Publications by authors named "Brian W Simons"

45 Publications

Microparticle Encapsulation of a Prostate-Targeted Biologic for the Treatment of Liver Metastases in a Preclinical Model of Castration-Resistant Prostate Cancer.

Mol Cancer Ther 2020 Sep 17. Epub 2020 Sep 17.

The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University

PRX302 is a highly potent mutant bacterial pore-forming biologic protoxin engineered for selective activation by prostate specific antigen (PSA), a serine protease expressed by benign and malignant prostate epithelial cells. Though being developed as a local therapy for benign prostatic hyperplasia and localized prostate cancer, PRX302 cannot be administered systemically as a treatment for metastatic disease due to binding to ubiquitously expressed glycosylphosphatidylinositol (GPI)-anchored proteins, which leads to poor accumulation within the tumor microenvironment. To overcome this limitation, poly-lactic-co-glycolic acid (PLGA) microparticles encapsulating the protoxin were developed, which are known to accumulate in the liver, a major site of metastasis for prostate cancer and other solid tumors. A highly sensitive and reproducible sandwich ELISA to quantify PRX302 released from microparticles was developed. Utilizing this assay, PRX302 release from different microparticle formulations was assessed over multiple days. Hemolysis assays documented PSA-dependent pore formation and lytic potential (i.e. function) of the released protoxin. MTT assays demonstrated that conditioned supernatant from PRX302-loaded but not blank (i.e. unloaded) PLGA microparticles was highly cytotoxic to PC3 and DU145 human prostate cancer cells in the presence of exogenous PSA. Microparticle encapsulation prevented PRX302 from immediately interacting with GPI-anchored proteins as demonstrated in a competition assay, which resulted in an increased therapeutic index and significant anti-tumor efficacy following a single dose of PRX302-loaded microparticles in a preclinical model of prostate cancer liver metastasis with no obvious toxicity. These results document PRX302 released from PLGA microparticles demonstrate in vivo anti-tumor efficacy in a clinically-relevant preclinical model of metastatic prostate cancer.
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http://dx.doi.org/10.1158/1535-7163.MCT-20-0227DOI Listing
September 2020

A hemi-spleen injection model of liver metastasis for prostate cancer.

Prostate 2020 10 6;80(14):1263-1269. Epub 2020 Aug 6.

Department of Urology, James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland.

Background: Liver metastasis is not uncommon in men with metastatic castration-resistant prostate cancer (mCRPC), estimated at ~20% to 60% of advanced late-stage patients. Liver and other visceral metastases are associated with worse overall survival. Recent evidence suggests the frequency of visceral metastases may be increasing for reasons that are unclear but may be related to selective pressures induced by modern therapies, including second-generation antiandrogen receptor signaling inhibitors such as enzalutamide and abiraterone. Consequently, robust models to study the pathobiology of prostate cancer liver metastases and their response to therapy are urgently needed.

Methods: Hemi-spleen injection of human (LN95, PC3, VCaP, and MDA-PCa-2b) or syngeneic (Myc-CaP) prostate cancer cells (1 × 10 ) was performed to seed liver metastases via the splenic vessels. Plasma levels of prostate-specific antigen (PSA) were monitored longitudinally in human androgen receptor-positive (AR+) models. Immunohistochemical staining of AR and HoxB13 was performed to document the prostatic origin of hepatic lesions.

Results: LN95, PC3, and Myc-CaP produced distinct liver micrometastases that progressed to macrometastases by ~2 to 4 weeks postinoculation, while inoculation of MDA-PCa-2b and VCaP only produced occasional micrometastases and seeding of individual cells adjacent to blood vessels, respectively, at the time points analyzed. All lesions are characterized by positive staining for nuclear AR and/or the prostate-specific differentiation marker HoxB13 depending on the model. Circulating PSA levels are strongly correlated with overall tumor burden in mice seeded with LN95. Histologic micrometastases and low levels of circulating PSA are detected in mice seeded with MDA-PCa-2b at ~60 days postinoculation, but no circulating PSA was detected in animals inoculated with VCaP up to ~75 days despite the presence of rare AR+ cells in the liver.

Conclusion: The studies reported herein establish intrasplenic injection as a robust model of mCRPC liver metastasis. In addition, circulating PSA was validated as a noninvasive biomarker to longitudinally monitor overall tumor burden when using PSA+ models. Therefore, this model can be used to interrogate the pathophysiology of prostate cancer liver metastases, the microenvironmental factors permissive to such growth, immunologic variables, and the response of hepatic lesions to therapy.
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http://dx.doi.org/10.1002/pros.24055DOI Listing
October 2020

Stromal CAVIN1 Controls Prostate Cancer Microenvironment and Metastasis by Modulating Lipid Distribution and Inflammatory Signaling.

Mol Cancer Res 2020 09 3;18(9):1414-1426. Epub 2020 Jun 3.

Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland.

Lipid uptake occurs through caveolae, plasma membrane invaginations formed by caveolins (CAV) and caveolae-associated protein 1 (CAVIN1). Genetic alterations of and modify lipid metabolism and underpin lipodystrophy syndromes. Lipids contribute to tumorigenesis by providing fuel to cancer metabolism and supporting growth and signaling. Tumor stroma promotes tumor proliferation, invasion, and metastasis, but how stromal lipids influence these processes remain to be defined. Here, we show that stromal CAVIN1 regulates lipid abundance in the prostate cancer microenvironment and suppresses metastasis. We show that depletion of CAVIN1 in prostate stromal cells markedly reduces their lipid droplet accumulation and increases inflammation. Stromal cells lacking CAVIN1 enhance prostate cancer cell migration and invasion. Remarkably, they increase lipid uptake and M2 inflammatory macrophage infiltration in the primary tumors and metastasis to distant sites. Our data support the concept that stromal cells contribute to prostate cancer aggressiveness by modulating lipid content and inflammation in the tumor microenvironment. IMPLICATIONS: This study showed that stromal CAVIN1 suppresses prostate cancer metastasis by modulating tumor microenvironment, lipid content, and inflammatory response.
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http://dx.doi.org/10.1158/1541-7786.MCR-20-0364DOI Listing
September 2020

Nanoparticle interactions with immune cells dominate tumor retention and induce T cell-mediated tumor suppression in models of breast cancer.

Sci Adv 2020 03 25;6(13):eaay1601. Epub 2020 Mar 25.

Department of Radiation Oncology and Molecular Radiation Sciences, School of Medicine, Johns Hopkins University, Baltimore, MD 21231, USA.

