Increased Prostate Cancer Cell Invasion Research Articles

MP20-10 ENZALUTAMIDE INCREASES PROSTATE CANCER (PCa) CELL INVASION YET DECREASES BLADDER CANCER (BCa) CELL INVASION VIA DIFFERENTIALLY REGULATING THE AR/circRNA-ARC1/miR-125b-2-3p OR MiR-4736/PPARγ/MMP-9 SIGNALS

You have accessJournal of UrologyCME1 Apr 2023MP20-10 ENZALUTAMIDE INCREASES PROSTATE CANCER (PCa) CELL INVASION YET DECREASES BLADDER CANCER (BCa) CELL INVASION VIA DIFFERENTIALLY REGULATING THE AR/circRNA-ARC1/miR-125b-2-3p OR MiR-4736/PPARγ/MMP-9 SIGNALS Gang Deng, Yixi Hu, Yin Sun, Jean Joseph, Shuyuan Yeh, Edward M. Messing, and Chawnshang Chang Gang DengGang Deng More articles by this author , Yixi HuYixi Hu More articles by this author , Yin SunYin Sun More articles by this author , Jean JosephJean Joseph More articles by this author , Shuyuan YehShuyuan Yeh More articles by this author , Edward M. MessingEdward M. Messing More articles by this author , and Chawnshang ChangChawnshang Chang More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003245.10AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Androgen-deprivation therapy (ADT) is a standard treatment to prevent and shrink PCa growing. However, some patients undergoing ADT may finally develop to hormone-insensitive PCa. The underlying mechanisms haven't been fully elucidated. Here we found ADT-Enz led to increased PCa cell invasion, yet decreased BCa cell invasion. Our goal is to 1.reveal mechanisms of Enz induced hormone-insensitive PCa and find a potential combination therapy. 2. reveal mechanisms of ADT role in BCa and provide an evidence of applying ADT in BCa. METHODS: The human PCa and BCa cells: C4-2, CWR22Rv1, T24 and TCC-SUP were used. Lentiviral plasmids were used to generate gene engineering tools. qPCR and Western blot were used to detect gene expressions. Invasion assay were applied to determine cancer cell invasion capability. Protein-DNA binding complexes were detected by Chromatin immunoprecipitation (ChIP) assays. PPARGC1B/PDK1 3′UTR regions were cloned into the psiCHECKTM-2 vector to assay the miRNA functions. Preclinical mouse PCa model was used to evaluate the anti-cancer efficacy of Enz and circRNA-ARC1 blockage. RESULTS: Mechanistic dissection revealed that suppressing androgens/AR signals could result in differential alterations of the selective circular RNAs (circRNAs) as a result of differential endogenous AR transcription. A negative autoregulation in PCa, yet a positive autoregulation in BCa, as a result of differential binding of AR to different androgen-response elements (AREs) and a discriminating histone H3K4 methylation. Further mechanistic studies indicated that AR-encoded circRNA-ARC1 might sponge the availability of the miR-125b-2-3p and/or miR-4736 to impact the metastasis-related PPARγ/MMP-9 signals. The preclinical mouse model confirms in vitro cell lines data, showing that Enz treatment could increase PCa metastasis, which can be suppressed after iknockdown of circRNA-ARC1. Together, these results demonstrate that antiandrogen therapy with Enz treatment may differentially lead to promoting PCa cell invasion, yet decreasing BCa cell invasion. CONCLUSIONS: Our study is the first to reveal ADT-Enz treatment can promote PCa Cell Invasion yet decrease BCa cell Invasion via differentially regulating the AR/circRNA-ARC1/miR-125b-2-3p or MiR-4736/PPARγ/MMP-9 Signals. Furthermore, our findings may help in development of novel therapeutic approaches to increase the Enz efficacy with less adverse effects in patients with PCa, and providing an evidence of applying ADT in BCa. Source of Funding: This work was partially supported by URMC Urology Department Research fund and George H. Whipple Professorship Endowment © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e279 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Gang Deng More articles by this author Yixi Hu More articles by this author Yin Sun More articles by this author Jean Joseph More articles by this author Shuyuan Yeh More articles by this author Edward M. Messing More articles by this author Chawnshang Chang More articles by this author Expand All Advertisement PDF downloadLoading ...

