ABSTRACT: Transcript and protein profiling identify signaling, growth arrest, apoptosis and NFκB-survival signatures following GnRH receptor activation.
Project description:Gonadotrophin-releasing hormone (GnRH) significantly inhibits proliferation of a proportion of cancer cell lines by activating GnRH receptor-G protein signaling. Therefore, manipulation of GnRH receptor signaling may have an under-utilized role in treating certain breast and ovarian cancers. However, the precise signaling pathways necessary for the effect and the features of cellular responses remain poorly defined. We used transcriptomic and proteomic profiling approaches to characterize the effects of GnRH receptor activation in sensitive cells (HEK293-GnRHR, SCL60) in in vitro and in vivo settings, compared to unresponsive HEK293. Analyses of gene expression demonstrated a dynamic SCL60 response to the GnRH super-agonist Triptorelin. Early and mid-phase changes (0.5-1.0 h) comprised mainly transcription factors. Later changes (8-24 h) included a GnRH target gene, CGA, and up or down-regulation of transcripts encoding signaling and cell division machinery. Pathway analysis exposed identified altered mitogen-activated protein kinase and cell cycle pathways, consistent with occurrence of G2/M arrest and apoptosis. NFκB pathway gene transcripts were differentially expressed between control and Triptorelin-treated SCL60 cultures. Reverse phase protein and phospho-proteomic array analyses profiled responses in cultured cells and SCL60 xenografts in vivo during Triptorelin anti-proliferation. Increased phosphorylated NFκB (p65) occurred in SCL60 in vitro, and p-NFκB and IκBε were higher in treated xenografts than controls after 4 days Triptorelin. NFκB inhibition enhanced the anti-proliferative effect of Triptorelin in SCL60 cultures. This study reveals details of pathways interacting with intense GnRH receptor signaling, identifies potential anti-proliferative target genes and implicates the NFκB survival pathway as a node for enhancing GnRH agonist-induced anti-proliferation. 55 samples: 35 SCL60 (15 Control, 20 Treated), 20 HEK293 (12 Control, 8 Treated). Samples collected after 0, 0.5, 1, 2, 8 or 24h after treatment with Triptorelin (100nM) or vehicle control (20% Propylene Glycol solution). SCL60 cells are HEK293 cells stably transfected with a high level of functional rat GnRHR.
Project description:Gonadotrophin-releasing hormone (GnRH) significantly inhibits proliferation of a proportion of cancer cell lines by activating GnRH receptor-G protein signaling. Therefore, manipulation of GnRH receptor signaling may have an under-utilized role in treating certain breast and ovarian cancers. However, the precise signaling pathways necessary for the effect and the features of cellular responses remain poorly defined. We used transcriptomic and proteomic profiling approaches to characterize the effects of GnRH receptor activation in sensitive cells (HEK293-GnRHR, SCL60) in in vitro and in vivo settings, compared to unresponsive HEK293. Analyses of gene expression demonstrated a dynamic SCL60 response to the GnRH super-agonist Triptorelin. Early and mid-phase changes (0.5-1.0 h) comprised mainly transcription factors. Later changes (8-24 h) included a GnRH target gene, CGA, and up or down-regulation of transcripts encoding signaling and cell division machinery. Pathway analysis exposed identified altered mitogen-activated protein kinase and cell cycle pathways, consistent with occurrence of G2/M arrest and apoptosis. NFκB pathway gene transcripts were differentially expressed between control and Triptorelin-treated SCL60 cultures. Reverse phase protein and phospho-proteomic array analyses profiled responses in cultured cells and SCL60 xenografts in vivo during Triptorelin anti-proliferation. Increased phosphorylated NFκB (p65) occurred in SCL60 in vitro, and p-NFκB and IκBε were higher in treated xenografts than controls after 4 days Triptorelin. NFκB inhibition enhanced the anti-proliferative effect of Triptorelin in SCL60 cultures. This study reveals details of pathways interacting with intense GnRH receptor signaling, identifies potential anti-proliferative target genes and implicates the NFκB survival pathway as a node for enhancing GnRH agonist-induced anti-proliferation.
Project description:TNFα is a potent inducer of inflammation due to its ability to promote gene expression, inpart via the NFκB pathway. Moreover, in some contexts, TNFα promotes Caspase-dependent apoptosis or RIPK1/RIPK3/MLKL-dependent necrosis. Engagement of the TNF Receptor Signaling Complex (TNF-RSC), which contains multiple kinase activities, promotes phosphorylation of several downstream components, including TAK1, IKKα/IKKβ, IκBα and NFκB. However, immediate downstream phosphorylation events occurring in response to TNFα signaling are poorly understood at a proteome-wide level. Here we use Tandem mass tagging-based proteomics to quantitatively characterize acute TNFα-mediated alterations in the proteome and phosphoproteome with or without inhibition of the cIAP-dependent survival arm of the pathway with a SMAC mimetic. We identify and quantify over 8,000 phosphorylated peptides, among which are numerous known sites in the TNF-RSC, NFκB, and MAP kinase signaling systems, as well as numerous previously unrecognized phosphorylation events. Functional analysis of S320 phosphorylation in RIPK1 demonstrates a role for this event in suppressing its kinase activity, association with CASPASE-8 and FADD proteins, and subsequent necrotic cell death during inflammatory TNFα stimulation. This study provides a resource for further elucidation of TNFα-dependent signaling pathways.
