Project description:Purpose: Validate the cell type specific (Epithelial, Endothelial, and Stromal) transcriptome profile between prostate primary tissue xenografts and of fresh prostate tissue. Nude-Fox1nu mice were castrated and silastic tubing containing dry testosterone (T) was inserted providing “humanized” levels of circulating T. 5-8 pieces of fresh human prostate tissue was then inserted subcutaneously along the flank of the animal. After 30 days the animal was euthanized and tissue was harvested. Tissue from xenograft and from fresh human prostate was then enriched into endothelial, epithelial and the remaining stromal compartments using magnetic bead enrichment. RNA-Seq was then preformed on cell types from both origins and the results compared to show the primary tissue xenograft model faithfully recapitulates transcriptomic profile of the human prostate for epithelial, endothelial and stromal cell types.
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: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.
Project description:Androgen deprivation is a standard of care front-line therapy for human prostate cancer, however, majority of patients will eventally develop resistance to androgen deprivation. In this study, using a human prostate cancer xenograft model -LuCaP35, we examiend the gene expression changes after castration.
Project description:Androgen deprivation is a standard of care front-line therapy for human prostate cancer, however, majority of patients will eventally develop resistance to androgen deprivation. In this study, using a human prostate cancer xenograft model -LuCaP35, we examiend the gene expression changes after castration. We compare the gene expression of 5 LuCaP35 xenografts from non-treated mice (Control), and 5 androgen-deprived LuCaP35 xenografts from castrated mice (Castration).
Project description:Treatment-emergent neuroendocrine prostate cancer (t-NEPC) is a lethal subtype of advanced prostate cancer that develops via NE transdifferentiation of prostate adenocarcinomas in response to androgen receptor (AR)-inhibition therapy. Study of t-NEPC has been hampered by a lack of clinically relevant models. We previously established a unique and first-in-field patient-derived xenograft (PDX) model of adenocarcinoma (LTL331)-to-NEPC (LTL331R) transdifferentiation. In this study, we applied conditional reprogramming (CR) culture to establish a LTL331 PDX-derived cancer cell line named LTL331_CR_Cell. LTL331_CR_Cells retain the same genomic mutations as the LTL331 parental tumor, can be continuously propagated in vitro, and can be genetically manipulated. Androgen deprivation treatment on LTL331_CR_Cells showed no effect on cell proliferation. Transcriptomic analyses comparing the LTL331_CR_Cell to its parental tumor revealed a profound downregulation of the androgen response pathway and an upregulation of stem and basal cell marker genes. The transcriptome of LTL331_CR_Cells partially resembles that of post-castrated LTL331 xenografts in mice. Notably, when grafted under the renal capsule of male NOD/SCID mice, LTL331_CR_Cells spontaneously give rise to NEPC tumors as manifested by the histological expression of the NE marker CD56 and the loss of adenocarcinoma markers such as PSA. Transcriptomic analyses of the newly developed NEPC tumors further demonstrate marked enrichment of NEPC signature genes and loss of AR signaling genes. This study provides a novel research tool based on a unique PDX model. It allows for the investigation of mechanisms underlying t-NEPC development by enabling gene manipulation ex vivo and subsequent functional evaluation in vivo.