Medical Specialties Commons^™

Increased Expression Of Fatty Acid Synthase Provides A Survival Advantage To Colorectal Cancer Cells Via Upregulation Of Cellular Respiration, Yekaterina Y. Zaytseva, Jennifer W. Harris, Mihail I. Mitov, Ji Tae Kim, D. Allan Butterfield, Eun Young Lee, Heidi L. Weiss, Tianyan Gao, B. Mark Evers

Markey Cancer Center Faculty Publications

Fatty acid synthase (FASN), a lipogenic enzyme, is upregulated in colorectal cancer (CRC). Increased de novo lipid synthesis is thought to be a metabolic adaptation of cancer cells that promotes survival and metastasis; however, the mechanisms for this phenomenon are not fully understood. We show that FASN plays a role in regulation of energy homeostasis by enhancing cellular respiration in CRC. We demonstrate that endogenously synthesized lipids fuel fatty acid oxidation, particularly during metabolic stress, and maintain energy homeostasis. Increased FASN expression is associated with a decrease in activation of energy-sensing pathways and accumulation of lipid droplets in CRC cells …

Structure-Based Screen Identifies A Potent Small Molecule Inhibitor Of Stat5a/B With Therapeutic Potential For Prostate Cancer And Chronic Myeloid Leukemia., Zhiyong Liao, Lei Gu, Jenny Vergalli, Samanta A. Mariani, Marco De Dominici, Ravi K. Lokareddy, Ayush Dagvadorj, Puranik Purushottamachar, Peter A. Mccue, Edouard J. Trabulsi, Costas D. Lallas, Shilpa Gupta, Elyse Ellsworth, Shauna Blackmon, Adam Ertel, Paolo Fortina, Benjamin E. Leiby, Guanjun Xia, Hallgeir Rui, David T. Hoang, Leonard G Gomella, Gino Cingolani, Vincent Njar, Nagarajan Pattabiraman, Bruno Calabretta, Marja T. Nevalainen

Department of Cancer Biology Faculty Papers

Bypassing tyrosine kinases responsible for Stat5a/b phosphorylation would be advantageous for therapy development for Stat5a/b-regulated cancers. Here, we sought to identify small molecule inhibitors of Stat5a/b for lead optimization and therapy development for prostate cancer and Bcr-Abl-driven leukemias. In silico screening of chemical structure databases combined with medicinal chemistry was used for identification of a panel of small molecule inhibitors to block SH2 domain-mediated docking of Stat5a/b to the receptor-kinase complex and subsequent phosphorylation and dimerization. We tested the efficacy of the lead compound IST5-002 in experimental models and patient samples of two known Stat5a/b-driven cancers, prostate cancer and chronic …

Nf-Κb Regulation Of C-Flip Promotes Tnfα-Mediated Raf Inhibitor Resistance In Melanoma., Yongping Shao, Kaitlyn Le, Hanyin Cheng, Andrew E. Aplin

Department of Cancer Biology Faculty Papers

Targeted inhibitors elicit heterogeneous clinical responses in genetically stratified groups of patients. Although most studies focus on tumor intrinsic properties, factors in the tumor microenvironment were recently found to modulate the response to inhibitors. Here, we show that in cutaneous BRAF V600E melanoma, the cytokine tumor necrosis factor-α (TNFα) blocks RAF inhibitor-induced apoptosis via activation of NF-κB. Several NF-κB-dependent factors are upregulated following TNFα and RAF inhibitor treatment. Of these factors, we show that death receptor inhibitor cellular caspase 8 (FLICE)-like inhibitory protein (c-FLIP) is required for TNFα-induced protection against RAF inhibitor. Overexpression of c-FLIP_S or c-FLIP_L isoform decreased RAF …

Paracrine Effect Of Nrg1 And Hgf Drives Resistance To Mek Inhibitors In Metastatic Uveal Melanoma., Hanyin Cheng, Mizue Terai, Ken Kageyama, Shinji Ozaki, Peter Mccue, Takami Sato, Andrew E. Aplin

