Project description:RAS proteins are key regulators of growth factor signaling. Here we show that deletion of all RAS genes in mouse embryonic stem cells (mES) leads to an overall reduction in protein translation, limits their long-term proliferative capacity and incapacitates them to differentiate. Deletion of ERF, a transcriptional repressor of the ETS family, rescues proliferation and differentiation of RAS-deficient mES cells and allows the development of teratomas lacking RAS genes. Upon RAS deletion, ERF translocates to the nucleus where it binds to multiple enhancers of key RAS targets suppressing their expression. We also reveal recurrent losses of ERF in cancer and show that ERF deficiency increases the resistance of cancer cells to pharmacological inhibition of the RAS pathway. In summary, we here reveal a central role for ERF in coordinating RAS signaling in pluripotent cells, and identify a synthetic viable interaction that bypasses the requirement for RAS proteins in mammalian cells.
Project description:RAS proteins are key regulators of growth factor signaling. Here we show that deletion of all RAS genes in mouse embryonic stem cells (mES) leads to an overall reduction in protein translation, limits their long-term proliferative capacity and incapacitates them to differentiate. Deletion of ERF, a transcriptional repressor of the ETS family, rescues proliferation and differentiation of RAS-deficient mES cells and allows the development of teratomas lacking RAS genes. Upon RAS deletion, ERF translocates to the nucleus where it binds to multiple enhancers of key RAS targets suppressing their expression. We also reveal recurrent losses of ERF in cancer and show that ERF deficiency increases the resistance of cancer cells to pharmacological inhibition of the RAS pathway. In summary, we here reveal a central role for ERF in coordinating RAS signaling in pluripotent cells, and identify a synthetic viable interaction that bypasses the requirement for RAS proteins in mammalian cells.
Project description:We show that reduced dosage of ERF, which encodes an inhibitory ETS transcription factor directly bound by ERK1/2 , causes complex craniosynostosis (premature fusion of the cranial sutures) in humans and mice. Features of this newly recognized clinical disorder include multiple suture synostosis, craniofacial dysmorphism, Chiari malformation and language delay. Mice with functional Erf reduced to ~30% of normal exhibit postnatal multisuture synostosis; by contrast, embryonic calvarial development appears mildly delayed. Using chromatin immunoprecipitation in mouse embryonic fibroblasts and high-throughput sequencing, we find that ERF binds preferentially to distal regulatory elements containing RUNX or AP1 motifs. This work identifies ERF as a novel regulator of osteogenic stimulation by RAS-ERK signaling, potentially by competing with activating ETS factors in multifactor transcriptional complexes. Examination of Erf binding site in E13.5 mouse embryo fibroblasts, growing in the presence or absence of serum for 4 hours
Project description:We show that reduced dosage of ERF, which encodes an inhibitory ETS transcription factor directly bound by ERK1/2 , causes complex craniosynostosis (premature fusion of the cranial sutures) in humans and mice. Features of this newly recognized clinical disorder include multiple suture synostosis, craniofacial dysmorphism, Chiari malformation and language delay. Mice with functional Erf reduced to ~30% of normal exhibit postnatal multisuture synostosis; by contrast, embryonic calvarial development appears mildly delayed. Using chromatin immunoprecipitation in mouse embryonic fibroblasts and high-throughput sequencing, we find that ERF binds preferentially to distal regulatory elements containing RUNX or AP1 motifs. This work identifies ERF as a novel regulator of osteogenic stimulation by RAS-ERK signaling, potentially by competing with activating ETS factors in multifactor transcriptional complexes.
Project description:Half of prostate cancers are caused by a gene-fusion that enables androgens to drive expression of the normally silent ETS transcription factor ERG in luminal prostate cells1-4. Recent prostate cancer genomic landscape studies5-10 have reported rare but recurrent point mutations in the ETS repressor ERF11. Here we show these ERF mutations cause decreased protein stability and ERF mutant tumours are mostly exclusive from those with ERG fusions. ERF loss recapitulates the morphologic and phenotypic features of ERG gain in primary mouse prostate tissue, including expansion of the androgen receptor (AR) transcriptional repertoire, and ERF has tumour suppressor activity in the same genetic background of PTEN loss that yields oncogenic activity by ERG. Furthermore, in a human prostate cancer model of ERG gain and wild-type ERF, ChIP-seq studies indicate that ERG inhibits the ability of ERF to bind DNA at consensus ETS sites. Consistent with a competition model, ERF loss rescues ERG-positive prostate cancer cells from ERG dependency. Collectively, these data provide evidence that the oncogenicity of ERG is mediated, in part, by displacement of ERF and raise the larger question of whether other gain-of-function oncogenic transcription factors might also inactivate endogenous tumour suppressors.
Project description:Half of prostate cancers are caused by a gene-fusion that enables androgens to drive expression of the normally silent ETS transcription factor ERG in luminal prostate cells1-4. Recent prostate cancer genomic landscape studies5-10 have reported rare but recurrent point mutations in the ETS repressor ERF11. Here we show these ERF mutations cause decreased protein stability and ERF mutant tumours are mostly exclusive from those with ERG fusions. ERF loss recapitulates the morphologic and phenotypic features of ERG gain in primary mouse prostate tissue, including expansion of the androgen receptor (AR) transcriptional repertoire, and ERF has tumour suppressor activity in the same genetic background of PTEN loss that yields oncogenic activity by ERG. Furthermore, in a human prostate cancer model of ERG gain and wild-type ERF, ChIP-seq studies indicate that ERG inhibits the ability of ERF to bind DNA at consensus ETS sites. Consistent with a competition model, ERF loss rescues ERG-positive prostate cancer cells from ERG dependency. Collectively, these data provide evidence that the oncogenicity of ERG is mediated, in part, by displacement of ERF and raise the larger question of whether other gain-of-function oncogenic transcription factors might also inactivate endogenous tumour suppressors.