The factors that influence nanoparticle fate in vivo following systemic delivery remain an area of intense interest. Of particular interest is whether labeling with a cancer-specific antibody ligand ("active targeting") is superior to its unlabeled counterpart ("passive targeting"). Using models of breast cancer in three immune variants of mice, we demonstrate that intratumor retention of antibody-labeled nanoparticles was determined by tumor-associated dendritic cells, neutrophils, monocytes, and macrophages and not by antibody-antigen interactions. Systemic exposure to either nanoparticle type induced an immune response leading to CD8 T cell infiltration and tumor growth delay that was independent of antibody therapeutic activity. These results suggest that antitumor immune responses can be induced by systemic exposure to nanoparticles without requiring a therapeutic payload. We conclude that immune status of the host and microenvironment of solid tumors are critical variables for studies in cancer nanomedicine and that nanoparticle technology may harbor potential for cancer immunotherapy.
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http://dx.doi.org/10.1126/sciadv.aay1601DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7096167PMC
March 2020

Preclinical Single Photon Emission Computed Tomography of Alpha Particle-Emitting Radium-223.

Cancer Biother Radiopharm 2020 Sep 17;35(7):520-529. Epub 2020 Mar 17.

Department of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA.

Dose optimization and pharmacokinetic evaluation of α-particle emitting radium-223 dichloride (RaCl) by planar γ-camera or single photon emission computed tomography (SPECT) imaging are hampered by the low photon abundance and injected activities. In this study, we demonstrate SPECT of Ra using phantoms and small animal models. Line phantoms and mice bearing Ra were imaged using a dedicated small animal SPECT by detecting the low-energy photon emissions from Ra. Localization of the therapeutic agent was verified by whole-body and whole-limb autoradiography and its radiobiological effect confirmed by immunofluorescence. A state-of-the-art commercial small animal SPECT system equipped with a highly sensitive collimator enables collection of sufficient counts for three-dimensional reconstruction at reasonable administered activities and acquisition times. Line sources of Ra in both air and in a water scattering phantom gave a line spread function with a full-width-at-half-maximum of 1.45 mm. Early and late-phase imaging of the pharmacokinetics of the radiopharmaceutical were captured. Uptake at sites of active bone remodeling was correlated with DNA damage from the α particle emissions. This work demonstrates the capability to noninvasively define the distribution of RaCl, a recently approved α-particle-emitting radionuclide. This approach allows quantitative assessment of Ra distribution and may assist radiation-dose optimization strategies to improve therapeutic response and ultimately to enable personalized treatment planning.
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http://dx.doi.org/10.1089/cbr.2019.3308DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7475100PMC
September 2020

Bovine papillomavirus prostate cancer antigen virus-like particle vaccines are efficacious in advanced cancers in the TRAMP mouse spontaneous prostate cancer model.

Cancer Immunol Immunother 2020 Apr 4;69(4):641-651. Epub 2020 Feb 4.

The Department of Pediatrics, Johns Hopkins University, 600 North Wolfe Street, Blalock Building 1153, Baltimore, MD, 21287, USA.

Prostate cancer is a candidate for immunotherapy because cancer cells express tissue-specific proteins that can be therapeutic targets. However, immune checkpoint inhibitors and active immunization have performed poorly in clinical trials. We developed a novel virus-like particle (VLP) vaccine composed of bovine papillomavirus L1 protein engineered to display surface docking sites. We decorated VLPs with peptides encoding T cell epitopes from two prostate cancer-associated tumor antigens, prostate stem cell antigen (PSCA), and prostatic acid phosphatase (PAP-1 and PAP-2), and a neo-antigen, stimulator of prostatic adenocarcinoma-specific T cells (SPAS-1). The VLP vaccines induced a mean frequency of antigen-specific IFN-γ secreting CD8 + T cells of 2.9% to PSCA, 9.5% to SPAS-1, 0.03% to PAP-1, and 0.03% to PAP-2 in tumor-bearing TRAMP mice. We treated TRAMP mice at 19-20 weeks of age, when mice have advanced stages of carcinogenesis, with either VLP vaccine, anti-PD1 antibody, or combination immunotherapy. The VLP vaccine alone or in combination with anti-PD1 antibody significantly reduced tumor burden, while anti-PD1 antibody had a modest non-significant therapeutic effect. All treatments significantly increased CD3 + and CD8 + T cell infiltration into tumor tissue compared to control mice, and combination therapy resulted in significantly greater CD3 + and CD8 + T cell infiltration than monotherapy. Reduction in tumor burden in vaccine-treated mice was inversely correlated with CD8 + T cell numbers in tumor tissue. No other immunotherapy has shown efficacy in this animal model of advanced prostate cancer, making bovine papillomavirus VLPs an attractive vaccine technology to test in patients with metastatic prostate cancer.
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http://dx.doi.org/10.1007/s00262-020-02493-zDOI Listing
April 2020

A mouse model of prostate cancer bone metastasis in a syngeneic immunocompetent host.

Oncotarget 2019 Dec 3;10(64):6845-6854. Epub 2019 Dec 3.

Department of Urology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.

We report the establishment of B6CaP, an allograft tumor line from a Hi-Myc transgenic mouse that had been backcrossed onto C57BL/6J background. This tumor line grows subcutaneously in wildtype C57BL/6J immunocompetent mice, expresses AR, and has a luminal cytokeratin profile. When digested into single cells and injected via intracardiac injection, B6CaP produces metastatic widespread metastases including frequent bone lesions. Metastatic lesions occur most often in the femur, spine, and skull, and have a mixed osteolytic/osteoblastic phenotype. B6CaP allografts are androgen dependent, and regress after castration. However, castration resistant tumors regrow after 4-6 months and can be maintained as androgen-independent clones. This is the first example of a prostate-derived tumor line that shows frequent metastasis to bone and grows in an immunocompetent host, making this model useful for studying mechanisms of bone metastasis and tumor immune response.
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http://dx.doi.org/10.18632/oncotarget.27317DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6901336PMC
December 2019

Genetic Alterations Detected in Cell-Free DNA Are Associated With Enzalutamide and Abiraterone Resistance in Castration-Resistant Prostate Cancer.

JCO Precis Oncol 2019 3;3. Epub 2019 Apr 3.

Johns Hopkins School of Medicine, Baltimore, MD.

Purpose: Androgen receptor () gene alterations, including ligand-binding domain mutations and copy number (CN) gain, have yet to be fully established as predictive markers of resistance to enzalutamide and abiraterone in men with metastatic castration-resistant prostate cancer (mCRPC). The goal of this study was to validate gene alterations detected in cell-free DNA (cfDNA) as markers of enzalutamide and abiraterone resistance in patients with mCRPC.

Methods: Patients with mCRPC (N = 62) were prospectively enrolled between 2014 and 2018. Blood was collected before therapies-enzalutamide (n = 25), abiraterone (n = 35), or enzalutamide and abiraterone (n -and at disease progression. We used deep next-generation sequencing to analyze cfDNA for sequence variants and CN status in and 45 additional cancer-associated genes. Primary end points were prostate-specific antigen response, progression-free survival (PFS), and overall survival (OS).