Department of Cancer Biology Faculty Papers

Uveal melanoma patients with metastatic disease usually die within one year, emphasizing an urgent need to develop new treatment strategies for this cancer. MEK inhibitors improve survival in cutaneous melanoma patients but show only modest efficacy in metastatic uveal melanoma patients. In this study, we screened for growth factors that elicited resistance in newly characterized metastatic uveal melanoma cell lines to clinical-grade MEK inhibitors, trametinib and selumetinib. We show that neuregulin 1 (NRG1) and hepatocyte growth factor (HGF) provide resistance to MEK inhibition. Mechanistically, trametinib enhances the responsiveness to NRG1 and sustained HGF-mediated activation of AKT. Individually targeting ERBB3 and …

The Endogenous Cell-Fate Factor Dachshund Restrains Prostate Epithelial Cell Migration Via Repression Of Cytokine Secretion Via A Cxcl Signaling Module., Ke Chen, Kongming Wu, Xuanmao Jiao, Liping Wang, Xiaoming Ju, Min Wang, Gabriele Disante, Shaohua Xu, Qiong Wang, Kevin Li, Xin Sun, Chongwen Xu, Zhiping Li, Mathew C. Casimiro, Adam Ertel, Sankar Addya, Peter Mccue, Michael P. Lisanti, Chenguang Wang, Richard J. Davis, Graeme Mardon, Richard Pestell

Department of Cancer Biology Faculty Papers

Prostate cancer is the second leading form of cancer-related death in men. In a subset of prostate cancer patients, increased chemokine signaling IL8 and IL6 correlates with castrate-resistant prostate cancer (CRPC). IL8 and IL6 are produced by prostate epithelial cells and promote prostate cancer cell invasion; however, the mechanisms restraining prostate epithelial cell cytokine secretion are poorly understood. Herein, the cell-fate determinant factor DACH1 inhibited CRPC tumor growth in mice. Using Dach1(fl/fl)/Probasin-Cre bitransgenic mice, we show IL8 and IL6 secretion was altered by approximately 1,000-fold by endogenous Dach1. Endogenous Dach1 is shown to serve as a key endogenous restraint to …

Translation Initiation Complex Eif4f Is A Therapeutic Target For Dual Mtor Kinase Inhibitors In Non-Hodgkin Lymphoma., Christos Demosthenous, Jing Jing Han, Mary J Stenson, Matthew J Maurer, Linda E Wellik, Brian Link, Kristen Hege, Ahmet Dogan, Eduardo Sotomayor, Thomas Witzig, Mamta Gupta

Medicine Faculty Publications

Deregulated mRNA translation has been implicated in disease development and in part is controlled by a eukaryotic initiation complex eIF4F (composed of eIF4E, eIF4G and eIF4A). We demonstrate here that the cap bound fraction from lymphoma cells was enriched with eIF4G and eIF4E indicating that lymphoma cells exist in an activated translational state. Moreover, 77% (110/142) of diffuse large B cell lymphoma tumors expressed eIF4E and this was associated with an inferior event free survival. Over-expression of wild-type eIF4E (eIF4E(WT)) but not cap-mutant eIF4E (eIF4E(cap mutant)) increased the activation of the eIF4F complex. Treatment with the active-site dual mTOR inhibitor …

Novel Actions Of Next-Generation Taxanes Benefit Advanced Stages Of Prostate Cancer., Renée De Leeuw, Lisa D. Berman-Booty, Matthew J. Schiewer, Stephen J Ciment, Robert Den, Adam P. Dicker, William Kelly, Edouard J. Trabulsi, Costas D. Lallas, Leonard G. Gomella, Karen E. Knudsen

Department of Cancer Biology Faculty Papers

PURPOSE: To improve the outcomes of patients with castration-resistant prostate cancer (CRPC), there is an urgent need for more effective therapies and approaches that individualize specific treatments for patients with CRPC. These studies compared the novel taxane cabazitaxel with the previous generation docetaxel, and aimed to determine which tumors are most likely to respond.

