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The development of benign prostatic hyperplasia (BPH) and medication-refractory lower urinary tract symptoms (LUTS) remain poorly understood. This study attempted to characterize the pathways associated with failure of medical therapy for BPH/LUTS.Transitional zone tissue levels of cholesterol and steroids were measured in patients who failed medical therapy for BPH/LUTS and controls. Prostatic gene expression was measured using qPCR and BPH cells were used in organoid culture to study prostatic branching.BPH patients on 5-α-reductase inhibitor (5ARI) showed low levels of tissue dihydrotestosterone (DHT), increased levels of steroid 5-α-reductase type II (SRD5A2), and diminished levels of androgen receptor (AR) target genes, prostate-specific antigen (PSA), and transmembrane serine protease 2 (TMPRSS2). 5ARI raised prostatic tissue levels of glucocorticoids (GC), whereas alpha-adrenergic receptor antagonists (α-blockers) did not. Nuclear localization of GR in prostatic epithelium and stroma appeared in all patient samples. Treatment of four BPH organoid cell lines with dexamethasone, a synthetic GC, resulted in budding and branching.After failure of medical therapy for BPH/LUTS, 5ARI therapy continued to inhibit androgenesis but a 5ARI-induced pathway increased tissue levels of GC not seen in patients on α-blockers. GC stimulation of organoids indicated that the GC receptors are a trigger for controlling growth of prostate glands. A 5ARI-induced pathway revealed GC activation can serve as a master regulator of prostatic branching and growth.

Supplemental Figures 1-5 with figure legends embedded.

Castration-resistant prostate cancer can be treated with the antiandrogen enzalutamide, but responses and duration of response are variable. To identify genes that support enzalutamide resistance, we performed a short hairpin RNA (shRNA) screen in the bone-homing, castration-resistant prostate cancer cell line, C4-2B. We identified 11 genes (TFAP2C, CAD, SPDEF, EIF6, GABRG2, CDC37, PSMD12, COL5A2, AR, MAP3K11, and ACAT1) whose loss resulted in decreased cell survival in response to enzalutamide. To validate our screen, we performed transient knockdowns in C4-2B and 22Rv1 cells and evaluated cell survival in response to enzalutamide. Through these studies, we validated three genes (ACAT1, MAP3K11, and PSMD12) as supporters of enzalutamide resistance in vitro. Although ACAT1 expression is lower in metastatic castration-resistant prostate cancer samples versus primary prostate cancer samples, knockdown of ACAT1 was sufficient to reduce cell survival in C4-2B and 22Rv1 cells. MAP3K11 expression increases with Gleason grade, and the highest expression is observed in metastatic castration-resistant disease. Knockdown of MAP3K11 reduced cell survival, and pharmacologic inhibition of MAP3K11 with CEP-1347 in combination with enzalutamide resulted in a dramatic increase in cell death. This was associated with decreased phosphorylation of AR-Serine650, which is required for maximal AR activation. Finally, although PSMD12 expression did not change during disease progression, knockdown of PSMD12 resulted in decreased AR and AR splice variant expression, likely contributing to the C4-2B and 22Rv1 decrease in cell survival. Our study has therefore identified at least three new supporters of enzalutamide resistance in castration-resistant prostate cancer cells in vitro.

Invasion assay of ARCaPM-TBX2 and ARCaPM-Neo cells

Legend to Supplementary Figures

Plot showing relative protein expression of TBX2 and WNT3A in human PCa cell lines

Invasion assay of PC3 (TBX2DN+WNT3A, TBX2DN, and Neo)cells with the addition of SFRP-2

Supplementary Materials and Methods

Schematic depiction of WNT3A gene promoter, and ChIP analysis of LNCaP-TBX2 and LNCaP-Neo cells to assess the binding of TBX2 on WNT3A promoter

Micro-CT images of mouse tibiae injected with ARCaPM-TBX2 and ARCaPM-Neo cells

Identification of factors that mediate visceral and bone metastatic spread and subsequent bone remodeling events is highly relevant to successful therapeutic intervention in advanced human prostate cancer. TBX2, a T-box family transcription factor that negatively regulates cell-cycle inhibitor p21, plays critical roles during embryonic development, and recent studies have highlighted its role in cancer. Here, we report that TBX2 is overexpressed in human prostate cancer specimens and bone metastases from xenograft mouse models of human prostate cancer. Blocking endogenous TBX2 expression in PC3 and ARCaPM prostate cancer cell models using a dominant-negative construct resulted in decreased tumor cell proliferation, colony formation, and invasion in vitro. Blocking endogenous TBX2 in human prostate cancer mouse xenografts decreased invasion and abrogation of bone and soft tissue metastasis. Furthermore, blocking endogenous TBX2 in prostate cancer cells dramatically reduced bone-colonizing capability through reduced tumor cell growth and bone remodeling in an intratibial mouse model. TBX2 acted in trans by promoting transcription of the canonical WNT (WNT3A) promoter. Genetically rescuing WNT3A levels in prostate cancer cells with endogenously blocked TBX2 partially restored the TBX2-induced prostate cancer metastatic capability in mice. Conversely, WNT3A-neutralizing antibodies or WNT antagonist SFRP-2 blocked TBX2-induced invasion. Our findings highlight TBX2 as a novel therapeutic target upstream of WNT3A, where WNT3A antagonists could be novel agents for the treatment of metastasis and for skeletal complications in prostate cancer patients. Cancer Res; 77(6); 1331–44. ©2017 AACR.