Results: Elevated tumor-specific cfDNA (circulating tumor DNA) was associated with a worse prostate-specific antigen response (hazard ratio [HR], 3.17; 95% CI, 1.11 to 9.05; = .031), PFS (HR, 1.76; 95% CI, 1.03 to 3.01; .039), and OS (HR, 2.92; 95% CI, 1.40 to 6.11; .004). ligand-binding domain missense mutations (HR, 2.51; 95% CI, 1.15 to 5.72; = .020) were associated with a shorter PFS in multivariable models. CN gain was associated with a shorter PFS; however, significance was lost in multivariable modeling. Genetic alterations in tumor protein p53 (HR, 2.70; 95% CI, 1.27 to 5.72; .009) and phosphoinositide 3-kinase pathway defects (HR, 2.62; 95% CI, 1.12 to 6.10; .026) were associated with a worse OS in multivariable models.

Conclusion: These findings support the conclusion that high circulating tumor DNA burden is associated with worse outcomes to enzalutamide and abiraterone in men with mCRPC. Tumor protein p53 loss and phosphoinositide 3-kinase pathway defects were associated with worse OS in men with mCRPC. status associations with outcomes were not robust, and additional validation is needed.
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http://dx.doi.org/10.1200/PO.18.00227DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6532665PMC
April 2019

Asporin Restricts Mesenchymal Stromal Cell Differentiation, Alters the Tumor Microenvironment, and Drives Metastatic Progression.

Cancer Res 2019 07 23;79(14):3636-3650. Epub 2019 May 23.

The James Buchanan Brady Urological Institute, Department of Urology, Johns Hopkins School of Medicine, Baltimore, Maryland.

Tumor progression to metastasis is not cancer cell autonomous, but rather involves the interplay of multiple cell types within the tumor microenvironment. Here we identify asporin (ASPN) as a novel, secreted mesenchymal stromal cell (MSC) factor in the tumor microenvironment that regulates metastatic development. MSCs expressed high levels of ASPN, which decreased following lineage differentiation. ASPN loss impaired MSC self-renewal and promoted terminal cell differentiation. Mechanistically, secreted ASPN bound to BMP-4 and restricted BMP-4-induced MSC differentiation prior to lineage commitment. ASPN expression was distinctly conserved between MSC and cancer-associated fibroblasts (CAF). ASPN expression in the tumor microenvironment broadly impacted multiple cell types. Prostate tumor allografts in ASPN-null mice had a reduced number of tumor-associated MSCs, fewer cancer stem cells, decreased tumor vasculature, and an increased percentage of infiltrating CD8 T cells. ASPN-null mice also demonstrated a significant reduction in lung metastases compared with wild-type mice. These data establish a role for ASPN as a critical MSC factor that extensively affects the tumor microenvironment and induces metastatic progression. SIGNIFICANCE: These findings show that asporin regulates key properties of mesenchymal stromal cells, including self-renewal and multipotency, and asporin expression by reactive stromal cells alters the tumor microenvironment and promotes metastatic progression.
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http://dx.doi.org/10.1158/0008-5472.CAN-18-2931DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6734938PMC
July 2019

Poxvirus Infection in a Colony of Laboratory Pigeons ().

Comp Med 2019 05 18;69(3):179-183. Epub 2019 Mar 18.

Center for Comparative Medicine, Baylor College of Medicine, Houston, Texas.

Pigeons () are used in biomedical research for studies of vision, cognition, neuronal pathways, and spatial orientation. Because there are few commercial laboratory sources, research pigeons are typically acquired from local fancier breeders or bred onsite. For acquired pigeons, the health and vaccine status is often unknown. A juvenile pigeon, born onsite and living in an enclosed outdoor loft, presented with small, bleeding, wart-like lesions on the medial aspects of digits 1 and 4. Topical treatment was initiated. Within a week, 4 fledglings were reported for small, dark papular lesions on the face, head, neck, and beak, and shortly thereafter, 2 additional juvenile pigeons developed similar lesions. The fledglings were euthanized, and histologic examination revealed numerous intralesional eosinophilic cytoplasmic viral inclusions (Bollinger bodies) confirming a diagnosis of poxvirus infection, likely pigeon pox. Although usually self-limiting, pigeon pox can cause moderate to severe lesions in fledgling and juvenile birds. Vaccination with a modified live poxvirus labeled for chickens was used to create herd immunity to pigeon poxvirus. Since vaccination of our entire flock and implementation of more stringent health protocols, all lesions have resolved, and no new lesions have been noted.
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http://dx.doi.org/10.30802/AALAS-CM-18-000074DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6591677PMC
May 2019

PSMA expression in the Hi-Myc model; extended utility of a representative model of prostate adenocarcinoma for biological insight and as a drug discovery tool.

Prostate 2019 05 17;79(6):678-685. Epub 2019 Jan 17.

Radiological Chemistry Imaging Laboratory, Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri.

Prostate-specific membrane antigen (PSMA), also known as glutamate carboxypeptidase II (GCPII), is highly overexpressed in primary and metastatic prostate cancer (PCa). This has led to the development of radiopharmaceuticals for targeted imaging and therapy under current clinical evaluation. Despite this progress, the exact biological role of the protein in prostate cancer development and progression has not been fully elucidated. This is in part because the human PSMA and mouse PSMA (mPSMA) have different patterns of anatomical expression which confound study in the most widely utilized model organisms. Most notably, mPSMA is not expressed in the healthy murine prostate. Here, we reveal that mPSMA is highly upregulated in the prostate adenocarcinoma of the spontaneous Hi-Myc mouse model, a highly accurate and well characterized mouse model of prostate cancer development. Antibody detection and molecular imaging tools are used to confirm that mPSMA is expressed from early prostatic intraepithelial neoplasia (PIN) through adenocarcinoma.
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http://dx.doi.org/10.1002/pros.23770DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6519119PMC
May 2019

Targeting the EMT transcription factor TWIST1 overcomes resistance to EGFR inhibitors in EGFR-mutant non-small-cell lung cancer.

Oncogene 2019 01 31;38(5):656-670. Epub 2018 Aug 31.

Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA.

