Primary Prostate Stromal Cells Research Articles

RNA sequencing and integrative analysis reveal pathways and hub genes associated with TGFβ1 stimulation on prostatic stromal cells.

Objective: Benign prostatic hyperplasia (BPH) is the most common urological disease in elderly men. The transforming growth factor beta 1 (TGFβ1) plays an important role in the proliferation and differentiation of BPH stroma. However, it is not clear yet which important pathways and key genes are the downstream of TGFβ1 acting on prostatic stromal cells. Methods: GSE132714 is currently the newer, available, and best high-throughput sequencing data set for BPH disease and includes the largest number of BPH cases. We examined the TGFβ1 expression level in BPH and normal prostate (NP) by analyzing the GSE132714 data set as well as carrying out immunohistochemistry of 15 BPH and 15 NP samples. Primary prostatic stromal cells (PrSCs) were isolated from five fresh BPH tissues. RNA sequencing and bioinformatics analysis were used to reveal important pathways and hub genes associated with TGFβ1 stimulation on PrSCs. Results: TGFβ1 was upregulated in BPH stroma compared to NP stroma. A total of 497 genes (244 upregulated and 253 downregulated) were differentially expressed in PrSCs with and without TGFβ1 stimulation. The Gene Ontology revealed that differentially expressed genes (DEGs) were mainly enriched in progesterone secretion, interleukin-7 receptor binding, and CSF1-CSF1R complex. The Wnt signaling pathway, PI3K−Akt signaling pathway, JAK−STAT signaling pathway, and Hippo signaling pathway were screened based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. FN1, SMAD3, CXCL12, VCAM1, and ICAM1 were selected as hub genes according to the degree of connection from the protein–protein interaction (PPI) network. Conclusion: This study sheds some new insights into the role of TGFβ1 in BPH stroma and provides some clues for the identification of potential downstream mechanisms and targets.

SEMA3C induces androgen synthesis in prostatic stromal cells through paracrine signaling.

Castration resistant prostate cancer progression is associated with an acquired intratumoral androgen synthesis. Signaling pathways that can upregulate androgen production in prostate tumor microenvironment are not entirely known. In this study, we investigate the potential effect of a secreted signaling protein named semaphorin 3C (SEMA3C) on steroidogenic activities of prostatic stromal cells. We treated human primary prostate stromal cells (PrSC) with 1uM recombinant SEMA3C protein and androgen precursor named dehydroepiandrosterone (DHEA) 1.7uM. Also, to test SEMA3C's effect on the conversion of DHEA to androgens, we exposed PrSCs to the conditioned media derived from LNCaP cells that were transduced with a lentiviral vector harboring full length SEMA3C gene or empty vector (CM-LNSEMA3C or CM-LNVector ). Then, liquid chromatography-mass spectrometry was performed on steroids isolated from PrSCs media. The messnger RNA expression of steroidogenic enzymes in PrSCs was quantified by quantitative polymerase chain reaction. Recombinant SEMA3C had no effect on steroidogenic activities in PrSCs. However, key steroidogenic enzymes expression and androgen synthesis were upregulated in PrSCs treated with CM-LNSEMA3C , compared to those treated with CM-LNVector . These results suggest that steroidogenic activities in PrSCs were upregulated in response to a signaling factor in CM-LNSEMA3C , other than SEMA3C. We hypothesized that SEMA3C overexpression in LNCaP cells affected androgen synthesis in PrSCs through sonic hedgehog (Shh) pathway activation in PrSCs. We verified this effect by blocking Shh signaling with smoothened antagonist. Based on known ability of Shh signaling pathway to activate steroidogenesis in stromal cells, we suggest that SEMA3C overexpression in LNCaP cells can upregulate Shh which in turn is able to stimulate steroidogenic activities in prostatic stromal cells.

Differential impact of paired patient-derived BPH and normal adjacent stromal cells on benign prostatic epithelial cell growth in 3D culture.

Benign prostatic hyperplasia (BPH) is an age-related disease characterized by nonmalignant abnormal growth of the prostate, which is also frequently associated with lower urinary tract symptoms. The prostate with BPH exhibits enhanced growth not only in the epithelium but also in the stroma, and stromal-epithelial interactions are thought to play an important role in BPH pathogenesis. However, our understanding of the mechanisms of stromal-epithelial interactions in the development and progression of BPH is very limited. Matched pairs of glandular BPH and normal adjacent prostate specimens were obtained from BPH patients undergoing simple prostatectomy for symptomatic BPH. Tissues were divided further into fresh specimens for culture of primary prostatic stromal cells, and specimens were embedded in paraffin for immunohistochemical analyses. Proliferation assays, immunohistochemistry, and immunoblotting were used to characterize the primary prostate stromal cells and tissue sections. Coculture of the primary stromal cells with benign human prostate epithelial cell lines BHPrE1 or BPH-1 was performed in three-dimensional (3D) Matrigel to determine the impact of primary stromal cells derived from BPH on epithelial proliferation. The effect of stromal-conditioned medium (CM) on BHPrE1 and BPH-1 cell growth was tested in 3D Matrigel as well. BPH stromal cells expressed less smooth muscle actin and calponin and increased vimentin, exhibiting a more fibroblast and myofibroblast phenotype compared with normal adjacent stromal cells both in culture and in corresponding paraffin sections. Epithelial spheroids formed in 3D cocultures with primary BPH stromal cells were larger than those formed in coculture with primary normal stromal cells. Furthermore, CM from BPH stromal cells stimulated epithelial cell growth while CM from normal primary stromal cells did not in 3D culture. These findings suggest that the stromal cells in BPH tissues are different from normal adjacent stromal cells and could promote epithelial cell proliferation, potentially contributing to the development and progression of BPH.

