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Full-Text Articles in Cancer Biology

Ube4b Levels Determine The Efficacy Of Egfr And Stat5 Inhibitors In Treatment Resistant Neuroblastoma, David James Savage Aug 2018

Ube4b Levels Determine The Efficacy Of Egfr And Stat5 Inhibitors In Treatment Resistant Neuroblastoma, David James Savage

UT GSBS Dissertations and Theses (Open Access)

Neuroblastoma is the most common malignancy in infants. Overexpression of the epidermal growth factor receptor (EGFR) in neuroblastoma tumors can result in enhanced EGFR signaling, uncontrolled proliferation, and may provide a mechanism for chemotherapy resistance. UBE4B, an E3/E4 ubiquitin ligase, ubiquitinates the EGFR and promotes its lysosomal degradation ultimately attenuating EGFR signaling. Interestingly, the UBE4B gene lies in a chromosomal region (1p36) whose loss is correlated with poor patient outcomes due to inefficient EGFR degradation and enhanced cell proliferation. We examined whether depletion of UBE4B in a chemoresistant neuroblastoma cell line would affect tumor responses to drugs that specifically ...


Egfr Signaling From The Early Endosome., Julie A. Gosney Aug 2018

Egfr Signaling From The Early Endosome., Julie A. Gosney

Electronic Theses and Dissertations

The epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase that is an integral component of proliferative signaling. When activated by a ligand at the plasma membrane, EGFR dimerizes with another ErbB family receptor, leading to kinase domain activation and transphosphorylation of C-terminus tyrosine residues. These phosphotyrosines act as crucial regulators of EGFR signaling as effector proteins dock to the receptor at these sites. The receptor undergoes clathrin-mediated endocytosis into early endosomes, where it can then be trafficked to a lysosome for degradation. However, the kinase domain of EGFR retains its activity during trafficking, suggesting that EGFR can continue ...


Contribution Of Activating Transcription Factor 3 To Development Of Acinar-To-Ductal Cell Metaplasia, Jelena Toma Aug 2017

Contribution Of Activating Transcription Factor 3 To Development Of Acinar-To-Ductal Cell Metaplasia, Jelena Toma

Electronic Thesis and Dissertation Repository

Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer death in North America. The highest risk factor for PDAC is recurrent pancreatitis. While the link between PDAC and pancreatitis is unknown, de-differentiation of acinar cells is common to both diseases. Our lab has shown that Activating Transcription Factor 3 (ATF3), a factor upregulated during pancreatic injury, contributes to the development of acinar-to-ductal cell metaplasia (ADM), a precursor phenotype of PDAC. The goal of this study was to identify how ATF3 contributes to ADM. I hypothesize that ATF3 regulates acinar gene expression promoting ADM. We observed decreased ADM development ...


Identifying The Signaling Mechanisms Of Egfr-Mediated Apoptosis., Nicole Marion Jackson May 2017

Identifying The Signaling Mechanisms Of Egfr-Mediated Apoptosis., Nicole Marion Jackson

Electronic Theses and Dissertations

The Epidermal Growth Factor Receptor (EGFR) is a 170-kilodalton transmembrane protein that belongs to the ErbB family of receptor tyrosine kinases. Upon ligand-mediated activation, the EGFR is responsible for cell growth, proliferation, and tissue homeostasis; however, the EGFR is overexpressed in many human malignancies, including MDA-MB-468 cells, a metastatic breast epithelial cell line. Studies within this cell line, and other cell lines characterized with high EGFR levels, have shown that EGF stimulation results in the induction of apoptosis. However, the mechanisms and signaling effectors implicated in this process have yet to be elucidated. The overarching research goal of this dissertation ...


Ibrutinib In Combination With Sorafenib Synergistically Inhibits Proliferation And Survival Of Hepatocellular Carcinoma Cells By Targeting Egfr Signaling Pathway, Cho-Hao Lin, Nissar Wani, Khadija Elkholy, Kalpana Ghoshal Jan 2017

Ibrutinib In Combination With Sorafenib Synergistically Inhibits Proliferation And Survival Of Hepatocellular Carcinoma Cells By Targeting Egfr Signaling Pathway, Cho-Hao Lin, Nissar Wani, Khadija Elkholy, Kalpana Ghoshal

Hepatobiliary Cancers: Pathobiology and Translational Advances

No abstract provided.


The Role Of Progesterone Receptor Membrane Component 1 In Receptor Trafficking And Disease, Kaia K. Hampton Jan 2017

The Role Of Progesterone Receptor Membrane Component 1 In Receptor Trafficking And Disease, Kaia K. Hampton

Theses and Dissertations--Pharmacology and Nutritional Sciences

The progesterone receptor membrane component 1 (PGRMC1) is a multifunctional protein with a heme-binding domain that promotes cellular signaling via receptor trafficking, and is essential for some elements of tumor growth and metastasis. PGRMC1 is upregulated in breast, colon, lung and thyroid tumors. We expanded the analysis of PGRMC1 in the clinical setting, and report the first analysis of PGRMC1 in human oral cavity and ovarian tumors and found PGRMC1 to correlate with lung and ovarian cancer patient survival. Furthermore, we discovered a specific role for PGRMC1 in cancer stem cell viability. PGRMC1 directly associates with the epidermal growth factor ...


