Publications by authors named "Ruth Birbe"

49 Publications

Increased expression of desmin and vimentin reduces bladder smooth muscle contractility via JNK2.

FASEB J 2020 02 16;34(2):2126-2146. Epub 2019 Dec 16.

Department of Medicine, Center for Translational Medicine, Thomas Jefferson University, Philadelphia, PA, USA.

Bladder dysfunction is associated with the overexpression of the intermediate filament (IF) proteins desmin and vimentin in obstructed bladder smooth muscle (BSM). However, the mechanisms by which these proteins contribute to BSM dysfunction are not known. Previous studies have shown that desmin and vimentin directly participate in signal transduction. In this study, we hypothesized that BSM dysfunction associated with overexpression of desmin or vimentin is mediated via c-Jun N-terminal kinase (JNK). We employed a model of murine BSM tissue in which increased expression of desmin or vimentin was induced by adenoviral transduction to examine the sufficiency of increased IF protein expression to reduce BSM contraction. Murine BSM strips overexpressing desmin or vimentin generated less force in response to KCl and carbachol relative to the levels in control murine BSM strips, an effect associated with increased JNK2 phosphorylation and reduced myosin light chain (MLC ) phosphorylation. Furthermore, desmin and vimentin overexpressions did not alter BSM contractility and MLC phosphorylation in strips isolated from JNK2 knockout mice. Pharmacological JNK2 inhibition produced results qualitatively similar to those caused by JNK2 knockout. These findings suggest that inhibition of JNK2 may improve diminished BSM contractility associated with obstructive bladder disease.
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http://dx.doi.org/10.1096/fj.201901301RDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7018560PMC
February 2020

Vasodilator-Stimulated Phosphoprotein Biomarkers Are Associated with Invasion and Metastasis in Colorectal Cancer.

Biomark Cancer 2018 5;10:1179299X18774551. Epub 2018 Jun 5.

BioDetego LLC, Philadelphia, PA, USA.

Background And Aims: The benefit of adjuvant chemotherapy for stage II colorectal cancer (CRC) patients remains unclear, emphasizing the need for improved prognostic biomarkers to identify patients at risk of metastatic recurrence. To address this unmet clinical need, we examined the expression and phosphorylation status of the vasodilator-stimulated phosphoprotein (VASP) in CRC tumor progression. VASP, a processive actin polymerase, promotes the formation of invasive membrane structures leading to extracellular matrix remodeling and tumor invasion. Phosphorylation of VASP serine (Ser) residues 157 and 239 regulate VASP function, directing subcellular localization and inhibiting actin polymerization, respectively.

Methods: The expression levels of VASP protein, pSer-VASP, and pSer-VASP were determined by immunohistochemistry in tumors and matched normal adjacent tissue from 141 CRC patients, divided into 2 cohorts, and the association of VASP biomarker expression with clinicopathologic features and disease recurrence was examined.

Results: We report that changes in VASP expression and phosphorylation were significantly associated with tumor invasion and disease recurrence. Furthermore, we disclose a novel 2-tiered methodology to maximize VASP positive and negative predictive value performance for prognostication.

Conclusion: VASP biomarkers may serve as prognostic biomarkers in CRC and should be evaluated in a larger clinical study.
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http://dx.doi.org/10.1177/1179299X18774551DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6419247PMC
June 2018

NF-κB and GATA-Binding Factor 6 Repress Transcription of Caveolins in Bladder Smooth Muscle Hypertrophy.

Am J Pathol 2019 04 30;189(4):847-867. Epub 2019 Jan 30.

Department of Medicine, Center for Translational Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania; Division of Urology, University of Pennsylvania, Philadelphia, Pennsylvania. Electronic address:

Caveolins (CAVs) are structural proteins of caveolae that function as signaling platforms to regulate smooth muscle contraction. Loss of CAV protein expression is associated with impaired contraction in obstruction-induced bladder smooth muscle (BSM) hypertrophy. In this study, microarray analysis of bladder RNA revealed down-regulation of CAV1, CAV2, and CAV3 gene transcription in BSM from models of obstructive bladder disease in mice and humans. We identified and characterized regulatory regions responsible for CAV1, CAV2, and CAV3 gene expression in mice with obstruction-induced BSM hypertrophy, and in men with benign prostatic hyperplasia. DNA affinity chromatography and chromatin immunoprecipitation assays revealed a greater increase in binding of GATA-binding factor 6 (GATA-6) and NF-κB to their cognate binding motifs on CAV1, CAV2, and CAV3 promoters in obstructed BSM relative to that observed in control BSM. Knockout of NF-κB subunits, shRNA-mediated knockdown of GATA-6, or pharmacologic inhibition of GATA-6 and NF-κB in BSM increased CAV1, CAV2, and CAV3 transcription and promoter activity. Conversely, overexpression of GATA-6 decreased CAV2 and CAV3 transcription and promoter activity. Collectively, these data provide new insight into the mechanisms by which CAV gene expression is repressed in hypertrophied BSM in obstructive bladder disease.
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http://dx.doi.org/10.1016/j.ajpath.2018.12.013DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6458544PMC
April 2019

PARP-1 regulates DNA repair factor availability.

EMBO Mol Med 2018 12;10(12)

Cedars-Sinai Medical Center, Los Angeles, CA, USA.

PARP-1 holds major functions on chromatin, DNA damage repair and transcriptional regulation, both of which are relevant in the context of cancer. Here, unbiased transcriptional profiling revealed the downstream transcriptional profile of PARP-1 enzymatic activity. Further investigation of the PARP-1-regulated transcriptome and secondary strategies for assessing PARP-1 activity in patient tissues revealed that PARP-1 activity was unexpectedly enriched as a function of disease progression and was associated with poor outcome independent of DNA double-strand breaks, suggesting that enhanced PARP-1 activity may promote aggressive phenotypes. Mechanistic investigation revealed that active PARP-1 served to enhance E2F1 transcription factor activity, and specifically promoted E2F1-mediated induction of DNA repair factors involved in homologous recombination (HR). Conversely, PARP-1 inhibition reduced HR factor availability and thus acted to induce or enhance "BRCA-ness". These observations bring new understanding of PARP-1 function in cancer and have significant ramifications on predicting PARP-1 inhibitor function in the clinical setting.
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http://dx.doi.org/10.15252/emmm.201708816DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6284389PMC
December 2018

Therapeutic Challenge with a CDK 4/6 Inhibitor Induces an RB-Dependent SMAC-Mediated Apoptotic Response in Non-Small Cell Lung Cancer.

Clin Cancer Res 2018 03 8;24(6):1402-1414. Epub 2018 Jan 8.

Department of Radiation Oncology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania.