Estrogen regulates the proliferation and inflammatory expression of primary stromal cell in benign prostatic hyperplasia.

BackgroundTo investigate the expression of estrogen receptor (ER) in prostate tissues of benign prostatic hyperplasia (BPH) individuals, and the effects of estrogen regulating the proliferation and inflammatory expressions of primary prostate stromal cells in BPH.MethodsA total of 44 human BPH prostate tissues were collected to explore the expression of ER by immunohistochemistry (IHC). Cell proliferation, mRNA and protein expressions were analyzed in primary prostate stromal cells treated with estrogen or estrogen plus fulvestrant through cell count kit-8 (CCK-8) assay, quantitative real-time polymerase chain reaction (qPCR), IHC and western blot, respectively.ResultsFirstly, ERβ was positive, and ERα was negative in the transition zone of prostate among all the 44 individuals with BPH. Secondly, the effects could be partially inhibited by fulvestrant, of estrogen promoting the proliferation of primary prostate stromal cells cultured in dulbecco’s modified eagle medium (DMEM) supplemented with 2% fetal bovine serum (FBS). Thirdly, estrogen up-regulates the mRNA levels of C-C chemokine receptor type 3 (CCR3), CD40 ligand (CD 40L), C-X-C motif chemokine ligand 9 (CXCL9) and interleukin 10 (IL10), and down-regulates the mRNA levels of C-C chemokine receptor type 4 (CCR4) and interleukin 17C (IL17C). Then, the protein expressions of CCR3, CCR4, CD40L, IL10 and IL17C are positive, and CXCL9 is negative in the third-generation primary prostate stromal cells. Finally, the effects could be partially inhibited by fulvestrant, of estrogen up-regulating the protein levels of CD40L and IL10.ConclusionsThe expressions of ER in human BPH prostate tissues are zone-dependent. Estrogen promoting the proliferation of primary prostate stromal cells cultured in DMEM supplemented with 2% FBS. The expressions of CCR3, CCR4, CD 40L, IL17C, CXCL9 and IL10 are regulated by estrogen in primary prostate stromal cells.

Obesity-associated inflammation induces androgenic to estrogenic switch in the prostate gland.

Our patient cohort revealed that obesity is strongly associated with steroid-5α reductase type 2 (SRD5A2) promoter methylation and reduced protein expression. The underlying mechanism of prostatic growth in this population is poorly understood. Here we addressed the question of how obesity, inflammation, and steroid hormones affect the development of benign prostatic hyperplasia (BPH). We used preadipocytes, macrophages, primary human prostatic stromal cells, prostate tissues from high-fat diet-induced obese mice, and 35 prostate specimens that were collected from patients who underwent transurethral resection of the prostate (TURP). RNA was isolated and quantified with RT-PCR. Genome DNA was extracted and SRD5A2 promoter methylation was determined. Sex hormones were determined by high-performance liquid chromatography-tandem mass spectrometry. Protein was extracted and determined by ELISA test. In prostatic tissues with obesity, the levels of inflammatory mediators were elevated. SRD5A2 promoter methylation was promoted, but SRD5A2 expression was inhibited. Inflammatory mediators and saturated fatty acid synergistically regulated aromatase activity. Obesity promoted an androgenic to estrogenic switch in the prostate. Our findings suggest that obesity-associated inflammation induces androgenic to estrogenic switch in the prostate gland, which may serve as an effective strategy for alternative therapies for management of lower urinary tract symptoms associated with BPH in select individuals.

Prostate Stroma Increases the Viability and Maintains the Branching Phenotype of Human Prostate Organoids

SummaryThe fibromuscular stroma of the prostate regulates normal epithelial differentiation and contributes to carcinogenesis in vivo. We developed and characterized a human 3D prostate organoid co-culture model that incorporates prostate stroma. Primary prostate stromal cells increased organoid formation and directed organoid morphology into a branched acini structure similar to what is observed in vivo. Organoid branching occurred distal to physical contact with stromal cells, demonstrating non-random branching. Stroma-induced phenotypes were similar in all patients examined, yet they maintained inter-patient heterogeneity in the degree of response. Stromal cells expressed growth factors involved in epithelial differentiation, which was not observed in non-prostatic fibroblasts. Organoids derived from areas of prostate cancer maintained differential expression of alpha-methylacyl-CoA racemase and showed increased viability and passaging when co-cultured with stroma. The addition of stroma to epithelial cells in vitro improves the ability of organoids to recapitulate features of the tissue and enhances the viability of organoids.

