Project description:Neuroendocrine prostate cancer (NEPC) is proliferative, invasive, and untreatable. Its molecular pathogenesis remains poorly understood but appears to require TP53 and RB1 aberration. In this study we modeled the development of NEPC from conventional prostatic adenocarcinoma using a unique patient-derived xenograft and identified up-regulation of the placental gene PEG10. We found that the androgen receptor and the E2F/RB pathway dynamically regulate distinct post-transcriptional and post-translational isoforms of PEG10 at different stages of NEPC development. In vitro, PEG10 promoted cell cycle progression from G0/G1 in the context of TP53 loss, and regulated Snail expression via TGF-β signaling to promote invasion. Finally we show in vivo proof of principal using antisense oligonucleotide that PEG10 is a novel therapeutic target for NEPC. Six patient-derived xenograft tumors from the LTL331 xenograft lineage (PMID: 24356420; http://www.livingtumorcentre.com/) after differing lengths of time post-host castration. No replicates.
Project description:Neuroendocrine prostate cancer (NEPC) is proliferative, invasive, and untreatable. Its molecular pathogenesis remains poorly understood but appears to require TP53 and RB1 aberration. In this study we modeled the development of NEPC from conventional prostatic adenocarcinoma using a unique patient-derived xenograft and identified up-regulation of the placental gene PEG10. We found that the androgen receptor and the E2F/RB pathway dynamically regulate distinct post-transcriptional and post-translational isoforms of PEG10 at different stages of NEPC development. In vitro, PEG10 promoted cell cycle progression from G0/G1 in the context of TP53 loss, and regulated Snail expression via TGF-? signaling to promote invasion. Finally we show in vivo proof of principal using antisense oligonucleotide that PEG10 is a novel therapeutic target for NEPC. 14 patient-derived xenograft tumors from the LTL331 xenograft lineage (PMID: 24356420; http://www.livingtumorcentre.com/) after differing lengths of time post-host castration. Three replicates present for days 1-3 post-host castration.
Project description:Neuroendocrine prostate cancer (NEPC) is proliferative, invasive, and untreatable. Its molecular pathogenesis remains poorly understood but appears to require TP53 and RB1 aberration. In this study we modeled the development of NEPC from conventional prostatic adenocarcinoma using a unique patient-derived xenograft and identified up-regulation of the placental gene PEG10. We found that the androgen receptor and the E2F/RB pathway dynamically regulate distinct post-transcriptional and post-translational isoforms of PEG10 at different stages of NEPC development. In vitro, PEG10 promoted cell cycle progression from G0/G1 in the context of TP53 loss, and regulated Snail expression via TGF-β signaling to promote invasion. Finally we show in vivo proof of principal using antisense oligonucleotide that PEG10 is a novel therapeutic target for NEPC.
Project description:Neuroendocrine prostate cancer (NEPC) is proliferative, invasive, and untreatable. Its molecular pathogenesis remains poorly understood but appears to require TP53 and RB1 aberration. In this study we modeled the development of NEPC from conventional prostatic adenocarcinoma using a unique patient-derived xenograft and identified up-regulation of the placental gene PEG10. We found that the androgen receptor and the E2F/RB pathway dynamically regulate distinct post-transcriptional and post-translational isoforms of PEG10 at different stages of NEPC development. In vitro, PEG10 promoted cell cycle progression from G0/G1 in the context of TP53 loss, and regulated Snail expression via TGF-β signaling to promote invasion. Finally we show in vivo proof of principal using antisense oligonucleotide that PEG10 is a novel therapeutic target for NEPC.
Project description:Peg10 (paternally expressed gene 10) is an imprinted gene that is essential for placental development (1). It is thought to derive from a Ty3-gyspy LTR (long terminal repeat) retrotransposon and retains Gag and Pol-like domains (2). Here we show that the Gag domain of PEG10 can promote vesicle budding similar to the HIV p24 Gag protein. Expressed in a subset of mouse endocrine organs in addition to the placenta, PEG10 was identified as a substrate of the deubiquitinating enzyme USP9X. Consistent with PEG10 having a critical role in placental development, PEG10-deficient trophoblast stem cells (TSCs) exhibited impaired differentiation into placental lineages. PEG10 expressed in wild-type, differentiating TSCs was bound to many cellular RNAs including Hbegf (Heparin-binding EGF-like growth factor), which is known to play an important role in placentation (3). Expression of Hbegf was reduced in PEG10-deficient TSCs suggesting that PEG10 might bind to and stabilize RNAs that are critical for normal placental development.