The retinoblastoma tumor suppressor (RB), a key regulator of cell-cycle progression and proliferation, is functionally suppressed in up to 50% of non-small cell lung cancer (NSCLC). RB function is exquisitely controlled by a series of proteins, including the CyclinD-CDK4/6 complex. In this study, we interrogated the capacity of a CDK4/6 inhibitor, palbociclib, to activate RB function. We employed multiple isogenic RB-proficient and -deficient NSCLC lines to interrogate the cytostatic and cytotoxic capacity of CDK 4/6 inhibition and We demonstrate that while short-term exposure to palbociclib induces cellular senescence, prolonged exposure results in inhibition of tumor growth. Mechanistically, CDK 4/6 inhibition induces a proapoptotic transcriptional program through suppression of IAPs FOXM1 and Survivin, while simultaneously augmenting expression of SMAC and caspase-3 in an RB-dependent manner. This study uncovers a novel function of RB activation to induce cellular apoptosis through therapeutic administration of a palbociclib and provides a rationale for the clinical evaluation of CDK 4/6 inhibitors in the treatment of patients with NSCLC. .
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http://dx.doi.org/10.1158/1078-0432.CCR-17-2074DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6004790PMC
March 2018

Pilot study demonstrating metabolic and anti-proliferative effects of in vivo anti-oxidant supplementation with N-Acetylcysteine in Breast Cancer.

Semin Oncol 2017 06 10;44(3):226-232. Epub 2017 Oct 10.

Department of Medical Oncology, Thomas Jefferson University, Philadelphia, PA. Electronic address:

Background: High oxidative stress as defined by hydroxyl and peroxyl activity is often found in the stroma of human breast cancers. Oxidative stress induces stromal catabolism, which promotes cancer aggressiveness. Stromal cells exposed to oxidative stress release catabolites such as lactate, which are up-taken by cancer cells to support mitochondrial oxidative phosphorylation. The transfer of catabolites between stromal and cancer cells leads to metabolic heterogeneity between these cells and increased cancer cell proliferation and reduced apoptosis in preclinical models. N-Acetylcysteine (NAC) is an antioxidant that reduces oxidative stress and reverses stromal catabolism and stromal-carcinoma cell metabolic heterogeneity, resulting in reduced proliferation and increased apoptosis of cancer cells in experimental models of breast cancer. The purpose of this clinical trial was to determine if NAC could reduce markers of stromal-cancer metabolic heterogeneity and markers of cancer cell aggressiveness in human breast cancer.

Methods: Subjects with newly diagnosed stage 0 and I breast cancer who were not going to receive neoadjuvant therapy prior to surgical resection were treated with NAC before definitive surgery to assess intra-tumoral metabolic markers. NAC was administered once a week intravenously at a dose of 150 mg/kg and 600 mg twice daily orally on the days not receiving intravenous NAC. Histochemistry for the stromal metabolic markers monocarboxylate transporter 4 (MCT4) and caveolin-1 (CAV1) and the Ki67 proliferation assay and TUNEL apoptosis assay in carcinoma cells were performed in pre- and post-NAC specimens.

Results: The range of days on NAC was 14-27 and the mean was 19 days. Post-treatment biopsies showed significant decrease in stromal MCT4 and reduced Ki67 in carcinoma cells. NAC did not significantly change stromal CAV1 and carcinoma TUNEL staining. NAC was well tolerated.

Conclusions: NAC as a single agent reduces MCT4 stromal expression, which is a marker of glycolysis in breast cancer with reduced carcinoma cell proliferation. This study suggests that modulating metabolism in the tumor microenvironment has the potential to impact breast cancer proliferation.
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http://dx.doi.org/10.1053/j.seminoncol.2017.10.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5737796PMC
June 2017

MCT1 in Invasive Ductal Carcinoma: Monocarboxylate Metabolism and Aggressive Breast Cancer.

Front Cell Dev Biol 2017 3;5:27. Epub 2017 Apr 3.

Department of Medical Oncology, Sidney Kimmel Cancer Center, Thomas Jefferson UniversityPhiladelphia, PA, USA.

Monocarboxylate transporter 1 (MCT1) is an importer of monocarboxylates such as lactate and pyruvate and a marker of mitochondrial metabolism. MCT1 is highly expressed in a subgroup of cancer cells to allow for catabolite uptake from the tumor microenvironment to support mitochondrial metabolism. We studied the protein expression of MCT1 in a broad group of breast invasive ductal carcinoma specimens to determine its association with breast cancer subtypes and outcomes. MCT1 expression was evaluated by immunohistochemistry on tissue micro-arrays (TMA) obtained through our tumor bank. Two hundred and fifty-seven cases were analyzed: 180 cases were estrogen receptor and/or progesterone receptor positive (ER+ and/or PR+), 62 cases were human epidermal growth factor receptor 2 positive (HER2+), and 56 cases were triple negative breast cancers (TNBC). MCT1 expression was quantified by digital pathology with Aperio software. The intensity of the staining was measured on a continuous scale (0-black to 255-bright white) using a co-localization algorithm. Statistical analysis was performed using a linear mixed model. High MCT1 expression was more commonly found in TNBC compared to ER+ and/or PR+ and compared to HER-2+ ( < 0.001). Tumors with an component were less likely to stain strongly for MCT1 ( < 0.05). High nuclear grade was associated with higher MCT1 staining ( < 0.01). Higher T stage tumors were noted to have a higher expression of MCT1 ( < 0.05). High MCT1 staining in cancer cells was associated with shorter progression free survival, increased risk of recurrence, and larger size independent of TNBC status ( < 0.05). MCT1 expression, which is a marker of high catabolite uptake and mitochondrial metabolism, is associated with recurrence in breast invasive ductal carcinoma. MCT1 expression as quantified with digital image analysis may be useful as a prognostic biomarker and to design clinical trials using MCT1 inhibitors.
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http://dx.doi.org/10.3389/fcell.2017.00027DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5376582PMC
April 2017

siRNA-Encapsulated Hybrid Nanoparticles Target Mutant K-ras and Inhibit Metastatic Tumor Burden in a Mouse Model of Lung Cancer.

Mol Ther Nucleic Acids 2017 Mar 31;6:259-268. Epub 2016 Dec 31.

