Identification of PHLPP1 as a tumor suppressor reveals the role of feedback compensation in PTEN-mutant prostate cancer progression
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE30987 | GEO | 2011/08/17
SECONDARY ACCESSION(S): PRJNA146201
REPOSITORIES: GEO
Similar Datasets
Project description:Hyper-activation of the PI 3-Kinase/ AKT pathway is a driving force of many cancers. Here we identify the AKT-inactivating phosphatase PHLPP1 as a prostate tumor suppressor. We show that Phlpp1-loss causes neoplasia and, upon partial Pten-loss, carcinoma in mouse prostate. This genetic setting initially triggers a growth suppressive response via p53 and the Phlpp2 ortholog, and reveals spontaneous Trp53 inactivation as a condition for full-blown disease. Surprisingly, the co-deletion of PTEN and PHLPP1 in patient samples is highly restricted to metastatic disease and tightly correlated to deletion of TP53 and PHLPP2. These data establish a conceptual framework for progression of PTEN-mutant prostate cancer to life-threatening disease. To better assess the role of Phlpp in prostate we performed micorarray analysis of gene expression in the WT and Pten+/-; Phlpp1-/- mice.
2011-08-16 | E-GEOD-30987 | biostudies-arrayexpress
Project description: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. Murine mutants with prostate specific loss of Pten and K-ras activation (K-rasG12D) under regulation of the probasin promoter developed high grade, invasive prostate cancer. RNA was extracted from dissected prostate lobes from individual mutants with pathology thought to closely mimic human disease. Prostate tissue was subject to RNA extraction and hybridization on Affymetrix cDNA microarrays.
2012-02-28 | E-GEOD-34839 | biostudies-arrayexpress
Project description: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.
2012-02-28 | GSE34839 | GEO
Project description:Prostate specific Pten deletion, Pten-Smad4 deletion, and Pten-p53 deletion
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Project description:Prostate-specific Pten deletion and Pten-Lrf deletion
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Project description:KLF5 is a basic transcription factor that regulates multiple biological processes, but its function in tumorigenesis appears contradictory in the current literature, with some studies showing tumor suppressor activity and others showing tumor promoting activity. In this study, we examined the function of Klf5 in prostatic tumorigenesis using mice with prostate specific deletion of Klf5 and Pten, both of which are frequently deleted in human prostate cancer. Histological and molecular analyses demonstrated that when one Pten allele was deleted, which causes mouse intraepithelial neoplasia (mPIN), Klf5 deletion accelerated the emergence and progression of mPIN. When both Pten alleles were deleted, which causes prostate cancer, Klf5 deletion promoted tumor growth and caused more severe morphological and molecular alterations, and homozygous deletion of Klf5 was more effective than hemizygous deletion. Unexpectedly, while Klf5 deletion clearly promoted tumorigenesis in luminal cells, it actually diminished the numbers of Ck5-positive basal cells in the Pten-null tumors. Klf5 deletion also increased the cell proliferation rate in tumors with Pten deletion, which involved extensive activation of the PI3K/AKT and MAPK mitogenic signaling pathways and inactivation of the p15 cell cycle inhibitor. Global gene expression and pathway analyses demonstrated that multiple mechanisms could be responsible for the tumor promoting effect of Klf5 deletion, We used microarrays to detail the global programme of gene expression of Klf5-wildtype and Klf5-null mouse dorsal prostates under Pten-null context to figure out the differential expression profiling underlying tumorigenesis 4 Klf5-wildtype and 4 Klf5-null mouse (6 months age) dorsal prostates under Pten-null context were used for RNA extraction and hybridization on Affymetrix mouse st 1.0 array
2014-06-21 | E-GEOD-58719 | biostudies-arrayexpress
Project description:KLF5 is a basic transcription factor that regulates multiple biological processes, but its function in tumorigenesis appears contradictory in the current literature, with some studies showing tumor suppressor activity and others showing tumor promoting activity. In this study, we examined the function of Klf5 in prostatic tumorigenesis using mice with prostate specific deletion of Klf5 and Pten, both of which are frequently deleted in human prostate cancer. Histological and molecular analyses demonstrated that when one Pten allele was deleted, which causes mouse intraepithelial neoplasia (mPIN), Klf5 deletion accelerated the emergence and progression of mPIN. When both Pten alleles were deleted, which causes prostate cancer, Klf5 deletion promoted tumor growth and caused more severe morphological and molecular alterations, and homozygous deletion of Klf5 was more effective than hemizygous deletion. Unexpectedly, while Klf5 deletion clearly promoted tumorigenesis in luminal cells, it actually diminished the numbers of Ck5-positive basal cells in the Pten-null tumors. Klf5 deletion also increased the cell proliferation rate in tumors with Pten deletion, which involved extensive activation of the PI3K/AKT and MAPK mitogenic signaling pathways and inactivation of the p15 cell cycle inhibitor. Global gene expression and pathway analyses demonstrated that multiple mechanisms could be responsible for the tumor promoting effect of Klf5 deletion, We used microarrays to detail the global programme of gene expression of Klf5-wildtype and Klf5-null mouse dorsal prostates under Pten-null context to figure out the differential expression profiling underlying tumorigenesis
2014-06-21 | GSE58719 | GEO
Project description:Alteration 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
2011-05-03 | GSE29010 | GEO
Project description:Alteration 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 Mouse embryonic fibroblasts (MEFs) carrying a tet-inducible Pten transgene were generated by retro viral infection and antibiotic selection. Cells were treated with 2 ug/ml doxycycline for 24 or 48 hours in tet-free FBS (5%)/MEF media (n=2). Reference samples were either cells before treatment (n=2). After each time point cells were washed twice with PBS and RNA trizol extracted. WT samples (n =2) were also included as a control.
2011-05-03 | E-GEOD-29010 | biostudies-arrayexpress
Project description:PTEN loss, one of the most frequent mutations in prostate cancer (PC), is presumed to drive disease progression through AKT activation. However, two transgenic PC models with Akt activation plus Rb loss exhibited different metastatic development: Pten/RbPE:-/- mice produced systemic metastatic adenocarcinomas with high AKT2 activation, whereas RbPE:-/- mice deficient for the Src-scaffolding protein, Akap12, induced high-grade prostatic intraepithelial neoplasias and indolent lymph node dissemination, correlating with upregulated phosphotyrosyl PI3K-p85α. Using PC cells isogenic for PTEN, we show that PTEN-deficiency correlated with dependence on both p110β and AKT2 for in vitro and in vivo parameters of metastatic growth or motility, and with downregulation of SMAD4, a known PC metastasis suppressor. In contrast, PTEN expression, which dampened these oncogenic behaviors, correlated with greater dependence on p110α plus AKT1. Our data suggest that metastatic PC aggressiveness is controlled by specific PI3K/AKT isoform combinations influenced by divergent Src activation or PTEN-loss pathways.
2023-11-01 | GSE242387 | GEO