EXPERIMENTAL DESIGN: Cabazitaxel and docetaxel were compared via in vitro modeling to determine the molecular mechanism, biochemical and cell biologic impact, and cell proliferation, which was further assessed ex vivo in human tumor explants. Isogenic pairs of RB knockdown and control cells were interrogated in vitro …

Tsc2/Mtorc1 Signaling Controls Paneth And Goblet Cell Differentiation In The Intestinal Epithelium, Y. Zhou, Piotr G. Rychahou, Q. Wang, Heidi L. Weiss, B. Mark Evers

Markey Cancer Center Faculty Publications

The intestinal mucosa undergoes a continual process of proliferation, differentiation and apoptosis, which is regulated by multiple signaling pathways. Notch signaling is critical for the control of intestinal stem cell maintenance and differentiation. However, the precise mechanisms involved in the regulation of differentiation are not fully understood. Previously, we have shown that tuberous sclerosis 2 (TSC2) positively regulates the expression of the goblet cell differentiation marker, MUC2, in intestinal cells. Using transgenic mice constitutively expressing a dominant negative TSC2 allele, we observed that TSC2 inactivation increased mTORC1 and Notch activities, and altered differentiation throughout the intestinal epithelium, with a marked …

Intracellular Cd24 Disrupts The Arf-Npm Interaction And Enables Mutational And Viral Oncogene-Mediated P53 Inactivation., Lizhong Wang, Runhua Liu, Peiying Ye, Chunshu Wong, Guo-Yun Chen, Penghui Zhou, +11 Additional Authors

Pediatrics Faculty Publications

CD24 is overexpressed in nearly 70% human cancers, whereas TP53 is the most frequently mutated tumour-suppressor gene that functions in a context-dependent manner. Here we show that both targeted mutation and short hairpin RNA (shRNA) silencing of CD24 retard the growth, progression and metastasis of prostate cancer. CD24 competitively inhibits ARF binding to NPM, resulting in decreased ARF, increase MDM2 and decrease levels of p53 and the p53 target p21/CDKN1A. CD24 silencing prevents functional inactivation of p53 by both somatic mutation and viral oncogenes, including the SV40 large T antigen and human papilloma virus 16 E6-antigen. In support of the …

Clinical Significance Of A Point Mutation In Dna Polymerase Beta (Polb) Gene In Gastric Cancer., Xiaohui Tan, Hongyi Wang, Guangbin Luo, Shuyang Ren, Wenmei Li, Jiantao Cui, Harindarpal S. Gill, Sidney W. Fu, Youyong Lu

Medicine Faculty Publications

Gastric cancer (GC) is a major cause of global cancer mortality. Genetic variations in DNA repair genes can modulate DNA repair capability and, consequently, have been associated with risk of developing cancer. We have previously identified a T to C point mutation at nucleotide 889 (T889C) in DNA polymerase beta (POLB) gene, a key enzyme involved in base excision repair in primary GCs. The purpose of this study was to evaluate the mutation and expression of POLB in a larger cohort and to identify possible prognostic roles of the POLB alterations in GC. Primary GC specimens and their matched normal …

Effect Of Cold Plasma On Glial Cell Morphology Studied By Atomic Force Microscopy., Nina Recek, Xiaoqian Cheng, Michael Keidar, Uros Cvelbar, Alenka Vesel, Miran Mozetic, Jonathan Sherman

Neurological Surgery Faculty Publications

The atomic force microscope (AFM) is broadly used to study the morphology of cells. The morphological characteristics and differences of the cell membrane between normal human astrocytes and glial tumor cells are not well explored. Following treatment with cold atmospheric plasma, evaluation of the selective effect of plasma on cell viability of tumor cells is poorly understood and requires further evaluation. Using AFM we imaged morphology of glial cells before and after cold atmospheric plasma treatment. To look more closely at the effect of plasma on cell membrane, high resolution imaging was used. We report the differences between normal human …

Kallikrein Family Proteases Klk6 And Klk7 Are Potential Early Detection And Diagnostic Biomarkers For Serous And Papillary Serous Ovarian Cancer Subtypes., Ayala Tamir, Ushma Jag, Sreeja Sarojini, Craig Schindewolf, Takemi Tanaka, Rajendra Gharbaran, Hiren Patel, Anil Sood, Wei Hu, Ruzeen Patwa, Patrick Blake, Polina Chirina, Jin Oh Jeong, Heejin Lim, Andre Goy, Andrew Pecora, K Stephen Suh

Department of Medicine Faculty Papers

BACKGROUND: Early detection of ovarian cancer remains a challenge due to widespread metastases and a lack of biomarkers for early-stage disease. This study was conducted to identify relevant biomarkers for both laparoscopic and serum diagnostics in ovarian cancer.