Epithelial membrane protein 1 promotes tumor metastasis by enhancing cell migration via copine-III and Rac1

Tumor metastasis is the most common cause of cancer death. Elucidation of the mechanism of tumor metastasis is therefore important in the development of novel, effective anti-cancer therapies to reduce cancer mortality. Interaction between cancer cells and surrounding stromal cells in the tumor microenvironment is a key factor in tumor metastasis. Using a co-culture assay system with human prostate cancer LNCaP cells and primary human prostate stromal cells, we identified epithelial membrane protein 1 (EMP1) as a gene with elevated expression in the cancer cells. The orthotopic injection of LNCaP cells overexpressing EMP1 (EMP1-LNCaP cells) into the prostate of nude mice induced lymph node and lung metastases, while that of control LNCaP cells did not. EMP1-LNCaP cells had higher cell motility and Rac1 activity than control LNCaP cells. These results were also observed in other lines of cancer cells. We newly identified copine-III as an intracellular binding partner of EMP1. Knockdown of copine-III attenuated the increased cell motility and Rac1 activity in EMP1-LNCaP cells. Reduced cell motility and Rac1 activity following knockdown of copine-III in EMP1-LNCaP cells were recovered by re-expression of wild-type copine-III, but not of a copine-III mutant incapable of interacting with EMP1, suggesting the importance of the EMP1–copine-III interaction. Phosphorylated and activated Src and a Rac guanine nucleotide exchange factor Vav2 were found to be involved in the EMP1-induced enhancement of cell motility and Rac1 activation. Moreover, EMP1 was highly expressed in prostate cancer samples obtained from patients with higher Gleason score. These results demonstrate that upregulation of EMP1 significantly increases cancer cell migration that leads to tumor metastasis, suggesting that EMP1 may play an essential role as a positive regulator of tumor metastasis.

Abstract 5772: Developing a patient derived 3D co-culture model of prostate organoids to examine biological mechanisms involved in prostate cancer disparities

Abstract The prostate is composed of a fibro-muscular stromal and glandular epithelial cells. Cross-talk between these cell populations is essential for normal prostate development and is involved in carcinogenesis. In the past year, an estimated 220,800 new cases of prostate cancer (PCa) were diagnosed and 27,540 died of PCa. PCa in African American men occurs more frequently, develops at a much earlier age, and is more aggressive and lethal compared to men of European descent. Both biological and socioeconomic factors likely contribute to this disparity. There is currently a paucity of relevant preclinical models in which to examine biological mechanisms in African American PCa. Patient-derived organoids are a recently developed in vitro preclinical model which facilitate examination of underlying mechanisms of disease etiology. However, current models of epithelial organoid growth lack the prostate stroma. To address this unmet need, we began development of a 3D organoid model that incorporated both primary human prostatic epithelial (PrE) and stromal (PrS) cells to better mimic the microenvironment of the organ. Prostate organoids were derived from cells collected from radical prostatectomy tissues from patients (UIC IRBs: 2006-0679 (PI Behm), (2013-0341(PI Nonn). Mixtures of single PrE-derived and single PrS-derived cells were seeded in 3D in matrigel. Bright-field microscopy of live organoids and histological examination of fixed organoids showed that the addition of PrS cells to the culture altered the shape of the organoids compared to the spherical phenotype observed in PrE only cultures. Immunofluorescent analysis of the basal cell marker p63 showed increased epithelial differentiation in the co-culture organoids. In summary, these data suggest that inclusion of prostate stroma in co-culture organoid models influences prostatic epithelial organoid development in vitro. Ongoing studies are focused on molecular analysis or organoid phenotypes and comparison of AA and EA-derived organoids. Citation Format: Joseph Marsili, Zachary Richards, Jason Garcia, Cindy Voisine, Larisa Nonn. Developing a patient derived 3D co-culture model of prostate organoids to examine biological mechanisms involved in prostate cancer disparities [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5772. doi:10.1158/1538-7445.AM2017-5772

MicroRNAs and DICER1 are regulated by 1,25-dihydroxyvitamin D in prostate stroma

Vitamin D deficiency increases the risk of lethal prostate adenocarcinomas (PCa) and the majority of older men are deficient. Although PCa arises from the epithelium, the surrounding stroma has hormonal regulatory control over the epithelium and contributes to carcinogenesis. Herein, we describe regulation of microRNAs (miRs) by the active hormone dihydroxyvitamin D (1,25(OH)2D) in human prostate stroma. 1,25(OH)2D binds the vitamin D receptor (VDR) transcription factor to regulate gene expression, including miRs, which have emerged as potent regulators of protein expression. 1,25(OH)2D–regulated miRs were identified by profiling in primary human prostatic stromal cells (PrS) and three miRs, miR-126-3p, miR 154-5p and miR-21-5p were subsequently validated in laser-capture micro-dissected prostate stromal tissue from a vitamin D3 clinical trial (N=45). Regulation of these miRs by 1,25(OH)2D was VDR-dependent. Network analysis of known and putative mRNA targets of these miRs was enriched with cancer and inflammation pathways, consistent with known roles of stroma and of vitamin D in carcinogenesis. Expression of the miR processing ribonuclease, DICER1, positively correlated with vitamin D metabolite levels in the clinical trial specimens. High epithelial/stromal ratios of DICER1 were significantly associated biochemical recurrence (OR 3.1, p=0.03) in a tissue microarray of 170 matched PCa patients. In summary, these results underscore the role of the prostate stroma in regulating responses to the hormone 1,25(OH)2D and identified miRs and DICER1 as being regulated in human prostate stroma. Regulation of stromal DICER1 by 1,25(OH)2D may also have clinical relevance in protection against aggressive PCa.

