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Articles 1 - 9 of 9

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Study Of The Structure And Function Of Cxc Chemokine Receptor 2, Hae Ryong Kwon Dec 2010

Study Of The Structure And Function Of Cxc Chemokine Receptor 2, Hae Ryong Kwon

Masters Theses

It has been shown that the amino terminus and second extracellular loop (EC2) of CXCR2 are crucial for ligand binding and receptor activation. The lack of an ionic lock motif in the third intracellular loop of CXCR2 focuses an investigation of the mechanism by which these two extracellular regions contribute to receptor recognition and activation.

The first objective of this investigation was to predict the structure of CXCR2 based on known structures of crystallized GPCRs. Rhodopsin, β2-adrenergic receptor, CXCR4 were used for homology modeling of CXCR2 structure. Highly conserved motifs found in sequence alignments of the template GPCRs were helpful ...


Mechanistic And Signaling Analysis Of Muc4-Erbb2 Signaling Module: New Insights Into The Mechanism Of Ligand-Independent Erbb2 Activity, Goldi Kozloski Sep 2010

Mechanistic And Signaling Analysis Of Muc4-Erbb2 Signaling Module: New Insights Into The Mechanism Of Ligand-Independent Erbb2 Activity, Goldi Kozloski

Goldi A Kozloski

The membrane mucin Muc4 is aberrantly expressed in numerous epithelial carcinomas and is currently used as a cancer diagnostic and prognostic tool. Muc4 can also potentiate signal transduction by modulating differential ErbB2 phosphorylation in the absence and in the presence of the ErbB3 soluble ligand heregulin (HRG-beta1). These features of Muc4 suggest that Muc4 is not merely a cancer marker, but an oncogenic factor with a unique-binding/activation relationship with the receptor ErbB2. In the present study, we examined the signaling mechanisms that are associated with the Muc4-ErbB2 module by analyzing ErbB2 differential signaling in response to Muc4 expression. Our ...


Role And Regulation Of Epha2 In Pancreatic Cancer, Pavel A. Levin Aug 2010

Role And Regulation Of Epha2 In Pancreatic Cancer, Pavel A. Levin

UT GSBS Dissertations and Theses (Open Access)

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cancer cause of death in the US. Gemcitabine is the first-line therapy for this disease, but unfortunately it shows only very modest benefit. The focus of the current study was to investigate the role and regulation of EphA2, a receptor tyrosine kinase expressed in PDAC, to further understand this disease and identify new therapeutic targets.

The role of EphA2 was determined in PDAC by siRNA mediated silencing. In combination with gemcitabine, silencing of EphA2 caused a dramatic increase in apoptosis even in highly resistant cells in vitro. Furthermore, EphA2 silencing was found ...


Characterizing The Role Of Dna Repair Proteins In Telomere Length Regulation And Maintenance: Fanconi Anemia Complementation Group C Protein And 8-Oxoguanine Dna Glycosylase, David Beomjin Rhee Aug 2010

Characterizing The Role Of Dna Repair Proteins In Telomere Length Regulation And Maintenance: Fanconi Anemia Complementation Group C Protein And 8-Oxoguanine Dna Glycosylase, David Beomjin Rhee

Doctoral Dissertations

Telomeres are the chromosome end structures consisting of telomere-associated proteins and short tandem repeat sequences, TTAGGG, in humans and mice. Telomeres prevent chromosome termini from being recognized as broken DNA ends. The structural integrity of DNA including telomeres is constantly threatened by a variety of DNA damaging agents on a daily basis. To counteract the constant threats from DNA damage, organisms have developed a number of DNA repair pathways to ensure that the integrity of genome remains intact. A number of DNA repair proteins localize to telomeres and contribute to telomere maintenance; however, it is still unclear as to what ...


Release Of Hmgb1 In Response To Pro-Apoptotic Glioma Killing Strategies: Efficacy And Neurotoxicity, Marianela Candolfi, Kader Yagiz, David Foulad, Gabrielle Alzadeh, Matthew Tesarfreund, Akm Ghulam Muhammad, Mariana Puntel, Kurt Kroeger, Chunyan Liu, Sharon Lee, James Curtin, Gwendalyn D. King, Jonathan Lerner, Katsuaki Sato, Yohei Mineharu, Weidong Xiong, Pedro R. Lowenstein, Maria Castro Jul 2010

Release Of Hmgb1 In Response To Pro-Apoptotic Glioma Killing Strategies: Efficacy And Neurotoxicity, Marianela Candolfi, Kader Yagiz, David Foulad, Gabrielle Alzadeh, Matthew Tesarfreund, Akm Ghulam Muhammad, Mariana Puntel, Kurt Kroeger, Chunyan Liu, Sharon Lee, James Curtin, Gwendalyn D. King, Jonathan Lerner, Katsuaki Sato, Yohei Mineharu, Weidong Xiong, Pedro R. Lowenstein, Maria Castro