Project description:We describe a novel method for obtaining discrete regions from the fronto-limbic circuits of a 4 year old and a 5 year old, male, intact, frozen non-human primate (NHP) brain, from which we use transcriptional profiling and a new algorithm to identify region-exclusive RNA signatures for Area 25 (NFκB and dopamine receptor signaling), the anterior cingulate cortex (LXR/RXR signaling), the amygdala (semaphorin signaling), and the hippocampus (Caþþ and retinoic acid signaling). Profiling of 4 discrete brain regions in 2 individual non-human primate subjects.
Project description:Human Papillomavirus (HPV) infection has been recently linked to a subset of cancers affecting the oral cavity. However, the molecular mechanisms underlying HPV-driven oral squamous cell carcinoma (OSCC) onset and/ progression are poorly understood. Methods: We perform a MS-based proteomic profiling based on HPV status on OSCC in young patients, following biological characterization and cell assays to explore the proteome functional landscape. Results: Thirty-nine proteins are differentially abundant between HPV (+) and HPV (-) OSCC. Among them, COPS3, DYHC1, and S100A8 are unfavorable for tumor recurrence and survival in contrast to A2M and Serpine1, which low levels show association with better DFS. Remarkably, S100A8 is considered an independent prognostic factor for lower survival rate, and at high levels, it alters tumor-associated immune profiling, showing a lower proportion of M1 macrophages and dendritic cells. HPV (+) OSCC also displayed the pathogen-associated patterns receptor which, when activated, triggered S100A8 and NFκB inflammatory responses. Conclusion: HPV (+) OSCC has a peculiar microenvironment pattern, distinctively of HPV (-), involving expression of pathogen-associated pattern receptors, S100A8 overexpression, and NFκB activation and responses that had important consequences in prognosis and may guide therapeutic decisions.
Project description:Gonadotropin-releasing hormone (GnRH) is secreted in brief pulses from the hypothalamus. GnRH regulates follicle-stimulating hormone b-subunit (FSHb) gene expression in pituitary gonadotropes in a frequency-sensitive manner that is central to reproductive physiology. The mechanisms underlying the preferential and paradoxical induction of FSHb by low frequency GnRH pulses are incompletely understood. Here, we identify growth differentiation factor 9 (GDF9) as a novel autocrine inducer of FSHb gene expression. GDF9 gene expression was preferentially suppressed by high frequency GnRH pulses due to reduced transcription. Exogenous GDF9 induced FSHb mRNA expression and knockdown or immunoneutralization of GDF9 reduced FSHb gene expression. Treatment with GDF9 stimulated Smad2/3 phosphorylation. The activin receptor-like kinase (ALK) receptor inhibitor SB-505124 antagonized GDF9-induced Smad2/3 phosphorylation and FSHb mRNA induction. Smad2 and Smad3 knockdown studies indicated that the induction of FSHb by GDF9 involves both Smad2 and Smad3. GDF9 and GnRH synergistically induced FSHb mRNA expression and high frequency GnRH pulses suppressed GDF9. We hypothesized that GDF9 contributes to a regulatory loop that tunes the GnRH frequency-response characteristics of the FSHb gene. To test this, we determined the effects of GDF9 knockdown on FSHb induction at different GnRH pulse frequencies using a parallel perifusion system. Reduction of GDF9 shifted the characteristic pattern of GnRH pulse frequency sensitivity. These results identify GDF9 as contributing to an incoherent feed-forward loop, comprised of both intracellular and secreted elementscomponents, that regulates FSHb expression in response to activation of the cell surface GnRH receptor. LbT2 microarray datasets as well as RNA-Seq data (GSE42120) were interrogated to determine the levels of expression of ALK4/5/7. LM-NM-2T2 cells were transfected with either scrambled siRNA or Gas siRNA for 48 h. RNA samples were snap-frozen in dry ice prior to whole-genome expression profiling analysis using MouseWG-6 v2.0 Expression BeadChip (Illumina, San Diego, CA). A total of 6 concentrated conditioned media samples were independently prepared: 3 replicates from control siRNA-treated cells, and 3 replicates from Gas siRNA-treated cells. This submission represents the microarray component of study.