Assessing angiogenic responses induced by primary human prostate stromal cells in a three-dimensional fibrin matrix assay.

Accurate modeling of angiogenesis in vitro is essential for guiding the preclinical development of novel anti-angiogenic agents and treatment strategies. The formation of new blood vessels is a multifactorial and multi-stage process dependent upon paracrine factors produced by stromal cells in the local microenvironment. Mesenchymal stem cells (MSCs) are multipotent cells in adults that can be recruited to sites of inflammation and tissue damage where they aid in wound healing through regenerative, trophic, and immunomodulatory properties. Primary stromal cultures derived from human bone marrow, normal prostate, or prostate cancer tissue are highly enriched in MSCs and stromal progenitors. Using conditioned media from these primary cultures, a robust pro-angiogenic response was observed in a physiologically-relevant three-dimensional fibrin matrix assay. To evaluate the utility of this assay, the allosteric HDAC4 inhibitor tasquinimod and the anti-VEGF monoclonal antibody bevacizumab were used as model compounds with distinct mechanisms of action. While both agents had a profound inhibitory effect on endothelial sprouting, only bevacizumab induced significant regression of established vessels. Additionally, the pro-angiogenic properties of MSCs derived from prostate cancer patients provides further evidence that selective targeting of this population may be of therapeutic benefit.

Activators and stimulators of soluble guanylate cyclase counteract myofibroblast differentiation of prostatic and dermal stromal cells

BackgroundFibrotic diseases encompass numerous systemic and organ-specific disorders characterized by the development and persistence of myofibroblasts. TGFβ1 is considered the key inducer of fibrosis and drives myofibroblast differentiation in cells of diverse histological origin by a pro-oxidant shift in redox homeostasis associated with decreased nitric oxide (NO)/cGMP signaling. Thus, enhancement of NO/cGMP represents a potential therapeutic strategy to target myofibroblast activation and therefore fibrosis. MethodsMyofibroblast differentiation was induced by TGFβ1 in human primary prostatic (PrSCs) and normal dermal stromal cells (NDSCs) and monitored by α smooth muscle cell actin (SMA) and IGF binding protein 3 (IGFBP3) mRNA and protein levels. The potential of enhanced cGMP production by the sGC stimulator BAY 41-2272 or the sGC activator BAY 60-2770 to inhibit and revert myofibroblast differentiation in vitro was analyzed. Moreover, potential synergisms of BAY 41-2272 or BAY 60-2770 and inhibition of cGMP degradation by the PDE5 inhibitor vardenafil were investigated. ResultsBAY 41-2272 and BAY 60-2770 at doses of 30µM significantly inhibited induction of SMA and IGFBP3 levels in PrSCs and reduced myofibroblast marker levels in TGFβ1-predifferentiated cells. At lower concentrations (3 and 10µM) only BAY 41-2272 but not BAY 60-2770 significantly inhibited and reverted myofibroblast differentiation. In NDSCs both substances significantly inhibited differentiation at all concentrations tested. Attenuation of SMA expression was more pronounced in NDSCs whereas reduction of IGFBP3 levels by BAY 41-2272 appeared more efficient in PrSCs. Moreover, administration of BAY 41-2272 or BAY 60-2770 enhanced the efficiency of the PDE5 inhibitor vardenafil to inhibit and revert myofibroblast differentiation in vitro. ConclusionsIncrease of cGMP by sGC stimulation/activation significantly inhibited and reverted myofibroblast differentiation. This effect was even more pronounced when a combination treatment with a PDE5 inhibitor was applied. Thus, enhancement of NO/cGMP-signaling by sGC stimulation/activation is a promising strategy for the treatment of fibrotic diseases. Whereas, in NDSCs BAY 60-2770 and BAY 41-2272 exerted similar effects on myofibroblast differentiation, higher potency of BAY 41-2272 was observed in PrSCs, indicating phenotypical differences between fibroblasts form different organs that should be taken into account in the search for antifibrotic therapies.

Down-regulated CFTR During Aging Contributes to Benign Prostatic Hyperplasia.