Quantitative Real-Time RT-PCR and Invasion assay of LNCaP-TBX2 and LNCaP-Neo cells

Cancer Outlier Profile Analysis (COPA) in Oncomine 4.4 showing TBX2 over-expression in PCa microarray data sets

In many patients with prostate cancer, the cancer will be recurrent and eventually progress to lethal metastatic disease after primary treatment, such as surgery or radiation therapy. Therefore, it would be beneficial to better predict which patients with early-stage prostate cancer would progress or recur after primary definitive treatment. In addition, many studies indicate that activation of NF-κB signaling correlates with prostate cancer progression; however, the precise underlying mechanism is not fully understood. Our studies show that activation of NF-κB signaling via deletion of one allele of its inhibitor, IκBα, did not induce prostatic tumorigenesis in our mouse model. However, activation of NF-κB signaling did increase the rate of tumor progression in the Hi-Myc mouse prostate cancer model when compared with Hi-Myc alone. Using the nonmalignant NF-κB–activated androgen-depleted mouse prostate, a NF-κB–activated recurrence predictor 21 (NARP21) gene signature was generated. The NARP21 signature successfully predicted disease-specific survival and distant metastases-free survival in patients with prostate cancer. This transgenic mouse model–derived gene signature provides a useful and unique molecular profile for human prostate cancer prognosis, which could be used on a prostatic biopsy to predict indolent versus aggressive behavior of the cancer after surgery. Cancer Res; 74(10); 2763–72. ©2014 AACR.

PDF file - 453KB, Supplementary Figure 1. NF-kappaB signaling is continuously activated in the prostate of IkappaBalpha+/- mouse. Supplementary Figure 2. NF-kappaB signaling activated in the prostate of Myc/IkappaBalpha bigenic mouse. Supplementary Figure 3. Continuous activation of NF-kappaB signaling promotes PCa progression in the Hi-Myc transgenic mouse. Supplementary Figure 4. The NF24 gene signature predicts significant differences in the overall cancer-specific survival of the PCa patients. Supplemental Figure 5. Molecular network analysis using Ingenuity Pathway Analysis (IPA). Supplemental Figure 6. NF-kappaB signaling is activated/inactivated in PCa cells by infecting with IKK2-EE or IKK2-KD retroviral vectors. Supplemental Figure 7. Activation of NF-kappaB signaling increases JNK phosphorylation in PCa cells. Supplemental Figure 8. Blocking JNK signaling inhibits NF-kappaB induced invasive ability efficiently in PCa cells. Tables 1 and 2. Matched human homolog genes. Supplementary Table 3. Stratification of 77 PCa patients.

