Project description:Dataset containing multiple Hyptis and Artemisia spp. used for the discovery of natural products inhibiting aberrant signaling, namely MAPK/ERK and PI3K/AKT, in melanoma
Project description:Lineage transformation between lung cancer subtypes is a poorly understood phenomenon associated with resistance to treatment and poor patient outcomes. Here, we aimed to model this transition in order to define underlying biological mechanisms and identify potential avenues for therapeutic intervention. Small cell lung cancer (SCLC) is neuroendocrine in origin and, in contrast to non-SCLC (NSCLC), rarely contains mutations that drive the MAPK pathway. Likewise, NSCLCs that transform to SCLC concomitantly with development of therapy resistance downregulate MAPK signaling, suggesting an inverse relationship between pathway activation and lineage state. To test this, we activated MAPK in SCLC through conditional expression of mutant KRAS or EGFR, which revealed suppression of the neuroendocrine differentiation program via ERK. We found that ERK induces the expression of ETS factors, phenocopying ERK-mediated effects on transformation into the NSCLC-like phenotype. ATAC-seq demonstrated ERK-driven changes in chromatin accessibility at putative regulatory regions and global chromatin rewiring at neuroendocrine and ETS transcriptional targets. Further, induction of ETS factors as well as suppression of neuroendocrine differentiation were dependent on histone acetyltransferase activities of CBP/p300. Overall, we describe how the ERK-CBP/p300-ETS axis promotes a lineage shift between neuroendocrine and non-neuroendocrine lung cancer phenotypes and provide rationale for the disruption of this program during transformation-driven resistance to targeted therapy.
Project description:Cursons2015 - Regulation of ERK-MAPK
signaling in human epidermis
Model comparing the abundance of
phosphorylated MAPK signalling proteins and calcium signalling in
the epidermis.
This model is described in the article:
Regulation of ERK-MAPK
signaling in human epidermis.
Cursons J, Gao J, Hurley DG, Print
CG, Dunbar PR, Jacobs MD, Crampin EJ.
BMC Syst Biol 2015; 9: 41
Abstract:
The skin is largely comprised of keratinocytes within the
interfollicular epidermis. Over approximately two weeks these
cells differentiate and traverse the thickness of the skin. The
stage of differentiation is therefore reflected in the
positions of cells within the tissue, providing a convenient
axis along which to study the signaling events that occur in
situ during keratinocyte terminal differentiation, over this
extended two-week timescale. The canonical ERK-MAPK signaling
cascade (Raf-1, MEK-1/2 and ERK-1/2) has been implicated in
controlling diverse cellular behaviors, including proliferation
and differentiation. While the molecular interactions involved
in signal transduction through this cascade have been well
characterized in cell culture experiments, our understanding of
how this sequence of events unfolds to determine cell fate
within a homeostatic tissue environment has not been fully
characterized.We measured the abundance of total and
phosphorylated ERK-MAPK signaling proteins within
interfollicular keratinocytes in transverse cross-sections of
human epidermis using immunofluorescence microscopy. To
investigate these data we developed a mathematical model of the
signaling cascade using a normalized-Hill differential equation
formalism.These data show coordinated variation in the
abundance of phosphorylated ERK-MAPK components across the
epidermis. Statistical analysis of these data shows that
associations between phosphorylated ERK-MAPK components which
correspond to canonical molecular interactions are dependent
upon spatial position within the epidermis. The model
demonstrates that the spatial profile of activation for
ERK-MAPK signaling components across the epidermis may be
maintained in a cell-autonomous fashion by an underlying
spatial gradient in calcium signaling.Our data demonstrate an
extended phospho-protein profile of ERK-MAPK signaling cascade
components across the epidermis in situ, and statistical
associations in these data indicate canonical ERK-MAPK
interactions underlie this spatial profile of ERK-MAPK
activation. Using mathematical modelling we have demonstrated
that spatially varying calcium signaling components across the
epidermis may be sufficient to maintain the spatial profile of
ERK-MAPK signaling cascade components in a cell-autonomous
manner. These findings may have significant implications for
the wide range of cancer drugs which therapeutically target
ERK-MAPK signaling components.
