Medical Cell Biology Commons^™

Proteasome Regulation Of Caspase-8: Significance In Cancer, Michael Vincent Fiandalo

Theses and Dissertations--Molecular and Cellular Biochemistry

Anti-tumor therapeutic strategies based on combinations of chemotherapeutic agents with a death inducing ligand such as TNF-α Related Apoptosis Inducing Ligand (TRAIL), are directed towards selective and effective cancer cell apoptosis and enhanced therapeutic response. We previously demonstrated that proteasome inhibition sensitizes TRAIL resistant prostate cancer cells to TRAIL-mediated apoptosis via stabilization of the active p18 subunit of initiator caspase-8. The present study investigated the functional link between caspase-8 and the proteasome, by analyzing the impact of caspase-8 ubiquitination and proteasomal degradation on the outcomes of the extrinsic apoptosis pathway in cancer cells. Caspase-8 ubiquitination status was assessed by polyubiquitin …

Cd2ap Regulates Sumoylation Of Cin85 In Podocytes, Irini Tossidou, Rainer Niedenthal, Malte Klaus, Beina Teng, Kirstin Worthmann, Benjamin King, Kevin Peterson

Dartmouth Scholarship

Podocytes are highly differentiated and polarized epithelial cells located on the visceral side of the glomerulus. They form an indispensable component of the glomerular filter, the slit diaphragm, formed by several transmembrane proteins and adaptor molecules. Disruption of the slit diaphragm can lead to massive proteinuria and nephrotic syndrome in mice and humans. CD2AP is an adaptor protein that is important for the maintenance of the slit diaphragm. Together with its paralogue, CIN85, CD2AP belongs to a family of adaptor proteins that are primarily described as being involved in endocytosis and downregulation of receptor tyrosine kinase activity. We have shown …

Cns Recruitment Of Cd8+ T Lymphocytes Specific For A Peripheral Virus Infection Triggers Neuropathogenesis During Polymicrobial Challenge., Christine M Matullo, Kevin J O'Regan, Mark Curtis, Glenn F Rall

Department of Microbiology and Immunology Faculty Papers

Although viruses have been implicated in central nervous system (CNS) diseases of unknown etiology, including multiple sclerosis and amyotrophic lateral sclerosis, the reproducible identification of viral triggers in such diseases has been largely unsuccessful. Here, we explore the hypothesis that viruses need not replicate in the tissue in which they cause disease; specifically, that a peripheral infection might trigger CNS pathology. To test this idea, we utilized a transgenic mouse model in which we found that immune cells responding to a peripheral infection are recruited to the CNS, where they trigger neurological damage. In this model, mice are infected with …

A Meta-Analysis Of Array-Cgh Studies Implicates Antiviral Immunity Pathways In The Development Of Hepatocellular Carcinoma., Xu Guo, Yanna Ba, Xi Ma, Jiaze An, Yukui Shang, Qichao Huang, Hushan Yang, Zhinan Chen, Jinliang Xing

Kimmel Cancer Center Faculty Papers

BACKGROUND: The development and progression of hepatocellular carcinoma (HCC) is significantly correlated to the accumulation of genomic alterations. Array-based comparative genomic hybridization (array CGH) has been applied to a wide range of tumors including HCCs for the genome-wide high resolution screening of DNA copy number changes. However, the relevant chromosomal variations that play a central role in the development of HCC still are not fully elucidated.

METHODS: In present study, in order to further characterize the copy number alterations (CNAs) important to HCC development, we conducted a meta-analysis of four published independent array-CGH datasets including total 159 samples.

RESULTS: Eighty …

Mutant Tdp-43 In Motor Neurons Promotes The Onset And Progression Of Als In Rats, Cao Huang, Jianbin Tong, Fangfang Bi, Hongxia Zhou, Xu-Gang Xia

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Amyotrophic lateral sclerosis (ALS) is characterized by progressive motor neuron degeneration, which ultimately leads to paralysis and death. Mutation of TAR DNA binding protein 43 (TDP-43) has been linked to the development of an inherited form of ALS. Existing TDP-43 transgenic animals develop a limited loss of motor neurons and therefore do not faithfully reproduce the core phenotype of ALS. Here, we report the creation of multiple lines of transgenic rats in which expression of ALS-associated mutant human TDP-43 is restricted to either motor neurons or other types of neurons and skeletal muscle and can be switched on and off. …