Background Little is known about how benign prostatic hyperplasia (BPH) develops and why patients respond differently to medical therapy designed to reduce lower urinary tract symptoms (LUTS). The Medical Therapy of Prostatic Symptoms (MTOPS) trial randomized men with symptoms of BPH and followed response to medical therapy for up to 6 years. Treatment with a 5α-reductase inhibitor (5ARI) or an alpha-adrenergic receptor antagonist (α-blocker) reduced the risk of clinical progression, while men treated with combination therapy showed a 66% decrease in risk of progressive disease. However, medical therapies for BPH/LUTS are not effective in many patients. The reasons for nonresponse or loss of therapeutic response in the remaining patients over time are unknown. A better understanding of why patients fail to respond to medical therapy may have a major impact on developing new approaches for the medical treatment of BPH/LUTS. Prostaglandins (PG) act on G-protein-coupled receptors (GPCRs), where PGE2 and PGF2 elicit smooth muscle contraction. Therefore, we measured PG levels in the prostate tissue of BPH/LUTS patients to assess the possibility that this signaling pathway might explain the failure of medical therapy in BPH/LUTS patients. Method Surgical BPH (S-BPH) was defined as benign prostatic tissue collected from the transition zone (TZ) of patients who failed medical therapy and underwent surgical intervention to relieve LUTS. Control tissue was termed Incidental BPH (I-BPH). I-BPH was TZ obtained from men undergoing radical prostatectomy for low-volume, low-grade prostatic adenocarcinoma (PCa, Gleason score ≤ 7) confined to the peripheral zone. All TZ tissue was confirmed to be cancer-free. S-BPH patients divided into four subgroups: patients on α-blockers alone, 5ARI alone, combination therapy (α-blockers plus 5ARI), or no medical therapy (none) before surgical resection. I-BPH tissue was subgrouped by prior therapy (either on α-blockers or without prior medical therapy before prostatectomy). We measured prostatic tissue levels of prostaglandins (PGF2α , PGI2 , PGE2 , PGD2 , and TxA2 ), quantitative polymerase chain reaction levels of mRNAs encoding enzymes within the PG synthesis pathway, cellular distribution of COX1 (PTGS1) and COX2 (PTGS2), and tested the ability of PGs to contract bladder smooth muscle in an in vitro assay. Results All PGs were significantly elevated in TZ tissues from S-BPH patients (n = 36) compared to I-BPH patients (n = 15), regardless of the treatment subgroups. In S-BPH versus I-BPH, mRNA for PG synthetic enzymes COX1 and COX2 were significantly elevated. In addition, mRNA for enzymes that convert the precursor PGH2 to metabolite PGs were variable: PTGIS (which generates PGI2 ) and PTGDS (PGD2 ) were significantly elevated; nonsignificant increases were observed for PTGES (PGE2 ), AKR1C3 (PGF2α ), and TBxAS1 (TxA2 ). Within the I-BPH group, men responding to α-blockers for symptoms of BPH but requiring prostatectomy for PCa did not show elevated levels of COX1, COX2, or PGs. By immunohistochemistry, COX1 was predominantly observed in the prostatic stroma while COX2 was present in scattered luminal cells of isolated prostatic glands in S-BPH. PGE2 and PGF2α induced contraction of bladder smooth muscle in an in vitro assay. Furthermore, using the smooth muscle assay, we demonstrated that α-blockers that inhibit alpha-adrenergic receptors do not appear to inhibit PG stimulation of GPCRs in bladder muscle. Only patients who required surgery to relieve BPH/LUTS symptoms showed significantly increased tissue levels of PGs and the PG synthetic enzymes. Conclusions Treatment of BPH/LUTS by inhibition of alpha-adrenergic receptors with pharmaceutical α-blockers or inhibiting androgenesis with 5ARI may fail because of elevated paracrine signaling by prostatic PGs that can cause smooth muscle contraction. In contrast to patients who fail medical therapy for BPH/LUTS, control I-BPH patients do not show the same evidence of elevated PG pathway signaling. Elevation of the PG pathway may explain, in part, why the risk of clinical progression in the MTOPS study was only reduced by 34% with α-blocker treatment.

Castration-resistant prostate cancer can be treated with the anti-androgen enzalutamide, but responses and duration of response are variable. To identify genes that support enzalutamide resistance, we performed a short hairpin RNA (shRNA) screen in the bone-homing, castration-resistant prostate cancer cell line, C4-2B. We identified eleven genes (TFAP2C, CAD, SPDEF, EIF6, GABRG2, CDC37, PSMD12, COL5A2, AR, MAP3K11, andACAT1), whose loss resulted in decreased cell survival in response to enzalutamide. To validate our screen, we performed transient knockdowns in C4-2B and 22Rv1 cells and evaluated cell survival in response to enzalutamide. Through these studies, we validated three genes (ACAT1, MAP3K11, andPSMD12) as supporters of enzalutamide resistancein vitro. AlthoughACAT1expression is lower in metastatic castration-resistant prostate cancer samples versus primary prostate cancer samples, knockdown ofACAT1was sufficient to reduce cell survival in C4-2B and 22Rv1 cells.MAP3K11expression increases with Gleason grade, and the highest expression is observed in metastatic castration-resistant disease. Knockdown ofMAP3K11reduced cell survival and pharmacologic inhibition of MAP3K11 with CEP-1347 in combination with enzalutamide resulted in a dramatic increase in cell death. This was associated with decreased phosphorylation of AR-Serine650, which is required for maximal AR activation. Finally, whilePSMD12expression did not change during disease progression, knockdown ofPSMD12resulted in decreased AR and AR splice variant expression, likely contributing to the C4-2B and 22Rv1 decrease in cell survival. Our study has therefore identified at least three new supporters of enzalutamide resistance in castration-resistant prostate cancer cellsin vitro.Financial supportThe authors would like to acknowledge funding from the Joe C. Davis Foundation (to RJM), the Vanderbilt Institute for Clinical and Translational Research (VICTR, to YY, PEC, and RJM). The Vanderbilt Institute for Clinical and Translational Research (VICTR) is funded by the National Center for Advancing Translational Sciences (NCATS) Clinical Translational Science Award (CTSA) Program, Award Number 5UL1TR002243. The content of this manuscript solely the responsibility of the authors and does not necessarily represent the official views of the NIH. We would also like to acknowledge the Case Research Institute, a joint venture between University Hospitals and Case Western Reserve University, start-up funds (to MMG), and the Cell and Molecular Biology Training Program (T32 GM 008056 to SEK).