Patients with EGFR-mutant non-small-cell lung cancer (NSCLC) have significantly benefited from the use of EGFR tyrosine kinase inhibitors (TKIs). However, long-term efficacy of these therapies is limited due to de novo resistance (~30%) as well as acquired resistance. Epithelial-mesenchymal transition transcription factors (EMT-TFs), have been identified as drivers of EMT-mediated resistance to EGFR TKIs, however, strategies to target EMT-TFs are lacking. As the third generation EGFR TKI, osimertinib, has now been adopted in the first-line setting, the frequency of T790M mutations will significantly decrease in the acquired resistance setting. Previously less common mechanisms of acquired resistance to first generation EGFR TKIs including EMT are now being observed at an increased frequency after osimertinib. Importantly, there are no other FDA approved targeted therapies after progression on osimertinib. Here, we investigated a novel strategy to overcome EGFR TKI resistance through targeting the EMT-TF, TWIST1, in EGFR-mutant NSCLC. We demonstrated that genetic silencing of TWIST1 or treatment with the TWIST1 inhibitor, harmine, resulted in growth inhibition and apoptosis in EGFR-mutant NSCLC. TWIST1 overexpression resulted in erlotinib and osimertinib resistance in EGFR-mutant NSCLC cells. Conversely, genetic and pharmacological inhibition of TWIST1 in EGFR TKI-resistant EGFR-mutant cells increased sensitivity to EGFR TKIs. TWIST1-mediated EGFR TKI resistance was due in part to TWIST1 suppression of transcription of the pro-apoptotic BH3-only gene, BCL2L11 (BIM), by directly binding to BCL2L11 intronic regions and promoter. As such, pan-BCL2 inhibitor treatment overcame TWIST1-mediated EGFR TKI resistance and were more effective in the setting of TWIST1 overexpression. Finally, in a mouse model of autochthonous EGFR-mutant lung cancer, Twist1 overexpression resulted in erlotinib resistance and suppression of erlotinib-induced apoptosis. These studies establish TWIST1 as a driver of resistance to EGFR TKIs and provide rationale for use of TWIST1 inhibitors or BCL2 inhibitors as means to overcome EMT-mediated resistance to EGFR TKIs.
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http://dx.doi.org/10.1038/s41388-018-0482-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6358506PMC
January 2019

O-GlcNAcylation is required for mutant KRAS-induced lung tumorigenesis.

J Clin Invest 2018 11 24;128(11):4924-4937. Epub 2018 Sep 24.

Department of Radiation Oncology and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center.

Mutant KRAS drives glycolytic flux in lung cancer, potentially impacting aberrant protein glycosylation. Recent evidence suggests aberrant KRAS drives flux of glucose into the hexosamine biosynthetic pathway (HBP). HBP is required for various glycosylation processes, such as protein N- or O-glycosylation and glycolipid synthesis. However, its function during tumorigenesis is poorly understood. One contributor and proposed target of KRAS-driven cancers is a developmentally conserved epithelial plasticity program called epithelial-mesenchymal transition (EMT). Here we showed in novel autochthonous mouse models that EMT accelerated KrasG12D lung tumorigenesis by upregulating expression of key enzymes of the HBP pathway. We demonstrated that HBP was required for suppressing KrasG12D-induced senescence, and targeting HBP significantly delayed KrasG12D lung tumorigenesis. To explore the mechanism, we investigated protein glycosylation downstream of HBP and found elevated levels of O-linked β-N-acetylglucosamine (O-GlcNAcylation) posttranslational modification on intracellular proteins. O-GlcNAcylation suppressed KrasG12D oncogene-induced senescence (OIS) and accelerated lung tumorigenesis. Conversely, loss of O-GlcNAcylation delayed lung tumorigenesis. O-GlcNAcylation of proteins SNAI1 and c-MYC correlated with the EMT-HBP axis and accelerated lung tumorigenesis. Our results demonstrated that O-GlcNAcylation was sufficient and required to accelerate KrasG12D lung tumorigenesis in vivo, which was reinforced by epithelial plasticity programs.
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http://dx.doi.org/10.1172/JCI94844DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6205381PMC
November 2018

The impact of age on radium-223 distribution and an evaluation of molecular imaging surrogates.

Nucl Med Biol 2018 Jul - Aug;62-63:1-8. Epub 2018 May 8.

Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Johns Hopkins University School of Medicine, United States; Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, United States. Electronic address:

Introduction: Radium-223 dichloride is the first alpha-particle emitting therapeutic agent approved by FDA and EMA for bone metastatic castration-resistant prostate cancer. We studied its age-dependent biodistribution in mice, and compared it with [Tc]Tc-MDP and [F]NaF aiming to identify a potential imaging surrogate to predict [Ra]RaCl whole-body localization.

Methods: Male C57Bl/6 mice dosed with [Ra]RaCl were sacrificed at different time points to explore [Ra]RaCl whole-body distribution. In another experiment, mice at different ages were dosed with [Ra]RaCl to evaluate the aging impact. Finally, [Tc]Tc-MDP and [F]NaF were administered to mice, and we compared their biodistributions with [Ra]RaCl. Detailed micro-localization of each tracer was visualized using autoradiography and histochemical staining.

Results: [Ra]RaCl uptake in bone was rapid and stable. We observed persistent localization at bone epiphyses, as well as the red pulp of the spleen, while its uptake in most soft tissues cleared within 24 h. [Ra]RaCl distribution in soft tissues is similar in all age groups tested, while bone activity significantly decreased with aging. Although the diagnostic tracers cleared much faster from soft tissues than the therapeutic radionuclide, [Tc]Tc-MDP and [F]NaF both co-localized with [Ra]RaCl in the skeletal compartment.

Conclusions: Radium-223 localization to the bone is dependent on age-varying factors, which implies that radium-223 dosimetry should take patient age into account. [Tc]Tc-MDP shows a different biodistribution from [Ra]RaCl, both in soft tissues and in bone. [F]NaF presents a high similarity with [Ra]RaCl in skeletal uptake, which validates the potential of [F]NaF as an imaging surrogate to predict radium-223 radiotherapeutic distribution in bone.
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http://dx.doi.org/10.1016/j.nucmedbio.2018.05.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6054814PMC
February 2019

Combining immune check-point blockade and cryoablation in an immunocompetent hormone sensitive murine model of prostate cancer.

Prostate Cancer Prostatic Dis 2018 04 20;21(1):126-136. Epub 2018 Mar 20.

Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA.

Background: Prostate cancer remains the second leading cause of cancer related death in men. Immune check point blocking antibodies have revolutionized treatment of multiple solid tumors, but results in prostate cancer remain marginal. Previous reports have suggested that local therapies, in particular cryoablation might increase tumor immunogenicity. In this work, we examine potential synergism between tumor cryoabalation and check point blocking antibodies.

Methods: FVB/NJ mice were injected subcutaneously into each flank with either 1 × 10 or 0.2 × 10 isogenic hormone sensitive Myc-Cap cells to establish synchronous grafts. Mice were treated with four intraperitoneal injections of anti-PD-1 (10 mg/kg), anti-CTLA-4 (1 mg/kg), or isotype control antibody with or without adjuvant cryoablation of the larger tumor graft and with or without neo-adjuvant androgen deprivation with degarelix (ADT). Mouse survival and growth rates of tumor grafts were measured. The immune dependency of observed oncological effects was evaluated by T cell depletion experiments.