Targeting androgen receptor (AR) with antiandrogen Enzalutamide increases prostate cancer cell invasion yet decreases bladder cancer cell invasion via differentially altering the AR/circRNA-ARC1/miR-125b-2-3p or miR-4736/PPAR\u03b3/MMP-9 signals

Androgen-deprivation therapy (ADT) via targeting androgens/androgen receptor (AR) signals may suppress cell proliferation in both prostate cancer (PCa) and bladder cancer (BCa), yet its impact on the cell invasion of these two urological cancers remains unclear. Here we found targeting androgens/AR with either the recently developed antiandrogen Enzalutamide (Enz) or AR-shRNAs led to increase PCa cell invasion, yet decrease BCa cell invasion. Mechanistic dissection revealed that suppressing androgens/AR signals could result in differential alterations of the selective circular RNAs (circRNAs) as a result of differential endogenous AR transcription. A negative autoregulation in PCa, yet a positive autoregulation in BCa, as a result of differential binding of AR to different androgen-response elements (AREs) and a discriminating histone H3K4 methylation, likely contributes to this outcome between these two urological tumors. Further mechanistic studies indicated that AR-encoded circRNA-ARC1 might sponge/alter the availability of the miRNAs miR-125b-2-3p and/or miR-4736, to impact the metastasis-related PPARγ/MMP-9 signals to alter the PCa vs. BCa cell invasion. The preclinical study using the in vivo mouse model confirms in vitro cell lines data, showing that Enz treatment could increase PCa metastasis, which can be suppressed after suppressing circRNA-ARC1 with sh-circRNA-ARC1. Together, these in vitro/in vivo results demonstrate that antiandrogen therapy with Enz via targeting AR may lead to either increase PCa cell invasion or decrease BCa cell invasion. Targeting these newly identified AR/circRNA-ARC1/miR-125b-2-3p and/or miR-4736/PPARγ/MMP-9 signals may help in the development of new therapies to better suppress the Enz-altered PCa vs. BCa metastasis.

Androgen receptor reverses the oncometabolite R-2-hydroxyglutarate-induced prostate cancer cell invasion via suppressing the circRNA-51217/miRNA-646/TGFβ1/p-Smad2/3 signaling.

IDH1 (Isocitrate dehydrogenase 1) mutation occurring at codon 132 (R132) in prostate cancer (PCa) is considered as a classifier for a subgroup of PCas with accumulation of oncometabolite R-2HG (R-2-hydroxyglutarate). Here we found that adding R-2HG or the mutant IDH1 R132H could promote PCa cell invasion in androgen receptor (AR)-negative PC3 cells or suppressing the AR in AR-positive C4-2cells. Mechanism dissection revealed that R-2HG could increase circRNA-51217 expression to sponge miRNA-646, which might then lead to increase TGFβ1 expression and thus induce TGFβ1/p-Smad2/3 signaling to increase PCa cell invasion. AR can suppress this R-2HG/circRNA-51217/miRNA-646/TGFβ1/p-Smad2/3 signaling-increased PCa cell invasion via repressing TGFβ1 transcription and inhibiting circRNA-51217 expression through regulating ADAR2 expression. Preclinical studies with an in vivo xenograft mouse model also revealed that PCa cells with the IDH1 R132H mutation have more invasive metastasis. This study demonstrates that IDH1 R132H mutation with increased oncometabolite R-2HG in PCa cells may play important roles to increase PCa cell invasion.