Sterol regulatory element-binding protein 1 (SREBP-1), a master transcription factor in lipogenesis and lipid metabolism, is critical for disease progression and associated with poor outcomes in prostate cancer (PCa) patients. However, the mechanism of SREBP-1 regulation in PCa remains elusive. Here, we report that SREBP-1 is transcriptionally regulated by microRNA-21 (miR-21) in vitro in cultured cells and in vivo in mouse models. We observed aberrant upregulation of SREBP-1, fatty acid synthase (FASN) and acetyl-CoA carboxylase (ACC) in Pten/Trp53 double-null mouse embryonic fibroblasts (MEFs) and Pten/Trp53 double-null mutant mice. Strikingly, miR-21 loss significantly reduced cell proliferation and suppressed the prostate tumorigenesis of Pten/Trp53 mutant mice. Mechanistically, miR-21 inactivation decreased the levels of SREBP-1, FASN, and ACC in human PCa cells through downregulation of insulin receptor substrate 1 (IRS1)-mediated transcription and induction of cellular senescence. Conversely, miR-21 overexpression increased cell proliferation and migration; as well as the levels of IRS1, SREBP-1, FASN, and ACC in human PCa cells. Our findings reveal that miR-21 promotes PCa progression by activating the IRS1/SREBP-1 axis, and targeting miR-21/SREBP-1 signaling pathway can be a novel strategy for controlling PCa malignancy.

The present studies were conducted to evaluate key serum proteins and other components that mediate anchorage-independent growth (3-D growth) of LNCaP prostate cancer cells as spheroids. The cells were cultured on ultra-low attachment plates in the absence and presence of fetuin-A and with or without extracellular vesicles. The data show that fetuin-A (alpha 2HS glycoprotein) is the serum protein that mediates 3-D growth in these cells. It does so by sequestering extracellular vesicles of various sizes on the surfaces of rounded cells that grow as spheroids. These vesicles in turn transmit growth signals such as the activation of AKT and MAP kinases in a pattern that differs from the activation of these key growth signaling pathways in adherent and spread cells growing in 2-D. In the process of orchestrating the movement and disposition of extracellular vesicles on these cells, fetuin-A is readily internalized in adhered and spread cells but remains on the surfaces of non-adherent cells. Taken together, our studies suggest the presence of distinct signaling domains or scaffolding platforms on the surfaces of prostate tumor cells growing in 3-D compared to 2-D.

Galois hulls of linear codes have important applications in quantum coding theory. In this paper, we construct some new classes of (extended) generalized Reed-Solomon (GRS) codes with Galois hulls of arbitrary dimensions. We also propose a general method on constructing GRS codes with Galois hulls of arbitrary dimensions from special Euclidean orthogonal GRS codes. Finally, we construct several new families of entanglement-assisted quantum error-correcting codes (EAQECCs) and MDS EAQECCs by utilizing the above results.

In this paper, we produce two new classes of entanglement-assisted quantum MDS codes (EAQMDS codes) with length $n|q^2-1$ and $n|q^2+1$ via cyclic codes over finite fields of odd characteristic. Among our constructions there are many EAQMDS codes with new parameters which have never been reported. And some of them have great larger minimum distance than known results., Comment: 10 pages

// Jingbo Qiao 1, 2 , Magdalena M. Grabowska 1, 3 , Ingrid S. Forestier-Roman 4 , Janni Mirosevich 1, 3 , Thomas C. Case 1, 3 , Dai H. Chung 1, 2 , Justin M.M. Cates 5 , Robert J. Matusik 1, 3 , H. Charles Manning 6 , Renjie Jin 1, 3 1 Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN, USA 2 Department of Pediatric Surgery, Vanderbilt University Medical Center, Nashville, TN, USA 3 Vanderbilt Prostate Cancer Center and Department of Urologic Surgery, Vanderbilt University Medical Center, Nashville, TN, USA 4 Department of Biochemistry, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico 5 Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA 6 Institute of Imaging Science and Center for Molecular Probes, Vanderbilt University Medical Center, Nashville, TN, USA Correspondence to: Renjie Jin, email: renjie.jin@vanderbilt.edu Keywords: GRP/GRP-R, NF-kappa B, androgen receptor variants, prostate cancer, progression Received: April 04, 2016 Accepted: July 27, 2016 Published: August 17, 2016 ABSTRACT Numerous studies indicate that androgen receptor splice variants (ARVs) play a critical role in the development of castration-resistant prostate cancer (CRPC), including the resistance to the new generation of inhibitors of androgen receptor (AR) action. Previously, we demonstrated that activation of NF-κB signaling increases ARVs expression in prostate cancer (PC) cells, thereby promoting progression to CRPC. However, it is unclear how NF-κB signaling is activated in CRPC. In this study, we report that long-term treatment with anti-androgens increases a neuroendocrine (NE) hormone — gastrin-releasing peptide (GRP) and its receptor (GRP-R) expression in PC cells. In addition, activation of GRP/GRP-R signaling increases ARVs expression through activating NF-κB signaling. This results in an androgen-dependent tumor progressing to a castrate resistant tumor. The knock-down of AR-V7 restores sensitivity to antiandrogens of PC cells over-expressing the GRP/GRP-R signaling pathway. These findings strongly indicate that the axis of Androgen-Deprivation Therapy (ADT) induces GRP/GRP-R activity, activation NF-κB and increased levels of AR-V7 expression resulting in progression to CRPC. Both prostate adenocarcinoma and small cell NE prostate cancer express GRP-R. Since the GRP-R is clinically targetable by analogue-based approach, this provides a novel therapeutic approach to treat advanced CRPC.

