PTEN loss or PI3K/AKT signaling pathway activation correlates with human prostate cancer progression and metastasis. However, in preclinical murine models, deletion of Pten alone fails to mimic the significant metastatic burden that frequently accompanies the end stage of human disease. To identify additional pathway alterations that cooperate with PTEN loss in prostate cancer progression, we surveyed human prostate cancer tissue microarrays and found that the RAS/MAPK pathway is significantly elevated both in primary and metastatic lesions. In an attempt to model this event, we crossed conditional activatable K-rasG12D/WT mice with the prostate conditional Pten deletion model we previously generated. Although RAS activation alone cannot initiate prostate cancer development, it significantly accelerated progression caused by PTEN loss, accompanied by epithelial-to-mesenchymal transition (EMT) and macrometastasis with 100% penitence. A novel stem/progenitor subpopulation with mesenchymal characteristics was isolated from the compound mutant prostates, which was highly metastatic upon orthotopic transplantation. Importantly, inhibition of RAS/MAPK signaling by PD325901, a MEK inhibitor, significantly reduced the metastatic progression initiated from transplanted stem/progenitor cells. Collectively, these data indicate that activation of RAS/MAPK signaling serves as a potentiating second hit to alteration of the PTEN/PI3K/AKT axis and co-targeting both pathways is highly effective in preventing the development of metastatic prostate cancers.
Pten loss and RAS/MAPK activation cooperate to promote EMT and metastasis initiated from prostate cancer stem/progenitor cells.
Specimen part
View SamplesAlteration of the PTEN/PI3K pathway is associated with late stage and castrate resistant prostate cancer (CRPC). However, how PTEN loss involves in CRPC development is not clear. Here we show that castration-resistant growth is an intrinsic property of Pten-null prostate cancer (CaP) cells, independent of cancer development stage.PTEN loss suppresses androgen-responsive gene expressions by modulating androgen receptor (AR) transcription factor activity. Conditional deletion of AR in the epithelium promotes the proliferation of Pten-null cancer cells, at least in part, by down-regulating androgen-responsive gene FKBP5 and preventing PHLPP-mediated AKT inhibition. Our findings identify PI3K and AR pathway crosstalk as a mechanism of CRPC development, with potentially important implications for CaP etiology and therapy
Cell autonomous role of PTEN in regulating castration-resistant prostate cancer growth.
Specimen part, Time
View SamplesPI3K (phosphoinositide 3-kinase)/AKT and RAS/MAPK (mitogen-activated protein kinase) pathway coactivation in the prostate epithelium promotes both epithelial–mesenchymal transition (EMT) and metastatic castration-resistant prostate cancer (mCRPC), which is currently incurable. To study the dynamic regulation of the EMT process, we developed novel genetically defined cellular and in vivo model systems from which epithelial, EMT and mesenchymal-like tumor cells with Pten deletion and Kras activation can be isolated. When cultured individually, each population has the capacity to regenerate all three tumor cell populations, indicative of epithelial–mesenchymal plasticity. Despite harboring the same genetic alterations, mesenchymal-like tumor cells are resistant to PI3K and MAPK pathway inhibitors, suggesting that epigenetic mechanisms may regulate the EMT process, as well as dictate the heterogeneous responses of cancer cells to therapy. Among differentially expressed epigenetic regulators, the chromatin remodeling protein HMGA2 is significantly upregulated in EMT and mesenchymal-like tumors cells, as well as in human mCRPC. Knockdown of HMGA2, or suppressing HMGA2 expression with the histone deacetylase inhibitor LBH589, inhibits epithelial–mesenchymal plasticity and stemness activities in vitro and markedly reduces tumor growth and metastasis in vivo through successful targeting of EMT and mesenchymal-like tumor cells. Importantly, LBH589 treatment in combination with castration prevents mCRPC development and significantly prolongs survival following castration by enhancing p53 and androgen receptor acetylation and in turn sensitizing castration-resistant mesenchymal-like tumor cells to androgen deprivation therapy. Taken together, these findings demonstrate that cellular plasticity is regulated epigenetically, and that mesenchymal-like tumor cell populations in mCRPC that are resistant to conventional and targeted therapies can be effectively treated with the epigenetic inhibitor LBH589. Overall design: RNA was extracted from pooled Epithelial, EMT and Mesenchymal-like tumor cells isolated by FACS sorting CD45-CD31-Ter119-EpCAM+GFP-, CD45-CD31-Ter119-EpCAM+GFP+, and CD45-CD31-Ter119-EpCAM-GFP+ cells, respectively, from the prostates of 10-12 week old Pb-Cre+/-;PtenL/L;KrasG12D/+;Vim-GFP (CPKV) mice (n=17) and separated into two technical replicates. Paired-end sequencing data with read lengths of 100 bp were generated using the Illumina HiSeq2000 system.
HDAC inhibition impedes epithelial-mesenchymal plasticity and suppresses metastatic, castration-resistant prostate cancer.
No sample metadata fields
View SamplesTo probe the tissue source (cancer cell VS stromal cell) of gene expression in the mixed tumor samples, we took advantage of a set of Urothelial Cancer patient-derived xenograft (PDX) models given that the transcriptome in these models is a mixture of human RNA (derived from cancer cells) and mouse RNA (derived from stromal cells). Overall design: The cohort includes 5 different patient-derived PDX models, 3 replicates for each model, and thus a total of 15 samples
EMT- and stroma-related gene expression and resistance to PD-1 blockade in urothelial cancer.