This model is hosted on
BioModels Database
and identified by:
BIOMD0000000659.
To cite BioModels Database, please use:
Chelliah V et al. BioModels: ten-year
anniversary. Nucl. Acids Res. 2015, 43(Database
issue):D542-8.
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:Fgf signaling via Erk activation has been associated with both neural induction and the generation of a primed state for the differentiation of embryonic stem cells (ESCs) to all somatic lineages. To dissect the role of Erk in both ESC self-renewal and lineage specification we explore the requirements for this pathway in various in vitro differentiation settings. A combination of pharmacological inhibition of Erk signaling and genetic loss of function experiments reveal a role for Erk signaling in suppressing endodermal differentiation, but not neural specification. Activation of Erk signaling in ESCs de-represses primitive endoderm (PrE) gene expression as a consequence of inhibiting the pluripotent/epiblast network. The early response to Erk activation correlates with functional PrE priming while sustained Erk activity results in PrE differentiation. Taken together, our results suggest that Erk signaling suppresses pluripotent gene expression to enable endodermal differentiation. We use microarray analysis to determine the transcription response to Erk1/2 in mouse embryonic stem cells across a 24 hour window of time Mouse ESCs carrying a tamoxifen inducible constitutively active c-Raf fusion protein were stimulated for 6 time points (30minutes, 1 hour, 2 hours, 4 hours, 8 hours, and 24 hours) in the presence of 250nM PD173074. Uninduced (0h hours) and DMSO only treated cells served as controls.
Project description:During gastrulation, dynamic interplay among cell signaling pathways dictates cell fate decisions. While extensive studies have elucidated their critical roles in morphological regulation, how these signals orchestrate the epigenome to confer developmental competence remains unclear. In this study, we demonstrate that H3K9me3-marked facultative heterochromatin domains undergo global reorganization during differentiation of human pluripotent stem cells (hPSCs) into mesendoderm (ME) and definitive endoderm (DE), which arise through epithelial-mesenchymal transition (EMT), but not into early neural ectoderm (NE), which retains epithelial state. We identify the MAPK/ERK pathway, acting downstream of FGF signaling, as a key mediator of this reorganization within a critical temporal window during hPSC-to-ME differentiation. Mechanistically, phosphorylated-ERK is enriched across chromatin domains spanning key developmental gene loci and exhibits a reciprocal genomic pattern with H3K9me3, which becomes ectopically accumulated upon MAPK/ERK inhibition. Furthermore, using CRISPRi-mediated perturbation of H3K9me3 methyltransferases, we reveal that proper establishment of H3K9me3 domains plays a dual role in repressing off-target genes and enabling robust activation of lineage-specific programs. Collectively, our findings reveal a previously unrecognized role for MAPK/ERK signaling in reorganizing the H3K9me3 landscape to confer developmental competence, providing mechanistic insight into how signaling pathways shape the epigenetic landscape during development.
Project description:During gastrulation, dynamic interplay among cell signaling pathways dictates cell fate decisions. While extensive studies have elucidated their critical roles in morphological regulation, how these signals orchestrate the epigenome to confer developmental competence remains unclear. In this study, we demonstrate that H3K9me3-marked facultative heterochromatin domains undergo global reorganization during differentiation of human pluripotent stem cells (hPSCs) into mesendoderm (ME) and definitive endoderm (DE), which arise through epithelial-mesenchymal transition (EMT), but not into early neural ectoderm (NE), which retains epithelial state. We identify the MAPK/ERK pathway, acting downstream of FGF signaling, as a key mediator of this reorganization within a critical temporal window during hPSC-to-ME differentiation. Mechanistically, phosphorylated-ERK is enriched across chromatin domains spanning key developmental gene loci and exhibits a reciprocal genomic pattern with H3K9me3, which becomes ectopically accumulated upon MAPK/ERK inhibition. Furthermore, using CRISPRi-mediated perturbation of H3K9me3 methyltransferases, we reveal that proper establishment of H3K9me3 domains plays a dual role in repressing off-target genes and enabling robust activation of lineage-specific programs. Collectively, our findings reveal a previously unrecognized role for MAPK/ERK signaling in reorganizing the H3K9me3 landscape to confer developmental competence, providing mechanistic insight into how signaling pathways shape the epigenetic landscape during development.
