP-positive and infiltrating monocytes as GFP and RFP positive, for subsequent transcriptome analysis on specifically sorted myeloid populations from wild type and AD mouse models. Immunohistochemical analysis of mice aged to 2, 5, 7 and 10 months showed no change in amyloid beta (Ab) deposition in the Arctic C5aR1 knockout (KO) mice relative to that seen in the Arctic mice. Of importance, no CCR2+ monocytes/macrophages were found near the plaques in the Arctic brain with or without C5aR1. RNA-seq analysis on microglia from these mice identified inflammation related genes as differentially expressed, with increased expression in the Arctic mice relative to wildtype and decreased expression in the Arctic/C5aR1KO relative to Arctic. In addition, phagosomal-lysosomal proteins and protein degradation pathways that were increased in the Arctic mice were further increased in the Arctic/C5aR1KO mice. These data are consistent with a microglial polarization state with restricted induction of inflammatory genes and enhancement of clearance pathways. Overall design: Microglia mRNA profiles of wildtype (WT), C5aR1 knockout (C5aR1KO), Arctic (ARC) and Arctic C5aR1 knockout (ARCKO) mice at 2, 5, 7 and 10-11 month. Duplicates were sequenced for each genotype on Illumina HiSeq 2500 platform.
Prevention of C5aR1 signaling delays microglial inflammatory polarization, favors clearance pathways and suppresses cognitive loss.
Age, Specimen part, SubjectView Samples
The Wilms'' Tumour gene 1 (WT1), encodes for a complex protein with transcription factor activity which is essential in mammals throughout life. We provide a complete study of WT1 expression across different breast cancer subtypes as well as isoform specific expression analysis. Using in vitro cell lines, clinical samples and publicly available gene expression datasets, we demonstrate that WT1 plays a role in regulating the epithelial-mesenchymal balance of breast cancer cells and that WT1-expressing tumours are mainly associated with a mesenchymal phenotype. WT1 gene expression also correlates with CYP3A4 levels and is associated with poorer response to taxane treatment. Overall design: RNA profiles of breast cancer cells (MDA-MB-157) were generated by deep sequencing on the Illumina HiSeq 2000 platform. Untreated MDA-MB-157 cells, MDA-MB-157 cells transduced with a lacZ control vector, and MDA-MB-157 cells transduced with a lentiviral vector carrying a Wt1 shRNA were sequenced (titled untreated, lacZ and Wt1 respectively).
WT1 expression in breast cancer disrupts the epithelial/mesenchymal balance of tumour cells and correlates with the metabolic response to docetaxel.
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The encapsulated yeast Cryptococcus neoformans can cause a fatal meningoencephalitis in immunocompromised patients. C. neoformans infection is acquired through the respiratory tract, but the cellular and molecular mechanisms of the pulmonary innate immune response are still not well defined. To investigate the response of CCR2+ inflammatory monocytes to C. neoformans, we compared the transcriptomes of CCR2+ inflammatory monocytes from the lungs of naïve versus infected mice. Overall design: Sorted pulmonary CCR2+ inflammatory monocytes were pooled from 6-7 CCR2-GFP reporter mice per group, including naïve mice and mice challenged with intratracheal Cryptococcus neoformans on days 5 and 10 post-infection.
Inflammatory monocytes are detrimental to the host immune response during acute infection with Cryptococcus neoformans.
Specimen part, Cell line, SubjectView Samples
The transcriptome of the three atino80 allelic mutants was compared to that of wild-type and 50B Arabidopsis plants (see Fritsch et al. 2004). Since the transcriptomes of 50B and wild-type plants were found to be identical, we compared expression in the mutant with 50B and with wild-type without distinction. Therefore, we had four replicates of the wild type condition (50B line, wild-type) and two replicates for each of the mutant alleles (atino80-1, atino80-2 and atino80-3), all ecotype Columbia. All lines were profiled in duplicate (grown independently at 2-week-intervals).
The INO80 protein controls homologous recombination in Arabidopsis thaliana.
Age, Specimen partView Samples
Genome occupancy profiling by high throughput sequencing Overall design: PolyA selected RNA-seq for shRNA-expressing MLL-AF9 transformed acute myeloid leukemia cells (RN2)
BET Bromodomain Inhibition Releases the Mediator Complex from Select cis-Regulatory Elements.
Specimen part, Cell line, SubjectView Samples
The homeodomain transcription factor, Pdx-1, has important roles in pancreatic development and -cell function and survival. In the present study, we demonstrate that adenovirus-mediated overexpression of Pdx-1 in rat or human islets also stimulates cell replication. Moreover, co-overexpression of Pdx-1 with another homeodomain transcription factor, Nkx6.1, has an additive effect on proliferation compared to either factor alone, implying discrete activating mechanisms. Consistent with this, Nkx6.1 stimulates mainly -cell proliferation, whereas Pdx-1 stimulates both - and -cell proliferation. Furthermore, cyclins D1/D2 are upregulated by Pdx-1 but not by Nkx6.1, and inhibition of cdk4 blocks Pdx-1- but not Nkx6.1-stimulated islet cell proliferation. Genes regulated by Pdx-1 and not Nkx6.1 were identified by microarray analysis. Two members of the transient receptor potential cation (TRPC) channel family, TRPC3 and TRPC6, are upregulated by Pdx-1 overexpression, and siRNA-mediated knockdown of TRPC3/6 or TRPC6 alone inhibits Pdx-1-induced but not Nkx6.1-induced islet cell proliferation. Pdx-1 also stimulates ERK1/2 phosphorylation, an effect partially blocked by knockdown of TRPC3/6, and blockade of ERK1/2 activation with a MEK1/2 inhibitor partially impairs Pdx-1-stimulated proliferation. These studies define a pathway by which overexpression of Pdx-1 activates islet cell proliferation that is distinct from and additive to a pathway activated by Nkx6.1.
Pdx-1 activates islet α- and β-cell proliferation via a mechanism regulated by transient receptor potential cation channels 3 and 6 and extracellular signal-regulated kinases 1 and 2.
Sex, Age, Specimen partView Samples