Medicine and Health Sciences Commons^™

The Janus Kinase 1 Is Critical For Pancreatic Cancer Initiation And Progression, Hridaya Shrestha, Patrick Rädler, Rayane Dennaoui, Madison Wicker, Nirakar Rajbhandari, Yunguang Sun, Amy Peck, Kerry Vistisen, Aleata Triplett, Rafic Beydoun, Esta Sterneck, Dieter Saur, Hallgeir Rui, Kay-Uwe Wagner

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Interleukin-6 (IL-6)-class inflammatory cytokines signal through the Janus tyrosine kinase (JAK)/signal transducer and activator of transcription (STAT) pathway and promote the development of pancreatic ductal adenocarcinoma (PDAC); however, the functions of specific intracellular signaling mediators in this process are less well defined. Using a ligand-controlled and pancreas-specific knockout in adult mice, we demonstrate in this study that JAK1 deficiency prevents the formation of KRAS^G12D-induced pancreatic tumors, and we establish that JAK1 is essential for the constitutive activation of STAT3, whose activation is a prominent characteristic of PDAC. We identify CCAAT/enhancer binding protein δ (C/EBPδ) as a biologically relevant …

Xpo1 Blockade With Kpt-330 Promotes Apoptosis In Cutaneous T-Cell Lymphoma By Activating The P53-P21 And P27 Pathways, Nitin Chakravarti, Amy Boles, Rachel Burzinski, Paola Sindaco, Colleen Isabelle, Kathleen Mcconnell, Anjali Mishra, Pierluigi Porcu

Kimmel Cancer Center Faculty Papers

Dysregulated nuclear-cytoplasmic trafficking has been shown to play a role in oncogenesis in several types of solid tumors and hematological malignancies. Exportin 1 (XPO1) is responsible for the nuclear export of several proteins and RNA species, mainly tumor suppressors. KPT-330, a small molecule inhibitor of XPO1, is approved for treating relapsed multiple myeloma and diffuse large B-cell lymphoma. Cutaneous T-cell lymphoma (CTCL) is an extranodal non-Hodgkin lymphoma with an adverse prognosis and limited treatment options in advanced stages. The effect of therapeutically targeting XPO1 with KPT-330 in CTCL has not been established. We report that XPO1 expression is upregulated in …

Nf-Κb As An Inducible Regulator Of Inflammation In The Central Nervous System, Sudha Anilkumar, Elizabeth Wright-Jin

Department of Medicine Faculty Papers

The NF-κB (nuclear factor K-light-chain-enhancer of activated B cells) transcription factor family is critical for modulating the immune proinflammatory response throughout the body. During the resting state, inactive NF-κB is sequestered by IκB in the cytoplasm. The proteasomal degradation of IκB activates NF-κB, mediating its translocation into the nucleus to act as a nuclear transcription factor in the upregulation of proinflammatory genes. Stimuli that initiate NF-κB activation are diverse but are canonically attributed to proinflammatory cytokines and chemokines. Downstream effects of NF-κB are cell type-specific and, in the majority of cases, result in the activation of pro-inflammatory cascades. Acting as …

Stat5 Induces Androgen Receptor (Ar) Gene Transcription In Prostate Cancer And Offers A Druggable Pathway To Target Ar Signaling, Cristina Maranto, Lavannya Sabharwal, Vindhya Udhane, Samuel P. Pitzen, Braedan Mccluskey, Songyan Qi, Christine O'Connor, Savita Devi, Scott Johnson, Kenneth Jacobsohn, Anjishnu Banerjee, Kenneth A. Iczkowski, Liang Wang, Scott M. Dehm, Marja T. Nevalainen

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Androgen receptor (AR) drives prostate cancer (PC) growth and progression, and targeting AR signaling is the mainstay of pharmacological therapies for PC. Resistance develops relatively fast as a result of refueled AR activity. A major gap in the field is the lack of understanding of targetable mechanisms that induce persistent AR expression in castrate-resistant PC (CRPC). This study uncovers an unexpected function of active Stat5 signaling, a known promoter of PC growth and clinical progression, as a potent inducer of AR gene transcription. Stat5 suppression inhibited AR gene transcription in preclinical PC models and reduced the levels of wild-type, mutated, …