Results: Treatment with anti-CTLA-4 antibody and cryoablation delayed the growth of the distant tumor by 14.8 days (p = 0.0006) and decreased the mortality rate by factor of 4 (p = 0.0003) when compared to cryoablation alone. This synergy was found to be dependent on CD3 and CD8 cells. Combining PD-1 blockade with cryoablation did not show a benefit over use of either treatment alone. Addition of ADT to anti-PD1 therapy and cryoablation doubled the time to accelerated growth in the untreated tumors (p = 0.0021) and extended survival when compared to cryoablation combined with ADT in 25% of the mice. Effects of combining anti-PD1 with ADT and cryoablation on mouse survival were obviated by T cell depletion.

Conclusion: Trimodal therapy consisting of androgen deprivation, cryoablation and PD-1 blockade, as well as the combination of cryoablation and low dose anti-CTLA-4 blockade showed that local therapies with cryoablation could be considered to augment the effects of checkpoint blockade in prostate cancer.
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http://dx.doi.org/10.1038/s41391-018-0035-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5990963PMC
April 2018

Absence of myeloid Klf4 reduces prostate cancer growth with pro-atherosclerotic activation of tumor myeloid cells and infiltration of CD8 T cells.

PLoS One 2018 11;13(1):e0191188. Epub 2018 Jan 11.

Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.

The microenvironment of prostate cancer often includes abundant tumor-associated macrophages (TAMs), with their acquisition of an M2 phenotype correlating with local aggressiveness and metastasis. Tumor-derived M-CSF contributes to TAM M2 polarization, and M-CSF receptor inhibition slows prostate cancer growth in model systems. As additional cytokines can direct TAM M2 polarization, targeting downstream transcription factors could avoid resistance. Klf4 and C/EBPβ each contribute to monocyte development, and reduced expression of macrophage Klf4 or C/EBPβ favors their adoption of a pro-inflammatory M1 state. We find that a Hi-Myc C57BL/6 prostate cancer line grows more slowly in syngeneic Klf4(f/f);Lys-Cre compared with Klf4(f/f) mice when inoculated subcutaneously, but grows equally rapidly in C/EBPβ(f/f);Lys-Cre and C/EBPβ(f/f) hosts. In the absence of myeloid Klf4, TAMs have reduced expression of surface mannose receptor and Fizz1 mRNA, both M2 markers. Global gene expression analysis further revealed activation of pro-inflammatory, pro-atherosclerotic pathways. Analysis of tumor-infiltrating lymphocytes (TILs) demonstrated markedly increased activated CD8 T cell numbers, and CD8 T cell depletion obviated the inhibitory effect of myeloid Klf4 deletion on prostate cancer growth. These findings suggest that reducing expression or activity of the Klf4 transcription factor in tumor myeloid cells may contribute to prostate cancer therapy.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0191188PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5764416PMC
February 2018

Therapeutic potential of an anti-angiogenic multimodal biomimetic peptide in hepatocellular carcinoma.

Oncotarget 2017 Nov 21;8(60):101520-101534. Epub 2017 Sep 21.

Department of Radiation Oncology and Molecular and Radiation Sciences, Sidney Kimmel Comprehensive Cancer Centre, Johns Hopkins School of Medicine, Baltimore, MD, USA.

Hepatocellular carcinoma (HCC) is a major cause of cancer-related death worldwide. Due to inadequate screening methods and the common coexistence of limited functional liver reserves, curative treatment options are limited. Liver transplantation is the only curative treatment modality for early HCC. There are multidisciplinary treatment options like ablative treatments, radiation and systemic therapy available for more advanced patients or those that are inoperable. Treatment resistance and progression is inevitable for these HCC patients. Newer therapeutics need to be explored for better management of HCC. HCC is a hypervascular tumor and many pro-angiogenic proteins are found significantly overexpressed in HCC. Here we explored the therapeutic potential of the anti-angiogenic, anti-lymphangiogenic, and directly anti-tumorigenic biomimetic collagen IV-derived peptide developed by our group. Human HCC cell lines HuH7, Hep3b and HepG2 showed significant disruption of cell adhesion and migration upon treatment with the peptide. Consistent with previously described multimodal inhibitory properties, the peptide was found to inhibit both c-Met and IGF1R signaling in HepG2 cells and blocked HepG2 conditioned media stimulation of microvascular endothelial cell (MEC) tube formation. Furthermore, the peptide treatment of mouse HepG2 tumor xenografts significantly inhibited growth relative to untreated controls. The peptide was also found to improve the survival of autochthonous Myc-induced HCC in a transgenic mouse model. Mechanistically, we found that the peptide treatment reduced microvascular density in the autochthonous liver tumors with increased apoptosis. This study shows the promising therapeutic potential of our biomimetic peptide in the treatment of HCC.
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http://dx.doi.org/10.18632/oncotarget.21148DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5731893PMC
November 2017

A Murine Orthotopic Allograft to Model Prostate Cancer Growth and Metastasis.

Bio Protoc 2017 Feb;7(4)

The James Buchanan Brady Urological Institute, Department of Urology, Johns Hopkins School of Medicine, Baltimore, USA.

Prostate cancer is one of the most common cancers in men in the United States. Comprehensive understanding of the biology contributing to prostate cancer will have important clinical implications. Animal models have greatly impacted our knowledge of disease and will continue to be a valuable resource for future studies. Herein, we describe a detailed protocol for the orthotopic engraftment of a murine prostate cancer cell line (Myc-CaP) into the anterior prostate of an immune competent mouse.
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http://dx.doi.org/10.21769/BioProtoc.2137DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5701568PMC
February 2017

Magnetic Resonance Imaging and Molecular Characterization of a Hormone-Mediated Murine Model of Prostate Enlargement and Bladder Outlet Obstruction.

Am J Pathol 2017 Nov 18;187(11):2378-2387. Epub 2017 Aug 18.

Department of Surgery, Section of Urology, The University of Chicago, Chicago, Illinois. Electronic address:

Urinary complications resulting from benign prostatic hyperplasia and bladder outlet obstruction continue to be a serious health problem. Novel animal model systems and imaging approaches are needed to understand the mechanisms of disease initiation, and to develop novel therapies for benign prostatic hyperplasia. Long-term administration of both estradiol and testosterone in mice can result in prostatic enlargement and recapitulate several clinical components of lower urinary tract symptoms. Herein, we use longitudinal magnetic resonance imaging and histological analyses to quantify changes in prostatic volume, urethral volume, and genitourinary vascularization over time in response to estradiol-induced prostatic enlargement. Our data demonstrate significant prostatic enlargement by 12 weeks after treatment, with no detectable immune infiltration by macrophages or T- or B-cell populations. Importantly, the percentage of cell death, as measured by terminal deoxynucleotidyl transferase dUTP nick-end labeling, was significantly decreased in the prostatic epithelium of treated animals as compared to controls. We found no significant change in prostate cell proliferation in treated mice when compared to controls. These studies highlight the utility of magnetic resonance imaging to quantify changes in prostatic and urethral volumes over time. In conjunction with histological analyses, this approach has the high potential to enable mechanistic studies of initiation and progression of clinically relevant lower urinary tract symptoms. In addition, this model is tractable for investigation and testing of therapeutic interventions to ameliorate or potentially reverse prostatic enlargement.
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http://dx.doi.org/10.1016/j.ajpath.2017.07.014DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5762949PMC
November 2017

AIM1 is an actin-binding protein that suppresses cell migration and micrometastatic dissemination.

