Project description:We performed tanscriptional profiling of ARPE19 and four isogenic transformed cells lines in which Ras or two downstream pathways, MAPK or PI3K/mTOR, were up-regulated. The purpose of this study is to understand how Ras signaling impacts kinetochore function.
Project description:Mitochondrial dysfunction causes biophysical, metabolic and signalling changes that alter homeostasis and reprogram cells. We used a Drosophila model in which TFAM is overexpressed in the nervous system with or without Ras/MAPK pathway inhibition, by knock-down of the ETS transcription factor pointed, to investigate the how mitochondrial dysfunction and Ras/MAPK signalling affect the transcriptome. We used microarray analysis to investigate gene expression in cases of mitochondrial dysfunction in the CNS with or without Ras/MAPK pathway inhibition by knock-down of pointed (Pnt) and anterior open (Aop).
Project description:Basal cell carcinomas (BCCs) rely on Hedgehog (HH) pathway growth signal amplification by the microtubule-based organelle, the primary cilium. Despite naïve tumors responsiveness to Smoothened inhibitors (Smoi), resistance in advanced tumors remains frequent. While the resistant BCCs usually maintain HH pathway activation, squamous cell carcinomas with Ras/MAPK pathway activation also arise, with the molecular basis of tumor type and pathway selection still obscure. Here we identify the primary cilium as a critical determinant controlling tumor pathway switching. Strikingly, Smoi-resistant BCCs possess an increased mutational load in ciliome genes, resulting in reduced primary cilia and HH pathway activation compared to naive or Gorlin patient BCCs. Gene set enrichment analysis of resistant BCCs with a low HH pathway signature reveals increased Ras/MAPK pathway activation. Tissue analysis confirms an inverse relationship between primary cilia presence and Ras/MAPK activation, and primary cilia removal in BCCs potentiates Ras/MAPK pathway activation. Moreover, activating Ras in HH-responsive cell lines confers resistance to both canonical (vismodegib) and non-canonical (aPKC and MRTF inhibitors) HH pathway inhibitors, while conferring sensitivity to MAPK inhibitors. Our results provide new insights into BCC treatment and identify the primary cilium as an important lineage gatekeeper, preventing HH to Ras/MAPK pathway switching.
Project description:Approximately 50% of prostate cancers have chromosomal translocations resulting in the over-expression one of four ETS family transcription factors. However, it is not known why these four four family members are selected for oncogenic roles, while other ETS proteins are not. We found that the four oncogenic ETS family members have a specific role in prostate cell migration. Using chromatin immunoprecipitation coupled with next-generation sequencing, this specific biological function was matched to a specific set of genomic targets highlighted by the presence of an AP-1 binding site. ETS/AP-1 binding sites are prototypical Ras-responsive elements, but oncogenic ETS proteins could activate a Ras/MAPK transcriptional program in the absence of MAPK activation. These findings indicate that the specific function of ETS proteins over-expressed in prostate cancer is the activation of a Ras/MAPK gene expression program in the absence of signaling pathway mutations. 16 samples were analyzed, comprised of four replicates each of four different biological conditions. RNA from U0126 treated RWPE-1 empty vector cell RNA serves as a control for each experiment. Cell lines have retroviral expression constructs expressing either empty vector, Flag-ERG, or Flag-ETV1.
Project description:Approximately 50% of prostate cancers have chromosomal translocations resulting in the over-expression one of four ETS family transcription factors. However, it is not known why these four four family members are selected for oncogenic roles, while other ETS proteins are not. We found that the four oncogenic ETS family members have a specific role in prostate cell migration. Using chromatin immunoprecipitation coupled with next-generation sequencing, this specific biological function was matched to a specific set of genomic targets highlighted by the presence of an AP-1 binding site. ETS/AP-1 binding sites are prototypical Ras-responsive elements, but oncogenic ETS proteins could activate a Ras/MAPK transcriptional program in the absence of MAPK activation. These findings indicate that the specific function of ETS proteins over-expressed in prostate cancer is the activation of a Ras/MAPK gene expression program in the absence of signaling pathway mutations. ChIP sequencing two transcription factors in PC3 cells, four transcription factors plus a FLAG control in RWPE-1 cells and input DNA sequencing from each cell line.
Project description:Approximately 50% of prostate cancers have chromosomal translocations resulting in the over-expression one of four ETS family transcription factors. However, it is not known why these four four family members are selected for oncogenic roles, while other ETS proteins are not. We found that the four oncogenic ETS family members have a specific role in prostate cell migration. Using chromatin immunoprecipitation coupled with next-generation sequencing, this specific biological function was matched to a specific set of genomic targets highlighted by the presence of an AP-1 binding site. ETS/AP-1 binding sites are prototypical Ras-responsive elements, but oncogenic ETS proteins could activate a Ras/MAPK transcriptional program in the absence of MAPK activation. These findings indicate that the specific function of ETS proteins over-expressed in prostate cancer is the activation of a Ras/MAPK gene expression program in the absence of signaling pathway mutations.
Project description:Approximately 50% of prostate cancers have chromosomal translocations resulting in the over-expression one of four ETS family transcription factors. However, it is not known why these four four family members are selected for oncogenic roles, while other ETS proteins are not. We found that the four oncogenic ETS family members have a specific role in prostate cell migration. Using chromatin immunoprecipitation coupled with next-generation sequencing, this specific biological function was matched to a specific set of genomic targets highlighted by the presence of an AP-1 binding site. ETS/AP-1 binding sites are prototypical Ras-responsive elements, but oncogenic ETS proteins could activate a Ras/MAPK transcriptional program in the absence of MAPK activation. These findings indicate that the specific function of ETS proteins over-expressed in prostate cancer is the activation of a Ras/MAPK gene expression program in the absence of signaling pathway mutations.