Benign prostatic hyperplasia (BPH) is a hyper-proliferative disease of the aging prostate; however, the exact mechanism underlying the development of BPH remains incompletely understood. The present study investigated the possible involvement of the cystic fibrosis transmembrane conductance regulator (CFTR), which has been previously shown to negatively regulate nuclear factor-κB (NF-κB)/cyclooxygenase 2 (COX2)/prostaglandin E2 (PGE2) pathway, in the pathogenesis of BPH. Our results showed decreasing CFTR and increasing COX2 expression in rat prostate tissues with aging. Furthermore, suppression of CFTR led to increased expression of COX2 and over-production of PGE2 in a normal human prostate epithelial cell line (PNT1A) with elevated NF-κB activity. PGE2 stimulated the proliferation of primary rat prostate stromal cells but not epithelial cells, with increased PCNA expression. In addition, the condition medium from PNT1A cells after inhibition or knockdown of CFTR promoted cell proliferation of prostate stromal cells which could be reversed by COX2 or NF-κB inhibitor. More importantly, the involvement of CFTR in BPH was further demonstrated by the down-regulation of CFTR and up-regulation of COX2/NF-κB in human BPH samples. The present results suggest that CFTR may be involved in regulating PGE2 production through its negative regulation on NF-κB/COX2 pathway in prostate epithelial cells, which consequently stimulates cell growth of prostate stromal cells. The overstimulation of prostate stromal cell proliferation by down-regulation of CFTR-enhanced PGE2 production and release during aging may contribute to the development of BPH.

Gene Expression Profiles in Human and Mouse Primary Cells Provide New Insights into the Differential Actions of Vitamin D3 Metabolites

1α,25-Dihydroxyvitamin D3 (1α,25(OH)2D3) had earlier been regarded as the only active hormone. The newly identified actions of 25-hydroxyvitamin D3 (25(OH)D3) and 24R,25-dihydroxyvitamin D3 (24R,25(OH)2D3) broadened the vitamin D3 endocrine system, however, the current data are fragmented and a systematic understanding is lacking. Here we performed the first systematic study of global gene expression to clarify their similarities and differences. Three metabolites at physiologically comparable levels were utilized to treat human and mouse fibroblasts prior to DNA microarray analyses. Human primary prostate stromal P29SN cells (hP29SN), which convert 25(OH)D3 into 1α,25(OH)2D3 by 1α-hydroxylase (encoded by the gene CYP27B1), displayed regulation of 164, 171, and 175 genes by treatment with 1α,25(OH)2D3, 25(OH)D3, and 24R,25(OH)2D3, respectively. Mouse primary Cyp27b1 knockout fibroblasts (mCyp27b1 −/−), which lack 1α-hydroxylation, displayed regulation of 619, 469, and 66 genes using the same respective treatments. The number of shared genes regulated by two metabolites is much lower in hP29SN than in mCyp27b1 −/−. By using DAVID Functional Annotation Bioinformatics Microarray Analysis tools and Ingenuity Pathways Analysis, we identified the agonistic regulation of calcium homeostasis and bone remodeling between 1α,25(OH)2D3 and 25(OH)D3 and unique non-classical actions of each metabolite in physiological and pathological processes, including cell cycle, keratinocyte differentiation, amyotrophic lateral sclerosis signaling, gene transcription, immunomodulation, epigenetics, cell differentiation, and membrane protein expression. In conclusion, there are three distinct vitamin D3 hormones with clearly different biological activities. This study presents a new conceptual insight into the vitamin D3 endocrine system, which may guide the strategic use of vitamin D3 in disease prevention and treatment.

Dickkopf‐related protein 3 promotes pathogenic stromal remodeling in benign prostatic hyperplasia and prostate cancer

BACKGROUND Compartment-specific epithelial and stromal expression of the secreted glycoprotein Dickkopf-related protein (Dkk)-3 is altered in age-related proliferative disorders of the human prostate. This study aimed to determine the effect of Dkk-3 on prostate stromal remodeling that is stromal proliferation, fibroblast-to-myofibroblast differentiation and expression of angiogenic factors in vitro.METHODS Lentiviral-delivered overexpression and shRNA-mediated knockdown of DKK3 were applied to primary human prostatic stromal cells (PrSCs). Cellular proliferation was analyzed by BrdU incorporation ELISA. Expression of Dkk-3, apoptosis-related genes, cyclin-dependent kinase inhibitors and angiogenic factors were analyzed by qPCR, Western blot analysis or ELISA. Fibroblast-to-myofibroblast differentiation was monitored by smooth muscle cell actin and insulin-like growth factor binding protein 3 mRNA and protein levels. The relevance of Wnt/β-catenin and PI3K/AKT signaling pathways was assessed by cytoplasmic/nuclear β-catenin levels and phosphorylation of AKT.RESULTS Knockdown of DKK3 significantly attenuated PrSC proliferation as well as fibroblast-to-myofibroblast differentiation and increased the expression of the vessel stabilizing factor angiopoietin-1. DKK3 knockdown did not affect subcellular localization or levels of β-catenin but attenuated AKT phosphorylation in PrSCs. Consistently the PI3K/AKT inhibitor LY294002 mimicked the effects of DKK3 knockdown.CONCLUSIONS Dkk-3 promotes fibroblast proliferation and myofibroblast differentiation and regulates expression of angiopoietin-1 in prostatic stroma potentially via enhancing PI3K/AKT signaling. Thus, elevated Dkk-3 in the stroma of the diseased prostate presumably regulates stromal remodeling by enhancing proliferation and differentiation of stromal cells and contributing to the angiogenic switch observed in BPH and PCa. Therefore, Dkk-3 represents a potential therapeutic target for stromal remodeling in BPH and PCa. Prostate 73: 1441–1452, 2013. © 2013 The Authors. Prostate published by Willey-Blackwell. This is an open access article under the terms of the Creative Commons Attribution-Non-Commercial-NoDerivs Licence, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

TGFβ1 alters androgenic metabolites and hydroxysteroid dehydrogenase enzyme expression in human prostate reactive stromal primary cells: Is steroid metabolism altered by prostate reactive stromal microenvironment?