Autocrine Epiregulin Activates Egfr Pathway For Lung Metastasis Via Emt In Salivary Adenoid Cystic Carcinoma, Shuli Liu, Dongxia Ye, Dongliang Xu, Yueling Liao, Ling Zhang, Liu Liu, Wenwen Yu, Yanan Wang, Yue He, Jingzhou Hu, Wenzheng Guo, Tong Wang, Beibei Sun, Hongyong Song, Huijing Yin, Jingyi Liu, Yadi Wu, Hanguang Zhu, Binhua P. Zhou, Jiong Deng, Zhiyuan Zhang Mar 2016

Autocrine Epiregulin Activates Egfr Pathway For Lung Metastasis Via Emt In Salivary Adenoid Cystic Carcinoma, Shuli Liu, Dongxia Ye, Dongliang Xu, Yueling Liao, Ling Zhang, Liu Liu, Wenwen Yu, Yanan Wang, Yue He, Jingzhou Hu, Wenzheng Guo, Tong Wang, Beibei Sun, Hongyong Song, Huijing Yin, Jingyi Liu, Yadi Wu, Hanguang Zhu, Binhua P. Zhou, Jiong Deng, Zhiyuan Zhang

Markey Cancer Center Faculty Publications

Salivary adenoid cystic carcinoma (SACC) is characterized by invasive local growth and a high incidence of lung metastasis. Patients with lung metastasis have a poor prognosis. Treatment of metastatic SACC has been unsuccessful, largely due to a lack of specific targets for the metastatic cells. In this study, we showed that epidermal growth factor receptors (EGFR) were constitutively activated in metastatic lung subtypes of SACC cells, and that this activation was induced by autocrine expression of epiregulin (EREG), a ligand of EGFR. Autocrine EREG expression was increased in metastatic SACC-LM cells compared to that in non-metastatic parental SACC cells. Importantly ...


Igfbp2 Potentiates Egfr-Stat3 Signaling In Glioma, Yingxuan Chua May 2015

Igfbp2 Potentiates Egfr-Stat3 Signaling In Glioma, Yingxuan Chua

UT GSBS Dissertations and Theses (Open Access)

Gliomas are clinically challenging brain tumors with dismal survival rates due to its infiltrative nature and ineffective standard therapy. Insulin-like growth factor binding protein 2 (IGFBP2) is a pleiotropic oncogenic protein that has both extracellular and intracellular functions. Despite a clear causal role in cancer development, the contributions of intracellular IGFBP2 to tumor development and progression are poorly understood. Here we present evidence that both exogenous IGFBP2 treatment and cellular IGFBP2 overexpression lead to aberrant activation of EGFR, which subsequently activates STAT3 signaling. Furthermore, we demonstrate that IGFBP2 augments the nuclear accumulation of EGFR to potentiate STAT3 transactivation activities, via ...


Targeting Cox-2 And Rank In Aggressive Breast Cancers: Inflammatory Breast Cancer And Triple-Negative Breast Cancer, Monica Elizabeth Reyes Dec 2014

Targeting Cox-2 And Rank In Aggressive Breast Cancers: Inflammatory Breast Cancer And Triple-Negative Breast Cancer, Monica Elizabeth Reyes

UT GSBS Dissertations and Theses (Open Access)

Inflammatory breast cancer (IBC) and triple-negative breast cancer (TNBC) are two highly aggressive breast cancer subtypes associated with a poor outcome. Despite sensitivity to current treatment, these breast cancers subtypes have a high recurrence rate and proclivity to metastasize early. The aggressiveness of IBC and TNBC have been linked to CSCs and epithelial to mesenchymal transition (EMT), which are critical features of breast cancer progression and metastasis. The clinical challenge faced in the treatment of IBC and TNBC is finding a treatment strategy to target the cancer stem-like (CSC) population to block metastasis. Cyclooxygenase-2 (COX-2) and receptor activator of nuclear ...


Tyrosine 370 Phosphorylation Of Atm Positively Regulates Dna Damage Response, Hong-Jen Lee Aug 2014

Tyrosine 370 Phosphorylation Of Atm Positively Regulates Dna Damage Response, Hong-Jen Lee

UT GSBS Dissertations and Theses (Open Access)

Ataxia telangiectasia-mutated (ATM) mediates DNA damage response by controlling irradiation (IR)-induced foci formation, cell cycle checkpoint, and apoptosis. However, how upstream signaling regulates ATM is not completely understood. Here, we show that upon IR stimulation, ATM associates with and is phosphorylated by epidermal growth factor receptor (EGFR) at Y370 at the site of double-strand breaks. Depletion of endogenous EGFR impairs ATM-mediated foci formation, homologous recombination, and DNA repair. Moreover, ATM Y370F mutant or pretreatment with an EGFR kinase inhibitor gefitinib blocks EGFR and ATM association, hinders CHK2 activation and subsequent foci formation, and increases radio-sensitivity. Thus, we reveal a ...


