Advanced prostate cancers comprise distinct phenotypes, but tumor classification remains clinically challenging. Here, we harnessed circulating tumor DNA (ctDNA) to study tumor phenotypes by ascertaining nucleosome positioning patterns... more
Advanced prostate cancers comprise distinct phenotypes, but tumor classification remains clinically challenging. Here, we harnessed circulating tumor DNA (ctDNA) to study tumor phenotypes by ascertaining nucleosome positioning patterns associated with transcription regulation. We sequenced plasma ctDNA whole genomes from patient-derived xenografts representing a spectrum of androgen receptor active (ARPC) and neuroendocrine (NEPC) prostate cancers. Nucleosome patterns associated with transcriptional activity were reflected in ctDNA at regions of genes, promoters, histone modifications, transcription factor binding, and accessible chromatin. We identified the activity of key phenotype-defining transcriptional regulators from ctDNA, including AR, ASCL1, HOXB13, HNF4G, and GATA2. To distinguish NEPC and ARPC in patient plasma samples, we developed prediction models that achieved accuracies of 97% for dominant phenotypes and 87% for mixed clinical phenotypes. While phenotype classificat...
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Purpose: Neuroendocrine prostate cancer (NEPC) is an aggressive form of castration-resistant prostate cancer (CRPC) for which effective therapies are lacking. We previously identified carcinoembryonic antigen-related cell adhesion... more
Purpose: Neuroendocrine prostate cancer (NEPC) is an aggressive form of castration-resistant prostate cancer (CRPC) for which effective therapies are lacking. We previously identified carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5) as a promising NEPC cell surface antigen. Here we investigated the scope of CEACAM5 expression in end-stage prostate cancer, the basis for CEACAM5 enrichment in NEPC, and the therapeutic potential of the CEACAM5 antibody–drug conjugate labetuzumab govitecan in prostate cancer. Experimental Design: The expression of CEACAM5 and other clinically relevant antigens was characterized by multiplex immunofluorescence of a tissue microarray comprising metastatic tumors from 34 lethal metastatic CRPC (mCRPC) cases. A genetically defined neuroendocrine transdifferentiation assay of prostate cancer was developed to evaluate mechanisms of CEACAM5 regulation in NEPC. The specificity and efficacy of labetuzumab govitecan was determined in CEACAM5+ p...
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Tumor androgens in castration resistant prostate cancer (CRPC) reflect de novo intra-tumoral synthesis or adrenal androgens. We used C.B.-17 SCID mice in which we observed adrenal CYP17A activity to isolate the impact of adrenal steroids... more
Tumor androgens in castration resistant prostate cancer (CRPC) reflect de novo intra-tumoral synthesis or adrenal androgens. We used C.B.-17 SCID mice in which we observed adrenal CYP17A activity to isolate the impact of adrenal steroids on CRPC tumors in vivo Experimental Design: We evaluated tumor growth and androgens in LuCaP35CR and LuCaP96CR xenografts in response to adrenalectomy. We assessed protein expression of key steroidogenic enzymes in 185 CRPC metastases from 42 patients. Adrenal glands of intact and castrated mice expressed CYP17A. Serum DHEA, AED and T in castrated mice became undetectable after adrenalectomy (all p<0.05). Adrenalectomy prolonged median survival (days) in both CRPC models (33 vs 179; 25 vs 301) and suppressed tumor steroids vs castration alone (T 0.64 vs 0.03pg/mg; DHT 2.3 vs 0.23pg/mg; and T 0.81 vs 0.03pg/mg, DHT 1.3 vs 0.04pg/mg; all p=<0.001). A subset of tumors recurred with increased steroid levels, and/or induction of AR, truncated AR va...