Prostate cancer (PCa) is the leading cancer among men. Androgen Deprivation Therapy (ADT) is a common treatment for advanced PCa. However, ADT eventually fails and PCa relapses, developing into castration-resistant prostate cancer (CRPCa). Although alternative pathways such as cancer stem-cell pathway and neuroendocrine differentiation bypass androgen receptor (AR) signaling, AR remains the central player in mediating CRPCa. In this study, we identified a mechanism that retains AR signaling after androgen deprivation. The TRAMP SV40 T antigen transgenic mouse is a model for PCa. The expression of SV40 T-antigen is driven by the androgen-responsive, prostate specific, Probasin promoter. It has been recognized that in this model, T-antigen is still expressed even after androgen ablation. It is unclear how the androgen-responsive Probasin promoter remains active and drives the expression of T-antigen in these tumors. In our study, we found that the expression of Foxa2, a forkhead transcription factor that is expressed in embryonic prostate and advanced stage prostate cancer, is co-expressed in T-antigen positive cells. To test if Foxa2 activates AR-responsive promoters and promotes the expression of T-antigen, we established the prostate epithelial cells that stably express Foxa2, NeoTag1/Foxa2 cells. Neotag1 cells were derived from the Probasin promoter driven SV40 T-antigen transgenic mouse. We found ectopic expression of Foxa2 drives the T-antigen expression regardless of the presence of androgens. Using this model system, we further explored the mechanism that activates AR-responsive promoters in the absence of androgens. Chromatin immunoprecipitation revealed the occupancy of both H3K27Ac, an epigenetic mark of an active transcription, and Foxa2 at the known AR target promoters, Probasin and FKBP5, in the absence of androgen stimulation. In conclusion, we have identified a mechanism that enables PCa to retain the AR signaling pathway after androgen ablation.

Identification of factors that mediate visceral and bone metastatic spread and subsequent bone remodeling events is highly relevant to successful therapeutic intervention in advanced human prostate cancer. TBX2, a T-box family transcription factor that negatively regulates cell-cycle inhibitor p21, plays critical roles during embryonic development, and recent studies have highlighted its role in cancer. Here, we report that TBX2 is overexpressed in human prostate cancer specimens and bone metastases from xenograft mouse models of human prostate cancer. Blocking endogenous TBX2 expression in PC3 and ARCaPM prostate cancer cell models using a dominant-negative construct resulted in decreased tumor cell proliferation, colony formation, and invasion in vitro. Blocking endogenous TBX2 in human prostate cancer mouse xenografts decreased invasion and abrogation of bone and soft tissue metastasis. Furthermore, blocking endogenous TBX2 in prostate cancer cells dramatically reduced bone-colonizing capability through reduced tumor cell growth and bone remodeling in an intratibial mouse model. TBX2 acted in trans by promoting transcription of the canonical WNT (WNT3A) promoter. Genetically rescuing WNT3A levels in prostate cancer cells with endogenously blocked TBX2 partially restored the TBX2-induced prostate cancer metastatic capability in mice. Conversely, WNT3A-neutralizing antibodies or WNT antagonist SFRP-2 blocked TBX2-induced invasion. Our findings highlight TBX2 as a novel therapeutic target upstream of WNT3A, where WNT3A antagonists could be novel agents for the treatment of metastasis and for skeletal complications in prostate cancer patients. Cancer Res; 77(6); 1331–44. ©2017 AACR.

Androgen receptor splicing variants (ARVs) that lack the ligand-binding domain (LBD) are associated with the development of castration-resistant prostate cancer (CRPC), including resistance to the new generation of high-affinity anti-androgens. However, the mechanism by which ARV expression is regulated is not fully understood. In this study, we show that the activation of classical nuclear factor-kappa B (NF-κB) signaling increases the expression of ARVs in prostate cancer (PCa) cells and converts androgen-sensitive PCa cells to become androgen-insensitive, whereas downregulation of NF-κB signaling inhibits ARV expression and restores responsiveness of CRPC to anti-androgen therapy. In addition, we demonstrated that combination of anti-androgen with NF-κB-targeted therapy inhibits efficiently tumor growth of human CRPC xenografts. These results indicate that induction of ARVs by activated NF-κB signaling in PCa cells is a critical mechanism by which the PCa progresses to CRPC. This has important implications as it can prolong the survival of CRPC patients by restoring the tumors to once again respond to conventional androgen-deprivation therapy (ADT).