METHODS: Bioinformatics analysis and expression screening in ovarian cancer cell lines were employed. Selected biomarkers were further validated in bio-specimens of diverse cancer types and ovarian cancer subtypes. For non-invasive detection, biomarker proteins were evaluated in serum samples from ovarian cancer patients.

RESULTS: Two kallikrein (KLK) serine protease family members (KLK6 and KLK7) were found to be significantly overexpressed relative to normal …

Suppression Of Invasion And Metastasis Of Triple-Negative Breast Cancer Lines By Pharmacological Or Genetic Inhibition Of Slug Activity., Giovanna Ferrari-Amorotti, Claudia Chiodoni, Fei Shen, Sara Cattelani, Angela Rachele Soliera, Gloria Manzotti, Giulia Grisendi, Massimo Dominici, Francesco Rivasi, Mario Paolo Colombo, Alessandro Fatatis, Bruno Calabretta

Department of Cancer Biology Faculty Papers

Most triple-negative breast cancers (TNBCs) exhibit gene expression patterns associated with epithelial-to-mesenchymal transition (EMT), a feature that correlates with a propensity for metastatic spread. Overexpression of the EMT regulator Slug is detected in basal and mesenchymal-type TNBCs and is associated with reduced E-cadherin expression and aggressive disease. The effects of Slug depend, in part, on the interaction of its N-terminal SNAG repressor domain with the chromatin-modifying protein lysine demethylase 1 (LSD1); thus, we investigated whether tranylcypromine [also known as trans-2-phenylcyclopropylamine hydrochloride (PCPA) or Parnate], an inhibitor of LSD1 that blocks its interaction with Slug, suppresses the migration, invasion, and metastatic …

The Long Non-Coding Rna Pcat-1 Promotes Prostate Cancer Cell Proliferation Through Cmyc., John R. Prensner, Wei Chen, Sumin Han, Matthew K. Iyer, Qi Cao, Vishal Kothari, Joseph R. Evans, Karen E. Knudsen, Michelle T. Paulsen, Mats Ljungman, Theodore S. Lawrence, Arul M. Chinnaiyan, Felix Y. Feng

Department of Cancer Biology Faculty Papers

Long non-coding RNAs (lncRNAs) represent an emerging layer of cancer biology, contributing to tumor proliferation, invasion, and metastasis. Here, we describe a role for the oncogenic lncRNA PCAT-1 in prostate cancer proliferation through cMyc. We find that PCAT-1-mediated proliferation is dependent on cMyc protein stabilization, and using expression profiling, we observed that cMyc is required for a subset of PCAT-1-induced expression changes. The PCAT-1-cMyc relationship is mediated through the post-transcriptional activity of the MYC 3' untranslated region, and we characterize a role for PCAT-1 in the disruption of MYC-targeting microRNAs. To further elucidate a role for post-transcriptional regulation, we demonstrate …

Fructose-2,6-Bisphosphate Synthesis By 6-Phosphofructo-2-Kinase/Fructose-2,6-Bisphosphatase 4 (Pfkfb4) Is Required For The Glycolytic Response To Hypoxia And Tumor Growth, Jason Chesney, Jennifer Clark, Alden C. Klarer, Yoannis Imbert-Fernandez, Andrew N. Lane, Sucheta Telang

Markey Cancer Center Faculty Publications

Fructose-2,6-bisphosphate (F2,6BP) is a shunt product of glycolysis that allosterically activates 6-phosphofructo-1-kinase (PFK-1) resulting in increased glucose uptake and glycolytic flux to lactate. The F2,6BP concentration is dictated by four bifunctional 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatases (PFKFB1-4) with distinct kinase:phosphatase activities. PFKFB4 is over-expressed in human cancers, induced by hypoxia and required for survival and growth of several cancer cell lines. Although PFKFB4 appears to be a rational target for anti-neoplastic drug development, it is not clear whether its kinase or phosphatase activity is required for cancer cell survival. In this study, we demonstrate that recombinant human PFKFB4 kinase activity is 4.3-fold greater than …