Scutellaria Baicalensis Enhances 5-Fluorouracil-Based Chemotherapy Via Inhibition Of Proliferative Signaling Pathways, Haizhou Liu, Hui Liu, Zhiyi Zhou, Jessica Chung, Guojing Zhang, Jin Chang, Robert A Parise, Edward Chu, John C Schmitz

Abington Jefferson Health Papers

Fluoropyridine-based chemotherapy remains the most widely used treatment for colorectal cancer (CRC). In this study, we investigated the mechanism by which the natural product Scutellaria baicalensis (Huang Qin; HQ) and one of its main components baicalin enhanced 5-fluorouracil (5-FU) antitumor activity against CRC. Cell proliferation assays, cell cycle analysis, reverse-phase protein array (RPPA) analysis, immunoblot analysis, and qRT-PCR were performed to investigate the mechanism(s) of action of HQ and its active components on growth of CRC cells. HQ exhibited in vitro antiproliferative activity against drug resistant human CRC cells, against human and mouse CRC cells with different genetic backgrounds and …

Intestinal Neuropod Cell Gucy2c Regulates Visceral Pain, Joshua R. Barton, Annie K. Londregran, Tyler D. Alexander, Ariana A. Entezari, Shely Bar-Ad, Lan Cheng, Angelo C. Lepore, Adam E. Snook, Manuel Covarrubias, Scott A. Waldman

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Visceral pain (VP) is a global problem with complex etiologies and limited therapeutic options. Guanylyl cyclase C (GUCY2C), an intestinal receptor producing cyclic GMP(cGMP), which regulates luminal fluid secretion, has emerged as a therapeutic target for VP. Indeed, FDA-approved GUCY2C agonists ameliorate VP in patients with chronic constipation syndromes, although analgesic mechanisms remain obscure. Here, we revealed that intestinal GUCY2C was selectively enriched in neuropod cells, a type of enteroendocrine cell that synapses with submucosal neurons in mice and humans. GUCY2Chi neuropod cells associated with cocultured dorsal root ganglia neurons and induced hyperexcitability, reducing the rheobase and increasing the resulting …

Serpinb3 Drives Cancer Stem Cell Survival In Glioblastoma, Adam Lauko, Josephine Volovetz, Soumya M Turaga, Defne Bayik, Daniel J Silver, Kelly Mitchell, Erin E Mulkearns-Hubert, Dionysios C Watson, Kiran Desai, Manav Midha, Jing Hao, Kathleen Mccortney, Alicia Steffens, Ulhas Naik, Manmeet S Ahluwalia, Shideng Bao, Craig Horbinski, Jennifer S Yu, Justin D Lathia

Department of Medicine Faculty Papers

Despite therapeutic interventions for glioblastoma (GBM), cancer stem cells (CSCs) drive recurrence. The precise mechanisms underlying CSC resistance, namely inhibition of cell death, are unclear. We built on previous observations that the high cell surface expression of junctional adhesion molecule-A drives CSC maintenance and identified downstream signaling networks, including the cysteine protease inhibitor SerpinB3. Using genetic depletion approaches, we found that SerpinB3 is necessary for CSC maintenance, survival, and tumor growth, as well as CSC pathway activation. Knockdown of SerpinB3 also increased apoptosis and susceptibility to radiation therapy. SerpinB3 was essential to buffer cathepsin L-mediated cell death, which was enhanced …

Endorepellin Evokes An Angiostatic Stress Signaling Cascade In Endothelial Cells., Aastha Kapoor, Carolyn G Chen, Renato V Iozzo

