Project description:Prostate cancer cell lines that express ERG acquire a neuron-like phenotype. The human prostate tumor cell line LNCap was transfected with lenti-ERG or control lenti-vector. Gene expression profiling was performed to establish the ERG-associated phenotype.
Project description:ERG is a transcriptional factor, which is recombined with promoter of TMPRSS2 and prominently overexpressed in half of human prostate cancers. The mechanisms of ERG-mediated oncogenesis are not completely understood. We performed an unbiased Mass Spectrometry screen for ERG-binding proteins and found that ERG binds to MTDH/SND1 protein complex in prostate cancer cells. We determined that ERG binds to the SND1/MTDH protein complex via SND1 and this interaction plays a critical role in ERG-mediated cancer.
Project description:Structural rearrangements leading to the TMPRSS2:ERG (T2E) fusion typify ~50% of prostate tumors and result in overexpression of the ERG transcription factor. Using T2E and non-T2E primary prostate tumors, we assessed the impact of ERG overexpression on chromatin by integrating ChIP-seq against H3K27ac, a chromatin modification found at active cis-regulatory elements, with paired genomic and expression data. We show that T2E tumors have a consistent and distinct cis-regulatory landscape to non-T2E tumors which drives their unique transcriptional profile. The T2E-specific cis-regulatory landscape is driven by ERG-mediated co-option of prostate master transcription factors HOXB13 and FOXA1 and is typified by Cluster Of Regulatory Elements (COREs) including one spreading into the ERG locus of the structurally rearranged allele. This gives rise to a cis-regulatory element within the rearranged ERG gene that contributes to ERG overexpression. The unique cis-regulatory landscape in T2E primary prostate tumors also reveals the activation of the NOTCH signalling pathway. Accordingly, chemical NOTCH pathway inhibition limited the invasive nature of T2E prostate cancer cells, revealing an actionable vulnerability against T2E prostate tumors. Taken together, our work delineates the role of ERG over-expression in co-opting master transcription factors to deploy a unique cis-regulatory landscape inducing a dependency on NOTCH signaling in T2E prostate tumors.
Project description:ERG overexpression is the most frequent molecular alteration in prostate cancer. We analyzed different stages of prostate cancer to identify genes that were coexpressed with ERG overexpression. In primary prostate tumors, it was shown that TDRD1 expression was the strongest correlated gene with ERG overexpression and we suggest TDRD1 as a direct ERG target gene.
Project description:We report the effects of ERG on prostate tumorigenesis, ERG-mediated oncogene addiction, and downstream AR signaling pathways. We determined that ERG facilitates AR-signaling and mediates transformation of prostate cells by maintaining coregulator complex formation at AR-bound sites across the genome.
Project description:The ETS transcription factor ERG is aberrantly expressed in approximately 50% of prostate tumors due to chromosomal rearrangements such as TMPRSS2/ERG. The ability of ERG to drive oncogenesis in prostate epithelial cells requires interaction with distinct co-activators, such as the RNA-binding protein EWS. Here, we find that ERG has both direct and indirect interactions with EWS, and the indirect interaction is mediated by the poly-A RNA-binding protein PABPC1. PABPC1 directly bound both ERG and EWS. ERG expression in prostate cells promoted PABPC1 localization to the nucleus and recruited PABPC1 to ERG/EWS binding sites in the genome. Knockdown of PABPC1 in prostate cells abrogated ERG-mediated phenotypes and decreased the ability of ERG to activate transcription. These findings define a complex including ERG and the RNA-binding proteins EWS and PABPC1 that represents a novel therapeutic target for ERG-positive prostate cancer and identify a novel nuclear role for PABPC1.
Project description:Transcription factors play a key role in the development of a number of cancers, and therapeutically targeting them has remained a challenge. In prostate cancer, the ETS transcription factor ERG is recurrently rearranged and likely plays a critical role in prostate oncogenesis. Here we identified a series of peptides from a phage-display library that interact specifically with the DNA binding domain of ERG. The interactive interface was mapped to 9-residues in the 3rd -helix of the ETS domain that is critical for ERG transcriptional activity. The peptides were found to efficiently disrupt ERG-mediated protein-protein interactions, transcription, DNA damage, and cell invasion, as well as attenuate ERG recruitment to target gene loci. Furthermore, a retroinverso peptidomimetic version of the peptide sequence suppressed tumor growth, intravasation, and metastasis in vivo. Taken together, our results demonstrate that transcription factors have specific residues important for protein-protein interactions and disrupting those critical interactions may be an effective therapeutic strategy. Prostate cancer cell line VCaP were treated with 10µM of RI-EIP1 or RI-muEIP1 for 48 hr
Project description:ERG overexpression is the most frequent molecular alteration in prostate cancer. We analyzed different stages of prostate cancer to identify genes that were coexpressed with ERG overexpression. In primary prostate tumors, it was shown that TDRD1 expression was the strongest correlated gene with ERG overexpression and we suggest TDRD1 as a direct ERG target gene.
Project description:ERG overexpression is the most frequent molecular alteration in prostate cancer. We analyzed different stages of prostate cancer to identify genes that were coexpressed with ERG overexpression. In primary prostate tumors, it was shown that TDRD1 expression was the strongest correlated gene with ERG overexpression and we suggest TDRD1 as a direct ERG target gene. 48 Prostate cancer samples from radical prostatectomies were included in this study. These samples contained more than 70% cancer and less than 30% stromal tissue. Each sample was analyzed once.
Project description:SND1 and its partner MTDH promote cancer and therapeutic resistance; however, the mechanisms responsible for their function and potential cooperation with other oncogenes are not completely understood. We report here that oncoprotein ERG binds to the SND1/MTDH protein complex via the Tudor domain of SND1. ERG is an ETS-domain transcriptional factor, which is recombined and overexpressed in approximately half of human prostate cancers. siRNA-mediated knockdowns and CRISPR-Cas9-mediated knockout of SND1 in human prostate epithelium cell lines revealed a critical role of SND1 in proliferation of ERG-overexpressing prostate epithelial cells. Transcriptional analysis of ERG-positive human prostate cancer cells demonstrated significant overlap between genes regulated by ERG and SND1. Mechanistically, we found that ERG promoted nuclear localization of SND1/MTDH. Significantly, forced nuclear localization of SND1 by addition of exogenous nuclear localization sequences (NLS) prominently increased its growth promoting function irrespective of the status of ERG expression. To determine if SND1 is necessary for prostate cancer tumorigenesis in vivo, we generated mice with prostate-epithelium-specific deletion of Snd1. We found that inactivation of Snd1 did not impact normal prostate gland homeostasis. However, prostate epithelium-specific deletion of Snd1 in autochthonous mouse model of prostate cancer (PB-Cre/ERG/PTENflox/flox mice) showed greatly reduced invasive cancer growth and tumor burden. Moreover, gene expression analysis revealed a significant overlap between in vivo prostate transcriptional signatures of ERG and Snd1. We conclude that SND1 plays a critical role in prostate tumorigenesis and targeting SND1 may represent a potential therapeutic target in prostate cancer.