Department of Pharmaceutical Science, College of Pharmacy, Thomas Jefferson University, Philadelphia, PA 19107, USA. Electronic address:

There is an unmet need in the development of an effective therapy for mutant K-ras-expressing non-small-cell lung cancer (NSCLC). Although various small molecules have been evaluated, an effective therapy remains a dream. siRNAs have the potential to downregulate mutant K-ras both at the protein and mRNA levels. However, a safe and effective delivery of siRNAs to tumors remains a limitation to their translational application in the treatment of this highly debilitating disease. Here we developed a novel hybrid nanoparticle carrier for effective delivery of anti-mutant K-ras to NSCLC (AKSLHN). The ability of this treatment modality to regress lung tumors in mouse models was evaluated as a monotherapy or as a combination treatment with erlotinib. Further, the toxicity of this treatment modality to healthy tissues was evaluated, along with its ability to elicit immune/inflammatory reactions. The results suggest that this treatment modality is a promising prospect for the treatment of mutant K-ras-expressing NSCLC without any accompanying toxicity. However, further understanding of the cellular-level interaction between AHSLHN and erlotinib needs to be attained before this promising treatment modality can be brought to the bedside.
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http://dx.doi.org/10.1016/j.omtn.2016.12.009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5363504PMC
March 2017

Metformin effects on head and neck squamous carcinoma microenvironment: Window of opportunity trial.

Laryngoscope 2017 08 10;127(8):1808-1815. Epub 2017 Feb 10.

Department of Medical Oncology, Philadelphia, Pennsylvania, U.S.A.

Objective: The tumor microenvironment frequently displays abnormal cellular metabolism, which contributes to aggressive behavior. Metformin inhibits mitochondrial oxidative phosphorylation, altering metabolism. Though the mechanism is unclear, epidemiologic studies show an association between metformin use and improved outcomes in head and neck squamous cell carcinoma (HNSCC). We sought to determine if metformin alters metabolism and apoptosis in HNSCC tumors.

Study Design: Window of opportunity trial of metformin between diagnostic biopsy and resection. Participants were patients with newly diagnosed HNSCC. Fifty patients were enrolled, and 39 completed a full-treatment course. Metformin was titrated to standard diabetic dose (2,000 mg/day) for a course of 9 or more days prior to surgery.

Methods: Immunohistochemistry (IHC) for the metabolic markers caveolin-1 (CAV1), B-galactosidase (GALB), and monocarboxylate transporter 4 (MCT4), as well as the Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) apoptosis assay and Ki-67 IHC, were performed in pre- and postmetformin specimens. Exploratory mass spectroscopy imaging (MSI) to assess lactate levels also was performed in three subjects.

Results: Metformin was well tolerated. The average treatment course was 13.6 days. Posttreatment specimens showed a significant increase in stromal CAV1 (P < 0.001) and GALB (P < 0.005), as well as tumor cell apoptosis by TUNEL assay (P < 0.001). There was no significant change in stromal MCT4 expression or proliferation measured by Ki67. Lactate levels in carcinoma cells were increased 2.4-fold postmetformin (P < 0.05), as measured by MSI.

Conclusion: Metformin increases markers of reduced catabolism and increases senescence in stromal cells as well as carcinoma cell apoptosis. This study demonstrates that metformin modulates metabolism in the HNSCC microenvironment.

Level Of Evidence: 4. Laryngoscope, 127:1808-1815, 2017.
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http://dx.doi.org/10.1002/lary.26489DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5515672PMC
August 2017

RB Loss Promotes Prostate Cancer Metastasis.

Cancer Res 2017 02 6;77(4):982-995. Epub 2016 Dec 6.

Department of Radiation Oncology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania.

RB loss occurs commonly in neoplasia but its contributions to advanced cancer have not been assessed directly. Here we show that RB loss in multiple murine models of cancer produces a prometastatic phenotype. Gene expression analyses showed that regulation of the cell motility receptor RHAMM by the RB/E2F pathway was critical for epithelial-mesenchymal transition, motility, and invasion by cancer cells. Genetic modulation or pharmacologic inhibition of RHAMM activity was sufficient and necessary for metastatic phenotypes induced by RB loss in prostate cancer. Mechanistic studies in this setting established that RHAMM stabilized F-actin polymerization by controlling ROCK signaling. Collectively, our findings show how RB loss drives metastatic capacity and highlight RHAMM as a candidate therapeutic target for treating advanced prostate cancer. .
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http://dx.doi.org/10.1158/0008-5472.CAN-16-1589DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5700768PMC
February 2017

TP53-inducible Glycolysis and Apoptosis Regulator (TIGAR) Metabolically Reprograms Carcinoma and Stromal Cells in Breast Cancer.

J Biol Chem 2016 Dec 1;291(51):26291-26303. Epub 2016 Nov 1.

From the Department of Medical Oncology,

A subgroup of breast cancers has several metabolic compartments. The mechanisms by which metabolic compartmentalization develop in tumors are poorly characterized. TP53 inducible glycolysis and apoptosis regulator (TIGAR) is a bisphosphatase that reduces glycolysis and is highly expressed in carcinoma cells in the majority of human breast cancers. Hence we set out to determine the effects of TIGAR expression on breast carcinoma and fibroblast glycolytic phenotype and tumor growth. The overexpression of this bisphosphatase in carcinoma cells induces expression of enzymes and transporters involved in the catabolism of lactate and glutamine. Carcinoma cells overexpressing TIGAR have higher oxygen consumption rates and ATP levels when exposed to glutamine, lactate, or the combination of glutamine and lactate. Coculture of TIGAR overexpressing carcinoma cells and fibroblasts compared with control cocultures induce more pronounced glycolytic differences between carcinoma and fibroblast cells. Carcinoma cells overexpressing TIGAR have reduced glucose uptake and lactate production. Conversely, fibroblasts in coculture with TIGAR overexpressing carcinoma cells induce HIF (hypoxia-inducible factor) activation with increased glucose uptake, increased 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3 (PFKFB3), and lactate dehydrogenase-A expression. We also studied the effect of this enzyme on tumor growth. TIGAR overexpression in carcinoma cells increases tumor growth in vivo with increased proliferation rates. However, a catalytically inactive variant of TIGAR did not induce tumor growth. Therefore, TIGAR expression in breast carcinoma cells promotes metabolic compartmentalization and tumor growth with a mitochondrial metabolic phenotype with lactate and glutamine catabolism. Targeting TIGAR warrants consideration as a potential therapy for breast cancer.
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http://dx.doi.org/10.1074/jbc.M116.740209DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5159492PMC
December 2016

Suppression of progranulin expression inhibits bladder cancer growth and sensitizes cancer cells to cisplatin.

Oncotarget 2016 Jun;7(26):39980-39995

Department of Urology and Biology and The Prostate Cancer Program, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA.