Nat Commun 2017 07 26;8(1):142. Epub 2017 Jul 26.

Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, MD, USA.

A defining hallmark of primary and metastatic cancers is the migration and invasion of malignant cells. These invasive properties involve altered dynamics of the cytoskeleton and one of its major structural components β-actin. Here we identify AIM1 (absent in melanoma 1) as an actin-binding protein that suppresses pro-invasive properties in benign prostate epithelium. Depletion of AIM1 in prostate epithelial cells increases cytoskeletal remodeling, intracellular traction forces, cell migration and invasion, and anchorage-independent growth. In addition, decreased AIM1 expression results in increased metastatic dissemination in vivo. AIM1 strongly associates with the actin cytoskeleton in prostate epithelial cells in normal tissues, but not in prostate cancers. In addition to a mislocalization of AIM1 from the actin cytoskeleton in invasive cancers, advanced prostate cancers often harbor AIM1 deletion and reduced expression. These findings implicate AIM1 as a key suppressor of invasive phenotypes that becomes dysregulated in primary and metastatic prostate cancer.
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http://dx.doi.org/10.1038/s41467-017-00084-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5529512PMC
July 2017

TWIST1-WDR5- Regulates Chromatin to Facilitate Prostate Cancer Metastasis.

Cancer Res 2017 06 8;77(12):3181-3193. Epub 2017 May 8.

Department of Radiation Oncology and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland.

TWIST1 is a transcription factor critical for development that can promote prostate cancer metastasis. During embryonic development, TWIST1 and HOXA9 are coexpressed in mouse prostate and then silenced postnatally. Here we report that TWIST1 and HOXA9 coexpression are reactivated in mouse and human primary prostate tumors and are further enriched in human metastases, correlating with survival. TWIST1 formed a complex with WDR5 and the lncRNA Hottip/HOTTIP, members of the MLL/COMPASS-like H3K4 methylases, which regulate chromatin in the Hox/HOX cluster during development. TWIST1 overexpression led to coenrichment of TWIST1 and WDR5 as well as increased H3K4me3 chromatin at the Hoxa9/HOXA9 promoter, which was dependent on WDR5. Expression of WDR5 and Hottip/HOTTIP was also required for TWIST1-induced upregulation of HOXA9 and aggressive cellular phenotypes such as invasion and migration. Pharmacologic inhibition of HOXA9 prevented TWIST1-induced aggressive prostate cancer cellular phenotypes and metastasis This study demonstrates a novel mechanism by which TWIST1 regulates chromatin and gene expression by cooperating with the COMPASS-like complex to increase H3K4 trimethylation at target gene promoters. Our findings highlight a TWIST1-HOXA9 embryonic prostate developmental program that is reactivated during prostate cancer metastasis and is therapeutically targetable. .
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http://dx.doi.org/10.1158/0008-5472.CAN-16-2797DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5489316PMC
June 2017

Nanoparticles that do not adhere to mucus provide uniform and long-lasting drug delivery to airways following inhalation.

Sci Adv 2017 Apr 5;3(4):e1601556. Epub 2017 Apr 5.

The Center for Nanomedicine, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA.

Mucoadhesive particles (MAP) have been widely explored for pulmonary drug delivery because of their perceived benefits in improving particle residence in the lungs. However, retention of particles adhesively trapped in airway mucus may be limited by physiologic mucus clearance mechanisms. In contrast, particles that avoid mucoadhesion and have diameters smaller than mucus mesh spacings rapidly penetrate mucus layers [mucus-penetrating particles (MPP)], which we hypothesized would provide prolonged lung retention compared to MAP. We compared in vivo behaviors of variously sized, polystyrene-based MAP and MPP in the lungs following inhalation. MAP, regardless of particle size, were aggregated and poorly distributed throughout the airways, leading to rapid clearance from the lungs. Conversely, MPP as large as 300 nm exhibited uniform distribution and markedly enhanced retention compared to size-matched MAP. On the basis of these findings, we formulated biodegradable MPP (b-MPP) with an average diameter of <300 nm and examined their behavior following inhalation relative to similarly sized biodegradable MAP (b-MAP). Although b-MPP diffused rapidly through human airway mucus ex vivo, b-MAP did not. Rapid b-MPP movements in mucus ex vivo correlated to a more uniform distribution within the airways and enhanced lung retention time as compared to b-MAP. Furthermore, inhalation of b-MPP loaded with dexamethasone sodium phosphate (DP) significantly reduced inflammation in a mouse model of acute lung inflammation compared to both carrier-free DP and DP-loaded MAP. These studies provide a careful head-to-head comparison of MAP versus MPP following inhalation and challenge a long-standing dogma that favored the use of MAP for pulmonary drug delivery.
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http://dx.doi.org/10.1126/sciadv.1601556DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5381952PMC
April 2017

Characterization of aldehyde dehydrogenase 1 high ovarian cancer cells: Towards targeted stem cell therapy.

Gynecol Oncol 2016 08 11;142(2):341-8. Epub 2016 Jun 11.

Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, 1650 Orleans St., Baltimore, MD, USA. Electronic address:

Objective: The cancer stem cell (CSC) paradigm hypothesizes that successful clinical eradication of CSCs may lead to durable remission for patients with ovarian cancer. Despite mounting evidence in support of ovarian CSCs, their phenotype and clinical relevance remain unclear. We and others have found high aldehyde dehydrogenase 1 (ALDH(high)) expression in a variety of normal and malignant stem cells, and sought to better characterize ALDH(high) cells in ovarian cancer.

Methods: We compared ALDH(high) to ALDH(low) cells in two ovarian cancer models representing distinct subtypes: FNAR-C1 cells, derived from a spontaneous rat endometrioid carcinoma, and the human SKOV3 cell line (described as both serous and clear cell subtypes). We assessed these populations for stem cell features then analyzed expression by microarray and qPCR.

Results: ALDH(high) cells displayed CSC properties, including: smaller size, quiescence, regenerating the phenotypic diversity of the cell lines in vitro, lack of contact inhibition, nonadherent growth, multi-drug resistance, and in vivo tumorigenicity. Microarray and qPCR analysis of the expression of markers reported by others to enrich for ovarian CSCs revealed that ALDH(high) cells of both models showed downregulation of CD24, but inconsistent expression of CD44, KIT and CD133. However, the following druggable targets were consistently expressed in the ALDH(high) cells from both models: mTOR signaling, her-2/neu, CD47 and FGF18/FGFR3.