Protective effect of stromal Dickkopf-3 in prostate cancer: opposing roles for TGFBI and ECM-1

Aberrant transforming growth factor–β (TGF-β) signaling is a hallmark of the stromal microenvironment in cancer. Dickkopf-3 (Dkk-3), shown to inhibit TGF-β signaling, is downregulated in prostate cancer and upregulated in the stroma in benign prostatic hyperplasia, but the function of stromal Dkk-3 is unclear. Here we show that DKK3 silencing in WPMY-1 prostate stromal cells increases TGF-β signaling activity and that stromal cell-conditioned media inhibit prostate cancer cell invasion in a Dkk-3-dependent manner. DKK3 silencing increased the level of the cell-adhesion regulator TGF-β–induced protein (TGFBI) in stromal and epithelial cell-conditioned media, and recombinant TGFBI increased prostate cancer cell invasion. Reduced expression of Dkk-3 in patient tumors was associated with increased expression of TGFBI. DKK3 silencing reduced the level of extracellular matrix protein-1 (ECM-1) in prostate stromal cell-conditioned media but increased it in epithelial cell-conditioned media, and recombinant ECM-1 inhibited TGFBI-induced prostate cancer cell invasion. Increased ECM1 and DKK3 mRNA expression in prostate tumors was associated with increased relapse-free survival. These observations are consistent with a model in which the loss of Dkk-3 in prostate cancer leads to increased secretion of TGFBI and ECM-1, which have tumor-promoting and tumor-protective roles, respectively. Determining how the balance between the opposing roles of extracellular factors influences prostate carcinogenesis will be key to developing therapies that target the tumor microenvironment.

Quantification of the Release of NGF from Osteoblasts and Osteocytes in Response to Mechanical Load

Prostate cancer (PCa) is the second most common type of cancer in men with an estimated 161,360 new cases to be diagnosed in 2017 according to the American Cancer Society. Approximately 80% of prostate cancer patients experience metastases to bone. Within the bone environment, prostate cancer metastases form osteosclerotic lesions that cause a reduction in bone strength and an increase in mechanical strains in the bone. This new environment leads to the release of signaling molecules and growth factors from bone cells that heighten cancer invasion and proliferation. Nerve Growth Factor (NGF) is a signaling molecule released from osteoblasts that we have previously shown can increase proliferation in bone‐derived PCa cells. From these previous studies, I hypothesized that mechanical load increases the amount of NGF released from osteoblasts and osteocytes. To determine the effects of mechanical load on bone cells, osteoblasts and osteocytes were subjected to different magnitudes (5, 12, and 20 dynes/cm2) of oscillatory fluid shear. At each magnitude, cells in culture were sheared for 2 hours. Media was collected and cells were lysed. NGF concentrations were quantified from the conditioned media using an ELISA assay. Protein concentrations were determined from the cell lysate using a BCA assay. Results were measured in NGF concentration per protein concentration to account for differences in cell density. Osteocytes released significantly more NGF during fluid shear than static cells, although NGF release was variable. The static osteocytes released approximately 0.022 pg/mg NGF while the maximum concentration of NGF released in sheared cells was 0.054 pg/mg at 5 dynes/cm2. However, osteoblastic MC3T3 cells had no significant response to shear in terms of NGF release. This indicates that while both types of cells exhibited a basal release of NGF, only the osteocytes increased this release in response to fluid shear. Additionally, these findings support the concept that the osteocytes are more sensitive than osteoblasts to mechanical load. Osteocytes are located in lacuna‐canalicular system and are exposed to comparable forces of fluids flowing through these small channels. Since osteocytes make up the majority of bone cells, their NGF release could have a significant impact on the bone microenvironment. We can then predict that the changes in load caused by ostesclerotic lesions could increase prostate cancer cell invasion and proliferation through upregulation of NGF release. Future studies include the treatment of prostate cancer cells with conditioned media from sheared osteocytes and observing any changes in proliferation. These data will further our understanding of the cellular mechanisms involved in prostate cancer proliferation and help to identify potential therapeutic targets for the treatment of metastatic prostate cancer in bone.Support or Funding InformationThis study was supported by the Milton H. Stetson Undergraduate Research Fellowship, a grant from the National Institutes for Health (DC014461) and a private donation from Dr. Jeremie Axe at First State Orthopedics. We also thank Nick Trompeter and Lindsey Stevens for their help and advice.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Correction: Infiltrated pre-adipocytes increase prostate cancer metastasis via modulation of the miR-301a/androgen receptor (AR)/TGF-β1/Smad/MMP9 signals.

