GATA2 shRNA Expression in Castration Resistant Prostate Cancer Cell Lines
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ABSTRACT: The transcription factor GATA2 regulates chemotherapy resistance in prostate cancer. We report a novel GATA2 transcriptional program that has implications for chemotherapy resistance disease and aggressiveness in castration resistant prostate cancer.
Project description:The transcription factor GATA2 regulates chemotherapy resistance in prostate cancer. We report a novel GATA2 transcriptional program that has implications for chemotherapy resistance disease and aggressiveness in castration resistant prostate cancer. Examination of the transcriptional network changes induced in human Ch-CRPC cell lines by two shRNA mediated knock down of GATA2 versus random shRNA control
Project description:Metastatic prostate cancer (PCa) is a terminal disease and establishment of novel therapeutic strategy specifically targeting metastasis is critically required for its management. This study was aimed at identifying metastasis-driving genes which could potentially be therapeutic targets for metastatic prostate cancer. Integrative analysis of gene expression profiles from a pair of metastatic and non-metastatic prostate cancer tissue xenografts was used to identify potential prostate cancer metastasis-driving genes. Among the candidate genes found, GATA2, a master regulator gene in the development of hematopoietic system, was particularly interesting since it is an important pioneer factor in the regulation of AR-target gene in prostate cancer. In consistent with our finding, elevated expression of the GATA2 gene in metastatic prostate cancers was found and its expression was significantly correlated with poor prognosis in prostate cancer patients. Furthermore, indication of the GATA2 gene maybe the metastasis-driving gene was evidenced in decreased of cell migration, tissue invasion and focal adhesion disassembly in GATA2-down-regulated LNCaP cells. Global gene expression analysis after silencing of the GATA2 gene revealed a significant changed in cell transcriptomes with ~ 2500 genes with > 2 fold mRNA level changed and FDR <0.05, indicates that GATA2 plays a critical role in cell reprogramming as pioneer factor in the development of prostate cancer metastasis. LNCaP human prostate cancer cells transiently knockdown with siRNA that specifically targeting GATA2 (siGATA2) or scrambled siRNA (sicontrol). RNAs were isolated from cells after 72 hours of incubation. Gene expression profiles of four biological replicates from each sample group were analyzed to identify differentially regulated downstream genes after knockdown of GATA2.
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:Docetaxel-based chemotherapy is the standard first-line therapy in metastatic castration-resistant prostate cancer. However, most patients eventually develop resistance to this treatment. The aim of the study was to identify key molecular genes and networks associated with docetaxel resistance in 2 models of docetaxel-resistant castration-resistant prostate cancer cell lines.
Project description:More effective therapeutic approaches for castration-resistant prostate cancer (CRPC) are urgently needed, thus reinforcing the need to understand how prostate tumors progress to castration resistance. We have established a novel mouse xenograft model of prostate cancer, KUCaP-2, which expresses the wild-type androgen receptor (AR) and which produces the prostate-specific antigen (PSA). In this model, tumors regress soon after castration, but then reproducibly restore their ability to proliferate after 1 to 2 months without AR mutation, mimicking the clinical behavior of CRPC. In the present study, we used this model to identify novel therapeutic targets for CRPC. Evaluating tumor tissues at various stages by gene expression profiling, we discovered that the prostaglandin E receptor EP4 subtype (EP4) was significantly upregulated during progression to castration resistance. Immunohistochemical results of human prostate cancer tissues confirmed that EP4 expression was higher in CRPC compared with hormone-naïve prostate cancer. Ectopic overexpression of EP4 in LNCaP cells (LNCaP-EP4 cells) drove proliferation and PSA production in the absence of androgen supplementation in vitro and in vivo. Androgen-independent proliferation of LNCaP-EP4 cells was suppressed when AR expression was attenuated by RNA interference. Treatment of LNCaP-EP4 cells with a specific EP4 antagonist, ONO-AE3-208, decreased intracellular cyclic AMP levels, suppressed PSA production in vitro, and inhibited castration-resistant growth of LNCaP-EP4 or KUCaP-2 tumors in vivo. Our findings reveal that EP4 overexpression, via AR activation, supports an important mechanism for castration-resistant progression of prostate cancer. Furthermore, they prompt further evaluation of EP4 antagonists as a novel therapeutic modality to treat CRPC. 4 samples in each group: androgen-dependent growth (AD), castration-induced regression nadir (ND), and castration-resistant regrowth (CR) stages
Project description:Docetaxel and cabazitaxel are the chemotherapy agents used in castration-resistant prostate cancer. However, most patients eventually develop resistance to these treatments. The aim of the study was to identify key molecular genes and networks associated with taxanes resistance in 2 models of docetaxel-resistant and cabazitaxel-resistant castration-resistant prostate cancer cell lines.
Project description:Purpose: Resistance to androgen deprivation therapies is a major driver of mortality in advanced prostate cancer. Therefore, there is a need to develop new pre-clinical models that allow the investigation of resistance mechanisms and the assessment of drugs for the treatment of castration resistant prostate cancer. Methods: We generated two novel cell line models (LAPC4-CR and VCaP-CR) which were derived by passaging LAPC4 and VCaP cells in vivo and in vitro under castrate conditions. We performed detailed transcriptomic (RNA-seq) to delineate expression differences between castration-sensitive and castration-resistant cell lines. LAPC4-CR and VCaP-CR cell lines maintained AR expression, but exhibited distinct expression changes on the mRNA and protein level. Integrated analyses including data from LNCaP and the previously described castration resistant LNCaP-abl cells revealed an expression signature of castration resistance. Results: Integrated analyses including data from LNCaP and the previously described castration resistant LNCaP-abl cells revealed an expression signature of castration resistance.
Project description:Metastatic prostate cancer (PCa) is a terminal disease and establishment of novel therapeutic strategy specifically targeting metastasis is critically required for its management. This study was aimed at identifying metastasis-driving genes which could potentially be therapeutic targets for metastatic prostate cancer. Integrative analysis of gene expression profiles from a pair of metastatic and non-metastatic prostate cancer tissue xenografts was used to identify potential prostate cancer metastasis-driving genes. Among the candidate genes found, GATA2, a master regulator gene in the development of hematopoietic system, was particularly interesting since it is an important pioneer factor in the regulation of AR-target gene in prostate cancer. In consistent with our finding, elevated expression of the GATA2 gene in metastatic prostate cancers was found and its expression was significantly correlated with poor prognosis in prostate cancer patients. Furthermore, indication of the GATA2 gene maybe the metastasis-driving gene was evidenced in decreased of cell migration, tissue invasion and focal adhesion disassembly in GATA2-down-regulated LNCaP cells. Global gene expression analysis after silencing of the GATA2 gene revealed a significant changed in cell transcriptomes with ~ 2500 genes with > 2 fold mRNA level changed and FDR <0.05, indicates that GATA2 plays a critical role in cell reprogramming as pioneer factor in the development of prostate cancer metastasis.