Subject
View SamplesMesenchymal stromal cells (MSC) are crucial components of the bone marrow (BM) microenvironment essential for regulating self-renewal, survival and differentiation of hematopoietic stem/progenitor cells (HSPC) in the stem cell niche. MSC are functionally and phenotypically altered in myelodysplastic syndromes (MDS), contributing to disease progression. MDS MSC do not harbor recurrent genetic alterations but have been shown to exhibit an altered methylome compared to MSC from healthy controls. We examined growth, differentiation and HSPC-supporting capacity of ex vivo expanded MSC from MDS patients in comparison to age-matched healthy controls after direct treatment in vitro with the hypomethylating agent azacitidine (AZA). We show that AZA exerts a direct effect on MSC by modulating their differentiation potential. Osteogenesis was significantly boosted in healthy MSC while adipogenesis was inhibited in both healthy and MDS MSC. In co-culture experiments, both AZA treated MDS MSC and healthy MSC exhibited enhanced support of non-clonal HSPC which was associated with increased cell cycle induction. Conversely, clonal MDS HSPC were inhibited by contact with AZA treated MSC. RNA-sequencing analyses of stromal cells revealed changes in pathways essential for HSPC support as well as in immune regulatory pathways. In sum, our data demonstrate that AZA treatment of stromal cells leads to upregulation of HSPC-supportive genes and cell cycle induction in co-cultured healthy HSPC, resulting in a proliferative advantage over clonal HSPC. Thus, restoration of functional hematopoiesis by AZA may be driven by activated stromal support factors in MSC providing cell cycle cues to healthy HSPC. Overall design: RNA sequencing was performed on a mesenchymal stromal cell line (EL08-1D2), either untreated or treated with Azacitidine [(-)AZA vs. (+)AZA].
Direct modulation of the bone marrow mesenchymal stromal cell compartment by azacitidine enhances healthy hematopoiesis.
Treatment, Subject
View SamplesIsocitrate dehydrogenase 1 mutations drive human gliomagenesis, probably through neomorphic enzyme activity that produces D-2-hydroxyglutarate. To model this disease, we conditionally expressed Idh1R132H in the subventricular zone (SVZ) of the adult mouse brain. The mice developed hydrocephalus and grossly dilated lateral ventricles, with accumulation of 2-hydroxyglutarate and reduced -ketoglutarate. Stem and transit amplifying/progenitor cell populations were expanded, and proliferation increased.Cells expressing SVZ markers infiltrated surrounding brain regions. SVZ cells also gave rise to proliferative subventricular nodules. DNA methylation was globally increased, while hydroxymethylation was decreased. Mutant SVZ cells over-expressed Wnt, cell cycle and stem cell genes, and shared an expression signature with human gliomas. Idh1R132H mutation in the major adult neurogenic stem cell niche causes a phenotype resembling gliomagenesis. Isocitrate dehydrogenase 1 mutations drive human gliomagenesis, probably through neomorphic enzyme activity that produces D-2-hydroxyglutarate. To model this disease, we conditionally expressed Idh1R132H in the subventricular zone (SVZ) of the adult mouse brain. The mice developed hydrocephalus and grossly dilated lateral ventricles, with accumulation of 2-hydroxyglutarate and reduced -ketoglutarate. Stem and transit amplifying/progenitor cell populations were expanded, and proliferation increased. Cells expressing SVZ markers infiltrated surrounding brain regions. SVZ cells also gave rise to proliferative subventricular nodules. DNA methylation was globally increased, while hydroxymethylation was decreased. Mutant SVZ cells over-expressed Wnt, cell cycle and stem cell genes, and shared an expression signature with human gliomas. Idh1R132H mutation in the major adult neurogenic stem cell niche causes a phenotype resembling gliomagenesis.
Expression of Idh1<sup>R132H</sup> in the Murine Subventricular Zone Stem Cell Niche Recapitulates Features of Early Gliomagenesis.
Sex, Age, Specimen part
View SamplesIschaemic preconditioning is a method of protecting tissue against ischaemia-reperfusion injury. It is an innate protective mechanism that increases a tissue's tolerance to prolonged ischaemia when it is first subjected to short burst of ischaemia and reperfusion. It is thought to provide this protection by increasing the tissue's tolerance to ischaemia, therby reducing oxidative stress, inflammation and apoptosis in the preconditioned tissue.
Transcriptional responses in the adaptation to ischaemia-reperfusion injury: a study of the effect of ischaemic preconditioning in total knee arthroplasty patients.
Specimen part, Time
View SamplesIn this experiments different treatments were applied to lung cancer cell lines
Ingenuity network-assisted transcription profiling: Identification of a new pharmacologic mechanism for MK886.
No sample metadata fields
View SamplesHuh7/5-2 cells (Binder et al., Hepatology 2007) were mock infected (DMEM) (time points 4 and 48 h) or infected with the chimeric HCV virus Jc1 (Pietschmann et al., PNAS 2006) (all time points).
Viral immune modulators perturb the human molecular network by common and unique strategies.
Specimen part, Time
View SamplesNeuronal differentiation of PC12 cells in response to NGF is a prototypical model in which signal duration determines a biological response. Sustained ERK activity induced by NGF, as compared to transient activity induced by EGF, is critical to the differentiation of these cells. To characterize the transcriptional program activated preferentially by NGF, we compared global gene expression profiles between cells treated with NGF and EGF for 2-4 hrs, when sustained ERK signaling in response to NGF is most distinct from the transient signal elicited by EGF. This analysis identified 69 genes that were preferentially upregulated in response to NGF.
Global expression analysis identified a preferentially nerve growth factor-induced transcriptional program regulated by sustained mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) and AP-1 protein activation during PC12 cell differentiation.
Specimen part, Cell line, Time
View Samples