Dataset Information

Aberrant stabilized ETV4 expression cooperates with loss of p53 to promote invasive prostate carcinoma

ABSTRACT: Chromosomal translocations or upregulations involving ETS transcription factor are frequent events in prostate cancer pathogenesis and significantly co-occurrence with p53 or PTEN loss. Caused by the low stabilities of ETS proteins in cytosol, mouse models with aberrant expression of wild type ETS transcription factors had subtle phenotypes and only drive prostate cancer progression in the setting of Pten loss. Here we show that prostate specific aberrant expression of mutated ETV4 (V70P71D72-AAA, ETV4-AAA), which is resistence to COP1 mediated protein degradation, results in more stabilized ETV4 protein in mouse prostate. We found that ETV4-AAA mice develop marked prostatic intraepithelial neoplasia (mPin) and p53-dependent cell senescence within 2 weeks, but without tumor development when aged. Interestingly, ETV4-AAA positive cells reduce dramatically in a PTEN loss background, which means that there is no cooperation between ETV4-AAA and PTEN loss. Aberrant ETV4-AAA expression promotes progression of mPin to prostatic adenocarcinoma in a Tp53 deficiency or haploinsufficiency background. In contrast to PTEN loss induced mouse prostate cancers which loss NKX3.1 expression and resistant to castration therapy, these ETV4-AAA tumor cells well maintain AR and NKX3.1 expression and are sensitive to castration therapy.

ORGANISM(S): Mus musculus

PROVIDER: GSE130311 | GEO | 2021/01/01

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:The proto-oncogenes ETV1, ETV4, and ETV5 encode members of the E26 transformation-specific (ETS) transcription factor family, which includes the most frequently rearranged and overexpressed genes in prostate cancer. Despite being critical regulators of development, little is known about their post-translational regulation. Here we identify the ubiquitin ligase COnstitutive Photomorphogenic-1 (COP1, also called RFWD2) as a tumor suppressor that negatively regulates ETV1, ETV4, and ETV5. ETV1, which is the member mutated more frequently in prostate cancer, was degraded after being ubiquitinated by COP1. Truncated ETV1 encoded by prostate cancer translocation TMPRSS2:ETV1 lacks the critical COP1 binding motifs (degrons) and was 50-fold more stable than wild-type ETV1. Almost all patient translocations eliminate these ETV1 degrons, implying that translocations rendering ETV1 insensitive to COP1 confer a significant selective advantage to prostate epithelial cells. Indeed, COP1 deficiency in mouse prostate elevated ETV1 levels and produced increased cell proliferation, hyperplasia, and early prostate intraepithelial neoplasia. The combined loss of COP1 and PTEN enhanced the invasiveness of mouse prostate adenocarcinomas. Finally, relatively rare human prostate cancer samples showed hemizygous loss of the COP1 gene, loss of COP1 protein expression, and abnormally elevated ETV1 protein while lacking a translocation event. These findings identify COP1 as a bona fide tumor suppressor whose down-regulation promotes prostatic epithelial cell proliferation and tumorigenesis. LNCap prostate cancer cell line were treated with 5 different sets of siRNAs: (1) control siRNA; (2) COP1 (RFWD2) siRNA; (3) COP1 siRNA + ETV1 siRNA; (4) COP1 siRNA + c-JUN siRNA; (5) COP1 siRNA + ETV1 siRNA + c-JUN siRNA. The experiments were conducted in two batches; each batch has its own control siRNA group, so that the batch effect can be properly modelled. Each group has 4-6 replicates; there are 31 samples in total.

Project description:Castration-resistant prostate cancer is a lethal disease. The cell type(s) that survive androgen-deprivation remain poorly described despite global efforts to understand the various mechanisms of therapy resistance. We recently identified in wild type mouse prostates a rare population of luminal progenitor cells that we called LSCmed according to their FACS profile (Lin?/Sca-1+/CD49fmed). Here we investigated the prevalence and castration resistance of LSCmed in various mouse models of prostate tumorigenesis. In intact mice, we show that LSCmed prevalence remains low (5-10% of epithelial cells) when prostatic androgen receptor signaling unaltered (malignant Hi-Myc mice) but significantly increases in models exhibiting reduced prostatic androgen receptor signaling, rising up to 30% in premalignant tumors (Pb-PRL mice) and to >80% in castration-resistant prostate tumors driven by Pten loss (Ptenpc-/- mice). LSCmed tolerance to androgen deprivation was demonstrated by their persistence (Ptenpc-/-) or further enrichment (Pb-PRL) 2-3 weeks after castration as evidenced by FACS analysis. Transcriptomic analysis revealed that LSCmed represent a unique cell entity as their gene-expression profile is different from luminal and basal/stem cells, but shares markers of each. Their intrinsic androgen signaling is markedly decreased, which explains why LSCmed tolerate androgen-deprivation. This also enlightens why Ptenpc-/- tumors are castration-resistant since LSCmed represent the most prevalent cell type in this model. We validated CK4 as a specific marker for LSCmed on sorted cells and prostate tissues by immunostaining, allowing for the detection of LSCmed in various mouse prostate specimens. In castrated Ptenpc-/- prostates, BrdU staining revealed massive proliferation of CK4+ cells, further demonstrating their key role in castration-resistant prostate cancer progression. In all, this study identifies LSCmed as a probable source of prostate cancer relapse after androgen deprivation and as a new therapeutic target for the prevention of castrate-resistant prostate cancer.

Project description:In our investigations of the molecular pathways of prostate tumorigenesis in Nkx3.1; Pten mutant mice using gene expression profiling, we now find that the AP-1 transcription factors, c-Jun and c-Fos, are significantly up-regulated during cancer progression. Forced expression of c-Fos and c-Jun in prostate cancer cells results in increased tumorigenicity, activation of Erk MAP kinase, and enhanced survival in the absence of androgens, which are hallmarks of disease progression. In humans, Jun and Fos proteins are significantly up-regulated during prostate cancer progression and significantly correlated with activation of Erk MAP kinase. Most notably, expression of Jun is associated with disease recurrence independent of other currently used prognostic indicators. These analyses reveal a hitherto unappreciated role for AP-1 transcription factors in prostate cancer progression vis-Ã -vis Erk MAP kinase signaling, as well as the identification of a novel marker of disease recurrence, namely c-Jun. Experiment Overall Design: Mouse prostate was collected from wild-type or the Nkx3.1; Pten compound mutant mice at the age of 8-16 months. One lobe of dosolateral prostate was snap-frozen in OCT and stored at -80ÂºC for laser capture microdissection (LCM). To obtain androgen-independent lesions, mice were castrated at 7 to 14 months of age. Mice were sacrificed for analysis at 8 to 16 months of age and one dosolateral prostatic lobe was snap-frozen in OCT and stored at -80ÂºC for LCM. Approximate 1000 Prostate epithelial cells were isolated from normal prostate, dysplasia, prostatic intraepithelial neoplasia (PIN) or cancer lesions using PixCell IIE LCM system (Arcturus), followed by RNA linear amplification and labeling using Small Sample Labeling Protocol VII (Affymetrix). Samples were labeled using a BioArray High Yield RNA transcript labeling kit (Enzo Life Scientific) and were hybridized to MOE430A GeneChips containing 22,690 well characterized mouse genes/ESTs (Affymetrix).

Dataset Information

Aberrant stabilized ETV4 expression cooperates with loss of p53 to promote invasive prostate carcinoma

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure