Resection surgery of lymph node metastasis of PC3-PSCA-fluc tumor with fluorescence navigation by A11 Mb-IRDye800CW

Abstract Activation of androgen receptor (AR) stimulates the growth of not only androgen-dependent but also of androgen-refractory prostate cancer. However, neither the role of AR in invasion/metastasis nor the relationship between invasiveness and androgen-refractory status has been established. In this study, we used the androgen-dependent prostate cancer cell line MDA PCa 2b, derived from a human bone metastasis, to generate an invasive subline (MDA-I) using a Matrigel chamber. MDA-I cells expressed higher levels of AR and prostate-specific antigen than their less invasive parental cells. Blocking AR function or removal of androgen suppressed the invasion of MDA-I cells, whereas stimulating AR increased invasion. In addition, forced AR overexpression increased the invasiveness of MDA PCa 2b cells. Next, we showed that an androgen-refractory subline (MDA-hr) of MDA PCa 2b cells also expressed higher levels of AR and were more invasive than their parental androgen-dependent cells. Blocking AR function suppressed the invasiveness of MDA-hr cells. Gelatin zymography indicated that matrix metalloproteinase 2 (MMP-2) and MMP-9 activities were regulated by AR signaling and closely correlated with the invasiveness of the androgen-dependent and androgen-refractory prostate cancer cells. These data suggest that AR promotes the invasiveness of both androgen-dependent and androgen-refractory prostate cancer and that a more invasive phenotype might develop through AR activation during cancer progression. These findings potentially support the use of adjuvant hormonal therapy and the future development of more potent androgen blockade therapy. [Cancer Res 2008;68(4):1128–35]

Surgical resection of intramuscular 22Rv1-PSCA-Fluc tumors with real-time fluorescence guidance

Supplementary Figures 1-2 from Androgen Receptor and Invasion in Prostate Cancer

Supplementary Figure S1, S2, S3, S4, S5, S6, S7

Group A streptococcal (GAS) strains causing severe, invasive infections often have mutations in the control of virulence two-component regulatory system (CovRS) which represses capsule production, and high-level capsule production is considered critical to the GAS hypervirulent phenotype. Additionally, based on studies in emm1 GAS, hyperencapsulation is thought to limit transmission of CovRS-mutated strains by reducing GAS adherence to mucosal surfaces. It has recently been identified that about 30% of invasive GAS strains lacks capsule, but there are limited data regarding the impact of CovS inactivation in such acapsular strains. Using publicly available complete genomes (n = 2,455) of invasive GAS strains, we identified similar rates of CovRS inactivation and limited evidence for transmission of CovRS-mutated isolates for both encapsulated and acapsular emm types. Relative to encapsulated GAS, CovS transcriptomes of the prevalent acapsular emm types emm28, emm87, and emm89 revealed unique impacts such as increased transcript levels of genes in the emm/mga region along with decreased transcript levels of pilus operon-encoding genes and the streptokinase-encoding gene ska. CovS inactivation in emm87 and emm89 strains, but not emm28, increased GAS survival in human blood. Moreover, CovS inactivation in acapsular GAS reduced adherence to host epithelial cells. These data suggest that the hypervirulence induced by CovS inactivation in acapsular GAS follows distinct pathways from the better studied encapsulated strains and that factors other than hyperencapsulation may account for the lack of transmission of CovRS-mutated strains. IMPORTANCE Devastating infections due to group A streptococci (GAS) tend to occur sporadically and are often caused by strains that contain mutations in the control of virulence regulatory system (CovRS). In well-studied emm1 GAS, the increased production of capsule induced by CovRS mutation is considered key to both hypervirulence and limited transmissibility by interfering with proteins that mediate attachment to eukaryotic cells. Herein, we show that the rates of covRS mutations and genetic clustering of CovRS-mutated isolates are independent of capsule status. Moreover, we found that CovS inactivation in multiple acapsular GAS emm types results in dramatically altered transcript levels of a diverse array of cell-surface protein-encoding genes and a unique transcriptome relative to encapsulated GAS. These data provide new insights into how a major human pathogen achieves hypervirulence and indicate that factors other than hyperencapsulation likely account for the sporadic nature of the severe GAS disease.

Chimeric antigen receptor (CAR) T cell therapy has led to impressive clinical responses in patients with hematological malignancies; however, its utility in patients with solid tumors has been limited. While CAR T cells for the treatment of advanced prostate cancer are being clinically evaluated and are anticipated to show bioactivity, their safety and the impact of the immunosuppressive tumor microenvironment (TME) have not been faithfully explored preclinically. Using a novel human prostate stem cell antigen knock-in (hPSCA-KI) immunocompetent mouse model and syngeneic murine PSCA CAR T cells, we performed analyses of normal and tumor tissues by flow cytometry, immunohistochemistry, and/or RNA sequencing. We further assessed the beneficial impact of cyclophosphamide (Cy) pre-conditioning on modifications to the immunosuppressive TME and impact on PSCA-CAR T cell safety and efficacy. We observed an in vivo requirement of Cy pre-conditioning in uncovering the efficacy of PSCA-CAR T cells in prostate and pancreas cancer models, with no observed toxicities in normal tissues with endogenous PSCA expression. This combination also dampened the immunosuppressive TME, generated pro-inflammatory myeloid and T cell signatures in tumors, and enhanced the recruitment of antigen-presenting cells, and endogenous as well as adoptively-transferred CAR T cells, resulting in long-term anti-tumor immunity.

AbstractPurpose: The inability to intraoperatively distinguish primary tumor, as well as lymphatic spread, increases the probability of positive surgical margins, tumor recurrence, and surgical toxicity. The goal of this study was to develop a tumor-specific optical probe for real-time fluorescence-guided surgery. Experimental Design: A humanized antibody fragment against PSCA (A11 minibody, A11 Mb) was conjugated with a near-infrared fluorophore, IRDye800CW. The integrity and binding of the probe to PSCA were confirmed by gel electrophoresis, size-exclusion chromatography, and flow cytometry, respectively. The ability of the probe to detect tumor-infiltrated lymph nodes and metastatic lesions was evaluated in 2 xenograft models, as well as in transgenic mice expressing human PSCA (hPSCA). An invasive intramuscular model was utilized to evaluate the efficacy of the A11 Mb-IRDye800CW-guided surgery. Results: A11 Mb was successfully conjugated with IRDye800CW and retained specific binding to PSCA. In vivo imaging showed maximal signal-to-background ratios at 48 hours. The A11 Mb-IRDye800CW specifically detected PSCA-positive primary tumors, tumor-infiltrated lymph nodes, and distant metastases with high contrast. Fluorescence guidance facilitated more complete tumor resection, reduced tumor recurrence, and improved overall survival, compared with conventional white light surgery. The probe successfully identified primary orthotopic tumors and metastatic lesions in hPSCA transgenic mice. Conclusions: Real-time fluorescence image–guided surgery with A11 Mb-IRDye800CW enabled detection of lymph node metastases and positive surgical margins, facilitated more complete tumor removal, and improved survival, compared with white light surgery. These results may be translatable into clinical practice to improve surgical and patient outcomes.

Abstract Introduction: Docetaxel is a common therapeutic agent given to men with castration-resistant prostate cancer (CRPC). However, a number of patients show poor response or eventually develop resistance. Previously, different groups have suggested an association between chemoresistance and epithelial to mesenchimal transition (EMT) in certain advanced cancers. N-cadherin, a calcium-dependent cell-cell adhesion surface protein associated with EMT, is implicated in castration resistance and metastasis in prostate cancer. We have shown in previous studies that monoclonal antibodies raised against the extracellular domain of N-cadherin have potential therapeutic effects in castration-resistant tumor growth and metastasis. In this study, our objective is to determine the role of N-cadherin expression in chemoresistance and whether treatment with monoclonal antibodies restores chemosensitivity. Methods: Tissue microarrays of CRPC and high grade prostate cancer clinical samples were stained for TLR4. N-cadherin positive and negative cell lines were evaluated for sensitivity against docetaxel. N-cadherin and TLR4 were ectopically expressed in N-cadherin negative prostate cancer cells (LNCaP, VCaP). Docetaxel resistant cell lines (LNCaP-DocR and VCaP-DocR) were established through prolonged exposure to 10-20uM Docetaxel. For in vitro experiments, these models were used to evaluate cytotoxicity and apoptosis in the presence of docetaxel. N-cadherin expressing cell lines were treated with 2A9 monoclonal antibody (mAb), which was raised against the extracellular domain of N-cadherin, and by N-cadherin siRNA knockdown. For in vivo studies, N-cadherin positive xenografts were treated with 2A9 mAb and docetaxel, and tumor growth monitored over time. Results: Tissue microarray results showed significant TLR4 expression in CRPC samples (p < 0.005). In vitro studies showed TLR4 induction correlated with N-cadherin expression. This upregulation of N-cadherin and TLR4 expression promoted docetaxel resistance in CRPC by the activation of NF-kB signaling. Monoclonal antibodies against N-cadherin and TLR4 potentiated docetaxel induced cytotoxicity. Docetaxel resistant cells exhibited EMT phenotypes with increased invasion and castration resistant growth. Treatment with 2A9 antibody restored sensitivity to docetaxel. Combination therapy with 2A9 monoclonal antibody and docetaxel significantly affected tumor growth in N-cadherin positive CRPC xenograft models. Conclusions: These studies suggest that N-cadherin promotes TLR4-dependent docetaxel resistance in CRPC. Although further investigation will be needed, therapeutic targeting of N-cadherin with monoclonal antibodies in combination with therapeutic agents such as docetaxel may have significant clinical benefit. Citation Format: Tatsuya Shimomura, Evelyn Kono, Chau P. Tran, Joyce Yamashiro, Shu Lin, Sean Hyung-Kwon Lee, Zev A. Wainberg, Robert E. Reiter. N-cadherin promotes docetaxel resistance through upregulated TLR4 signaling in castration resistant prostate cancers. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3310. doi:10.1158/1538-7445.AM2014-3310

Abstract Introduction: Fibroblast growth factor 2 (FGF2) has been reported to synergize with N-cadherin, a cell surface marker of epithelial mesenchymal transition (EMT), to enhance migration and invasion in breast cancer and other cancers. Recent studies from our group suggested that N-cadherin promotes castration resistance and metastasis in prostate cancer. In addition, our studies showed that antibodies against N-cadherin ectodomains blocked prostate cancer invasion and castration resistant growth. To investigate the mechanism of action of N-cadherin antibodies in prostate cancer cells, we seek to determine the contribution of the different N-cadherin domains in promoting invasion and growth in prostate cancer cells, with particular focus on interaction with FGF2. Methods: Chimeric constructs, in which a N-cadherin domain was swapped with an E-cadherin domain, were generated and ectopically expressed in androgen dependent prostate cancer cell line LNCaP. The following combinations were made: 1/ NE: N-cadherin ectodomains linked to E-cadherin cytoplasmic domain (NE), 2/ EN: the reverse of NE, 3/ NEN: swapping N-cadherin ectodomain 4 for that of E-cadherin. Full length N-cadherin and empty vector sublines served as positive and negative controls. All cell lines were assayed for invasion and growth in androgen depleted media in combination with recombinant FGF2, FGF2 neutralizing antibody and N-cadherin antibodies. Results: Ectopic expression of N-cadherin in N-cadherin negative cells result in a 5-fold increase of FGF2 secreted in the media. In vitro studies have shown that the addition of recombinant FGF2 enhanced invasion by 56%± 0.04 in N-cadherin positive cells while treatment with FGF2 neutralizing antibody resulted in a 65%± 0.03 reduction in invasion. Chimeric cell lines which harbor extracellular domain 4 of N-cadherin, N and NE cell lines, showed >56%± 0.11 enhanced invasion to the addition of recombinant FGF2 while EN, NEN, and control cell lines did not. Monoclonal antibodies developed against regions in the extracellular domain of N-cadherin block the response to recombinant FGF2 with 2A9 (antibody raised against extracellular domain 4) being the least responsive. Conclusions: These studies suggest that the relationship between N-cadherin and FGF2 is involved in prostate cancer progression. Therapeutic targeting of N-cadherin with monoclonal antibodies, alone or in combination with other drugs targeting those potentially involved in downstream pathways may have significant clinical benefit. Future experiments include in vivo models where chimeric cell lines will be implanted in mice as xenografts, and will be monitored for tumor growth, local invasion, and metastasis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3623. doi:10.1158/1538-7445.AM2011-3623

You have accessJournal of UrologyProstate Cancer: Basic Research1 Apr 2011736 PRO-INFLAMMATORY AND MITOGENIC ACTIVITY OF PERIPROSTATIC ADIPOSE TISSUE IN PROSTATE CANCER David S. Finley, Colette Galet, Joyce Yamashiro, Evelyn Kono, Chau Tran, Alan Pantuck, Jean Dekernion, William Aronson, and Robert Reiter David S. FinleyDavid S. Finley Los Angeles, CA More articles by this author , Colette GaletColette Galet Los Angeles, CA More articles by this author , Joyce YamashiroJoyce Yamashiro Los Angeles, CA More articles by this author , Evelyn KonoEvelyn Kono Los Angeles, CA More articles by this author , Chau TranChau Tran Los Angeles, CA More articles by this author , Alan PantuckAlan Pantuck Los Angeles, CA More articles by this author , Jean DekernionJean Dekernion Los Angeles, CA More articles by this author , William AronsonWilliam Aronson Los Angeles, CA More articles by this author , and Robert ReiterRobert Reiter Los Angeles, CA More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.1705AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Obesity has been characterized as a state of chronic, low-grade inflammation. There is evidence linking obesity with prostate cancer (CaP) aggressiveness. Visceral adipose tissue has recently been recognized as a bioactive endocrine organ that secretes a host of cytokines and growth factors, many of which are pro-inflammatory and may modulate the tumor microenvironment. The objective of this pilot study was to characterize inflammatory gene expression in various adipose tissue depots and its effect on prostate cancer cell growth. METHODS Periprostatic (PAT) and subcutaneous adipose control tissue (SAT) were harvested from patients with prostate cancer undergoing radical prostatectomy or from control patients with BPH undergoing simple prostatectomy. Adipose was directly analyzed by inflammatory PCR array (n=8) or used to generate conditioned medium (CM) for cell proliferation assays using a 22Rv1 prostate cancer cell line (n=9). RESULTS A host of inflammatory genes (e.g. IL8RA, ILRAB, CXCL2, CCL8) were modestly upregulated (5-6X) in high-grade (Gleason 9) CaP associated-PAT compared with SAT (Figure 1). Several genes including CCL21 and TOLLIP were upregulated 5.9 and 4.8X, respectively, in high-grade CaP associated-PAT compared with BPH associated-PAT while CCL2,CCL4 and CXCL1-3 were down-regulated 4-9.9X, respectively. In both BRDU and MTS assays, high-grade CaP associated PAT-CM stimulated 22Rv1 cell proliferation more than SAT, low-grade or BPH-associated PAT (Figure 2). CONCLUSIONS In this pilot study, PAT from CaP patients demonstrated upregulation of pro-inflammatory gene expression. Conditioned media generated from cancer associated PAT stimulated 22Rv1 cell growth and proliferation more than BPH associated PAT or SAT. In addition, the magnitude of the effect was greatest for high grade cancer associated PAT. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e295-e296 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information David S. Finley Los Angeles, CA More articles by this author Colette Galet Los Angeles, CA More articles by this author Joyce Yamashiro Los Angeles, CA More articles by this author Evelyn Kono Los Angeles, CA More articles by this author Chau Tran Los Angeles, CA More articles by this author Alan Pantuck Los Angeles, CA More articles by this author Jean Dekernion Los Angeles, CA More articles by this author William Aronson Los Angeles, CA More articles by this author Robert Reiter Los Angeles, CA More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

BACKGROUND. Prostate stem/progenitor cells function in glandular development and maintenance. They may be targets for tumor initiation, so characterization of these cells may have therapeutic implications. Cells from dissociated tissues that form spheres in vitro often represent stem/progenitor cells. A subset of human prostate cells that form prostaspheres were evaluated for self-renewal and tissue regeneration capability in the present study.METHODS. Prostaspheres were generated from 59 prostatectomy specimens. Lineage marker expression and TMPRSS-ERG status was determined via immunohistochemistry and fluorescence in situ hybridization (FISH). Subpopulations of prostate epithelial cells were isolated by cell sorting and interrogated for sphere-forming activity. Tissue regeneration potential was assessed by combining sphere-forming cells with rat urogenital sinus mesenchyme (rUGSM) subcutaneously in immunocompromised mice.RESULTS. Prostate tissue specimens were heterogeneous, containing both benign and malignant (Gleason 3-5) glands. TMPRSS-ERG fusion was found in approximately 70% of cancers examined. Prostaspheres developed from single cells at a variable rate (0.5-4%) and could be serially passaged. A basal phenotype (CD44+CD49f+CK5-hp63+CK8AR-PSA-) was observed among sphere-forming cells. Subpopulations of prostate cells expressing tumor-associated calcium signal transducer 2 (Trop2), CD44, and CD49f preferentially formed spheres. In vivo implantation of sphere-forming cells and rUGSM regenerated tubular structures containing discreet basal and luminal layers. The TMPRSS-ERG fusion was absent in prostaspheres derived from fusion-positive tumor tissue, suggesting a survival/growth advantage of benign prostate epithelial cells.CONCLUSION. Human prostate sphere-forming cells self-renew, have tissue regeneration capability, and represent a subpopulation of basal cells. Prostate 70: 491-501, 2010. (C) 2009 Wiley-Liss, Inc.