In many patients with prostate cancer, the cancer will be recurrent and eventually progress to lethal metastatic disease after primary treatment, such as surgery or radiation therapy. Therefore, it would be beneficial to better predict which patients with early-stage prostate cancer would progress or recur after primary definitive treatment. In addition, many studies indicate that activation of NF-κB signaling correlates with prostate cancer progression; however, the precise underlying mechanism is not fully understood. Our studies show that activation of NF-κB signaling via deletion of one allele of its inhibitor, IκBα, did not induce prostatic tumorigenesis in our mouse model. However, activation of NF-κB signaling did increase the rate of tumor progression in the Hi-Myc mouse prostate cancer model when compared with Hi-Myc alone. Using the nonmalignant NF-κB–activated androgen-depleted mouse prostate, a NF-κB–activated recurrence predictor 21 (NARP21) gene signature was generated. The NARP21 signature successfully predicted disease-specific survival and distant metastases-free survival in patients with prostate cancer. This transgenic mouse model–derived gene signature provides a useful and unique molecular profile for human prostate cancer prognosis, which could be used on a prostatic biopsy to predict indolent versus aggressive behavior of the cancer after surgery. Cancer Res; 74(10); 2763–72. ©2014 AACR.

When the National Institutes of Health Mouse Models of Human Cancer Consortium initiated the Prostate Steering Committee 15years ago, there were no genetically engineered mouse (GEM) models of prostate cancer (PCa). Today, a PubMed search for "prostate cancer mouse model" yields 3,200 publications and this list continues to grow. The first generation of GEM utilized the newly discovered and characterized probasin promoter driving viral oncogenes such as Simian virus 40 large T antigen to yield the LADY and TRAMP models. As the PCa research field has matured, the second generation of models has incorporated the single and multiple molecular changes observed in human disease, such as loss of PTEN and overexpression of Myc. Application of these models has revealed that mice are particularly resistant to developing invasive PCa, and once they achieve invasive disease, the PCa rarely resembles human disease. Nevertheless, these models and their application have provided vital information on human PCa progression. The aim of this review is to provide a brief primer on mouse and human prostate histology and pathology, provide descriptions of mouse models, as well as attempt to answer the age old question: Which GEM model of PCa is the best for my research question? © 2014 Springer Science+Business Media New York.

Introduction. Approximately 30,000 men will die from prostate cancer (PCa) in 2018. When localized and detected early, it has a low rate of progression and metastasis, with successful treatment. However, some patients may progress to a more lethal castrate-resistant PCa. While this occurs, frequent bone metastases will arise, and patient prognosis typically falls to 3-5 years due to lack of therapy available. The purpose of this study was to unveil the mechanisms of PCa bone colonization, allowing us to identify novel targeted therapies to prevent and treat PCa. Methods. Gene expression profiling studies revealed a subset of metastatic PCa samples express the pioneer forkhead transcription factor, FOXA2. Consistently, we found FOXA2 abundance in a sample set of human PCa bone metastases, which may suggest a functional role for FOXA2. Protein analysis of common PCa cell lines revealed high levels of FOXA2 in aggressive bone metastatic PCa PC3 cells. To understand the role of FOXA2 in PCa metastasis, FOXA2 was stably knocked down in PC3 cells. Results. PC3 cells with FOXA2 knocked down (FOXA2-KD) failed to generate in vivo bone destruction following intra-tibial injection contradictory to their parental cell line. To elucidate how FOXA2 is orchestrating these changes, we assessed the expression of all integrins and observed that loss of FOXA2 decreased mRNA and protein expression of the collagen-I binding integrin α1. Furthermore, we found FOXA2-KD decreased PC3 cells’ adhesion, spreading, and downstream Integrin α1 signaling cascades on collagen-I (a major component of bone ECM) coated surfaces. Additionally, a neutralizing antibody to integrin α1 was administered to PC3 Control cells, prompting the same adhesion pattern, solidifying that this integrin is critical to collagen-I adherence. Through ChIP analysis, we learned that FOXA2 directly regulates the ITGA1 gene promoter. Lastly, we overexpressed integrin α1 in PC3 FOXA2-KD cells and rescued the adherence properties. Conclusions. Taken together, the FOXA2-controlled expression of integrin α1 resulted in changes to adherence, spreading, and integrin signaling, providing a mechanism for how PCa cells colonize the bones. Funding: This research is supported by DOD grant (W81XWH-12-1-0212), NIH grants (R03 CA212567 and R01 CA226285), LSUHSC startups (FWCC and Office of Research) to XY, and Carroll Feist Pre-doctoral Fellowship to ZC. Citation Format: Zachary M. Connelly, Shu Yang, Nazih Khater, A. Wayne Orr, Renjie Jin, David Degraff, Colm Morrissey, Eva Corey, Robert Matusik, Xiuping Yu. The pioneer transcription factor FOXA2 regulates integrin alpha 1 expression controlling prostate cancer bone colonization [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 59.