Articles

Purpose In preparation for a Phase I clinical trial utilizing a combined cytotoxic/immunotherapeutic strategy using adenoviruses expressing Flt3L (Ad-Flt3L) and thymidine kinase (Ad-TK) to treat glioblastoma (GBM), we tested the hypothesis that Ad-TK+GCV would be the optimal tumor killing agent in relation to efficacy and safety when compared to other pro-apoptotic approaches. Experimental Design and Results The efficacy and neurotoxicity of Ad-TK+GCV was compared with Ads encoding the pro-apoptotic cytokines (TNF-α, TRAIL, FasL), alone or in combination with Ad-Flt3L. In rats bearing small GBMs (day 4), only Ad-TK+GCV or Ad-FasL improved survival. In rats bearing large ...


Mechanisms Of The Downregulation Of Prolactin Receptor And Their Role In Cell Proliferation, Bentley J. Varghese May 2010

Mechanisms Of The Downregulation Of Prolactin Receptor And Their Role In Cell Proliferation, Bentley J. Varghese

Publicly Accessible Penn Dissertations

Cells react to diverse stimuli by expressing specific receptors that recognize these stimuli and initiate specific signaling pathways that enable a cell to change with the environment. Downregulation of these signaling receptors represents the most direct method for limiting the magnitude and duration of downstream signal transduction. For cell surface transmembrane receptors, ligand-stimulated endocytosis is a major mechanism by which the ability of a cell to react to a ligand is restricted. In order to investigate the downregulation of the prolactin receptor (PRLr), we investigated the mechanism and key determinants in the endocytosis and downregulation of PRLr. In Chapter 2 ...


Functions Of Dna Damage Response Factors In Lymphocyte Development And Transformation, Bu Yin May 2010

Functions Of Dna Damage Response Factors In Lymphocyte Development And Transformation, Bu Yin

Publicly Accessible Penn Dissertations

DNA double strand breaks (DSBs) can activate cell cycle checkpoints or apoptosis, and lead to genomic alterations that drive malignant transformation. The H2AX core histone variant is phosphorylated in chromatin around DSBs by kinases such as ATM and DNA-PKcs. However, how H2AX suppresses chromosome breaks and translocations in cells and prevents tumorigenesis in mice and humans is not well understood. V(D)J recombination is a genetically programmed DNA damage and repair process that assembles the variable region exons of antigen receptor genes in developing lymphocytes. Using an inducible V(D)J recombination system, I found that H2AX is phosphorylated ...


Xenoestrogen-Specific Mechanisms Of Developmental Reprogramming Correlate With Gene Expression And Tumor Development, Kristen L. Greathouse May 2010

Xenoestrogen-Specific Mechanisms Of Developmental Reprogramming Correlate With Gene Expression And Tumor Development, Kristen L. Greathouse

UT GSBS Dissertations and Theses (Open Access)

Environmental exposures during sensitive windows of development can reprogram normal physiological responses and alter disease susceptibility later in life in a process known as developmental reprogramming. We have shown that neonatal exposure to the xenoestrogen diethylstilbestrol (DES) can developmentally reprogram the reproductive tract in genetically susceptible Eker rats giving rise to complete penetrance of uterine leiomyoma. Based on this, we hypothesized that xenoestrogens, including genistein (GEN) and bisphenol A (BPA), reprogram estrogen-responsive gene expression in the myometrium and promote the development of uterine leiomyoma. We proposed the mechanism that is responsible for the developmental reprogramming of gene expression was through ...


Functional Analysis Of Chromodomain Helicase Dna Binding Protein 2(Chd2) Mediated Genomic Stability, Sangeetha Rajagopalan May 2010

Functional Analysis Of Chromodomain Helicase Dna Binding Protein 2(Chd2) Mediated Genomic Stability, Sangeetha Rajagopalan

Doctoral Dissertations

Histone modifying enzymes and chromatin remodeling complexes play an important regulatory role in chromatin dynamics that dictate the interaction of regulatory factors involved in processes such as DNA replication, recombination, repair and transcription, with DNA template. The CHD (Chromodomain Helicase DNA Binding Protein) family of proteins is known to be involved in the regulation of gene expression, recombination and chromatin remodeling via their chromatin specific interactions and activities. Phenotypic analysis of the Chd2 mutant mouse model developed by our laboratory indicates that the Chd2 protein plays a critical role in tumor suppression as the heterozygous mutant mice develop spontaneous lymphomas ...