The transition from androgen-dependent to castration-resistant prostate cancer is a lethal event. N-cadherin seems to be a major cause underlying this transition, and targeting this adhesion molecule may have positive clinical benefit. The transition from androgen-dependent to castration-resistant prostate cancer (CRPC) is a lethal event of uncertain molecular etiology. Comparing gene expression in isogenic androgen-dependent and CRPC xenografts, we found a reproducible increase in N-cadherin expression, which was also elevated in primary and metastatic tumors of individuals with CRPC. Ectopic expression of N-cadherin in nonmetastatic, androgen-dependent prostate cancer models caused castration resistance, invasion and metastasis. Monoclonal antibodies against the ectodomain of N-cadherin reduced proliferation, adhesion and invasion of prostate cancer cells in vitro. In vivo, these antibodies slowed the growth of multiple established CRPC xenografts, blocked local invasion and metastasis and, at higher doses, led to complete regression. N-cadherin–specific antibodies markedly delayed the time to emergence of castration resistance, markedly affected tumor histology and angiogenesis, and reduced both AKT serine-threonine kinase activity and serum interleukin-8 (IL-8) secretion. These data indicate that N-cadherin is a major cause of both prostate cancer metastasis and castration resistance. Therapeutic targeting of this factor with monoclonal antibodies may have considerable clinical benefit.

You have accessJournal of UrologyModerated Poster 16, Sunday, May 20, 2007, 3:30 - 5:30 pm1 Apr 2007530: Defining Human Prostate Stem Cells Via Development and Characterization of Prostaspheres Isla Garraway, Chau Tran, Ying Cai, Scott Hahm, Robert Reiter, and Owen Witte Isla GarrawayIsla Garraway More articles by this author , Chau TranChau Tran More articles by this author , Ying CaiYing Cai More articles by this author , Scott HahmScott Hahm More articles by this author , Robert ReiterRobert Reiter More articles by this author , and Owen WitteOwen Witte More articles by this author View All Author Informationhttps://doi.org/10.1016/S0022-5347(18)30770-5AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail "530: Defining Human Prostate Stem Cells Via Development and Characterization of Prostaspheres." The Journal of Urology, 177(4S), p. 176 © 2016 by American Urological AssociationFiguresReferencesRelatedDetails Volume 177Issue 4SApril 2007Page: 176 Advertisement Copyright & Permissions© 2016 by American Urological AssociationMetricsAuthor Information Isla Garraway More articles by this author Chau Tran More articles by this author Ying Cai More articles by this author Scott Hahm More articles by this author Robert Reiter More articles by this author Owen Witte More articles by this author Expand All Advertisement PDF downloadLoading ...

Prostate stem cell antigen (PSCA, named for its strong sequence homology to the thymocyte marker stem cell antigen 2) is a cell surface antigen expressed in normal prostate and associated with human and murine prostate cancer. To begin to investigate a possible link between PSCA expression in normal prostate and prostate carcinogenesis, we characterized the phenotype and proliferative behavior of normal PSCA-expressing prostate epithelial cells (PrEC) in tissue culture. PSCA was expressed in a subset of prostate epithelial cells that coexpress basal and secretory cytokeratins. PSCA-positive cells were the direct progeny of PSCA-negative cells and were characterized by a more differentiated morphology and a slower proliferative rate than PSCA-negative cells. Although PSCA-positive cells continued to express basal cell markers such as CD44, they lost expression of the basal cell marker p63. In contrast, expression of prostate specific antigen and androgen receptor transcripts was detectable in PSCA-positive PrEC. These findings suggest that PSCA is a unique marker of an intermediate subpopulation of PrEC in transition from a basal to a terminally differentiated secretory phenotype and may be a useful marker for the study of normal and malignant prostate development.