The inflammatory tissue microenvironment can be an active promoter in preneoplastic cancer lesions. Altered steroid hormone metabolism as induced by the inflammatory microenvironment may contribute to epithelial cancer progression. Dehydroepiandrosterone sulfate (DHEAS) is the most abundant endogenous steroid hormone present in human serum and can be metabolized to DHEA, androgens and/or estrogens in peripheral tissues. We have previously reported that TGFβ1-induced reactive prostate stromal cells increase DHEA metabolism to active androgens and alter prostate cancer cell gene expression. While much of the focus on mechanisms of prostate cancer and steroid metabolism is in the epithelial cancer cells, this study focuses on TGFβ1-induced effects on DHEA metabolic pathways and enzymes in human prostate stromal cells. In DHEA-treated primary prostate stromal cells, TGFβ1 produced time- and dose-dependent increases in metabolism of DHEA to androstenedione and testosterone. Also TGFβ1-treated prostate stromal cells exhibited changes in the gene expression of enzymes involved in steroid metabolism including up-regulation of 3β hydroxysteroid dehydrogenase (HSD), and down-regulation of 17βHSD5, and 17βHSD2. These studies suggest that reactive prostate stroma and the inflammatory microenvironment may contribute to altered steroid metabolism and increased intratumoral androgens.

Stromal Insulin-Like Growth Factor Binding Protein 3 (IGFBP3) Is Elevated in the Diseased Human Prostate and Promotes ex Vivo Fibroblast-to-Myofibroblast Differentiation

Dysregulation of the IGF axis is implicated in the development of benign prostatic hyperplasia (BPH) and prostate cancer (PCa), 2 of the most common diseases affecting elderly males. PCa is the second leading cause of male-related cancer death in Western societies. Although distinct pathologies, BPH and PCa are both characterized by extensive stromal remodeling, in particular fibroblast-to-myofibroblast differentiation, thought to be induced by elevated local production of TGFβ1. We previously showed that TGFβ1-mediated fibroblast-to-myofibroblast differentiation of primary human prostatic stromal cells resulted in the dsyregulation of several components of the IGF axis, including the induction of IGF binding protein 3 (IGFBP3). Using isoform-specific lentiviral-mediated knockdown, we demonstrate herein that IGFBP3 is essential for TGFβ1-mediated differentiation. Although recombinant human IGFBP3 alone was not sufficient to induce differentiation, IGFBP3 synergistically potentiated TGFβ1-mediated stromal remodeling predominantly via an IGF-independent mechanism. Consistent with these in vitro findings, IGFBP3 immunohistochemistry revealed elevated levels of IGFBP3 in the hyperplastic fibromuscular stroma of BPH specimens and in the tumor-adjacent stroma of high-grade PCa. Collectively these data indicate that the dysregulation of the stromal IGF axis, in particular elevated IGFBP3, plays a crucial role in fibroblast-to-myofibroblast differentiation in the diseased prostatic stroma and indicate the therapeutic potential of inhibiting stromal remodeling and the resulting dysregulation of the stromal IGF axis as a novel strategy for the treatment of advanced PCa and BPH.

Abstract 5068: Differential regulation of tissue inhibitor of metalloproteinase (TIMP-1) expression in primary stromal fibroblast cells by androgen sensitive and resistant prostate cancer cells.

Abstract Background: The tissue inhibitor of metalloproteinase 1 (TIMP-1) regulates matrix metalloproteinases (MMPs) activities and is involved in cancer invasion and metastasis. TIMP-1 level is significantly elevated in prostate cancer patient blood and the elevated plasma TIMP-1 level predicts decreased survival of metastatic castration-resistant prostate cancer (mCRPC) patients. Methods and findings: In this study, we examined serum TIMP-1 levels in 114 prostate cancer patient samples by ELISA and found mCRPC patients have significantly higher serum TIMP-1 (mean value of 373.5 ng/ml) than patients with recurrent hormone-sensitive disease (mean value of 304.8 ng/ml) (p<0.001). Then we examined TIMP-1 expression in androgen-sensitive (AS) and androgen resistant (AR) prostate cancer cell lines (LNCaP, VCaP, LAPC-4, 22RV1, DU145, PC-3 and PC-3M) and primary prostate stromal fibroblast cells (HPrF) by realtime PCR and ELISA. Our results showed that AS and AR cells regulate TIMP-1 expression differently. AS cells barely expressed any TIMP-1, whereas AR prostate cancer cells not only expressed moderate amount of TIMP-1, but also induced stromal fibroblast cells to secrete more TIMP-1. But overall, fibroblast cells secreted at least 10 times more TIMP-1 than AR prostate cancer cells, indicating that stromal fibroblasts are the major source of TIMP-1 in prostate cancer. To identify the soluble factors secreted by AR cells to induce TIMP-1 expression in HPrF, we analyzed cytokine and growth factor profiles of AR and AS cell condition medium (CM) by RayBio cytokine and growth factor arrays and found that multiple cytokines and growth factors were upregulated in AR cell line condition medium including IL-6, IL-10, GM-SCF, GRO alpha and etc. More investigation is underway to verify the roles of the cytokines and growth factors in TIMP-1 regulation in prostate cancer. In addition, using pharmaceutical inhibitors, we showed that AZD6244 (a MEK inhibitor) and BAY11-7082 (an NF-kB inhibitor) completely blocked prostate cancer cell line CM-induced TIMP-1 expression in stromal fibroblasts. Conclusion: Our studies have demonstrated that androgen resistance is associated with TIMP-1 overproduction in prostate cancer and suggested that we can potentially inhibit TIMP-1 overexpression in prostate cancer patients with MEK and NF-kB inhibitors. Citation Format: Yixuan Gong, Lan He, Matthew Galsky, William Oh. Differential regulation of tissue inhibitor of metalloproteinase (TIMP-1) expression in primary stromal fibroblast cells by androgen sensitive and resistant prostate cancer cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5068. doi:10.1158/1538-7445.AM2013-5068 Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.