Wnt Signaling Exerts An Antiproliferative Effect On Adult Cardiac Progenitor Cells Through Igfbp3., Angelos Oikonomopoulos, Konstantina-Ioanna Sereti, Frank Conyers, Michael Bauer, Annette Liao, Jian Guan, Dylan Crapps, Jung-Kyu Han, Hanhua Dong, Ahmad F Bayomy, Gabriel C Fine, Karen Westerman, Travis L Biechele, Randall T Moon, Thomas Force, Ronglih Liao

Center for Translational Medicine Faculty Papers

RATIONALE: Recent work in animal models and humans has demonstrated the presence of organ-specific progenitor cells required for the regenerative capacity of the adult heart. In response to tissue injury, progenitor cells differentiate into specialized cells, while their numbers are maintained through mechanisms of self-renewal. The molecular cues that dictate the self-renewal of adult progenitor cells in the heart, however, remain unclear.

OBJECTIVE: We investigate the role of canonical Wnt signaling on adult cardiac side population (CSP) cells under physiological and disease conditions.

METHODS AND RESULTS: CSP cells isolated from C57BL/6J mice were used to study the effects of canonical …

The Role Of Receptor Tyrosine Kinase Axl In Pancreatic Ductal Adenocarcinoma And Its Regulation By Hematopoietic Progenitor Kinase 1, Xianzhou Song

Dissertations and Theses (Open Access)

Pancreatic ductal adenocarcinoma (PDA) is one of the most aggressive malignancies with less than 5% of five year survival rate. New molecular markers and new therapeutic targets are urgently needed for patients with PDA. Oncogenic receptor tyrosine kinase Axl has been reported to be overexpressed in many types of human malignancies, including diffuse glioma, melanoma, osteosarcoma, and carcinomas of lung, colon, prostate, breast, ovary, esophagus, stomach, and kidney. However, the expression and functions of Axl in PDA are unclear. We hypothesized that Axl contributes to the development and progression of PDA. We examined Axl expression in 54 human PDA samples …

Epitope Characterization Of Sero-Specific Monoclonal Antibody To Clostridium Botulinum Neurotoxin Type A., Cindi R Corbett, Erin Ballegeer, Kelly A Weedmark, M D Elias, Fetweh H Al-Saleem, Denise M Ancharski, Lance L Simpson, Jody D Berry

Department of Medicine Faculty Papers

Botulinum neurotoxins (BoNTs) are extremely potent toxins that can contaminate foods and are a public health concern. Anti-BoNT antibodies have been described that are capable of detecting BoNTs; however there still exists a need for accurate and sensitive detection capabilities for BoNTs. Herein, we describe the characterization of a panel of eight monoclonal antibodies (MAbs) generated to the non-toxic receptor-binding domain of BoNT/A (H(C)50/A) developed using a high-throughput screening approach. In two independent hybridoma fusions, two groups of four IgG MAbs were developed against recombinant H(C)50/A. Of these eight, only a single MAb, F90G5-3, bound to the whole BoNT/A protein …

Switches, Excitable Responses And Oscillations In The Ring1b/Bmi1 Ubiquitination System., Lan K Nguyen, Javier Muñoz-García, Helene Maccario, Aaron Ciechanover, Walter Kolch, Boris N Kholodenko

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

In an active, self-ubiquitinated state, the Ring1B ligase monoubiquitinates histone H2A playing a critical role in Polycomb-mediated gene silencing. Following ubiquitination by external ligases, Ring1B is targeted for proteosomal degradation. Using biochemical data and computational modeling, we show that the Ring1B ligase can exhibit abrupt switches, overshoot transitions and self-perpetuating oscillations between its distinct ubiquitination and activity states. These different Ring1B states display canonical or multiply branched, atypical polyubiquitin chains and involve association with the Polycomb-group protein Bmi1. Bistable switches and oscillations may lead to all-or-none histone H2A monoubiquitination rates and result in discrete periods of gene (in)activity. Switches, overshoots …

Contribution Of Ectodomain Mutations In Epidermal Growth Factor Receptor To Signaling In Glioblastoma Multiforme, Marta L. Rojas

Dissertations and Theses (Open Access)

CONTRIBUTION OF ECTODOMAIN MUTATIONS IN EPIDERMAL GROWTH FACTOR RECEPTOR TO SIGNALING IN GLIOBLASTOMA MULTIFORME

Publication No._________

Marta Rojas, M.S.

Supervisory Professor: Oliver Bögler, Ph.D.