Conclusions: Based on functional characterization, ALDH(high) ovarian cancer cells represent an ovarian CSC population. Differential gene expression identified druggable targets that have the potential for therapeutic efficacy against ovarian CSCs from multiple subtypes.
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http://dx.doi.org/10.1016/j.ygyno.2016.03.022DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5843190PMC
August 2016

Germline Variants in Asporin Vary by Race, Modulate the Tumor Microenvironment, and Are Differentially Associated with Metastatic Prostate Cancer.

Clin Cancer Res 2016 Jan 7;22(2):448-58. Epub 2015 Oct 7.

Brady Urological Institute, Department of Urology, Johns Hopkins University, Baltimore, Maryland. Department of Oncology, Johns Hopkins University, Baltimore, Maryland. Sidney Kimmel Comprehensive Cancer Institute, Johns Hopkins University, Baltimore, Maryland.

Purpose: Prostate cancers incite tremendous morbidity upon metastatic growth. We previously identified Asporin (ASPN) as a potential mediator of metastatic progression found within the tumor microenvironment. ASPN contains an aspartic acid (D)-repeat domain and germline polymorphisms in D-repeat-length have been associated with degenerative diseases. Associations of germline ASPN D polymorphisms with risk of prostate cancer progression to metastatic disease have not been assessed.

Experimental Design: Germline ASPN D-repeat-length was retrospectively analyzed in 1,600 men who underwent radical prostatectomy for clinically localized prostate cancer and in 548 noncancer controls. Multivariable Cox proportional hazards models were used to test the associations of ASPN variations with risk of subsequent oncologic outcomes, including metastasis. Orthotopic xenografts were used to establish allele- and stroma-specific roles for ASPN D variants in metastatic prostate cancer.

Results: Variation at the ASPN D locus was differentially associated with poorer oncologic outcomes. ASPN D14 [HR, 1.72; 95% confidence interval (CI), 1.05-2.81, P = 0.032] and heterozygosity for ASPN D13/14 (HR, 1.86; 95% CI, 1.03-3.35, P = 0.040) were significantly associated with metastatic recurrence, while homozygosity for the ASPN D13 variant was significantly associated with a reduced risk of metastatic recurrence (HR, 0.44; 95% CI, 0.21-0.94, P = 0.035) in multivariable analyses. Orthotopic xenografts established biologic roles for ASPN D14 and ASPN D13 variants in metastatic prostate cancer progression that were consistent with patient-based data.

Conclusions: We observed associations between ASPN D variants and oncologic outcomes, including metastasis. Our data suggest that ASPN expressed in the tumor microenvironment is a heritable modulator of metastatic progression.
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http://dx.doi.org/10.1158/1078-0432.CCR-15-0256DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4715968PMC
January 2016

Androgen-Regulated SPARCL1 in the Tumor Microenvironment Inhibits Metastatic Progression.

Cancer Res 2015 Oct 20;75(20):4322-34. Epub 2015 Aug 20.

The James Buchanan Brady Urological Institute, Department of Urology, Johns Hopkins University, Baltimore, Maryland. The Department of Oncology, Johns Hopkins University, Baltimore, Maryland. The Sidney Kimmel Cancer Center, Johns Hopkins University, Baltimore, Maryland.

Prostate cancer is a leading cause of cancer death in men due to the subset of cancers that progress to metastasis. Prostate cancers are thought to be hardwired to androgen receptor (AR) signaling, but AR-regulated changes in the prostate that facilitate metastasis remain poorly understood. We previously noted a marked reduction in secreted protein, acidic and rich in cysteine-like 1 (SPARCL1) expression during invasive phases of androgen-induced prostate growth, suggesting that this may be a novel invasive program governed by AR. Herein, we show that SPARCL1 loss occurs concurrently with AR amplification or overexpression in patient-based data. Mechanistically, we demonstrate that SPARCL1 expression is directly suppressed by androgen-induced AR activation and binding at the SPARCL1 locus via an epigenetic mechanism, and these events can be pharmacologically attenuated with either AR antagonists or HDAC inhibitors. We establish using the Hi-Myc model of prostate cancer that in Hi-Myc/Sparcl1(-/-) mice, SPARCL1 functions to suppress cancer formation. Moreover, metastatic progression of Myc-CaP orthotopic allografts is restricted by SPARCL1 in the tumor microenvironment. Specifically, we show that SPARCL1 both tethers to collagen in the extracellular matrix (ECM) and binds to the cell's cytoskeleton. SPARCL1 directly inhibits the assembly of focal adhesions, thereby constraining the transmission of cell traction forces. Our findings establish a new insight into AR-regulated prostate epithelial movement and provide a novel framework whereby SPARCL1 in the ECM microenvironment restricts tumor progression by regulating the initiation of the network of physical forces that may be required for metastatic invasion of prostate cancer.
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http://dx.doi.org/10.1158/0008-5472.CAN-15-0024DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4609262PMC
October 2015

IDENTIFICATION OF MYCOBACTERIUM GENAVENSE IN A DIANA MONKEY (CERCOPITHECUS DIANA) BY POLYMERASE CHAIN REACTION AND HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY.

J Zoo Wildl Med 2015 Jun;46(2):339-44

A 25-yr-old Diana monkey (Cercopithecus diana) with a 1.5-yr history of chronic colitis and diarrhea was found to have disseminated granulomatous disease with intralesional acid fast bacilli. Bacilli were identified as Mycobacterium genavense by polymerase chain reaction, sequencing of the 16S-23S ribosomal RNA intergenic spacer (ITS) gene, and mycolic acid analysis by high-performance liquid chromatography. Mycobacterium genavense is a common cause of mycobacteriosis in free-ranging and captive birds. In addition, recognition of opportunistic infection in human immunodeficiency virus-positive patients is increasing. Disease manifestations of M. genavense are similar to Mycobacterium avium complex (MAC) and include fever, wasting, and diarrhea with disseminated disease. Similar clinical signs and lesions were observed in this monkey. Mycobacterium genavense should be considered as a differential for disseminated mycobacterial disease in nonhuman primates as this agent can mimic MAC and related mycobacteria.
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http://dx.doi.org/10.1638/2013-0246R2.1DOI Listing
June 2015

Bacterial Prostatitis Enhances 2-Amino-1-Methyl-6-Phenylimidazo[4,5-b]Pyridine (PhIP)-Induced Cancer at Multiple Sites.

Cancer Prev Res (Phila) 2015 Aug 19;8(8):683-92. Epub 2015 May 19.

Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland. Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Johns Hopkins University School of Medicine, Baltimore, Maryland. Department of Urology, James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland.

