Project description:CD95 was found to be important for both the formation of CSCs and their maintenance. Using a stable isotope labeling by amino acids in cell culture (SILAC) analysis we have now identified STAT1 as a critical gene that mediates the CSC-driving activity of CD95. We report that chronic stimulation of CD95 by either agonist antibodies, soluble CD95L or stably expressed membrane CD95L causes both serine and tyrosine phosphorylation of STAT1 and activation of STAT1 regulated genes. The genes most significantly induced were part of an interferon (IFN)-related DNA damage resistance signature (IRDS) recently identified in a radiation resistant squamous cell carcinoma cell line Nu61 when compared to parental SCC61 cells. The IRDS was found to strongly correlate with therapy resistance (chemotherapy and radiation) in multiple cancer cells as well as in 5 human primary cancers. We now report that CD95 stimulation of breast cancer cell lines or the SCC61 cells induces the upregulation of Type I IFNs that bind to both Type I receptors IFNAR1 and IFNR2 resulting in activation of JAK kinases, activation of STAT1 and induction of a number of STAT1-regulated genes. This process can be inhibited by active caspases. Consequently, we identified Type I IFNs as drivers of cancer stemness. Knockdown of STAT1 using either siRNAs or shRNAs, or deleting two independent sites in the STAT1 gene in MCF-7 cells using the CRIPSR/Cas9 gene editing system resulted in a loss of the ability of CD95 to increase stemness. This identifies STAT1 as a critical mediator of the CSCs-inducing activity of CD95.
Project description:CD95 was found to be important for both the formation of CSCs and their maintenance. Using a stable isotope labeling by amino acids in cell culture (SILAC) analysis we have now identified STAT1 as a critical gene that mediates the CSC-driving activity of CD95. We report that chronic stimulation of CD95 by either agonist antibodies, soluble CD95L or stably expressed membrane CD95L causes both serine and tyrosine phosphorylation of STAT1 and activation of STAT1 regulated genes. The genes most significantly induced were part of an interferon (IFN)-related DNA damage resistance signature (IRDS) recently identified in a radiation resistant squamous cell carcinoma cell line Nu61 when compared to parental SCC61 cells. The IRDS was found to strongly correlate with therapy resistance (chemotherapy and radiation) in multiple cancer cells as well as in 5 human primary cancers. We now report that CD95 stimulation of breast cancer cell lines or the SCC61 cells induces the upregulation of Type I IFNs that bind to both Type I receptors IFNAR1 and IFNR2 resulting in activation of JAK kinases, activation of STAT1 and induction of a number of STAT1-regulated genes. This process can be inhibited by active caspases. Consequently, we identified Type I IFNs as drivers of cancer stemness. Knockdown of STAT1 using either siRNAs or shRNAs, or deleting two independent sites in the STAT1 gene in MCF-7 cells using the CRIPSR/Cas9 gene editing system resulted in a loss of the ability of CD95 to increase stemness. This identifies STAT1 as a critical mediator of the CSCs-inducing activity of CD95. androgen receptor (AR) activation independently of androgen. We have previously reported that AR can directly repress the expression of many target genes, one of which is NOV/CCN3. Here we show that NOV, primarily localized in the cytoplasm, physically interacts with AR at its Nterminus and sequesters AR and AR variants in the cytoplasm, thereby reducing AR chromatintargeting. This negative feedback loop, however, is disrupted in CRPC due to epigenetic silencing of NOV by the Polycomb group protein EZH2, rendering AR transcriptional activities and drug-resistant prostate cancer progression. Our findings thus suggest a working model wherein AR-repressed genes critically prevent CRPC through negative feedback loops inhibiting AR signaling.
Project description:Begitt2014 - STAT1 cooperative DNA binding - double GAS polymer model
The importance of STAT1-cooperative DNA binding in type 1 and type 2 interferon signalling has been studies using experimental and modelling approaches. The authors have developed two ODE models to describe STAT1 binding to short promoter regions of DNA, namely "single GAS polymer model" and "double GAS polymer model" considering binding to single or double GAS sites, respectively. The length of DNA in the single GAS model was three sites and four sites in double GAS model. This model correspond to the "double GAS polymer model".