Car-Modified T Cells Capable Of Distinguishing Normal Cells From Malignant Cells, Hillary G. Caruso May 2014

Car-Modified T Cells Capable Of Distinguishing Normal Cells From Malignant Cells, Hillary G. Caruso

UT GSBS Dissertations and Theses (Open Access)

T cells can be redirected to target tumor-associated antigen (TAA) by genetic modification to express a chimeric antigen receptor (CAR), which fuses the specificity derived from an antibody to T-cell activation domains to result in lysis of TAA-expressing cells. Due to the potential for on-target, off-tissue toxicity, CAR+ T-cell therapy is currently limited to unique or lineage-restricted TAAs. Glioblastoma, a grade IV brain malignancy, overexpresses epidermal growth factor receptor (EGFR) in 40-50% of patients. EGFR also has widespread normal tissue expression. To target EGFR on glioblastoma while reducing the potential for normal tissue toxicity, EGFR-specific CAR generated from cetuximab, Cetux-CAR ...


Mechanisms Underlying Distinct Egfr Versus Fgfr-3 And -1 Dependency In Human Bladder Cancer Cells, Tiewei Cheng May 2014

Mechanisms Underlying Distinct Egfr Versus Fgfr-3 And -1 Dependency In Human Bladder Cancer Cells, Tiewei Cheng

UT GSBS Dissertations and Theses (Open Access)

The epidermal growth factor receptor (EGFR) and fibroblast growth factor receptor (FGFR) are activated by gene amplification, mutation and overexpression in bladder cancer, which drives tumor development and progression. Both EGFR and FGFR inhibitors are currently being tested in clinical trials. However, bladder cancer (BC) cells show remarkably heterogeneous sensitivities to both inhibitors, and the molecular determinants of this heterogeneity are presently unclear. Therefore, in this study, using selective EGFR and FGFR inhibitors in BC cells, we demonstrated that FGFR3 and FGFR1 play largely non-overlapping roles in mediating proliferation and invasion in the distinct “epithelial” and “mesenchymal” subsets of human ...


Crosstalk Between R1175 Methylation And Y1173 Phosphorylation Negatively Modulates Egfr-Mediated Erk Activation, Jung-Mao Hsu Aug 2011

Crosstalk Between R1175 Methylation And Y1173 Phosphorylation Negatively Modulates Egfr-Mediated Erk Activation, Jung-Mao Hsu

UT GSBS Dissertations and Theses (Open Access)

Post-translational protein modifications are critical regulators of protein functions as they expand the signaling potentials of the modified proteins, leading to diverse physiological consequences. Currently, increasing evidence suggests that protein methylation is as important as other post-translational modifications in the regulation of various biological processes. This drives us to ask whether methylation is involved in the EGFR (epidermal growth factor receptor) signaling, a biological process extensively regulated by multiple post-translational modifications including phosphorylation, glycosylation and ubiquitination. We found that EGFR R1175 is methylated by a protein arginine methyltransferase named PRMT5. During EGFR activation, PRMT5-mediated R1175 methylation specifically enhances EGF-induced EGFR ...


The Role Of Tyrosine Phosphorylation In The Functions Of The Tumor Suppressor Gprc5a, Xiaofeng Lin Aug 2010

The Role Of Tyrosine Phosphorylation In The Functions Of The Tumor Suppressor Gprc5a, Xiaofeng Lin

UT GSBS Dissertations and Theses (Open Access)

The retinoic acid inducible G protein coupled receptor family C group 5 type A (GPRC5A) is expressed preferentially in normal lung tissue but its expression is suppressed in the majority of human non-small cell lung cancer cell lines and tissues. This differential expression has led to the idea that GPRC5A is a potential tumor suppressor. This notion was supported by the finding that mice with a deletion of the Gprc5a gene develop spontaneous lung tumors. However, there are various tumor cell lines and tissue samples, including lung, that exhibit higher GPRC5A expression than normal tissues and some reports by other ...


Mechanism Of Action And Regulation Of Membrane Serine Protease Prostasin In The Prostate And Prostate Cancer, Mengqian Chen Jan 2007

Mechanism Of Action And Regulation Of Membrane Serine Protease Prostasin In The Prostate And Prostate Cancer, Mengqian Chen

Electronic Theses and Dissertations

The glycosylphosphatidylinositol (GPI)-anchored serine protease prostasin (PRSS8) is expressed at the apical membrane surface of epithelial cells and acts as a suppressor of tumor invasion when re-expressed in highly invasive human prostate and breast cancer cell lines. To better understand the molecular mechanisms underlying the anti-invasion phenotype associated with prostasin re-expression in prostate cancer cells, we expressed wild-type human prostasin or a serine active-site mutant prostasin in the PC-3 human prostate carcinoma cells. Molecular changes were measured at the mRNA and the protein levels. The expression of several invasion-promoting molecules is regulated by prostasin re-expression, mediated by a protein-level ...