We have recently demonstrated a critical role for progranulin in bladder cancer. Progranulin contributes, as an autocrine growth factor, to the transformed phenotype by modulating Akt-and MAPK-driven motility, invasion and anchorage-independent growth. Progranulin also induces F-actin remodeling by interacting with the F-actin binding protein drebrin. In addition, progranulin is overexpressed in invasive bladder cancer compared to normal tissue controls, suggesting that progranulin might play a key role in driving the transition to the invasive phenotype of urothelial cancer. However, it is not established whether targeting progranulin could have therapeutic effects on bladder cancer. In this study, we stably depleted urothelial cancer cells of endogenous progranulin by shRNA approaches and determined that progranulin depletion severely inhibited the ability of tumorigenic urothelial cancer cells to migrate, invade and grow in anchorage-independency. We further demonstrate that progranulin expression is critical for tumor growth in vivo, in both xenograft and orthotopic tumor models. Notably, progranulin levels correlated with response to cisplatin treatment and were upregulated in bladder tumors. Our data indicate that progranulin may constitute a novel target for therapeutic intervention in bladder tumors. In addition, progranulin may serve as a novel biomarker for bladder cancer.
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http://dx.doi.org/10.18632/oncotarget.9556DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5129986PMC
June 2016

Potential Impact on Clinical Decision Making via a Genome-Wide Expression Profiling: A Case Report.

Urol Case Rep 2016 Nov 1;9:51-54. Epub 2016 Oct 1.

Sidney Kimmel Cancer Center, Thomas Jefferson University, PA, USA.

Management of men with prostate cancer is fraught with uncertainty as physicians and patients balance efficacy with potential toxicity and diminished quality of life. Utilization of genomics as a prognostic biomarker has improved the informed decision-making process by enabling more rationale treatment choices. Recently investigations have begun to determine whether genomic information from tumor transcriptome data can be used to impact clinical decision-making beyond prognosis. Here we discuss the potential of genomics to alter management of a patient who presented with high-risk prostate adenocarcinoma. We suggest that this information help selecting patients for advanced imaging, chemotherapies, or clinical trial.
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http://dx.doi.org/10.1016/j.eucr.2016.08.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5050262PMC
November 2016

Radiographic Kinetics of Sarcomatoid Renal Cell Carcinoma.

Urology 2016 Jul 31;93:e13-4. Epub 2016 Mar 31.

Department of Urology, Thomas Jefferson University Hospital, Philadelphia, PA.

Renal cell carcinoma is a common entity often managed surgically with excellent survival benefits. We report a rare case of sarcomatoid renal cell carcinoma with aggressive growth kinetics after palliative resection captured radiographically.
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http://dx.doi.org/10.1016/j.urology.2016.03.027DOI Listing
July 2016

Multicompartment metabolism in papillary thyroid cancer.

Laryngoscope 2016 10 15;126(10):2410-2418. Epub 2015 Dec 15.

Department of Medical Oncology, Thomas Jefferson University, Philadelphia, PA.

Objectives/hypothesis: In many cancers, varying regions within the tumor are often phenotypically heterogeneous, including their metabolic phenotype. Further, tumor regions can be metabolically compartmentalized, with metabolites transferred between compartments. When present, this metabolic coupling can promote aggressive behavior. Tumor metabolism in papillary thyroid cancer (PTC) is poorly characterized.

Study Design: Immunohistochemical staining of tissue samples.

Methods: Papillary thyroid cancer specimens from 46 patients with (n = 19) and without advanced disease (n = 27) were compared to noncancerous thyroid tissue (NCT) and benign thyroid specimens (n = 6 follicular adenoma [FA] and n = 5 nodular goiter [NG]). Advanced disease was defined as the presence of lateral neck lymphadenopathy. Immunohistochemistry was performed for translocase of outer mitochondrial membrane 20 (TOMM20), a marker of oxidative phosphorylation, and monocarboxylate transporter 4 (MCT4), a marker of glycolysis.

Results: Papillary thyroid cancer and FA thyrocytes had high staining for TOMM20 compared to NCT and nodular goiter (NG) (P < 0.01). High MCT4 staining in fibroblasts was more common in PTC with advanced disease than in any other tissue type studied (P < 0.01). High MCT4 staining was found in all 19 cases of PTC with advanced disease, in 11 of 19 samples with low-stage disease, in one of five samples of FA, in one of 34 NCT, and in 0 of six NG samples. Low fibroblast MCT4 staining in PTC correlated with the absence of clinical adenopathy (P = 0.028); the absence of extrathyroidal extension (P = 0.004); low American Thyroid Association risk (P = 0.001); low AGES (age, grade, extent, size) score (P = 0.004); and low age, metastasis, extent of disease, size risk (P = 0.002).

Conclusion: This study suggests that multiple metabolic compartments exist in PTC, and low fibroblast MCT4 may be a biomarker of indolent disease.

Level Of Evidence: N/A. Laryngoscope, 126:2410-2418, 2016.
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http://dx.doi.org/10.1002/lary.25799DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4909595PMC
October 2016

Mitochondrial Metabolism as a Treatment Target in Anaplastic Thyroid Cancer.

Semin Oncol 2015 Dec 24;42(6):915-22. Epub 2015 Sep 24.

Department of Otolaryngology, Thomas Jefferson University, Philadelphia, PA. Electronic address:

Anaplastic thyroid cancer (ATC) is one of the most aggressive human cancers. Key signal transduction pathways that regulate mitochondrial metabolism are frequently altered in ATC. Our goal was to determine the mitochondrial metabolic phenotype of ATC by studying markers of mitochondrial metabolism, specifically monocarboxylate transporter 1 (MCT1) and translocase of the outer mitochondrial membrane member 20 (TOMM20). Staining patterns of MCT1 and TOMM20 in 35 human thyroid samples (15 ATC, 12 papillary thyroid cancer [PTC], and eight non-cancerous thyroid) and nine ATC mouse orthotopic xenografts were assessed by visual and Aperio digital scoring. Staining patterns of areas involved with cancer versus areas with no evidence of cancer were evaluated independently where available. MCT1 is highly expressed in human anaplastic thyroid cancer when compared to both non-cancerous thyroid tissues and papillary thyroid cancers (P<.001 for both). TOMM20 is also highly expressed in both ATC and PTC compared to non-cancerous thyroid tissue (P<.01 for both). High MCT1 and TOMM20 expression is also found in ATC mouse xenograft tumors compared to non-cancerous thyroid tissue (P<.001). These xenograft tumors have high (13)C- pyruvate uptake. ATC has metabolic features that distinguish it from PTC and non-cancerous thyroid tissue, including high expression of MCT1 and TOMM20. PTC has low expression of MCT1 and non-cancerous thyroid tissue has low expression of both MCT1 and TOMM20. This work suggests that MCT1 blockade may specifically target ATC cells presenting an opportunity for a new drug target.
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http://dx.doi.org/10.1053/j.seminoncol.2015.09.025DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4663018PMC
December 2015

Parathyroid Hormone-Related Peptide-Linked Hypercalcemia in a Melanoma Patient Treated With Ipilimumab: Hormone Source and Clinical and Metabolic Correlates.