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Endorepellin, the C-terminal fragment of the heparan sulfate proteoglycan perlecan, influences various signaling pathways in endothelial cells by binding to VEGFR2. In this study, we discovered that soluble endorepellin activates the canonical stress signaling pathway consisting of PERK, eIF2α, ATF4, and GADD45α. Specifically, endorepellin evoked transient activation of VEGFR2, which, in turn, phosphorylated PERK at Thr980 Subsequently, PERK phosphorylated eIF2α at Ser51, upregulating its downstream effector proteins ATF4 and GADD45α. RNAi-mediated knockdown of PERK or eIF2α abrogated the endorepellin-mediated up-regulation of GADD45α, the ultimate effector protein of this stress signaling cascade. To functionally validate these findings, we utilized an ex …

Targeting The Stat5 Pathway In Ph+ Acute Lymphoblastic Leukemia, Valentina Minieri, Marco De Dominici, Marja T. Nevalainen, Bruno Calabretta

Department of Cancer Biology Faculty Papers

No abstract provided.

Extracellular Interactions Between Fibulins And Transforming Growth Factor (Tgf)-Β In Physiological And Pathological Conditions., Takeshi Tsuda

Department of Pediatrics Faculty Papers

Transforming growth factor (TGF)-β is a multifunctional peptide growth factor that has a vital role in the regulation of cell growth, differentiation, inflammation, and repair in a variety of tissues, and its dysregulation mediates a number of pathological conditions including fibrotic disorders, chronic inflammation, cardiovascular diseases, and cancer progression. Regulation of TGF-β signaling is multifold, but one critical site of regulation is via interaction with certain extracellular matrix (ECM) microenvironments, as TGF-β is primarily secreted as a biologically inactive form sequestrated into ECM. Several ECM proteins are known to modulate TGF-β signaling via cell⁻matrix interactions, including thrombospondins, SPARC (Secreted Protein …

Negative Regulation Of Urokinase Receptor Activity By A Gpi-Specific Phospholipase C In Breast Cancer Cells., Michiel Van Veen, Elisa Matas-Rico, Koen Van De Wetering, Daniela Leyton-Puig, Katarzyna M. Kedziora, Valentina De Lorenzi, Yvette Stijf-Bultsma, Bram Van Den Broek, Kees Jalink, Nicolai Sidenius, Anastassis Perrakis, Wouter H. Moolenaar

Department of Dermatology and Cutaneous Biology Faculty Papers

The urokinase receptor (uPAR) is a glycosylphosphatidylinositol (GPI)-anchored protein that promotes tissue remodeling, tumor cell adhesion, migration and invasion. uPAR mediates degradation of the extracellular matrix through protease recruitment and enhances cell adhesion, migration and signaling through vitronectin binding and interactions with integrins. Full-length uPAR is released from the cell surface, but the mechanism and significance of uPAR shedding remain obscure. Here we identify transmembrane glycerophosphodiesterase GDE3 as a GPI-specific phospholipase C that cleaves and releases uPAR with consequent loss of function, whereas its homologue GDE2 fails to attack uPAR. GDE3 overexpression depletes uPAR from distinct basolateral membrane domains in …

G Protein-Coupled Receptor Kinase-2 (Grk-2) Regulates Serotonin Metabolism Through The Monoamine Oxidase Amx-2 In Caenorhabditis Elegans., Jianjun Wang, Jiansong Luo, Dipendra K. Aryal, William C. Wetsel, Richard Nass, Jeffrey L. Benovic

Department of Biochemistry and Molecular Biology Faculty Papers

G protein-coupled receptors (GPCRs) regulate many animal behaviors. GPCR signaling is mediated by agonist-promoted interactions of GPCRs with heterotrimeric G proteins, GPCR kinases (GRKs), and arrestins. To further elucidate the role of GRKs in regulating GPCR-mediated behaviors, we utilized the genetic model system Caenorhabditis elegans Our studies demonstrate that grk-2 loss-of-function strains are egg laying-defective and contain low levels of serotonin (5-HT) and high levels of the 5-HT metabolite 5-hydroxyindole acetic acid (5-HIAA). The egg laying defect could be rescued by the expression of wild type but not by catalytically inactive grk-2 or by the selective expression of grk-2 in …

Hormone Whodunit: Clues For Solving The Case Of Intratumor Androgen Production., Karen E Knudsen

Department of Cancer Biology Faculty Papers

One of the key mechanisms by which prostate cancer cells evade hormone therapy is through intratumor testosterone production. New evidence points toward androstenedione as a potential precursor of intratumor androgen production and furthers nomination of AKR1C3 as a therapeutic target in advanced disease. Clin Cancer Res; 20(21); 5343-5. ©2014 AACR.