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Cardiac fibrosis is observed across diverse etiologies of heart failure. Granzyme B (GzmB) is a serine protease involved in cell-mediated cytotoxicity in conjunction with the pore-forming protein, perforin. Recent evidence suggests that... more
Cardiac fibrosis is observed across diverse etiologies of heart failure. Granzyme B (GzmB) is a serine protease involved in cell-mediated cytotoxicity in conjunction with the pore-forming protein, perforin. Recent evidence suggests that GzmB also contributes to matrix remodeling and fibrosis through an extracellular, perforin-independent process. However, the role of GzmB in the onset and progression of cardiac fibrosis remains elusive. The present study investigated the role of GzmB in the pathogenesis of cardiac fibrosis. GzmB was elevated in fibrotic human hearts and in angiotensin II-induced murine cardiac fibrosis. Genetic deficiency of GzmB reduced angiotensin II-induced cardiac hypertrophy and fibrosis, independently of perforin. GzmB deficiency also reduced microhemorrhage, inflammation, and fibroblast accumulation in vivo. In vitro, GzmB cleaved the endothelial junction protein, VE-cadherin, resulting in the disruption of endothelial barrier function. Together, these result...
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Diabetic nephropathy, the leading cause of end-stage renal disease, is characterized by a proapoptotic and prooxidative environment. The mechanisms by which lifestyle interventions, such as exercise, benefit diabetic nephropathy are... more
Diabetic nephropathy, the leading cause of end-stage renal disease, is characterized by a proapoptotic and prooxidative environment. The mechanisms by which lifestyle interventions, such as exercise, benefit diabetic nephropathy are unknown. We hypothesized that exercise inhibits early diabetic nephropathy via attenuation of the mitochondrial apoptotic pathway and oxidative damage. Type 2 diabetic db/db and normoglycemic wild-type mice were exercised for an hour everyday at a moderate intensity for 7 wk, following which renal function, morphology, apoptotic signaling, and oxidative stress were evaluated. Exercise reduced body weight, albuminuria, and pathological glomerular expansion in db/db mice independent of hyperglycemic status. Changes in renal morphology were also related to reduced caspase-3 (main effector caspase in renal apoptosis), caspase-8 (main initiator caspase of the “extrinsic” pathway) activities, and TNF-α expression. A role for the mitochondrial apoptotic pathway...
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Anaplastic lymphoma kinase (ALK) is a tyrosine kinase with genomic and expression changes in many solid tumors. ALK inhibition is first line therapy for lung cancers with ALK alterations, and an effective therapy in other tumor types, but... more
Anaplastic lymphoma kinase (ALK) is a tyrosine kinase with genomic and expression changes in many solid tumors. ALK inhibition is first line therapy for lung cancers with ALK alterations, and an effective therapy in other tumor types, but has not been well-studied in prostate cancer. Here, we aim to delineate the role of ALK genomic and expression changes in primary and metastatic prostate cancer. We determined ALK expression by immunohistochemistry and RNA-Seq, and genomic alterations by NGS. We assessed functional consequences of ALK overexpression and pharmacological ALK inhibition by cell proliferation and cell viability assays. Among 372 primary prostate cancer cases we identified one case with uniformly high ALK protein expression. Genomic analysis revealed a SLC45A3-ALK fusion which promoted oncogenesis in in vitro assays. We observed ALK protein expression in 5/52 (9%) of metastatic prostate cancer cases, of which 4 of 5 had neuroendocrine features. ALK-expressing neuroendoc...
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Abdominal aortic aneurysm (AAA) is an age-related disease resulting in aortic wall weakening and dilatation which may progress to the fatal point of abrupt aortic wall rupture. Chronic inflammation is a driving force in the pathogenesis... more
Abdominal aortic aneurysm (AAA) is an age-related disease resulting in aortic wall weakening and dilatation which may progress to the fatal point of abrupt aortic wall rupture. Chronic inflammation is a driving force in the pathogenesis of AAA and extracellular matrix (ECM) proteases are considered central to aortic wall degradation. Considerable effort is dedicated to identifying the proteases responsible as well as the mechanism by which these proteases contribute to disease progression. As such, they are considered important molecular targets for pharmacological intervention. Along with smoking, male gender and family history, aging is a major risk factor for AAA. Examination of age-related changes of the immune system reveals an interwoven relationship between the processes of aging and chronic inflammation, collectively predisposing to AAA development. The present review explores current evidence as to the role of specific ECM proteases in AAA pathogenesis. The contribution of the aging process to disease pathogenesis is also explored to provide the relevant context and highlight key molecular pathways that should be considered while attempting to develop effective treatment approaches.