Semin Oncol 2015 Dec 8;42(6):909-14. Epub 2015 Sep 8.

Department of Medical Oncology Thomas Jefferson University, Philadelphia, PA. Electronic address:

A patient diagnosed with metastatic melanoma developed the paraneoplastic syndrome of humoral hypercalcemia of malignancy and cachexia after receiving ipilumumab. The cause of the hypercalcemia was thought to be secondary to parathyroid hormone-related peptide (PTHrP) as plasma levels were found to be elevated. The patient underwent two tumor biopsies: at diagnosis (when calcium levels were normal) and upon development of hypercalcemia and cachexia. PTHrP expression was higher in melanoma cells when hypercalcemia had occurred than prior to its onset. Metabolic characterization of melanoma cells revealed that, with development of hypercalcemia, there was high expression of monocarboxylate transporter 1 (MCT1), which is the main importer of lactate and ketone bodies into cells. MCT1 is associated with high mitochondrial metabolism. Beta-galactosidase (β-GAL), a marker of senescence, had reduced expression in melanoma cells upon development of hypercalcemia compared to pre-hypercalcemia. In conclusion, PTHrP expression in melanoma is associated with cachexia, increased cancer cell lactate and ketone body import, high mitochondrial metabolism, and reduced senescence. Further studies are required to determine if PTHrP regulates cachexia, lactate and ketone body import, mitochondrial metabolism, and senescence in cancer cells.
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http://dx.doi.org/10.1053/j.seminoncol.2015.09.006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4663680PMC
December 2015

VPAC1 Targeted (64)Cu-TP3805 Positron Emission Tomography Imaging of Prostate Cancer: Preliminary Evaluation in Man.

Urology 2016 Feb 28;88:111-8. Epub 2015 Oct 28.

Department of Radiology, Thomas Jefferson University, Philadelphia, PA; Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA. Electronic address:

Objective: To evaluate (64)Cu-TP3805 as a novel biomolecule, to positron emission tomography (PET) image prostate cancer (PC), at the onset of which VPAC1, the superfamily of G protein-coupled receptors, is expressed in high density on PC cells, but not on normal cells.

Materials And Methods: Twenty-five patients undergoing radical prostatectomy were PET/X-ray computerized tomography imaged preoperatively with (64)Cu-TP3805. Standardized maximum uptake (SUVmax) values were determined and malignant lesions (standardized uptake value > 1.0) counted, and compared with histologic findings. Whole-mount pathology slides from 6 VPAC1 PET imaged patients, 3 benign prostatic hyperplasia patients, 1 malignant and 1 benign lymph node underwent digital autoradiography (DAR) after (64)Cu-TP3805 incubation and were compared to hematoxylin- and eosin-stained slides.

Results: In 25 patients who underwent PET imaging, 212 prostate gland lesions had SUVmax > 1.0 vs 127 lesions identified by histology of biopsy tissues. The status of the additional 85 PET identified prostate lesions remains to be determined. In 68 histologic slides from 6 PET imaged patients, DAR identified 105 of 107 PC foci, 19 of 19 high-grade prostatic intraepithelial neoplasias, and ejaculatory ducts and verumontanum involved with cancer. Additionally, DAR found 9 PC lesions not previously identified histologically. The positive and negative lymph nodes were correctly identified, and in 3 of 3 benign prostatic hyperplasia patients and 5 of 5 cysts, DAR was negative.

Conclusion: This feasibility study demonstrated that (64)Cu-TP3805 delineates PC in vivo and ex vivo, provided normal images for benign masses, and is worthy of further studies.
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http://dx.doi.org/10.1016/j.urology.2015.10.012DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4788593PMC
February 2016

DNA-PKcs-Mediated Transcriptional Regulation Drives Prostate Cancer Progression and Metastasis.

Cancer Cell 2015 Jul;28(1):97-113

Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA; Department of Urology, Thomas Jefferson University, Philadelphia, PA 19107, USA; Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, PA 19107, USA; Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA. Electronic address:

Emerging evidence demonstrates that the DNA repair kinase DNA-PKcs exerts divergent roles in transcriptional regulation of unsolved consequence. Here, in vitro and in vivo interrogation demonstrate that DNA-PKcs functions as a selective modulator of transcriptional networks that induce cell migration, invasion, and metastasis. Accordingly, suppression of DNA-PKcs inhibits tumor metastases. Clinical assessment revealed that DNA-PKcs is significantly elevated in advanced disease and independently predicts for metastases, recurrence, and reduced overall survival. Further investigation demonstrated that DNA-PKcs in advanced tumors is highly activated, independent of DNA damage indicators. Combined, these findings reveal unexpected DNA-PKcs functions, identify DNA-PKcs as a potent driver of tumor progression and metastases, and nominate DNA-PKcs as a therapeutic target for advanced malignancies.
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http://dx.doi.org/10.1016/j.ccell.2015.06.004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4531387PMC
July 2015

A novel role for drebrin in regulating progranulin bioactivity in bladder cancer.

Oncotarget 2015 May;6(13):10825-39

Department of Urology and Biology of Prostate Cancer Program, Thomas Jefferson University, Philadelphia, PA, USA.

We recently established a critical role for the growth factor progranulin in bladder cancer insofar as progranulin promotes urothelial cancer cell motility and contributes, as an autocrine growth factor, to the transformed phenotype by modulating invasion and anchorage-independent growth. In addition, progranulin expression is upregulated in invasive bladder cancer tissues compared to normal controls. However, the molecular mechanisms of progranulin action in bladder cancer have not been fully elucidated. In this study, we searched for novel progranulin-interacting proteins using pull-down assays with recombinant progranulin and proteomics. We discovered that drebrin, an F-actin binding protein, bound progranulin in urothelial cancer cells. We characterized drebrin function in urothelial cancer cell lines and showed that drebrin is critical for progranulin-dependent activation of the Akt and MAPK pathways and modulates motility, invasion and anchorage-independent growth. In addition, drebrin regulates tumor formation in vivo and its expression is upregulated in bladder cancer tissues compared to normal tissue controls. Our data are translationally relevant as indicate that drebrin exerts an essential functional role in the regulation of progranulin action and may constitute a novel target for therapeutic intervention in bladder tumors. In addition, drebrin may serve as novel biomarker for bladder cancer.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4484422PMC
http://dx.doi.org/10.18632/oncotarget.3424DOI Listing
May 2015

Predictors of positive surgical margins after radical prostatectomy at a single institution: preoperative and pathologic factors, and the impact of surgeon variability and technique on incidence and location.