// Hongjun Xie 1, 2, * , Lei Li 1, 2, * , Guodong Zhu 1, 2 , Qiang Dang 1, 2 , Zhenkun Ma 1 , Dalin He 1 , Luke Chang 1 , Wenbing Song 1, 2 , Hong-Chiang Chang 2 , John J. Krolewski 3 , Kent L. Nastiuk 3 , Shuyuan Yeh 2 , Chawnshang Chang 2, 4 1 Sex Hormone Research Center, Department of Urology, The First Affiliated Hospital, Xi’an Jiaotong University, Xi’an, China 2 George Whipple Lab for Cancer Research, Departments of Pathology and Urology, and The Wilmot Cancer Center, University of Rochester Medical Center, Rochester, New York, USA 3 Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, New York, USA 4 Sex Hormone Research Center, China Medical University/Hospital, Taichung, Taiwan * These authors have contributed equally to this work Correspondence to: Lei Li, e-mail: lilydr@163.com Chawnshang Chang, e-mail: chang@urmc.rochester.edu Keywords: prostate cancer, pre-adipocyte, mirna-301a, androgen receptor Received: February 15, 2015 Accepted: March 15, 2015 Published: April 8, 2015 ABSTRACT High fat dietary intake may increase the risk of prostate cancer (PCa). Pre-adipocytes, one of the basic components in the tumor microenvironment (TME), are capable of differentiating into adipose tissues and play key roles to affect PCa progression. Here we found the pre-adipocytes could be recruited more easily to PCa than its surrounding normal prostate tissue. In vitro co-culture system also confirmed PCa has a better capacity than normal prostate to recruit pre-adipocytes. The consequences of recruiting more pre-adipocytes may then increase PCa cell invasion. Mechanism dissection revealed infiltrating pre-adipocytes might function through down-regulation of the androgen receptor (AR) via modulation of miR-301a, and then increase PCa cell invasion via induction of TGF-β1/Smad/MMP9 signals. The mouse model with orthotopically xenografted PCa CWR22Rv1 cells with pre-adipocytes also confirmed that infiltrating pre-adipocytes could increase PCa cell invasion via suppressing AR signaling. Together, our results reveal a new mechanism showing pre-adipocytes in the prostate TME can be recruited to PCa to increase PCa metastasis via modulation of the miR-301a/AR/TGF-β1/Smad/MMP9 signals. Targeting this newly identified signaling may help us to better inhibit PCa metastasis.

Correction: Infiltrating mast cells enhance prostate cancer invasion via altering LncRNA-HOTAIR/PRC2-androgen receptor (AR)-MMP9 signals and increased stem/progenitor cell population.

// Lei Li 1,2,* , Qiang Dang 1,2,* , Hongjun Xie 1,2 , Zhao Yang 1 , Dalin He 1 , Liang Liang 1,2 , Wenbing Song 1,2 , Shuyuan Yeh 2 , Chawnshang Chang 2,3 1 Department of Urology, Sex Hormone Research Center, The First Affiliated Hospital, Xi’an Jiaotong University, Xi’an, China 2 Departments of Pathology and Urology, George Whipple Lab for Cancer Research, The Wilmot Cancer Center, University of Rochester Medical Center, Rochester, New York, USA 3 Sex Hormone Research Center, China Medical University/Hospital, Taichung, Taiwan * These authors have contributed equally to this work Correspondence to: Lei Li, email: // Chawnshang Chang, email: // Keywords : prostate cancer, mast cells, androgen receptor, stem cells, HOTAIR-PRC2 Received : November 04, 2014 Accepted : February 28, 2015 Published : March 26, 2015 Abstract Early studies indicated that selective inflammatory immune cells in the prostate tumor microenvironment might be able to influence prostate cancer (PCa) progression. Here we found treating PCa cells with androgen deprivation therapy (ADT) results in the recruitment of more mast cells, which might then increase PCa cell invasion via down-regulation of AR signals in 4 different PCa cell lines. Mechanism dissection revealed infiltrating mast cells could decrease AR transcription via modulation of the PRC2 complex with LncRNA–HOTAIR at the AR 5’ promoter region in PCa cells. The consequences of suppressing AR may then increase PCa cell invasion via increased MMP9 expression and/or increased stem/progenitor cell population. The in vivo mouse model with orthotopically xenografted PCa CWR22Rv1 cells with/without mast cells also confirmed that infiltrating mast cells could increase PCa cell invasion via suppression of AR signals. Together, our results provide a new mechanism for the ADT-enhanced PCa metastasis via altering the infiltrating mast cells to modulate PCa AR-MMP9 signals and/or AR-stem/progenitor cell population. Targeting these newly identified inflammatory mast cells-AR signals may help us to better suppress PCa metastasis at the castration resistant stage.

TR4 nuclear receptor increases prostate cancer invasion via decreasing the miR-373-3p expression to alter TGFβR2/p-Smad3 signals.

Testicular nuclear receptor 4 (TR4), a member of the nuclear receptor superfamily, may play important roles to modulate the metabolic diseases and prostate tumorigenesis. Here we found TR4 could increase prostate cancer (PCa) cell invasion. Mechanism dissection revealed that TR4 might increase PCa cell invasion via decreasing the miR-373-3p expression that resulted in the activation of the TGFβR2/p-Smad3 signals. The in vivo mouse model using orthotopically xenografted CWR22Rv1 cell line transfected with luciferase-reporter confirmed in vitro cell line studies showing TR4 increased PCa metastasis via decreasing the miR-373-3p expression. Together, these data suggest that TR4 may increase PCa metastasis via a newly identified signal and targeting these TR4/miR-473-3p/TGFβR2/p-Smad3 signals using TR4 antagonist or TR4-siRNA or miR-373-3p may allow us to develop a new potential therapeutic approach to better suppress PCa metastasis.

Infiltrated pre-adipocytes increase prostate cancer metastasis via modulation of the miR-301a/androgen receptor (AR)/TGF-β1/Smad/MMP9 signals.

High fat dietary intake may increase the risk of prostate cancer (PCa). Pre-adipocytes, one of the basic components in the tumor microenvironment (TME), are capable of differentiating into adipose tissues and play key roles to affect PCa progression. Here we found the pre-adipocytes could be recruited more easily to PCa than its surrounding normal prostate tissue. In vitro co-culture system also confirmed PCa has a better capacity than normal prostate to recruit pre-adipocytes. The consequences of recruiting more pre-adipocytes may then increase PCa cell invasion. Mechanism dissection revealed infiltrating pre-adipocytes might function through down-regulation of the androgen receptor (AR) via modulation of miR-301a, and then increase PCa cell invasion via induction of TGF-β1/Smad/MMP9 signals. The mouse model with orthotopically xenografted PCa CWR22Rv1 cells with pre-adipocytes also confirmed that infiltrating pre-adipocytes could increase PCa cell invasion via suppressing AR signaling. Together, our results reveal a new mechanism showing pre-adipocytes in the prostate TME can be recruited to PCa to increase PCa metastasis via modulation of the miR-301a/AR/TGF-β1/Smad/MMP9 signals. Targeting this newly identified signaling may help us to better inhibit PCa metastasis.

Infiltrating mast cells enhance prostate cancer invasion via altering LncRNA-HOTAIR/PRC2-androgen receptor (AR)-MMP9 signals and increased stem/progenitor cell population.

Early studies indicated that selective inflammatory immune cells in the prostate tumor microenvironment might be able to influence prostate cancer (PCa) progression. Here we found treating PCa cells with androgen deprivation therapy (ADT) results in the recruitment of more mast cells, which might then increase PCa cell invasion via down-regulation of AR signals in 4 different PCa cell lines. Mechanism dissection revealed infiltrating mast cells could decrease AR transcription via modulation of the PRC2 complex with LncRNA-HOTAIR at the AR 5' promoter region in PCa cells. The consequences of suppressing AR may then increase PCa cell invasion via increased MMP9 expression and/or increased stem/progenitor cell population. The in vivo mouse model with orthotopically xenografted PCa CWR22Rv1 cells with/without mast cells also confirmed that infiltrating mast cells could increase PCa cell invasion via suppression of AR signals. Together, our results provide a new mechanism for the ADT-enhanced PCa metastasis via altering the infiltrating mast cells to modulate PCa AR-MMP9 signals and/or AR-stem/progenitor cell population. Targeting these newly identified inflammatory mast cells-AR signals may help us to better suppress PCa metastasis at the castration resistant stage.

Monocyte-Induced Prostate Cancer Cell Invasion is Mediated by Chemokine ligand 2 and Nuclear Factor-κB Activity.

Study BackgroundThe tumor microenvironment contains inflammatory cells which can influence cancer growth and progression; however the mediators of these effects vary with different cancer types. The mechanisms by which prostate cancer cells communicate with monocytes to promote cancer progression are incompletely understood. This study tested prostate cancer cell and monocyte interactions that lead to increased prostate cancer cell invasion.MethodsWe analyzed the prostate cancer cell invasion and NF-κB activity and cytokine expression during interaction with monocyte-lineage cells in co-cultures. The roles of monocyte chemotactic factor (MCP-1/CCL2) and NF-κB activity for co-culture induced prostate cancer invasion were tested. Clinical prostate cancer NF-κB expression was analyzed by immunohistochemistry.ResultsIn co-cultures of prostate cancer cell lines with monocyte-lineage cells, (C-C motif) ligand 2 (CCL2) levels were significantly increased when compared with monocytes or cancer cells cultured alone. Prostate cancer cell invasion was induced by recombinant CCL2 in a dose dependent manner, similar to co-cultures with monocytes. The monocyte-induced prostate cancer cell invasion was inhibited by CCL2 neutralizing antibodies and by the CCR2 inhibitor, RS102895. Prostate cancer cell invasion and CCL2 expression induced in the co-cultures was inhibited by Lactacystin and Bay11-7082 NF-κB inhibitors. Prostate cancer cell NF-κB DNA binding activity depended on CCL2 dose and was inhibited by CCL2 neutralizing antibodies. Clinical prostate cancer NF-κB expression correlated with tumor grade.ConclusionsCo-cultures with monocyte-lineage cell lines stimulated increased prostate cancer cell invasion through increased CCL2 expression and increased prostate cancer cell NF-κB activity. CCL2 and NF-κB may be useful therapeutic targets to interfere with inflammation-induced prostate cancer invasion.

Abstract 4935: PDZ–domain binding kinase promotes invasion in prostate cancer cells through up–regulation of matrix metalloproteinases–2 and –9.

Abstract Members of the protein kinase superfamily of enzymes modulate many of the facets of the tumor phenotype, such as survival, proliferation, invasion and metastasis. Genetic, epigenetic or regulatory alterations can result in aberrant kinase behavior; the targeted inhibition of which has been a growing focus in anti-cancer drug development. PDZ-domain binding kinase (PBK) is an under-studied, dual-specificity serine/threonine kinase that has been shown to play a key role in cell division and regulation of multiple signaling pathways. It is expressed physiologically in spermatogenic germ and proliferating neural precursor cells, as well as aberrantly in a variety of cancer types. However, the role of PBK in prostate cancer has not been clearly defined. We have found that PBK expression varies greatly across a panel of human prostate cancer cell lines. Interestingly, the level of expression of PBK in prostate cancer cells directly correlates with their invasive ability. Since matrix metalloproteinases (MMP) -2 and -9 are key invasive effectors in a variety of cancers, we investigated their protein levels in relation to that of PBK. Expression of exogenous PBK in low PBK-expressing prostate cancer cell lines (LNCaP and VCaP) significantly upregulated levels of both the propeptide and active forms of MMP-2 and MMP-9; conversely, knockdown of PBK expression in a high PBK-expressing prostate cancer cell line (PC3M) significantly down-regulated both forms of these two MMPs. To determine if a change in PBK levels produces a significant phenotypic effect, we measured the effect of PBK overexpression or knockdown on the prostate cancer cell lines’ invasive ability, as measured in a modified Boyden chamber invasion assay. Overexpression of PBK increased prostate cancer cell invasion approximately ten fold, while PBK knockdown reduced PC3M invasive ability more than three fold. Moreover, immunohistochemical analysis revealed that PBK is present in the majority of human prostate cancer samples tested but not at all in the benign or normal human prostate tissue. These data indicate a novel function of PBK where its presence plays a role in invasion of human prostate cancer cells through up-regulation of MMP-2 and MMP-9. Therefore, the role of PBK in promoting cell invasion, combined with its general lack of expression in normal cells, nominates PBK as a potentially important therapeutic target for prostate cancer. Citation Format: Joshua D. Brown-Clay, Deepika N. Shenoy, Partha P. Banerjee. PDZ–domain binding kinase promotes invasion in prostate cancer cells through up–regulation of matrix metalloproteinases–2 and –9. [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 4935. doi:10.1158/1538-7445.AM2013-4935