The Cancer Genome Atlas (TCGA) has conducted a comprehensive analysis of a large tumor cohort and has cataloged genetic alterations involving primary sequence variations and copy number aberrations of genes involved in key signaling pathways in glioblastoma (GBM). This dataset revealed missense ectodomain point mutations in epidermal growth factor receptor (EGFR), but the biological and clinical significance of these mutations is not well defined in the context of gliomas.

In our study, we focused on understanding …

Characterization Of The Key Mouse Cochlear Developmental Genes For Auditory Hair Cell Regeneration, Zhiyong Liu

Theses and Dissertations (ETD)

Mammalian inner ear cochlear auditory hair cells (HCs) and adjacent supporting cells (SCs) are believed to derive from the same progenitors during development. However, unlike SCs of nonmammalian vertebrates, mammalian cochlear SCs cannot be converted into functional hair cells (HCs) after damage, thus leading to permanent deafness. To entitle mammals with the ability to restore hearing capacity after HC damage, we first achieved proliferation of SCs by acute ablation of p27 or Sox2. Secondly, we overactivated Notch1 signaling in the mouse inner ear at different developmental stages, and found that the ability of Notch signaling in generating new HCs declines …

Effect Of Protein Kinase C Delta (Pkc-Δ) Inhibition On The Transcriptome Of Normal And Systemic Sclerosis Human Dermal Fibroblasts In Vitro., Peter J Wermuth, Sankar Addya, Sergio A Jimenez

Jefferson Institute of Molecular Medicine Papers and Presentations

Previous studies demonstrated that protein kinase C- δ (PKC-δ) inhibition with the selective inhibitor, rottlerin, resulted in potent downregulation of type I collagen expression and production in normal human dermal fibroblasts and abrogated the exaggerated type I collagen production and expression in fibroblasts cultured from affected skin from patients with the fibrosing disorder systemic sclerosis (SSc). To elucidate the mechanisms involved in the ability of PKC-δ to regulate collagen production in fibroblasts, we examined the effects of PKC-δ inhibition on the transcriptome of normal and SSc human dermal fibroblasts. Normal and SSc human dermal fibroblasts were incubated with rottlerin (5 …

Abca12-Mediated Lipid Transport And Snap29-Dependent Trafficking Of Lamellar Granules Are Crucial For Epidermal Morphogenesis In A Zebrafish Model Of Ichthyosis., Qiaoli Li, Michael Frank, Masashi Akiyama, Shiu-Ying Ho, Hiroshi Shimizu, Christine Thisse, Bernard Thisse, Eli Sprecher, Jouni Uitto

Department of Dermatology and Cutaneous Biology Faculty Papers

Zebrafish (Danio rerio) can serve as a model system to study heritable skin diseases. The skin is rapidly developed during the first 5-6 days of embryonic growth, accompanied by expression of skin-specific genes. Transmission electron microscopy (TEM) of wild-type zebrafish at day 5 reveals a two-cell-layer epidermis separated from the underlying collagenous stroma by a basement membrane with fully developed hemidesmosomes. Scanning electron microscopy (SEM) reveals an ordered surface contour of keratinocytes with discrete microridges. To gain insight into epidermal morphogenesis, we have employed morpholino-mediated knockdown of the abca12 and snap29 genes, which are crucial for secretion of lipids and …

Chromosome Missegregation In Human Cells Arises Through Specific Types Of Kinetochore–Microtubule Attachment Errors, Sarah L. Thompson, Duane A. Compton

Dartmouth Scholarship

Most solid tumors are aneuploid, and many missegregate chromosomes at high rates in a phenomenon called chromosomal instability (CIN). CIN reflects the erosion of mitotic fidelity, and it correlates with poor patient prognosis and drug resistance. The most common mechanism causing CIN is the persistence of improper kinetochore–microtubule attachments called merotely. Chromosomes with merotelic kinetochores often manifest as lagging chromosomes in anaphase, suggesting that lagging chromosomes fail to segregate properly. However, it remains unknown whether the lagging chromosomes observed in anaphase segregate to the correct or incorrect daughter cell. To address this question, we tracked the segregation of a single …

Expression Of Cancer Stem Cell Biomarkers In Male Breast Cancer, Ping Gong, Md, Juan P. Palazzo, Md

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Male breast cancer is an uncommon disease, representing <1% of all breast cancer diagnoses. The prognostic factors and expression of molecular markers in male breast carcinomas are similar to female cancer. Cancer stem cell (CSC)s have been associated with tumor aggressiveness and drug resistance. CSCs are characterized by CD44 and/or ALDH1 expression. We investigated their expression in male breast cancer.

