Project description:TMPRSS2-ERG gene fusions that are frequently identified in prostate cancer can be generated either through chromosomal translocation or via interstitial deletion. The latter mechanism deletes an interstitial region of ~3Mb and it remains largely unanswered whether genes deleted within this region contribute to prostate cancer. By characterizing two knockin mouse models recapitulating TMPRSS2-ERG fusions with or without the interstitial deletion, we found that only those with deletion developed poorly differentiated adenocarcinomas with epithelial-to-mesenchymal transition, when under a Pten-null background. We identified several interstitial genes, including ETS2 and BACE2, whose reduced expression correlates with worse disease-free survival and lethal disease. By using an Ets2 conditional knockout allele, we demonstrated that loss of one copy of Ets2 was sufficient for prostate cancer progression when under a Pten-null background. Collectively, our data suggest that ETS2 is a prostate tumor suppressor and haploinsufficiency of one or more interstitial genes contributes to prostate cancer progression.
Project description:A neuronal PI(3,4,5)P3-dependent program of oligodendrocyte precursor recruitment and myelination was identified in mice that conditionally lack PTEN in cerebellar granular cells (PTEN cKO) Expression analysis was performed with RNA obtained selectively from cerebellar granular cell layer of PTEN conditional null mutants and controls
Project description:RNA-seq was carried out on prostate tumors from mice with prostate-conditional PTEN knockout with and without prostate-conditional FOXP1-SHQ1 locus deletion (12 month old PTEN-flox/flox Pb-Cre4 mice and FOXP1-SHQ1-flox/flox PTEN-flox/flox Pb-Cre4 mice )
Project description:Recurrent point mutations in SPOP define a distinct molecular subclass of prostate cancer. Here, we describe the first mouse model showing that mutant SPOP drives prostate tumorigenesis in vivo. Conditional expression of mutant SPOP in the prostate dramatically altered phenotypes in the setting of Pten loss, with early neoplastic lesions (high-grade prostatic intraepithelial neoplasia) with striking nuclear atypia, and invasive poorly differentiated carcinoma. In mouse prostate organoids, mutant SPOP drove increased proliferation and a transcriptional signature consistent with human prostate cancer. Using these models and human prostate cancer samples, we show that SPOP mutation activates both PI3K/mTOR and androgen receptor (AR) signaling, effectively uncoupling the normal negative feedback between these two pathways. Associated RNA-seq data deposited in GEO: GSE94839.
Project description:Mutations in the PTEN, TP53 and RB1 pathways are obligate events in the pathogenesis of human glioblastomas, the highest grade of astrocytoma. To investigate synergy between these tumor suppressors in mice, we induced various combinations of compound deletions conditionally in astrocytes and neural precursors in the mature brain. The resulting highly penetrant astrocytomas showed a spectrum of histopathological variation reminiscent of human tumors, and ranged from grade III to grade IV (glioblastoma). Secondary somatic mutations varied depending on the combination of initiating deletions and were relevant to human disease. Receptor tyrosine kinase amplifications were frequent in tumors initiated by combined conditional deletion of Pten and Tp53, but not when Rb, Pten and Tp53 were simultaneously deleted. Multiple mutations within PI3K and Rb pathways were acquired, however, Mapk activation was not consistently detected in astrocytomas. Gene expression profiling revealed striking similarities to previously described human astrocytoma subclasses. A subset of astrocytomas initiated outside of proliferative niches in the adult brain. Gene expression of 8 human brain samples including 2 normal brainstem and 6 brainstem low-grade gliomas were profiled using HG-U133 plus 2 arrays. Gene expression of 38 mouse tumor samples, including 24 Pten;p53 double knockout and 14 Pten;p53;Rb1 triple knockout, were profiled using Affymetrix Mouse Genome 430 v2 arrays. Copy number changes of 51 double knockout tumor samples were analysed using Roswell Park Cancer Institute 6.5k BAC arrays. Copy number changes of 21 triple knockout tumor samples were analysed using Agilent mouse genome CGH mocirarray 244A.