C-Jun Has Multiple Enhancing Activities in the Novel Cross Talk between the Androgen Receptor and Ets Variant Gene 1 in Prostate Cancer

The multiple transcriptional roles of c-Jun are shown in a novel cross-talk between the androgen receptor (AR) and its new target gene, Ets variant gene 1 (ETV1). In this report, we show that c-Jun can mediate AR induction of ETV1 expression independent of c-Jun transactivation function. Interestingly, c-Jun can transactivate the cloned ETV1 promoter also in the absence of ligand-activated AR, suggesting two mechanisms by which c-Jun can induce ETV1 expression. In addition, both wild-type c-Jun and a transactivation-deficient mutant can enhance the transcriptional activity of ETV1, as measured by both reporter gene assay and endogenous expression of matrix metalloproteinase genes, well-known targets of Ets proteins. Overexpression of the c-Jun mutant protein also led to increased prostate cancer cell invasion. Immunoprecipitation and immunocytochemistry experiments showed copurification and colocalization of c-Jun with AR or ETV1, suggesting that c-Jun acts on AR or ETV1 via a physical association. Collectively, these results, together with a parallel overexpression of ETV1, c-Jun, and AR in prostate tumors, imply that c-Jun plays a pivotal role in the pathway that connects ligand-activated AR to elevated ETV1 expression, leading to enhanced expression of matrix metalloproteinases and prostate cancer cell invasion.

Fibroblast Growth Factor-1 Induced Promatrilysin Expression Through the Activation of Extracellular-regulated Kinases and STAT3

The MMP, matrilysin. (20MMP-7), has been shown to be overexpressed in prostate cancer cells and to increase prostate cancer cell invasion. Prostate stromal fibroblasts secrete factor(s), including fibroblast growth factor-1. (20FGF-1) that induces promatrilysin expression in LNCaP cells. In the present study, we investigated the signal transduction pathway involved in the FGF-1-induced expression of promatrilysin. FGF-1 treatment significantly increased the activation of extracellular signal-regulated kinases 1 and 2. (20ERK1 and ERK2). This induction was time-dependent and was sustained until 24 hours after treatment. Treating the cells with MEK1/2 inhibitor. (20PD98059) eliminated ERK activation completely and blocked FGF-1-mediated induction of promatrilysin expression. Transient transfection studies with human matrilysin promoter resulted in a four-to-five-fold increase in reporter luciferase enzyme activity that was blocked by the MEK1/2 inhibitor. (20PD98059). Serine phosphorylation of signal transducer and activator of transcription 3. (20STAT3) was observed after FGF-1 treatment and pretreatment with 20 µM PD98059 abolished STAT3 phosphorylation. Transient transfection with dominant negative STAT3 inhibited FGF-1-induced transactivation of the matrilysin promoter indicating that STAT3 plays an important role in FGF-1-induced matrilysin expression. We propose that the FGF-1-induced signaling pathway that leads to promatrilysin expression is ERK-dependent and leads to phosphorylation of Ser-727 on STAT3, phosphorylated STAT3, then binds and transactivates the matrilysin promoter. Our results demonstrate that ERK-MAP kinase and transcription factor STAT3 are important components of FGF-1-mediated signaling, which induce promatrilysin expression in LNCaP cells.