Dietary carcinogens, such as 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), and chronic inflammation have each been implicated as etiologic agents in prostate cancer. We hypothesized that bacterial prostatitis would accelerate PhIP-induced preinvasive lesions in the rat prostate. Male Fischer 344 rats were assigned into 4 groups: Control (untreated), PhIP (200 ppm in the diet for 20 weeks), Escherichia coli (E. coli, prostatic inoculation in week 10), or PhIP + E. coli. Study animals were monitored for a total of 52 weeks and were euthanized as necessary based on strict criteria for health status and tumor burden. Animals treated with E. coli initially developed acute and chronic inflammation in all lobes of the prostate, whereas inflammation was observed predominantly in the ventral lobe at time of death. PhIP + E. coli-treated animals exhibited a marked decrease in survival compared with PhIP-alone-treated animals as a result of an increase in the number of invasive cancers that developed at multiple sites, including the skin, small intestine, and Zymbal's gland. Despite their earlier mortality, PhIP + E. coli-treated animals developed an increased average number of precancerous lesions within the prostate compared with PhIP-treated animals, with a significantly increased Ki-67 index. Multiplexed serum cytokine analysis indicated an increase in the level of circulating IL6 and IL12 in PhIP + E. coli-treated animals. Elevated serum IL6 levels correlated with the development of precancerous lesions within the prostate. These results suggest that bacterial infections and dietary carcinogens, two conceivably preventable cancer risk factors, may synergistically promote tumorigenesis.
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http://dx.doi.org/10.1158/1940-6207.CAPR-15-0090DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4527940PMC
August 2015

A human prostatic bacterial isolate alters the prostatic microenvironment and accelerates prostate cancer progression.

J Pathol 2015 Feb;235(3):478-89

The Brady Urological Institute, Department of Urology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.

Inflammation is associated with several diseases of the prostate including benign enlargement and cancer, but a causal relationship has not been established. Our objective was to characterize the prostate inflammatory microenvironment after infection with a human prostate-derived bacterial strain and to determine the effect of inflammation on prostate cancer progression. To this end, we mimicked typical human prostate infection with retrograde urethral instillation of CP1, a human prostatic isolate of Escherichia coli. CP1 bacteria were tropic for the accessory sex glands and induced acute inflammation in the prostate and seminal vesicles, with chronic inflammation lasting at least 1 year. Compared to controls, infection induced both acute and chronic inflammation with epithelial hyperplasia, stromal hyperplasia, and inflammatory cell infiltrates. In areas of inflammation, epithelial proliferation and hyperplasia often persist, despite decreased expression of androgen receptor (AR). Inflammatory cells in the prostates of CP1-infected mice were characterized at 8 weeks post-infection by flow cytometry, which showed an increase in macrophages and lymphocytes, particularly Th17 cells. Inflammation was additionally assessed in the context of carcinogenesis. Multiplex cytokine profiles of inflamed prostates showed that distinct inflammatory cytokines were expressed during prostate inflammation and cancer, with a subset of cytokines synergistically increased during concurrent inflammation and cancer. Furthermore, CP1 infection in the Hi-Myc mouse model of prostate cancer accelerated the development of invasive prostate adenocarcinoma, with 70% more mice developing cancer by 4.5 months of age. This study provides direct evidence that prostate inflammation accelerates prostate cancer progression and gives insight into the microenvironment changes induced by inflammation that may accelerate tumour initiation or progression.
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http://dx.doi.org/10.1002/path.4472DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4352321PMC
February 2015

Intraperitoneal delivery of paclitaxel by poly(ether-anhydride) microspheres effectively suppresses tumor growth in a murine metastatic ovarian cancer model.

Drug Deliv Transl Res 2014 Apr;4(2):203-9

Department of Biomedical Engineering, Johns Hopkins University School of Medicine, 720 Rutland Avenue, Baltimore, MD 21205 (USA) ; Department of Chemical and Biomolecular Engineering, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218 (USA) ; Department of Ophthalmology, The Wilmer Eye Institute, Johns Hopkins University School of Medicine, 400 N Broadway, Baltimore, MD 21287 (USA) ; Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, MD 21287 (USA) ; Center for Cancer Nanotechnology Excellence, Institute for NanoBioTechnology, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218 (USA) ; Center for Nanomedicine, Johns Hopkins University School of Medicine, 400 N Broadway, Baltimore, MD 21287 (USA).

Intraperitoneal (IP) chemotherapy is more effective than systemic chemotherapy for treating advanced ovarian cancer, but is typically associated with severe complications due to high dose, frequent administration schedule, and use of non-biocompatible excipients/delivery vehicles. Here, we developed paclitaxel (PTX)-loaded microspheres composed of di-block copolymers of poly(ethylene glycol) and poly(sebacic acid) (PEG-PSA) for safe and sustained IP chemotherapy. PEG-PSA microspheres provided efficient loading (~ 13% w/w) and prolonged release (~ 13 days) of PTX. In a murine ovarian cancer model, a single dose of IP PTX/PEG-PSA particles effectively suppressed tumor growth for more than 40 days and extended the median survival time to 75 days compared to treatments with Taxol(®) (47 days) or IP placebo particles (34 days). IP PTX/PEG-PSA was well tolerated, with only minimal to mild inflammation. Our findings support PTX/PEG-PSA microspheres as a promising drug delivery platform for IP therapy of ovarian cancer, and potentially other metastatic peritoneal cancers.
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http://dx.doi.org/10.1007/s13346-013-0190-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3956079PMC
April 2014

A novel viscous dissecting gel for endoscopic submucosal dissection: a prospective survival study in a porcine model.

Endoscopy 2014 Jul 25;46(7):605-9. Epub 2014 Apr 25.

Department of Medicine and Division of Gastroenterology and Hepatology, Johns Hopkins Medical Institutions, Baltimore, Maryland, USA.

Background And Study Aims: Endoscopic submucosal dissection (ESD) is a technically challenging procedure. A novel gel can facilitate ESD due to its submucosal dissecting properties. This prospective porcine survival study evaluated clinical and histologic parameters of hybrid ESD using the gel.

Patients And Methods: Gastric submucosal lesions were created in six pigs and hybrid ESD was performed. Healing was assessed weekly until necropsy at Day 28.

Results: En bloc resection was achieved in all lesions (mean size 40.7 mm). The mean total procedure time was 13.5 minutes and the mean resection time was 5.5 minutes. The mean total histologic injury score was 4. At necropsy, four ulcers had healed completely and two were < 6 mm in size.

Conclusion: Hybrid ESD of large gastric lesions in a porcine model can be facilitated by the novel gel, dramatically reducing procedure and resection times by eliminating the need for time-consuming submucosal dissection. The novel gel is safe and easy to use, and has the potential to simplify ESD. Further prospective human studies are needed to validate these findings.
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http://dx.doi.org/10.1055/s-0034-1365406DOI Listing
July 2014