Therapeutic Implications Of Estrogen For Cerebral Vasospasm And Delayed Cerebral Ischemia Induced By Aneurysmal Subarachnoid Hemorrhage., Dale Ding, Robert M Starke, Aaron S Dumont, Gary K Owens, David M Hasan, Nohra Chalouhi, Md, Ricky Medel, Chih-Lung Lin

Department of Neurosurgery Faculty Papers

Cerebral vasospasm (CV) remains the leading cause of delayed morbidity and mortality following aneurysmal subarachnoid hemorrhage (SAH). However, increasing evidence supports etiologies of delayed cerebral ischemia (DCI) other than CV. Estrogen, specifically 17 β -estradiol (E2), has potential therapeutic implications for ameliorating the delayed neurological deterioration which follows aneurysmal SAH. We review the causes of CV and DCI and examine the evidence for E2-mediated vasodilation and neuroprotection. E2 potentiates vasodilation by activating endothelial nitric oxide synthase (eNOS), preventing increased inducible NOS (iNOS) activity caused by SAH, and decreasing endothelin-1 production. E2 provides neuroprotection by increasing thioredoxin expression, decreasing c-Jun N-terminal …

Signal Transducer And Activator Of Transcription-5 Mediates Neuronal Apoptosis Induced By Inhibition Of Rac Gtpase Activity., Trisha R Stankiewicz, F Alexandra Loucks, Emily K Schroeder, Marja T Nevalainen, Kenneth L Tyler, Klaus Aktories, Ron J Bouchard, Daniel A Linseman

Department of Cancer Biology Faculty Papers

In several neuronal cell types, the small GTPase Rac is essential for survival. We have shown previously that the Rho family GTPase inhibitor Clostridium difficile toxin B (ToxB) induces apoptosis in primary rat cerebellar granule neurons (CGNs) principally via inhibition of Rac GTPase function. In the present study, incubation with ToxB activated a proapoptotic Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway, and a pan-JAK inhibitor protected CGNs from Rac inhibition. STAT1 expression was induced by ToxB; however, CGNs from STAT1 knock-out mice succumbed to ToxB-induced apoptosis as readily as wild-type CGNs. STAT3 displayed enhanced tyrosine phosphorylation following …

We Can Do It Together: Par1/Par2 Heterodimer Signaling In Vsmcs., Rafal Pawlinski, Michael Holinstat

Department of Medicine Faculty Papers

In this issue, Sevigny and colleagues demonstrate that a protease-activated receptor 1 (PAR1)-PAR2 heterodimer regulates vascular smooth muscle cell (VSMC) hyperplasia following vascular injury ¹. PARs belong to a family of G-protein coupled receptors that are proteolytically activated by a variety of proteases ^{2, 3}. Cleavage of PARs results in intracellular signaling mediated by activation of various G proteins including G_12/13, G_q, and G_i ^{2, 4-6}. The PAR family consists of 4 members, PAR1-PAR4, with PARs 1, 3, and 4 being primarily activated by thrombin, while PAR2 is activated by trypsin and …

Role Of Growth Factors In The Pathogenesis Of Tissue Fibrosis In Systemic Sclerosis., Sergio A. Jimenez, Susan V. Castro, Sonsoles Piera-Velazquez

Department of Medicine Faculty Papers

The most severe clinical and pathologic manifestations of systemic sclerosis (SSc) are the result of a fibrotic process characterized by the excessive and often progressive deposition of collagen and other connective tissue macromolecules in skin and numerous internal organs. The mechanisms involved in the initiation and progression of the remarkable fibrotic process in SSc remain largely unknown. Extensive recent studies have indicated that a variety of polypeptide growth factors play a crucial role in this process. The most commonly implicated growth factors include transforming growth factor beta (TGF-β), connective tissue growth factor (CTGF), platelet derived growth factor (PDGF), and vascular …