Loss Of 4e-Bp1 Function Induces Emt And Promotes Cancer Cell Migration And Invasion Via Cap-Dependent Translational Activation Of Snail, Weijia Cai, Qing Ye, Qing-Bai She

Markey Cancer Center Faculty Publications

The cap-dependent translation is frequently deregulated in a variety of cancers associated with tumor progression. However, the molecular basis of the translation activation for metastatic progression of cancer remains largely elusive. Here, we demonstrate that activation of cap-dependent translation by silencing the translational repressor 4E-BP1 causes cancer epithelial cells to undergo epithelial-mesenchymal transition (EMT), which is associated with selective upregulation of the EMT inducer Snail followed by repression of E-cadherin expression and promotion of cell migratory and invasive capabilities as well as metastasis. Conversely, inhibition of cap-dependent translation by a dominant active mutant 4E-BP1 effectively downregulates Snail expression and suppresses …

Rorα Binds To E2f1 To Inhibit Cell Proliferation And Regulate Mammary Gland Branching Morphogenesis, Gaofeng Xiong, Ren Xu

Markey Cancer Center Faculty Publications

Retinoic acid receptor-related orphan nuclear receptor alpha (RORα) is a potent tumor suppressor that reduces cell proliferation and inhibits tumor growth. However, the molecular mechanism by which it inhibits cell proliferation remains unknown. We demonstrate a noncanonical nuclear receptor pathway in which RORα binds to E2F1 to inhibit cell cycle progression. We showed that RORα bound to the heptad repeat and marked box region of E2F1 and suppressed E2F1-regulated transcription in epithelial cells. Binding of RORα inhibited E2F1 acetylation and its DNA-binding activity by recruiting histone deacetylase 1 (HDAC1) to the protein complexes. Knockdown of HDAC1 or inhibition of HDAC …

Pharmacologic Suppression Of Jak1/2 By Jak1/2 Inhibitor Azd1480 Potently Inhibits Il-6-Induced Experimental Prostate Cancer Metastases Formation., Lei Gu, Pooja Talati, Paraskevi Vogiatzi, Ana L Romero-Weaver, Junaid Abdulghani, Zhiyong Liao, Benjamin E. Leiby, David T. Hoang, Tuomas Mirtti, Kalle Alanen, Michael Zinda, Dennis Huszar, Marja T. Nevalainen

Department of Medical Oncology Faculty Papers

Metastatic prostate cancer is lethal and lacks effective strategies for prevention or treatment, requiring novel therapeutic approaches. Interleukin-6 (IL-6) is a cytokine that has been linked with prostate cancer pathogenesis by multiple studies. However, the direct functional roles of IL-6 in prostate cancer growth and progression have been unclear. In the present study, we show that IL-6 is produced in distant metastases of clinical prostate cancers. IL-6-activated signaling pathways in prostate cancer cells induced a robust 7-fold increase in metastases formation in nude mice. We further show that IL-6 promoted migratory prostate cancer cell phenotype, including increased prostate cancer cell …

Metformin Inhibits Androgen-Induced Igf-Ir Up-Regulation In Prostate Cancer Cells By Disrupting Membrane-Initiated Androgen Signaling., Roberta Malaguarnera, Antonella Sacco, Alaide Morcavallo, Sebastiano Squatrito, Antimo Migliaccio, Andrea Morrione, Marcello Maggiolini, Antonino Belfiore