Nuclear factor-κB (NF-κB) signaling contributes to human disease processes, notably inflammatory diseases and cancer. NF-κB has a role in tumorigenesis and tumor growth, as well as promotion of metastases. Mechanisms responsible for abnormal NF-κB activation are not fully elucidated; however, RelA phosphorylation, particularly at serine residues S536 and S276, is critical for RelA function. Kinases that phosphorylate RelA promote oncogenic behaviors, suggesting that phosphatases targeting RelA could have tumor-inhibiting activities; however, few RelA phosphatases have been identified. Here, we identified tumor inhibitory and RelA phosphatase activities of the protein phosphatase 2C (PP2C) phosphatase family member, PPM1A. We show that PPM1A directly dephosphorylated RelA at residues S536 and S276 and selectively inhibited NF-κB transcriptional activity, resulting in decreased expression of monocyte chemotactic protein-1/chemokine (C-C motif) ligand 2 and interleukin-6, cytokines implicated in cancer metastasis. PPM1A depletion enhanced NF-κB-dependent cell invasion, whereas PPM1A expression inhibited invasion. Analyses of human expression data revealed that metastatic prostate cancer deposits had lower PPM1A expression compared with primary tumors without distant metastases. A hematogenous metastasis mouse model revealed that PPM1A expression inhibited bony metastases of prostate cancer cells after vascular injection. In summary, our findings suggest that PPM1A is a RelA phosphatase that regulates NF-κB activity and that PPM1A has tumor suppressor-like activity. Our analyses also suggest that PPM1A inhibits prostate cancer metastases and as neither gene deletions nor inactivating mutations of PPM1A have been described, increasing PPM1A activity in tumors represents a potential therapeutic strategy to inhibit NF-κB signaling or bony metastases in human cancer.

Androgen receptor (AR) within prostatic mesenchymal cells, with the absence of AR in the epithelium, is still sufficient to induce prostate development. AR in the luminal epithelium is required to express the secretory markers associated with differentiation. Nkx3.1 is expressed in the epithelium in early prostatic embryonic development and expression is maintained in the adult. Induction of the mouse prostate gland by the embryonic mesenchymal cells results in the organization of a sparse basal layer below the luminal epithelium with rare neuroendocrine cells that are interdispersed within this basal layer. The human prostate shows similar glandular organization; however, the basal layer is continuous. The strong inductive nature of embryonic prostatic and bladder mesenchymal cells is demonstrated in grafts where embryonic stem (ES) cells are induced to differentiate and organize as a prostate and bladder, respectively. Further, the ES cells can be driven by the correct embryonic mesenchymal cells to form epithelium that differentiates into secretory prostate glands and differentiated bladders that produce uroplakin. This requires the ES cells to mature into endoderm that gives rise to differentiated epithelium. This process is control by transcription factors in both the inductive mesenchymal cells (AR) and the responding epithelium (FoxA1 and Nkx3.1) that allows for organ development and differentiation. In this review, we explore a molecular mechanism where the pattern of transcription factor expression controls cell determination, where the cell is assigned a developmental fate and subsequently cell differentiation, and where the assigned cell now emerges with it's own unique character.

p57Kip2 has been considered a candidate tumor suppressor gene because of its location in the genome, biochemical activities, and imprinting status. However, little is known about the role of p57Kip2 in tumorigenesis and cancer progression. Here, we show that the expression of p57Kip2 is significantly decreased in human prostate cancer, and the overexpression of p57Kip2 in prostate cancer cells significantly suppressed cell proliferation and reduced invasive ability. In addition, overexpression of p57Kip2 in LNCaP cells inhibited tumor formation in nude mice, resulting in well-differentiated squamous tumors rather than adenocarcinoma. Furthermore, the prostates of p57Kip2 knockout mice developed prostatic intraepithelial neoplasia and adenocarcinoma. Remarkably, this mouse prostate cancer is pathologically identical to human prostate adenocarcinoma. Therefore, these results strongly suggest that p57Kip2 is an important gene in prostate cancer tumorigenesis, and the p57Kip2 pathway may be a potential target for prostate cancer prevention and therapy. [Cancer Res 2008;68(10):3601–8]

Increases in neuroendocrine (NE) cells and their secretory products are closely correlated with tumor progression and androgen-independent prostate cancer. However, the mechanisms by which NE cells influence prostate cancer growth and progression, especially after androgen ablation therapy, are poorly understood. To investigate the role of NE cells on prostate cancer growth, LNCaP xenograft tumors were implanted into nude mice. After the LNCaP tumors were established, the NE mouse prostate allograft (NE-10) was implanted on the opposite flank of these nude mice to test whether NE tumor-derived systemic factors can influence LNCaP growth. Mice bearing LNCaP tumors with or without NE allografts were castrated 2 weeks after NE tumor inoculation, and changes in LNCaP tumor growth rate and gene expression were investigated. After castration, LNCaP tumor growth decreased in mice bearing LNCaP tumors alone, and this was accompanied by a loss of nuclear androgen receptor (AR) localization. In contrast, in castrated mice bearing both LNCaP and NE-10 tumors, LNCaP tumors continued to grow, had increased levels of nuclear AR, and secreted prostate-specific antigen. Therefore, in the absence of testicular androgens, NE secretions were sufficient to maintain LNCaP cell growth and androgen-regulated gene expression in vivo. Furthermore, in vitro experiments showed that NE secretions combined with low levels of androgens activated the AR, an effect that was blocked by the antiandrogen bicalutamide. Because an increase in AR level has been reported to be sufficient to account for hormone refractory prostate cancers, the NE cell population ability to increase AR level/activity can be another mechanism that allows prostate cancer to escape androgen ablation therapy.