Can J Urol 2014 Oct;21(5):7479-86

Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, USA.

Introduction: To identify and assess predictive factors for positive surgical margins (PSM) in patients undergoing radical prostatectomy (RP).

Materials And Methods: An Institution Review Board (IRB) approved retrospective review of 1751 patients that underwent RP from March 2000 to June 2013 was performed. Identified were 1740 patients whom had not received neoadjuvant therapy; these were used for the purpose of this analysis. Univariate and multivariate analysis were performed to determine factors associated with and predictive of PSMs, divided into preoperative and pathological. Variables analyzed include age, body mass index (BMI), race, surgeon, surgical modality, pathologic T-stage and Gleason sum, extracapsular extension (ECE), seminal vesicle involvement (SVI), perineural invasion (PNI) and prostate weight. Finally, each surgical technique was analyzed to determine the most common site of PSM.

Results: Rate of PSM was 23.6%. Our analysis showed that preoperative prostate-specific antigen (PSA) level ≥ 10ng/mL, and pathologic T3/T4-stage and PNI significantly predicted PSM. Age > 60 years and prostate weight > 60 g were predictive against PSM. Gleason score ≥ 7 and PSM were significant risk factors for biochemical recurrence (BCR). Surgical approach did not affect the rate of PSM. Open RP was associated with a higher apical PSM rate (38.5%) and robotic RP with a higher posterolateral PSM rate (52.3%).

Conclusions: High preoperative PSA levels, and advanced TNM-staging predicted positive surgical margins in our cohort. Patients with PSM were subsequently found to have higher risk of BCR.
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October 2014

The retinoblastoma tumor suppressor modulates DNA repair and radioresponsiveness.

Clin Cancer Res 2014 Nov 27;20(21):5468-5482. Epub 2014 Aug 27.

Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.

Purpose: Perturbations in the retinoblastoma pathway are over-represented in advanced prostate cancer; retinoblastoma loss promotes bypass of first-line hormone therapy. Conversely, preliminary studies suggested that retinoblastoma-deficient tumors may become sensitized to a subset of DNA-damaging agents. Here, the molecular and in vivo consequence of retinoblastoma status was analyzed in models of clinical relevance.

Experimental Design: Experimental work was performed with multiple isogenic prostate cancer cell lines (hormone sensitive: LNCaP and LAPC4 cells and hormone resistant C42, 22Rv1 cells; stable knockdown of retinoblastoma using shRNA). Multiple mechanisms were interrogated including cell cycle, apoptosis, and DNA damage repair. Transcriptome analysis was performed, validated, and mechanisms discerned. Cell survival was measured using clonogenic cell survival assay and in vivo analysis was performed in nude mice with human derived tumor xenografts.

Results: Loss of retinoblastoma enhanced the radioresponsiveness of both hormone-sensitive and castrate-resistant prostate cancer. Hypersensitivity to ionizing radiation was not mediated by cell cycle or p53. Retinoblastoma loss led to alteration in DNA damage repair and activation of the NF-κB pathway and subsequent cellular apoptosis through PLK3. In vivo xenografts of retinoblastoma-deficient tumors exhibited diminished tumor mass, lower PSA kinetics, and decreased tumor growth after treatment with ionizing radiation (P < 0.05).

Conclusions: Loss of retinoblastoma confers increased radiosensitivity in prostate cancer. This hypersensitization was mediated by alterations in apoptotic signaling. Combined, these not only provide insight into the molecular consequence of retinoblastoma loss, but also credential retinoblastoma status as a putative biomarker for predicting response to radiotherapy.
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http://dx.doi.org/10.1158/1078-0432.CCR-14-0326DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4216759PMC
November 2014

Genomic prostate cancer classifier predicts biochemical failure and metastases in patients after postoperative radiation therapy.

Int J Radiat Oncol Biol Phys 2014 Aug 8;89(5):1038-1046. Epub 2014 Jul 8.

Kimmel Cancer Center, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania.

Purpose: To test the hypothesis that a genomic classifier (GC) would predict biochemical failure (BF) and distant metastasis (DM) in men receiving radiation therapy (RT) after radical prostatectomy (RP).

Methods And Materials: Among patients who underwent post-RP RT, 139 were identified for pT3 or positive margin, who did not receive neoadjuvant hormones and had paraffin-embedded specimens. Ribonucleic acid was extracted from the highest Gleason grade focus and applied to a high-density-oligonucleotide microarray. Receiver operating characteristic, calibration, cumulative incidence, and Cox regression analyses were performed to assess GC performance for predicting BF and DM after post-RP RT in comparison with clinical nomograms.

Results: The area under the receiver operating characteristic curve of the Stephenson model was 0.70 for both BF and DM, with addition of GC significantly improving area under the receiver operating characteristic curve to 0.78 and 0.80, respectively. Stratified by GC risk groups, 8-year cumulative incidence was 21%, 48%, and 81% for BF (P<.0001) and for DM was 0, 12%, and 17% (P=.032) for low, intermediate, and high GC, respectively. In multivariable analysis, patients with high GC had a hazard ratio of 8.1 and 14.3 for BF and DM. In patients with intermediate or high GC, those irradiated with undetectable prostate-specific antigen (PSA ≤0.2 ng/mL) had median BF survival of >8 years, compared with <4 years for patients with detectable PSA (>0.2 ng/mL) before initiation of RT. At 8 years, the DM cumulative incidence for patients with high GC and RT with undetectable PSA was 3%, compared with 23% with detectable PSA (P=.03). No outcome differences were observed for low GC between the treatment groups.

Conclusion: The GC predicted BF and metastasis after post-RP irradiation. Patients with lower GC risk may benefit from delayed RT, as opposed to those with higher GC; however, this needs prospective validation. Genomic-based models may be useful for improved decision-making for treatment of high-risk prostate cancer.
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http://dx.doi.org/10.1016/j.ijrobp.2014.04.052DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4432840PMC
August 2014

Integrin αvβ6 promotes an osteolytic program in cancer cells by upregulating MMP2.

Cancer Res 2014 Mar 2;74(5):1598-608. Epub 2014 Jan 2.

Authors' Affiliations: Prostate Cancer Discovery and Development Program; Departments of Cancer Biology and Pathology, Thomas Jefferson University, Philadelphia, Pennsylvania; Department of Cell Biology, Radiation Oncology, Pathology, and Orthopedics, University of Massachusetts Medical School, Worcester; Biogen Idec, Inc., Cambridge, Massachusetts; and Department of Biochemistry, The University of Vermont, Burlington, Vermont.