Proteoglycans In Health And Disease: Novel Regulatory Signaling Mechanisms Evoked By The Small Leucine-Rich Proteoglycans., Renato V. Iozzo, Liliana Schaefer

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The small leucine-rich proteoglycans (SLRPs) are involved in many aspects of mammalian biology, both in health and disease. They are now being recognized as key signaling molecules with an expanding repertoire of molecular interactions affecting not only growth factors, but also various receptors involved in controlling cell growth, morphogenesis and immunity. The complexity of SLRP signaling and the multitude of affected signaling pathways can be reconciled with a hierarchical affinity-based interaction of various SLRPs in a cell- and tissue-specific context. Here, we review this interacting network, describe new relationships of the SLRPs with tyrosine kinase and Toll-like receptors and critically …

Diverse Antidepressants Increase Cdp-Diacylglycerol Production And Phosphatidylinositide Resynthesis In Depression-Relevant Regions Of The Rat Brain, Kimberly R. Tyeryar, Habiba O.U. Vongtau, Ashiwel S. Undieh

College of Pharmacy Faculty Papers

BACKGROUND: Major depression is a serious mood disorder affecting millions of adults and children worldwide. While the etiopathology of depression remains obscure, antidepressant medications increase synaptic levels of monoamine neurotransmitters in brain regions associated with the disease. Monoamine transmitters activate multiple signaling cascades some of which have been investigated as potential mediators of depression or antidepressant drug action. However, the diacylglycerol arm of phosphoinositide signaling cascades has not been systematically investigated, even though downstream targets of this cascade have been implicated in depression. With the ultimate goal of uncovering the primary postsynaptic actions that may initiate cellular antidepressive signaling, we …

Cell Autonomous Expression Of Inflammatory Genes In Biologically Aged Fibroblasts Associated With Elevated Nf-Kappab Activity., Andres Kriete, Kelli L Mayo, Nirupama Yalamanchili, William Beggs, Patrick Bender, Csaba Kari, Ulrich Rodeck

Department of Dermatology and Cutaneous Biology Faculty Papers

BACKGROUND: Chronic inflammation is a well-known corollary of the aging process and is believed to significantly contribute to morbidity and mortality of many age-associated chronic diseases. However, the mechanisms that cause age-associated inflammatory changes are not well understood. Particularly, the contribution of cell stress responses to age-associated inflammation in 'non-inflammatory' cells remains poorly defined. The present cross-sectional study focused on differences in molecular signatures indicative of inflammatory states associated with biological aging of human fibroblasts from donors aged 22 to 92 years. RESULTS: Gene expression profiling revealed elevated steady-state transcript levels consistent with a chronic inflammatory state in fibroblast cell-strains …

Sirtuins, Nuclear Hormone Receptor Acetylation And Transcriptional Regulation, James R. Whittle, Michael J. Powell, Vladimir M. Popov, L. Andrew Shirley, Chenguang Wang, Richard G. Pestell

Department of Cancer Biology Faculty Papers

Endocrine signaling via nuclear receptors (NRs) is known to play an important role in normal physiology as well as in human tumor progression. Hormones regulate gene expression by altering local chromatin structure and, thereby, accessibility of transcriptional co-regulators to DNA. Recently it has been shown that non-histone proteins involved in hormone signaling, such as nuclear receptors and NR co-activators, are regulated by acetylation, resulting in their altered transcriptional activity. NAD-dependent protein deacetylases, the sirtuins (Sir2-related enzymes), directly modify NRs. Because sirtuins have been shown to regulate tumor cellular growth, aging, metabolic signaling and endocrine hormone signaling, they might play a …