Department of Urology Faculty Papers

We have previously demonstrated that, in prostate cancer cells, androgens up-regulate IGF-I receptor (IGF-IR) by inducing cAMP-response element-binding protein (CREB) activation and CREB-dependent IGF-IR gene transcription through androgen receptor (AR)-dependent membrane-initiated effects. This IGF-IR up-regulation is not blocked by classical antiandrogens and sensitizes cells to IGF-I-induced biological effects. Metformin exerts complex antitumoral functions in various models and may inhibit CREB activation in hepatocytes. We, therefore, evaluated whether metformin may affect androgen-dependent IGF-IR up-regulation. In the AR(+) LNCaP prostate cancer cells, we found that metformin inhibits androgen-induced CRE activity and IGF-IR gene transcription. CRE activity requires the formation of a CREB-CREB …

Targeting Fibroblast Activation Protein In Tumor Stroma With Chimeric Antigen Receptor T Cells Can Inhibit Tumor Growth And Augment Host Immunity Without Severe Toxicity., Liang-Chuan S. Wang, Albert Lo, John Scholler, Jing Sun, Rajrupa S. Majumdar, Veena Kapoor, Michael Antzis, Cody E. Cotner, Laura A. Johnson, Amy C. Durham, Charalambos C. Solomides, Md, Carl H. June, Ellen Puré, Steven M. Albelda

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The majority of chimeric antigen receptor (CAR) T-cell research has focused on attacking cancer cells. Here, we show that targeting the tumor-promoting, nontransformed stromal cells using CAR T cells may offer several advantages. We developed a retroviral CAR construct specific for the mouse fibroblast activation protein (FAP), comprising a single-chain Fv FAP [monoclonal antibody (mAb) 73.3] with the CD8α hinge and transmembrane regions, and the human CD3ζ and 4-1BB activation domains. The transduced muFAP-CAR mouse T cells secreted IFN-γ and killed FAP-expressing 3T3 target cells specifically. Adoptively transferred 73.3-FAP-CAR mouse T cells selectively reduced FAP(hi) stromal cells and inhibited the …

Targeting Cell Cycle And Hormone Receptor Pathways In Cancer., C E S Comstock, M A Augello, J F Goodwin, R De Leeuw, M J Schiewer, W F Ostrander, R A Burkhart, A K Mcclendon, Peter Mccue, Edouard J. Trabulsi, Costas D. Lallas, Leonard G Gomella, Md, M M Centenera, Jonathan Brody, Md, L M Butler, W D Tilley, K E Knudsen, Phd

Department of Cancer Biology Faculty Papers

The cyclin/cyclin-dependent kinase (CDK)/retinoblastoma (RB)-axis is a critical modulator of cell cycle entry and is aberrant in many human cancers. New nodes of therapeutic intervention are needed that can delay or combat the onset of malignancies. The antitumor properties and mechanistic functions of PD-0332991 (PD; a potent and selective CDK4/6 inhibitor) were investigated using human prostate cancer (PCa) models and primary tumors. PD significantly impaired the capacity of PCa cells to proliferate by promoting a robust G1-arrest. Accordingly, key regulators of the G1-S cell cycle transition were modulated including G1 cyclins D, E and A. Subsequent investigation demonstrated the ability …

Nfkb Disrupts Tissue Polarity In 3d By Preventing Integration Of Microenvironmental Signals, Sabine Becker-Weimann, Gaofeng Xiong, Saori Furuta, Ju Han, Irene Kuhn, Uri-David Akavia, Dana Pe'er, Mina J. Bissell, Ren Xu

Markey Cancer Center Faculty Publications

The microenvironment of cells controls their phenotype, and thereby the architecture of the emerging multicellular structure or tissue. We have reported more than a dozen microenvironmental factors whose signaling must be integrated in order to effect an organized, functional tissue morphology. However, the factors that prevent integration of signaling pathways that merge form and function are still largely unknown. We have identified nuclear factor kappa B (NFkB) as a transcriptional regulator that disrupts important microenvironmental cues necessary for tissue organization. We compared the gene expression of organized and disorganized epithelial cells of the HMT-3522 breast cancer progression series: the non-malignant …

Coupling S100a4 To Rhotekin Alters Rho Signaling Output In Breast Cancer Cells, Min Chen, Anne R. Bresnick, Kathleen L. O'Connor