This model is described in the article:
STAT1-cooperative DNA binding distinguishes type 1 from type 2 interferon signaling.
Begitt A, Droescher M, Meyer T, Schmid CD, Baker M, Antunes F, Owen MR, Naumann R, Decker T, Vinkemeier U
Nat Immunol. 2014 Feb;15(2):168-76.
Abstract:
STAT1 is an indispensable component of a heterotrimer (ISGF3) and a STAT1 homodimer (GAF) that function as transcription regulators in type 1 and type 2 interferon signaling, respectively. To investigate the importance of STAT1-cooperative DNA binding, we generated gene-targeted mice expressing cooperativity-deficient STAT1 with alanine substituted for Phe77. Neither ISGF3 nor GAF bound DNA cooperatively in the STAT1F77A mouse strain, but type 1 and type 2 interferon responses were affected differently. Type 2 interferon-mediated transcription and antibacterial immunity essentially disappeared owing to defective promoter recruitment of GAF. In contrast, STAT1 recruitment to ISGF3 binding sites and type 1 interferon-dependent responses, including antiviral protection, remained intact. We conclude that STAT1 cooperativity is essential for its biological activity and underlies the cellular responses to type 2, but not type 1 interferon.
This model is hosted on BioModels Database
and identified
by: BIOMD0000000501
.
To cite BioModels Database, please use: BioModels Database: An enhanced, curated and annotated resource
for published quantitative kinetic models
.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to the public
domain worldwide. Please refer to CC0 Public Domain
Dedication
for more information.
Project description:Begitt2014 - STAT1 cooperative DNA binding - single GAS polymer model
The importance of STAT1-cooperative DNA binding in type 1 and type 2 interferon signalling has been studies using experimental and modelling approaches. The authors have developed two ODE models to describe STAT1 binding to short promoter regions of DNA, namely "single GAS polymer model" and "double GAS polymer model" considering binding to single or double GAS sites, respectively. The length of DNA in the single GAS model was three sites and four sites in double GAS model. This model correspond to the "single GAS polymer model".
This model is described in the article:
STAT1-cooperative DNA binding distinguishes type 1 from type 2 interferon signaling.
Begitt A, Droescher M, Meyer T, Schmid CD, Baker M, Antunes F, Owen MR, Naumann R, Decker T, Vinkemeier U
Nat Immunol. 2014 Feb;15(2):168-76.
Abstract:
STAT1 is an indispensable component of a heterotrimer (ISGF3) and a STAT1 homodimer (GAF) that function as transcription regulators in type 1 and type 2 interferon signaling, respectively. To investigate the importance of STAT1-cooperative DNA binding, we generated gene-targeted mice expressing cooperativity-deficient STAT1 with alanine substituted for Phe77. Neither ISGF3 nor GAF bound DNA cooperatively in the STAT1F77A mouse strain, but type 1 and type 2 interferon responses were affected differently. Type 2 interferon-mediated transcription and antibacterial immunity essentially disappeared owing to defective promoter recruitment of GAF. In contrast, STAT1 recruitment to ISGF3 binding sites and type 1 interferon-dependent responses, including antiviral protection, remained intact. We conclude that STAT1 cooperativity is essential for its biological activity and underlies the cellular responses to type 2, but not type 1 interferon.
This model is hosted on BioModels Database
and identified
by: BIOMD0000000500
.
To cite BioModels Database, please use: BioModels Database: An enhanced, curated and annotated resource
for published quantitative kinetic models
.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to the public
domain worldwide. Please refer to CC0 Public Domain
Dedication
for more information.
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.
Project description:U3A cells stably expressing wild-type STAT1 or STAT1-CC were treated with interferon beta (10U/ml) or control for 24 hours to assess effects of stat1 modifications, interferon, and the interaction on gene expression. Keywords: interferon, STAT1, STAT1-CC, STAT1CC, STAT-1C, antiviral RNA was isolated from stable U3A-STAT1 lines stably expressing wild-type STAT1 or STAT1CC, after 24 hour treatment with interferon beta (10U/ml) or control.
Project description:Identifying interactors of IRF1 and STAT1 in bone marrow-derived macrophages during type I and type II interferon treatment using the proximity-dependent labeling approach TurboID followed by Mass Spectrometry