Computational Analysis Of Expression Of Human Embryonic Stem Cell-Associated Signatures In Tumors., Xiaosheng Wang

Journal Articles: Genetics, Cell Biology & Anatomy

BACKGROUND: The cancer stem cell model has been proposed based on the linkage between human embryonic stem cells and human cancer cells. However, the evidences supporting the cancer stem cell model remain to be collected. In this study, we extensively examined the expression of human embryonic stem cell-associated signatures including core genes, transcription factors, pathways and microRNAs in various cancers using the computational biology approach.

RESULTS: We used the class comparison analysis and survival analysis algorithms to identify differentially expressed genes and their associated transcription factors, pathways and microRNAs among normal vs. tumor or good prognosis vs. poor prognosis phenotypes …

Proliferating Cell Nuclear Antigen Is Required For Loading Of The Smcx/Kmd5c Histone Demethylase Onto Chromatin., Zhihui Liang, Marc Diamond, Johanna A Smith, Matthias Schnell, René Daniel

Department of Medicine Faculty Papers

UNLABELLED: ABSTRACT:

BACKGROUND: Histone methylation is regulated by a large number of histone methyltransferases and demethylases. The recently discovered SMCX/KMD5C demethylase has been shown to remove methyl residues from lysine 4 of histone H3 (H3K4), and constitutes an important component of the regulatory element-1-silencing transcription factor (REST) protein complex. However, little is known about the cellular mechanisms that control SMCX activity and intracellular trafficking.

RESULTS: In this study, we found that small interfering RNA-mediated knockdown of proliferating cell nuclear antigen (PCNA) resulted in the reduction of the chromatin-bound SMCX fraction. We identified a PCNA-interaction protein motif (PIP box) in the …

Deregulation Of Micrornas By Hiv-1 Vpr Protein Leads To The Development Of Neurocognitive Disorders, Ruma Mukerjee, J Robert Chang, Luis Del Valle, Asen Bagashev, Monika M. Gayed, Randolph B. Lyde, Brian J. Hawkins, Eugen Brailoiu, Eric Cohen, Chris Power, S Ausim Azizi, Benjamin B. Gelman, Bassel E. Sawaya

School of Medicine Faculty Publications

Studies have shown that HIV-infected patients develop neurocognitive disorders characterized by neuronal dysfunction. The lack of productive infection of neurons by HIV suggests that viral and cellular proteins, with neurotoxic activities, released from HIV-1-infected target cells can cause this neuronal deregulation. The viral protein R (Vpr), a protein encoded by HIV-1, has been shown to alter the expression of various important cytokines and inflammatory proteins in infected and uninfected cells; however the mechanisms involved remain unclear. Using a human neuronal cell line, we found that Vpr can be taken up by neurons causing: (i) deregulation of calcium homeostasis, (ii) endoplasmic …

Microarray-Based Cancer Prediction Using Single Genes., Xiaosheng Wang, Richard Simon

Journal Articles: Genetics, Cell Biology & Anatomy

BACKGROUND: Although numerous methods of using microarray data analysis for cancer classification have been proposed, most utilize many genes to achieve accurate classification. This can hamper interpretability of the models and ease of translation to other assay platforms. We explored the use of single genes to construct classification models. We first identified the genes with the most powerful univariate class discrimination ability and then constructed simple classification rules for class prediction using the single genes.

RESULTS: We applied our model development algorithm to eleven cancer gene expression datasets and compared classification accuracy to that for standard methods including Diagonal Linear …

Mast Cell Activation And Clinical Outcome In Pediatric Cholelithiasis And Biliary Dyskinesia., Craig A. Friesen, Nancy Neilan, James F. Daniel, Kim Radford, Jennifer Verrill Schurman, Ding-You Li, Linda Andre, Shawn D. St Peter, G W. Holcomb Iii

Manuscripts, Articles, Book Chapters and Other Papers

BACKGROUND: The current study was undertaken to determine the degree of activation of gallbladder mucosal mast cells, whether mast cell (MC) density or activation differ between patients with and without a positive clinical response to cholecystectomy, and whether either density or activation correlate with gallbladder emptying.

RESULTS: Fifteen biliary dyskinesia (BD) and 13 symptomatic cholelithiasis (CL) patients undergoing cholecystectomy were prospectively enrolled. Gallbladder wall MC density (by immunohistochemistry) and activation (by electron microscopy) were determined. Clinical response was evaluated 30 days post-cholecystectomy on a 5-point Likert-type scale. A complete or nearly complete clinical response was seen in 100% of CL …