The molecular circuitries controlling osseous prostate metastasis are known to depend on the activity of multiple pathways, including integrin signaling. Here, we demonstrate that the αvβ6 integrin is upregulated in human prostate cancer bone metastasis. In prostate cancer cells, this integrin is a functionally active receptor for fibronectin and latency-associated peptide-TGF-β1; it mediates attachment and migration upon ligand binding and is localized in focal contacts. Given the propensity of prostate cancer cells to form bone metastatic lesions, we investigated whether the αvβ6 integrin promotes this type of metastasis. We show for the first time that αvβ6 selectively induces matrix metalloproteinase 2 (MMP2) in vitro in multiple prostate cancer cells and promotes osteolysis in vivo in an immunodeficient mouse model of bone metastasis through upregulation of MMP2, but not MMP9. The effect of αvβ6 on MMP2 expression and activity is independent of androgen receptor in the analyzed prostate cancer cells. Increased levels of parathyroid hormone-related protein (PTHrP), known to induce osteoclastogenesis, were also observed in αvβ6-expressing cells. However, by using MMP2 short hairpin RNA, we demonstrate that the αvβ6 effect on bone loss is due to upregulation of soluble MMP2 by the cancer cells, not due to changes in tumor growth rate. Another related αv-containing integrin, αvβ5, fails to show similar responses, underscoring the significance of αvβ6 activity. Overall, these mechanistic studies establish that expression of a single integrin, αvβ6, contributes to the cancer cell-mediated program of osteolysis by inducing matrix degradation through MMP2. Our results open new prospects for molecular therapy for metastatic bone disease.
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http://dx.doi.org/10.1158/0008-5472.CAN-13-1796DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3967411PMC
March 2014

USP22 regulates oncogenic signaling pathways to drive lethal cancer progression.

Cancer Res 2014 Jan 6;74(1):272-86. Epub 2013 Nov 6.

Authors' Affiliations: Departments of Cancer Biology, Urology, Radiation Oncology, Pathology, and Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania; Sidney Kimmel Comprehensive Cancer Center; Department of Pathology, Johns Hopkins University, Baltimore, Maryland; and Institute of Biomedical Technology, University of Tampere and Tampere University Hospital, Tampere, Finland.

Increasing evidence links deregulation of the ubiquitin-specific proteases 22 (USP22) deubitiquitylase to cancer development and progression in a select group of tumor types, but its specificity and underlying mechanisms of action are not well defined. Here we show that USP22 is a critical promoter of lethal tumor phenotypes that acts by modulating nuclear receptor and oncogenic signaling. In multiple xenograft models of human cancer, modeling of tumor-associated USP22 deregulation demonstrated that USP22 controls androgen receptor accumulation and signaling, and that it enhances expression of critical target genes coregulated by androgen receptor and MYC. USP22 not only reprogrammed androgen receptor function, but was sufficient to induce the transition to therapeutic resistance. Notably, in vivo depletion experiments revealed that USP22 is critical to maintain phenotypes associated with end-stage disease. This was a significant finding given clinical evidence that USP22 is highly deregulated in tumors, which have achieved therapeutic resistance. Taken together, our findings define USP22 as a critical effector of tumor progression, which drives lethal phenotypes, rationalizing this enzyme as an appealing therapeutic target to treat advanced disease.
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http://dx.doi.org/10.1158/0008-5472.CAN-13-1954DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3947329PMC
January 2014

Oncogenes and inflammation rewire host energy metabolism in the tumor microenvironment: RAS and NFκB target stromal MCT4.

Cell Cycle 2013 Aug 8;12(16):2580-97. Epub 2013 Jul 8.

Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA.

Here, we developed a model system to evaluate the metabolic effects of oncogene(s) on the host microenvironment. A matched set of "normal" and oncogenically transformed epithelial cell lines were co-cultured with human fibroblasts, to determine the "bystander" effects of oncogenes on stromal cells. ROS production and glucose uptake were measured by FACS analysis. In addition, expression of a panel of metabolic protein biomarkers (Caveolin-1, MCT1, and MCT4) was analyzed in parallel. Interestingly, oncogene activation in cancer cells was sufficient to induce the metabolic reprogramming of cancer-associated fibroblasts toward glycolysis, via oxidative stress. Evidence for "metabolic symbiosis" between oxidative cancer cells and glycolytic fibroblasts was provided by MCT1/4 immunostaining. As such, oncogenes drive the establishment of a stromal-epithelial "lactate-shuttle", to fuel the anabolic growth of cancer cells. Similar results were obtained with two divergent oncogenes (RAS and NFκB), indicating that ROS production and inflammation metabolically converge on the tumor stroma, driving glycolysis and upregulation of MCT4. These findings make stromal MCT4 an attractive target for new drug discovery, as MCT4 is a shared endpoint for the metabolic effects of many oncogenic stimuli. Thus, diverse oncogenes stimulate a common metabolic response in the tumor stroma. Conversely, we also show that fibroblasts protect cancer cells against oncogenic stress and senescence by reducing ROS production in tumor cells. Ras-transformed cells were also able to metabolically reprogram normal adjacent epithelia, indicating that cancer cells can use either fibroblasts or epithelial cells as "partners" for metabolic symbiosis. The antioxidant N-acetyl-cysteine (NAC) selectively halted mitochondrial biogenesis in Ras-transformed cells, but not in normal epithelia. NAC also blocked stromal induction of MCT4, indicating that NAC effectively functions as an "MCT4 inhibitor". Taken together, our data provide new strategies for achieving more effective anticancer therapy. We conclude that oncogenes enable cancer cells to behave as selfish "metabolic parasites", like foreign organisms (bacteria, fungi, viruses). Thus, we should consider treating cancer like an infectious disease, with new classes of metabolically targeted "antibiotics" to selectively starve cancer cells. Our results provide new support for the "seed and soil" hypothesis, which was first proposed in 1889 by the English surgeon, Stephen Paget.
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http://dx.doi.org/10.4161/cc.25510DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3865048PMC
August 2013

Molecular diagnosis of prostate cancer: are we up to age?

Semin Oncol 2013 Jun;40(3):259-75

Department of Pathology, Thomas Jefferson University, Philadelphia, PA 19107, USA.

Prostate cancer (PCa), a highly heterogeneous disease, is the one of the leading cause of morbidity and mortality in the developed countries. Historically used biomarkers such as prostatic acid phosphatase (PAP), serum prostate-specific antigen (PSA), and its precursor have not stood the challenge of sensitivity and specificity. At present, there is need to re-evaluate the approach to diagnose and monitor PCa. To this end, molecular markers that can accurately identify men with PCa at an early stage, and those who would benefit from early therapeutic intervention, are the need of the hour. There has been unprecedented progress in the development of new PCa biomarkers through advancements in proteomics, tissue DNA and protein/RNA microarray, identification of microRNA, isolation of circulating tumor cells, and tumor immunohistochemistry. This review will examine the current status of prostate cancer biomarkers with emphasis on emerging biomarkers by evaluating their diagnostic and prognostic potentials.
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http://dx.doi.org/10.1053/j.seminoncol.2013.04.002DOI Listing
June 2013

The potential value of phosphohistone-h3 mitotic index determined by digital image analysis in the assessment of pancreatic endocrine tumors in fine-needle aspiration cytology specimens.