Project description:Gonadotropin-releasing hormone (GnRH) is secreted in brief pulses from the hypothalamus. GnRH regulates follicle-stimulating hormone b-subunit (FSHb) gene expression in pituitary gonadotropes in a frequency-sensitive manner that is central to reproductive physiology. The mechanisms underlying the preferential and paradoxical induction of FSHb by low frequency GnRH pulses are incompletely understood. Here, we identify growth differentiation factor 9 (GDF9) as a novel autocrine inducer of FSHb gene expression. GDF9 gene expression was preferentially suppressed by high frequency GnRH pulses due to reduced transcription. Exogenous GDF9 induced FSHb mRNA expression and knockdown or immunoneutralization of GDF9 reduced FSHb gene expression. Treatment with GDF9 stimulated Smad2/3 phosphorylation. The activin receptor-like kinase (ALK) receptor inhibitor SB-505124 antagonized GDF9-induced Smad2/3 phosphorylation and FSHb mRNA induction. Smad2 and Smad3 knockdown studies indicated that the induction of FSHb by GDF9 involves both Smad2 and Smad3. GDF9 and GnRH synergistically induced FSHb mRNA expression and high frequency GnRH pulses suppressed GDF9. We hypothesized that GDF9 contributes to a regulatory loop that tunes the GnRH frequency-response characteristics of the FSHb gene. To test this, we determined the effects of GDF9 knockdown on FSHb induction at different GnRH pulse frequencies using a parallel perifusion system. Reduction of GDF9 shifted the characteristic pattern of GnRH pulse frequency sensitivity. These results identify GDF9 as contributing to an incoherent feed-forward loop, comprised of both intracellular and secreted elementscomponents, that regulates FSHb expression in response to activation of the cell surface GnRH receptor. LbT2 microarray datasets as well as RNA-Seq data (GSE42120) were interrogated to determine the levels of expression of ALK4/5/7.
Project description:The transcriptional program underlying neuronal apoptosis and survival has to date been partially characterized. However, the complete spectrum of genes/proteins as well as the ‘regulatory software’ controlling neuronal fate decisions remain almost entirely unknown. Here, for the first time, we characterized the earliest molecular events following the induction of neuronal apoptosis and its rescue by three potent anti-apoptotic growth factors (GFs), in order to identify key genes and upstream regulators primarily responsible for driving execution of these processes. A core set of 175 survival-related genes (SRGs) with opposite transcriptional signatures between apoptosis and GF-mediated survival was identified. Promoter motif analysis of SRGs revealed a repertoire of intrinsic upstream regulators that may drive the apoptotic/survival switch, with Hoxd9 predicted to be the master regulator. Finally, the clinical implication of SRGs in the pathogenesis of neurological and neuropsychiatric diseases, here emerged, suggested their potential utility as targets for treating these severe disorders.
Project description:We describe a novel method for obtaining discrete regions from the fronto-limbic circuits of a 4 year old and a 5 year old, male, intact, frozen non-human primate (NHP) brain, from which we use transcriptional profiling and a new algorithm to identify region-exclusive RNA signatures for Area 25 (NFκB and dopamine receptor signaling), the anterior cingulate cortex (LXR/RXR signaling), the amygdala (semaphorin signaling), and the hippocampus (Caþþ and retinoic acid signaling).
Project description:Roblitz2013 - Menstrual Cycle following GnRH analogue administration
The model describes the menstrual cycle feedback mechanisms. GnRH, FSH, LH, E2, P4, inbibins A and B, and follicular development are modelled. The model predicts hormonal changes following GnRH analogue administration. Simulation results agree with measurements of hormone blood concentrations. The model gives insight into mechanisms underlying gonadotropin supression.
This model is described in the article:
A mathematical model of the human menstrual cycle for the administration of GnRH analogues.
Röblitz S, Stötzel C, Deuflhard P, Jones HM, Azulay DO, van der Graaf PH, Martin SW.
J. Theor. Biol. 2013 Mar; 321: 8-27
Abstract:
The paper presents a differential equation model for the feedback mechanisms between gonadotropin-releasing hormone (GnRH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), development of follicles and corpus luteum, and the production of estradiol (E2), progesterone (P4), inhibin A (IhA), and inhibin B (IhB) during the female menstrual cycle. Compared to earlier human cycle models, there are three important differences: The model presented here (a) does not involve any delay equations, (b) is based on a deterministic modeling of the GnRH pulse pattern, and (c) contains less differential equations and less parameters. These differences allow for a faster simulation and parameter identification. The focus is on modeling GnRH-receptor binding, in particular, by inclusion of a pharmacokinetic/pharmacodynamic (PK/PD) model for a GnRH agonist, Nafarelin, and a GnRH antagonist, Cetrorelix, into the menstrual cycle model. The final mathematical model describes the hormone profiles (LH, FSH, P4, E2) throughout the menstrual cycle of 12 healthy women. It correctly predicts hormonal changes following single and multiple dose administration of Nafarelin or Cetrorelix at different stages in the cycle.
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