Autocrine Prolactin Promotes Prostate Cancer Cell Growth Via Janus Kinase-2-Signal Transducer And Activator Of Transcription-5a/B Signaling Pathway., Ayush Dagvadorj, Sean Collins, Jean-Baptiste Jomain, Junaid Abdulghani, James Karras, Tobias Zellweger, Hongzhen Li, Martti Nurmi, Kalle Alanen, Tuomas Mirtti, Tapio Visakorpi, Lukas Bubendorf, Vincent Goffin, Marja T Nevalainen

Department of Cancer Biology Faculty Papers

The molecular mechanisms that promote progression of localized prostate cancer to hormone-refractory and disseminated disease are poorly understood. Prolactin (Prl) is a local growth factor produced in high-grade prostate cancer, and exogenously added Prl in tissue or explant cultures of normal and malignant prostate is a strong mitogen and survival factor for prostate epithelium. The key signaling proteins that mediate the biological effects of Prl in prostate cancer are Signal Transducer and Activator of Transcription (Stat)-5a/5b via activation of Janus kinase-2. Importantly, inhibition of Stat5a/b in prostate cancer cells induces apoptotic death. Using a specific Prl receptor antagonist (Delta1-9G129R-hPRL), we …

A Domain-Oriented Approach To The Reduction Of Combinatorial Complexity In Signal Transduction Networks, Holger Conzelmann, Julio Saez-Rodriguez, Thomas Sauter, Boris N. Kholodenko Phd, Dsci, Ernst D. Gilles

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Background:

Receptors and scaffold proteins possess a number of distinct domains and bind multiple partners. A common problem in modeling signaling systems arises from a combinatorial explosion of different states generated by feasible molecular species. The number of possible species grows exponentially with the number of different docking sites and can easily reach several millions. Models accounting for this combinatorial variety become impractical for many applications.

Results:

Our results show that under realistic assumptions on domain interactions, the dynamics of signaling pathways can be exactly described by reduced, hierarchically structured models. The method presented here provides a rigorous way to …

Inhibition Of Glucocorticoid-Induced Apoptosis By Targeting Splice Variants Of Bim Mrna With Small Interfering Rna And Short Hairpin Rna., Marc T. Abrams, Noreen M. Robertson, Kyonggeun Yoon, Eric Wickstrom

Department of Biochemistry and Molecular Biology Faculty Papers

Glucocorticoids (GCs) induce apoptosis in lymphocytes and are effective agents for the treatment of leukemia. The activated glucocorticoid receptor (GR) initiates a transcriptional program leading to caspase activation and cell death, but the critical signaling intermediates in GC-induced apoptosis remain largely undefined. We have observed that GC induction of the three major protein products of the Bcl-2 relative Bim (BimEL, BimS and BimL) correlates with GC sensitivity in a panel of human pre-B acute lymphoblastic leukemia (ALL) cell lines. To test the hypothesis that Bim facilitates GC-induced apoptosis, we reduced BIM mRNA levels and Bim protein levels by RNA interference …

The Nad(P)H Oxidase Homolog Nox4 Modulates Insulin-Stimulated Generation Of H202 And Plays An Integral Role In Insulin Signal Transduction, Kalyankar Mahadev, Hiroyuki Motoshima, Xiangdong Wu, Jean Marie Ruddy, Rebecca S. Arnold, Guangjie Cheng, J. David Lambeth, Barry J. Goldstein

Department of Medicine Faculty Papers

Insulin stimulation of target cells elicits a burst of H₂O₂ that enhances tyrosine phosphorylation of the insulin receptor and its cellular substrate proteins as well as distal signaling events in the insulin action cascade. The molecular mechanism coupling the insulin receptor with the cellular oxidant-generating apparatus has not been elucidated. Using reverse transcription-PCR and Northern blot analyses, we found that Nox4, a homolog of gp91phox, the phagocytic NAD(P)H oxidase catalytic subunit, is prominently expressed in insulin-sensitive adipose cells. Adenovirus-mediated expression of Nox4 deletion constructs lacking NAD(P)H or FAD/NAD(P)H cofactor binding domains acted in a dominant-negative …