992 A PARACRINE HEDGEHOG SIGNALING MICROENVIRONMENT IN ADT-TREATED PROSTATE TUMORS INDUCES STEROIDOGENESIS FROM BENIGN PROSTATE STROMAL CELLS

You have accessJournal of UrologyProstate Cancer: Basic Research (V)1 Apr 2013992 A PARACRINE HEDGEHOG SIGNALING MICROENVIRONMENT IN ADT-TREATED PROSTATE TUMORS INDUCES STEROIDOGENESIS FROM BENIGN PROSTATE STROMAL CELLS Amy Lubik, Emma Guns, Hans Adomat, and Ralph Buttyan Amy LubikAmy Lubik Vancouver, Canada More articles by this author , Emma GunsEmma Guns Vancouver, Canada More articles by this author , Hans AdomatHans Adomat Vancouver, Canada More articles by this author , and Ralph ButtyanRalph Buttyan Vancouver, Canada More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.574AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Androgen deprivation therapy (ADT) induces the expression and release of Hedgehog ligands (Hhs) from prostate cancer (PCa) cells. Previously we showed that treatment of primary human prostate stromal cells (PrSCs) with an HH agonist (SAG) increased the expression of steroidogenic genes and enabled them to significantly increase production of testosterone (T) when fed with DHEA, an adrenal precursor. We proposed that a paracrine HH microenvironment in ADT-treated PCas contribute to intratumoral steroidogenesis through this process. Here we show that steroidogenic activity of PrSCs is induced by alternate HH agonists and better describe the steroidogenic process leading to androgen production in PrSCs induced by paracrine HH. METHODS Human primary PrSCs (Clonetics) were grown in recommended medium. PrSCs were pre-starved of serum to induce primary cilia formation, then treated with 1 nM Ag1.5 (a HH agonist) for 48 hrs. Expression of steroidogenic genes was measured by quantitative PCR. Outputs of steroids from vehicle- or agonist-treated PrSC cells fed 22 OH-cholesterol were measured by LC/MS/MS. The HH antagonist, KAAD-cyclopamine (100 nM) or an HMGR inhibitor (simvastatin) was used to block the PrSC response to Ag1.5 or to inhibit active Hh release from Sonic Hh producing LNCaP cells. RESULTS Ag1.5 is as effective as 100 nM SAG in inducing expression of steroidogenic genes in PrSCs. Outputs of progesterone, DHEA, androsterone, T, or dihydrotestosterone (DHT) from 22 OH-cholesterol was significantly increased by Ag1.5. The effects of Ag1.5 on the expression of these genes was blocked by KAAD-cyclopamine. The ability of Ag1.5 to induce RDH5 expression and androsterone production show that the DHT output from PrSCs was a consequence of increased classical and backdoor pathway activities. Steroid outputs from HH-induced PrSCs was significantly higher (on a weight-per-weight basis) than production from parental LNCaP or the androgen growth-independent LNCaP-AI cells. Simvastatin reduced the release of active Hhs from LNCaP-Sonic Hh producing cells as measured by the reduced ability of conditioned medium from treated cells to induce steroidogenic genes in PrSCs. CONCLUSIONS Our results further confirm the potential of a paracrine HH signaling microenvironment of ADT-treated prostate tumor to induce steroidogenesis and androgen production from benign PrSCs. Outcomes show that a HH antagonist or cholesterol synthesis inhibitor might block the effects of paracrine HH in an ADT-treated tumor and delay progression to CRPC. © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 189Issue 4SApril 2013Page: e407 Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information Amy Lubik Vancouver, Canada More articles by this author Emma Guns Vancouver, Canada More articles by this author Hans Adomat Vancouver, Canada More articles by this author Ralph Buttyan Vancouver, Canada More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Ras Promotes Nonautonomous Cell Death in Response to Radiation: Insights From a Novel Drosophila-based Model of Radiation Therapy