Markey Cancer Center Faculty Publications

Rho signaling is increasingly recognized to contribute to invasion and metastasis. In this study, we discovered that metastasis-associated protein S100A4 interacts with the Rho-binding domain (RBD) of Rhotekin, thus connecting S100A4 to the Rho pathway. Glutathione S-transferase pull-down and immunoprecipitation assays demonstrated that S100A4 specifically and directly binds to Rhotekin RBD, but not the other Rho effector RBDs. S100A4 binding to Rhotekin is calcium-dependent and uses residues distinct from those bound by active Rho. Interestingly, we found that S100A4 and Rhotekin can form a complex with active RhoA. Using RNA interference, we determined that suppression of both S100A4 and …

Glucose Stimulation Induces Dynamic Change Of Mitochondrial Morphology To Promote Insulin Secretion In The Insulinoma Cell Line Ins-1e., Bong Sook Jhun, Hakjoo Lee, Zheng-Gen Jin, Yisang Yoon

Center for Translational Medicine Faculty Papers

Fission and fusion of mitochondrial tubules are the major processes regulating mitochondrial morphology. However, the physiological significance of mitochondrial shape change is poorly understood. Glucose-stimulated insulin secretion (GSIS) in pancreatic β-cells requires mitochondrial ATP production which evokes Ca(2+) influx through plasma membrane depolarization, triggering insulin vesicle exocytosis. Therefore, GSIS reflects mitochondrial function and can be used for evaluating functional changes associated with morphological alterations of mitochondria. Using the insulin-secreting cell line INS-1E, we found that glucose stimulation induced rapid mitochondrial shortening and recovery. Inhibition of mitochondrial fission through expression of the dominant-negative mutant DLP1-K38A eliminated this dynamic mitochondrial shape change …

The Tweak Receptor Fn14 Is A Therapeutic Target In Melanoma: Immunotoxins Targeting Fn14 Receptor For Malignant Melanoma Treatment., Hong Zhou, Suhendan Ekmekcioglu, John W Marks, Khalid A Mohamedali, Kaushal Asrani, Keeley K Phillips, Sharron A N Brown, Emily Cheng, Michele B Weiss, Walter N Hittelman, Nhan L Tran, Hideo Yagita, Jeffrey A Winkles, Michael G Rosenblum

Department of Cancer Biology Faculty Papers

Fibroblast growth factor-inducible protein 14 (Fn14), the cell surface receptor for tumor necrosis factor-like weak inducer of apoptosis (TWEAK), is overexpressed in various human solid tumor types and can be a negative prognostic indicator. We detected Fn14 expression in ∼60% of the melanoma cell lines we tested, including both B-Raf WT and B-Raf(V600E) lines. Tumor tissue microarray analysis indicated that Fn14 expression was low in normal skin, but elevated in 173/190 (92%) of primary melanoma specimens and in 86/150 (58%) of melanoma metastases tested. We generated both a chemical conjugate composed of the recombinant gelonin (rGel) toxin and the anti-Fn14 …

Fak Is A Critical Regulator Of Neuroblastoma Liver Metastasis, Sora Lee, Jingbo Qiao, Pritha Paul, Kathleen L. O'Connor, B. Mark Evers, Dai H. Chung

Surgery Faculty Publications

Neuroblastomas express increased levels of gastrin-releasing peptide receptor (GRP-R). However, the exact molecular mechanisms involved in GRP-R-mediated cell signaling in neuroblastoma growth and metastasis are unknown. Here, we report that focal adhesion kinase (FAK), as a critical downstream target of GRP-R, is an important regulator of neuroblastoma tumorigenicity. We found that FAK expression correlates with GRP-R expression in human neuroblastoma sections and cell lines. GRP-R overexpression in SK-N-SH cells increased FAK, integrin α3 and β1 expressions and cell migration. These cells demonstrated flatter cell morphology with broad lamellae, in which intense FAK expression was localized to the leading edges of …

Gsk3Β Inhibition Blocks Melanoma Cell/Host Interactions By Downregulating N-Cadherin Expression And Decreasing Fak Phosphorylation., Jobin K John, Kim H T Paraiso, Vito W Rebecca, Liliana P Cantini, Ethan V Abel, Nicholas Pagano, Eric Meggers, Rahel Mathew, Clemens Krepler, Victoria Izumi, Bin Fang, John M Koomen, Jane L Messina, Meenhard Herlyn, Keiran S M Smalley