We examined the functional role of clusterin in chemotherapy-induced apoptosis and tested whether anti-sense transfection targeted against clusterin enhances the chemosensitivity in human bladder cancer cells in vitro. Clusterin mRNA and protein expression of 253J cells, a human bladder carcinoma cell line, after treatment with cisplatin were measured by RT-PCR and Western blot analysis. Clusterin expression and cell growth were compared between 253J cells transfected with constructed a clusterin anti-sense plasmid vector (pCR-CLU-AS) and controls. Tumor cell viability was measured with MTT assay after cisplatin treatment. DNA fragmentation and CPP32 assay were performed. Clusterin expression was increased after treatment with cisplatin and highest at 8 h in 253J cells. Clusterin anti-sense transfectants were highly sensitive to apoptotic cell death induced by cisplatin compared with parental 253J cells or control transfectants. Collectively, our results showed that expression of clusterin was increased in the acute phase of cell death caused by cisplatin and that suppressing the expression of clusterin enhanced the susceptibility of apoptosis caused by cisplatin in human bladder cancer cells. These results suggest that lowering the expression of clusterin might increase the sensitivity of bladder cancer cells to chemotherapeutic agents.

In this study, the particle velocity, particle volume fraction (attenuation of transmission light), and heat transfer coefficient were simultaneously measured for a horizontal tube bundle immersed in a fluidized bed of 0.42 mm diameter glass beads. To improve the accuracy of the particle velocity measurements, an optical fiber probe composed of a combination of transmission and reflection types was designed. The particle velocities were calculated by using the cross-correlation method and the particle passing-time method, respectively. It was shown by comparison of particle velocities obtained by the two methods that the particle passing-time method gives more stable results. The particle velocities at the bottom and at the side of a tube were relatively large and appeared to have periodicity while those near the top of the tube were low. This particle contacting feature can be used to explain the heat transfer characteristics.

Metastasis, the main cause of death from cancer, remains poorly understood at the molecular level.Based on a pattern of reduced expression in human prostate cancer tissues and tumor cell lines, a candidate suppressor gene (SPARCL1) was identified. We used in vitro approaches to determine whether overexpression of SPARCL1 affects cell growth, migration, and invasiveness. We then employed xenograft mouse models to analyze the impact of SPARCL1 on prostate cancer cell growth and metastasis in vivo.SPARCL1 expression did not inhibit tumor cell proliferation in vitro. By contrast, SPARCL1 did suppress tumor cell migration and invasiveness in vitro and tumor metastatic growth in vivo, conferring improved survival in xenograft mouse models.We present the first in vivo data suggesting that SPARCL1 suppresses metastasis of prostate cancer.

Patients with advanced prostate cancer almost invariably develop osseous metastasis. Although many studies indicate that the activation of NF-κB signaling appears to be correlated with advanced cancer and promotes tumor metastasis by influencing tumor cell migration and angiogenesis, the influence of altered NF-κB signaling in prostate cancer cells within boney metastatic lesions is not clearly understood. While C4-2B and PC3 prostate cancer cells grow well in the bone, LNCaP cells are difficult to grow in murine bone following intraskeletal injection. Our studies show that when compared to LNCaP, NF-κB activity is significantly higher in C4-2B and PC3, and that the activation of NF-κB signaling in prostate cancer cells resulted in the increased expression of the osteoclast inducing genes PTHrP and RANKL. Further, conditioned medium derived from NF-κB activated LNCaP cells induce osteoclast differentiation. In addition, inactivation of NF-κB signaling in prostate cancer cells inhibited tumor formation in the bone, both in the osteolytic PC3 and osteoblastic/osteoclastic mixed C4-2B cells; while the activation of NF-κB signaling in LNCaP cells promoted tumor establishment and proliferation in the bone. The activation of NF-κB in LNCaP cells resulted in the formation of an osteoblastic/osteoclastic mixed tumor with increased osteoclasts surrounding the new formed bone, similar to metastases commonly seen in patients with prostate cancer. These results indicate that osteoclastic reaction is required even in the osteoblastic cancer cells and the activation of NF-κB signaling in prostate cancer cells increases osteoclastogenesis by up-regulating osteoclastogenic genes, thereby contributing to bone metastatic formation.