Project description:Fgf signaling via Erk activation has been associated with both neural induction and the generation of a primed state for the differentiation of embryonic stem cells (ESCs) to all somatic lineages. To dissect the role of Erk in both ESC self-renewal and lineage specification we explore the requirements for this pathway in various in vitro differentiation settings. A combination of pharmacological inhibition of Erk signaling and genetic loss of function experiments reveal a role for Erk signaling in suppressing endodermal differentiation, but not neural specification. Activation of Erk signaling in ESCs de-represses primitive endoderm (PrE) gene expression as a consequence of inhibiting the pluripotent/epiblast network. The early response to Erk activation correlates with functional PrE priming while sustained Erk activity results in PrE differentiation. Taken together, our results suggest that Erk signaling suppresses pluripotent gene expression to enable endodermal differentiation. We use microarray analysis to determine the transcription response to Erk1/2 in mouse embryonic stem cells across a 24 hour window of time
Project description:HNRNPA2B1, an RNA-binding protein, plays a key role in primary microRNA processing, alternative splicing, mRNA metabolism and transport. Interestingly, hnRNPA2B1 also works as an N6-methyladenosine(m6A) reader and is critical during tumorigenesis of various tissue types. However, its role in colon cancer is still unclear. In this study, we aimed to elucidate the biological functions of hnRNPA2B1 and to explore its underlying mechanisms in colon cancer. Methods We examined the expression of hnRNPA2B1 in Oncomine and TCGA databases. Then verified the findings in colon cancer cells and clinical samples with western blotting and immunohistochemistry (IHC). We used CRISPR/Cas9 directed gene editing to knockout hnRNPA2B1 expression in human colon cancer cell line SW480 and carried out both in vivo and in vitro experiments. The results were further confirmed by RNA-seq analysis. We found that hnRNPA2B1 significantly promoted colon cancer cell proliferation both in vitro and in vivo, while knockout of hnRNPA2B1 induced apoptosis and cell cycle arrest in SW480. RNA-seq analysis revealed that the ERK/MAPK pathway was activated by hnRNPA2B1 upregulation. In addition, both hnRNPA2B1 and MAPK pathway were activated in clinical colon cancer specimens and positively correlated. Mechanistically, hnRNPA2B1 appeared to be an upstream regulator of the ERK/MAPK pathway and inhibition of MAPK signaling blocked the effects of hnRNPA2B1. Taken together, our data demonstrated that the RNA-binding protein hnRNPA2B1 promotes cell proliferation and regulates cell cycle and apoptosis of human colon cancer by activating the ERK/MAPK signaling, which may provide a new insight into the development of hnRNPA2B1 as a potential therapeutic target for treatment of colon cancer.
Project description:Mitogen activated protein kinase (MAPK) signaling regulates differentiation of many cell types. During myogenesis in particular, p38a MAPK (MAPK14) phosphorylates multiple transcriptional regulators to modulate muscle-specific gene expression. Among the p38a MAPK modulated genes is the muscle-specific transcriptional regulator Myogenin (Myog) that is also essential to complete the muscle differentiation program, and while it is known that both p38a MAPK and Myog are critically required for myogenesis, the individual contribution of each of these proteins is poorly defined. Here we show that Myog expression (in the absence of p38a MAPK signaling) is sufficient to establish expression of many late markers of muscle differentiation and to mediate cell migration. However, Myog expression alone did not led to the formation of multinucleated muscle cells, highlighting a critical role for p38a MAPK in myoblast fusion. Using comparative microarray analysis we identified p38a MAPK-dependent genes that are not regulated by Myog We generated a stable C2C12-derived cell line (C2i-Myog) that expresses a Doxycycline (Dox)-inducible cDNA encoding Flag-tagged Myog. In this system, the chemical induction of exogenous Myog (Dox) combined with the pharmacological inhibition of p38a/b MAPK signaling by SB203580 (SB) would allow us to assess the functional contribution of these two pathways during myogenesis