Project description:Analysis of RISC bound short (s)RNAs in a HCT116 Drosha CD95 d.k.o. cell line expressing pLenti-CD95L and various CD95L mutant constructs.
Project description:Analysis of RISC bound short (s)RNAs in a HCT116 Drosha CD95 d.k.o. cell line expressing pLenti-CD95L and various CD95L mutant constructs.
Project description:>80% of a large number of tested siRNAs and shRNAs targeting CD95 or CD95 ligand (CD95L) induce a form of cell death that is characterized by the simultaneous activation of multiple death pathways and preferentially affects transformed and cancer stem cells. We now show that these si/shRNAs kill cancer cells through canonical RNAi by targeting the 3’UTR of critical survival genes in a unique form of off-target effect. We also provide evidence showing that the full length CD95L mRNA is also toxic and produces small Ago-associated RNAs.
Project description:>80% of a large number of tested siRNAs and shRNAs targeting CD95 or CD95 ligand (CD95L) induce a form of cell death that is characterized by the simultaneous activation of multiple death pathways and preferentially affects transformed and cancer stem cells. We now show that these si/shRNAs kill cancer cells through canonical RNAi by targeting the 3’UTR of critical survival genes in a unique form of off-target effect. We also provide evidence showing that the full length CD95L mRNA is also toxic and produces small Ago-associated RNAs.
Project description:>80% of a large number of tested siRNAs and shRNAs targeting CD95 or CD95 ligand (CD95L) induce a form of cell death that is characterized by the simultaneous activation of multiple death pathways and preferentially affects transformed and cancer stem cells. We now show that these si/shRNAs kill cancer cells through canonical RNAi by targeting the 3’UTR of critical survival genes in a unique form of off-target effect. We also provide evidence showing that the full length CD95L mRNA is also toxic and produces small Ago-associated RNAs.
Project description:>80% of a large number of tested siRNAs and shRNAs targeting CD95 or CD95 ligand (CD95L) induce a form of cell death that is characterized by the simultaneous activation of multiple death pathways and preferentially affects transformed and cancer stem cells. We now show that these si/shRNAs kill cancer cells through canonical RNAi by targeting the 3’UTR of critical survival genes in a unique form of off-target effect. We also provide evidence showing that the full length CD95L mRNA is also toxic and produces small Ago-associated RNAs.
Project description:Chronic viral infections incapacitate adaptive immune responses by 'exhausting' virus-specific T cells, inducing their deletion and reducing productive T cell memory. Viral infection rapidly induces death receptor Fas (CD95) expression by dendritic cells (DCs) making them susceptible to elimination by the immune response. Lymphocytic Choriomeningitis Virus (LCMV) Clone 13, which normally establishes a chronic infection, is rapidly cleared in C57Black/J mice with conditional deletion of Fas in DCs. The immune response to LCMV is characterized by an extended survival of virus-specific effector T cells. Moreover, transfer of Fas-negative DCs from non-infected mice to already-infected animals results in either complete clearance of the virus or a significant reduction of viral titers. Thus, DC-specific Fas expression plays a role in regulation of anti-viral responses and suggests a strategy for stimulation of T cells in chronically infected animals and humans in order to achieve the clearance of persistent viruses. We compared gene expression between splenic DCs from B6.FasKI and B6.CD11c-Cre.FasKI mice. DCs were isolated on day 5 after LCMV infection with 3 mice in each group, for a total of 6 samples. Spleens were collagenase-DNAse digested and sorted by flow to isolate DCs.
Project description:CD95 (also called FAS and APO-1) is a prototypical death receptor that regulates tissue homeostasis mainly in the immune system through induction of apoptosis. During cancer progression CD95 is frequently downregulated or cells are rendered apoptosis resistant raising the possibility that loss of CD95 is part of a mechanism for tumour evasion. However, complete loss of CD95 is rarely seen in human cancers and many cancer cells express large quantities of CD95 and are highly sensitive to CD95 mediated apoptosis in vitro. Furthermore, cancer patients frequently have elevated levels of the physiological ligand for CD95, CD95L. These data raise the intriguing possibility that CD95 could actually promote the growth of tumours through its nonapoptotic activities. Here we show that cancer cells in general, regardless of their CD95 apoptosis sensitivity, depend on constitutive activity of CD95, stimulated by cancer-produced CD95L, for optimal growth. Consistently, loss of CD95 in mouse models of ovarian cancer and liver cancer reduces cancer incidence as well as the size of the tumours. The tumorigenic activity of CD95 is mediated by a pathway involving JNK and c-Jun. These results demonstrate that CD95 plays a major growth promoting role during tumorigenesis and suggest that efforts to inhibit its activity rather than to enhance its activation should be considered during cancer therapy. There are 3 arrays for human ovarian cancer cell line, 2 arrays for human liver cancer cell line, and 2 arrays for mouse liver tissue. All the arrays are paired arrays with or without Fas knock-out.