Purpose/Objective: Blood flow and flow-related microenvironment play an important role in radiation therapy and chemotherapy. Increased perfusion heightens tumor radiosensitivity and drug delivery. 20-hydroxy5,8,11,14-eicosatetraenoic acid (20-HETE) is a cytochrome P450-derived arachidonic acid metabolite in the microcirculation where it increases vascular tone. In addition, 20-HETE mediates proliferation, angiogenesis, and inflammation, all of which are important in cancer pathogenesis. Studies in our laboratory identified 20-HETE as the mediator of androgen-induced vascular dysfunction and hypertension. Given that androgen plays a major role in prostate cancer (PCa), we examined whether 20-HETE is present in PCa, and whether it regulates PCa vasculature and blood flow. Materials/Methods: LNCaP cell line was from ATCC. RWPE-1 cell line was a gift from Dr. John Pinto (New York Medical College), and primary human prostate stromal cells (LONZA). 20-HETE and 20-hydroxy-6,15eicosadienoic acid (20-HEDE, a 20-HETE antagonist) were chemically synthesized. LNCaP suspension (4x10 cells in 100ml) was xenografted subcutaneously in nude mice. Tumors studied after reaching 1.5-2 cm diameter. Blood flow and vascular function were measured in situ by creating a tumor window submerged with Krebs and using laser Doppler. Tumors were removed and vessels were microdissected for functional and biochemical analyses. Ex vivo tumor blood vessel function was assessed with pressure-myograph. 20-HETE was measured in cells and tissue homogenates by LC/MS/MS. Results: Twenty-HETE was non-detected in normal RWPE-1 prostate epithelial cell line or in primary human prostate stroma cells. In contrast, 20-HETE levels in LNCaP cells amounted to 566 139 pg/mg protein. Similar levels of 20-HETE were detected in homogenized tumor tissue derived from LNCaP cells (425 97 pg/mg protein). Interestingly, 20HETE was not detected in tumor microvessels. Addition of the 20-HEDE (1 mM) in situ increased tumor vessel diameter by 30 mm; this increase was attenuated by 20-HETE in a dose-dependent manner. Similarly, addition of 20-HEDE (1 mM) increased tumor vessel perfusion by 1.7 0.2-fold, which was reversed with 20-HETE (1 mM). Tumor vessel function assessed ex vivo by pressure-myograph demonstrated vasoconstriction with the addition of 20-HETE that was attenuated by cotreatment of 20-HEDE. Conclusion: This study suggests that PCa derived 20-HETE exerts a vasoconstriction influence on the tumor vasculature leading to reduction in blood flow. Inhibition of 20-HETE synthesis or blockade of 20-HETE actions may lead to increase blood flow, and thereby increasing drug delivery and radiosensitivity. Author Disclosure: C. Wu: None. Y. Liu: None. F.F. Zhang: None. M. Schwartzman: None.

Phosphodiesterase Type 5 Inhibition Reverts Prostate Fibroblast-to-Myofibroblast Trans-Differentiation

Phosphodiesterase type 5 (PDE5) inhibitors have been demonstrated to improve lower urinary tract symptoms secondary to benign prostatic hyperplasia (BPH). Because BPH is primarily driven by fibroblast-to-myofibroblast trans-differentiation, this study aimed to evaluate the potential of the PDE5 inhibitor vardenafil to inhibit and reverse trans-differentiation of primary human prostatic stromal cells (PrSC). Vardenafil, sodium nitroprusside, lentiviral-delivered short hairpin RNA-mediated PDE5 knockdown, sodium orthovanadate, and inhibitors of MAPK kinase, protein kinase G, Ras homolog family member (Rho) A, RhoA/Rho kinase, phosphatidylinositol 3 kinase and protein kinase B (AKT) were applied to PrSC treated with basic fibroblast growth factor (fibroblasts) or TGFβ1 (myofibroblasts) in vitro, in chicken chorioallantoic membrane xenografts in vivo, and to prostatic organoids ex vivo. Fibroblast-to-myofibroblast trans-differentiation was monitored by smooth muscle cell actin and IGF binding protein 3 mRNA and protein levels. Vardenafil significantly attenuated TGFβ1-induced PrSC trans-differentiation in vitro and in chorioallantoic membrane xenografts. Enhancement of nitric oxide/cyclic guanosine monophosphate signaling by vardenafil, sodium nitroprusside, or PDE5 knockdown reduced smooth muscle cell actin and IGF binding protein 3 mRNA and protein levels and restored fibroblast-like morphology in trans-differentiated myofibroblast. This reversal of trans-differentiation was not affected by MAPK kinase, protein kinase G, RhoA, or RhoA/Rho kinase inhibition, but vardenafil attenuated phospho-AKT levels in myofibroblasts. Consistently, phosphatidylinositol 3 kinase or AKT inhibition induced reversal of trans-differentiation, whereas the tyrosine phosphatase inhibitor sodium orthovanadate abrogated the effect of vardenafil. Treatment of prostatic organoids with vardenafil ex vivo reduced expression of myofibroblast markers, indicating reverse remodeling of stroma towards a desired higher fibroblast/myofibroblast ratio. Thus, enhancement of the nitric oxide/cyclic guanosine monophosphate signaling pathway by vardenafil attenuates and reverts fibroblast-to-myofibroblast trans-differentiation, hypothesizing that BPH patients might benefit from long-term therapy with PDE5 inhibitors.