Acta Cytol 2013 25;57(3):291-5. Epub 2013 Apr 25.

Department of Pathology, Anatomy and Cell Biology, Jefferson Medical College, Philadelphia, Pa. 19107, USA.

Objective: According to the World Health Organization, pancreatic endocrine tumors are graded by assessment of the Ki67 proliferation index and/or mitotic count. The objective was to find comparable grading on the basis of the novel mitotic marker phosphohistone-H3 (PHH3).

Study Design: A computer-assisted system was used to assess 23 cell blocks stained with PHH3 and Ki67 antibodies. We investigated possible cut-points for PHH3 and computed percent agreement between the PHH3- and Ki67-based grading.

Results: The Spearman correlation between percent Ki67 positive and percent PHH3 positive was 0.76 (p = 0.001). A value of 0.3% for the lower cut-point ('cut-point 1', differentiating between grades 1 and 2) and values of about 1.8-1.9% for the higher cut-point ('cut-point 2', differentiating between grades 2 and 3) shows optimal agreement between PHH3 and Ki67 grading. The percentage of positive cells was much higher for Ki67 than for PHH3 (mean 10.6 vs. 3.0%).

Conclusions: PHH3 has good correlation with Ki67, but the range of PHH3 positivity is much narrower than that of Ki67 (range 0-4% for PHH3 vs. 0-50% for Ki67). Therefore, to be as accurate, grading on the basis of PHH3 requires evaluation of a larger number of tumor cells for a precise determination of percent PHH3-positive nuclei.
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http://dx.doi.org/10.1159/000350885DOI Listing
July 2013

Convergence of oncogenic and hormone receptor pathways promotes metastatic phenotypes.

J Clin Invest 2013 Jan 21;123(1):493-508. Epub 2012 Dec 21.

Department of Cancer Biology and Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.

Cyclin D1b is a splice variant of the cell cycle regulator cyclin D1 and is known to harbor divergent and highly oncogenic functions in human cancer. While cyclin D1b is induced during disease progression in many cancer types, the mechanisms underlying cyclin D1b function remain poorly understood. Herein, cell and human tumor xenograft models of prostate cancer were utilized to resolve the downstream pathways that are required for the protumorigenic functions of cyclin D1b. Specifically, cyclin D1b was found to modulate the expression of a large transcriptional network that cooperates with androgen receptor (AR) signaling to enhance tumor cell growth and invasive potential. Notably, cyclin D1b promoted AR-dependent activation of genes associated with metastatic phenotypes. Further exploration determined that transcriptional induction of SNAI2 (Slug) was essential for cyclin D1b-mediated proliferative and invasive properties, implicating Slug as a critical driver of disease progression. Importantly, cyclin D1b expression highly correlated with that of Slug in clinical samples of advanced disease. In vivo analyses provided strong evidence that Slug enhances both tumor growth and metastatic phenotypes. Collectively, these findings reveal the underpinning mechanisms behind the protumorigenic functions of cyclin D1b and demonstrate that the convergence of the cyclin D1b/AR and Slug pathways results in the activation of processes critical for the promotion of lethal tumor phenotypes.
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http://dx.doi.org/10.1172/JCI64750DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3533295PMC
January 2013

BRCA1 mutations drive oxidative stress and glycolysis in the tumor microenvironment: implications for breast cancer prevention with antioxidant therapies.

Cell Cycle 2012 Dec 21;11(23):4402-13. Epub 2012 Nov 21.

Jefferson Stem Cell Biology and Regenerative Medicine Center, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA USA.

Mutations in the BRCA1 tumor suppressor gene are commonly found in hereditary breast cancer. Similarly, downregulation of BRCA1 protein expression is observed in the majority of basal-like breast cancers. Here, we set out to study the effects of BRCA1 mutations on oxidative stress in the tumor microenvironment. To mimic the breast tumor microenvironment, we utilized an in vitro co-culture model of human BRCA1-mutated HCC1937 breast cancer cells and hTERT-immortalized human fibroblasts. Notably, HCC1937 cells induce the generation of hydrogen peroxide in the fibroblast compartment during co-culture, which can be inhibited by genetic complementation with the wild-type BRCA1 gene. Importantly, treatment with powerful antioxidants, such as NAC and Tempol, induces apoptosis in HCC1937 cells, suggesting that microenvironmental oxidative stress supports cancer cell survival. In addition, Tempol treatment increases the apoptotic rates of MDA-MB-231 cells, which have wild-type BRCA1, but share a basal-like breast cancer phenotype with HCC1937 cells. MCT4 is the main exporter of L-lactate out of cells and is a marker for oxidative stress and glycolytic metabolism. Co-culture with HCC1937 cells dramatically induces MCT4 protein expression in fibroblasts, and this can be prevented by either BRCA1 overexpression or by pharmacological treatment with NAC. We next evaluated caveolin-1 (Cav-1) expression in stromal fibroblasts. Loss of Cav-1 is a marker of the cancer-associated fibroblast (CAF) phenotype, which is linked to high stromal glycolysis, and is associated with a poor prognosis in numerous types of human cancers, including breast cancers. Remarkably, HCC1937 cells induce a loss of Cav-1 in adjacent stromal cells during co-culture. Conversely, Cav-1 expression in fibroblasts can be rescued by administration of NAC or by overexpression of BRCA1 in HCC1937 cells. Notably, BRCA1-deficient human breast cancer samples (9 out of 10) also showed a glycolytic stromal phenotype, with intense mitochondrial staining specifically in BRCA1-deficient breast cancer cells. In summary, loss of BRCA1 function leads to hydrogen peroxide generation in both epithelial breast cancer cells and neighboring stromal fibroblasts, and promotes the onset of a reactive glycolytic stroma, with increased MCT4 and decreased Cav-1 expression. Importantly, these metabolic changes can be reversed by antioxidants, which potently induce cancer cell death. Thus, antioxidant therapy appears to be synthetically lethal with a BRCA1-deficiency in breast cancer cells and should be considered for future cancer prevention trials. In this regard, immunostaining with Cav-1 and MCT4 could be used as cost-effective biomarkers to monitor the response to antioxidant therapy.
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http://dx.doi.org/10.4161/cc.22776DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3552923PMC
December 2012