Department of Cancer Biology Faculty Papers

This study addresses the role of glycogen synthase kinase (GSK)-3β signaling in the tumorigenic behavior of melanoma. Immunohistochemical staining revealed GSK3β to be focally expressed in the invasive portions of 12 and 33% of primary and metastatic melanomas, respectively. GSK3 inhibitors and small interfering RNA (siRNA) knockdown of GSK3β were found to inhibit the motile behavior of melanoma cells in scratch wound, three-dimensional collagen-implanted spheroid, and modified Boyden chamber assays. Functionally, inhibition of GSK3β signaling was found to suppress N-cadherin expression at the messenger RNA and protein levels, and was associated with decreased expression of the transcription factor Slug. Pharmacological …

Necrostatin-1 Analogues: Critical Issues On The Specificity, Activity And In Vivo Use In Experimental Disease Models., N Takahashi, L Duprez, S Grootjans, A Cauwels, W Nerinckx, J B Duhadaway, V Goossens, R Roelandt, F Van Hauwermeiren, C Libert, W Declercq, N Callewaert, G C Prendergast, A Degterev, J Yuan, P Vandenabeele

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Necrostatin-1 (Nec-1) is widely used in disease models to examine the contribution of receptor-interacting protein kinase (RIPK) 1 in cell death and inflammation. We studied three Nec-1 analogs: Nec-1, the active inhibitor of RIPK1, Nec-1 inactive (Nec-1i), its inactive variant, and Nec-1 stable (Nec-1s), its more stable variant. We report that Nec-1 is identical to methyl-thiohydantoin-tryptophan, an inhibitor of the potent immunomodulatory enzyme indoleamine 2,3-dioxygenase (IDO). Both Nec-1 and Nec-1i inhibited human IDO, but Nec-1s did not, as predicted by molecular modeling. Therefore, Nec-1s is a more specific RIPK1 inhibitor lacking the IDO-targeting effect. Next, although Nec-1i was ∼100 × …

Trop-2 Inhibits Prostate Cancer Cell Adhesion To Fibronectin Through The Β1 Integrin-Rack1 Axis., Marco Trerotola, Jing Li, Saverio Alberti, Lucia R. Languino

Department of Cancer Biology Faculty Papers

Trop-2 is a transmembrane glycoprotein upregulated in several human carcinomas, including prostate cancer (PrCa). Trop-2 has been suggested to regulate cell-cell adhesion, given its high homology with the other member of the Trop family, Trop-1/EpCAM, and its ability to bind the tight junction proteins claudin-1 and claudin-7. However, a role for Trop-2 in cell adhesion to the extracellular matrix has never been postulated. Here, we show for the first time that Trop-2 expression in PrCa cells correlates with their aggressiveness. Using either shRNA-mediated silencing of Trop-2 in cells that endogenously express it, or ectopic expression of Trop-2 in cells that …

Inhibition Of Fatty Acid Synthase Attenuates Cd44-Associated Signaling And Reduces Metastasis In Colorectal Cancer, Yekaterina Y. Zaytseva, Piotr G. Rychahou, Pat Gulhati, Victoria Allison Elliott, William Conan Mustain, Kathleen O'Connor, Andrew J. Morris, Manjula Sunkara, Heidi L. Weiss, Eun Young Lee, B. Mark Evers

Markey Cancer Center Faculty Publications

Fatty acid synthase (FASN) and ATP-citrate lyase, key enzymes of de novo lipogenesis, are significantly upregulated and activated in many cancers and portend poor prognosis. Even though the role of lipogenesis in providing proliferative and survival advantages to cancer cells has been described, the impact of aberrant activation of lipogenic enzymes on cancer progression remains unknown. In this study, we found that elevated expression of FASN is associated with advanced stages of colorectal cancer (CRC) and liver metastasis, suggesting that it may play a role in progression of CRC to metastatic disease. Targeted inhibition of lipogenic enzymes abolished expression of …