Open Access. Powered by Scholars. Published by Universities.®

Biochemistry, Biophysics, and Structural Biology Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 21 of 21

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

Signaling Pathways Induced By Leptin During Epithelial(-)Mesenchymal Transition In Breast Cancer, Monserrat Olea-Flores, Juan Carlos Juarez-Cruz, Miguel A. Mendoza-Catalan, Teresita Padilla-Benavides, Napoleon Navarro-Tito Nov 2018

Signaling Pathways Induced By Leptin During Epithelial(-)Mesenchymal Transition In Breast Cancer, Monserrat Olea-Flores, Juan Carlos Juarez-Cruz, Miguel A. Mendoza-Catalan, Teresita Padilla-Benavides, Napoleon Navarro-Tito

Open Access Articles

Leptin is an adipokine that is overexpressed in obese and overweight people. Interestingly, women with breast cancer present high levels of leptin and of its receptor ObR. Leptin plays an important role in breast cancer progression due to the biological processes it participates in, such as epithelial(-)mesenchymal transition (EMT). EMT consists of a series of orchestrated events in which cell(-)cell and cell(-)extracellular matrix interactions are altered and lead to the release of epithelial cells from the surrounding tissue. The cytoskeleton is also re-arranged, allowing the three-dimensional movement of epithelial cells into the extracellular matrix. This transition provides ...


Deciphering The Role Of Human Arylamine N-Acetyltransferase 1 (Nat1) In Breast Cancer Cell Metabolism Using A Systems Biology Approach., Samantha Marie Carlisle Aug 2018

Deciphering The Role Of Human Arylamine N-Acetyltransferase 1 (Nat1) In Breast Cancer Cell Metabolism Using A Systems Biology Approach., Samantha Marie Carlisle

Electronic Theses and Dissertations

Background: Human arylamine N-acetyltransferase 1 (NAT1) is a phase II xenobiotic metabolizing enzyme found in almost all tissues. NAT1 can additionally hydrolyze acetyl-coenzyme A (acetyl-CoA) in the absence of an arylamine substrate. NAT1 expression varies inter-individually and is elevated in several cancers including estrogen receptor positive (ER+) breast cancers. Additionally, multiple studies have shown the knockdown of NAT1, by both small molecule inhibition and siRNA methods, in breast cancer cells leads to decreased invasive ability and proliferation and decreased anchorage-independent colony formation. However, the exact mechanism by which NAT1 expression affects cancer risk and progression remains unclear. Additionally, consequences ...


Etv4 Transcription Factor And Mmp13 Metalloprotease Are Interplaying Actors Of Breast Tumorigenesis, Mandy Dumortier, Franck Ladam, Isabelle Damour, Sophie Vacher, Ivan Bieche, Nathalie Marchand, Yvan De Launoit, David Tulasne, Anne Chotteau-Lelievre Jul 2018

Etv4 Transcription Factor And Mmp13 Metalloprotease Are Interplaying Actors Of Breast Tumorigenesis, Mandy Dumortier, Franck Ladam, Isabelle Damour, Sophie Vacher, Ivan Bieche, Nathalie Marchand, Yvan De Launoit, David Tulasne, Anne Chotteau-Lelievre

Open Access Articles

BACKGROUND: The ETS transcription factor ETV4 is involved in the main steps of organogenesis and is also a significant mediator of tumorigenesis and metastasis, such as in breast cancer. Indeed, ETV4 is overexpressed in breast tumors and is associated with distant metastasis and poor prognosis. However, the cellular and molecular events regulated by this factor are still misunderstood. In mammary epithelial cells, ETV4 controls the expression of many genes, MMP13 among them. The aim of this study was to understand the function of MMP13 during ETV4-driven tumorigenesis.

METHODS: Different constructs of the MMP13 gene promoter were used to study the ...


Identification Of A Novel Invasion-Promoting Region In Insulin Receptor Substrate 2, Jose Mercado-Matos, Jenny Janusis, Sha Zhu, Samuel S. Chen, Leslie M. Shaw Jun 2018

Identification Of A Novel Invasion-Promoting Region In Insulin Receptor Substrate 2, Jose Mercado-Matos, Jenny Janusis, Sha Zhu, Samuel S. Chen, Leslie M. Shaw

University of Massachusetts Medical School Faculty Publications

Although the insulin receptor substrate (IRS) proteins IRS1 and IRS2 share considerable homology and activate common signaling pathways, their contributions to breast cancer are distinct. IRS1 has been implicated in the proliferation and survival of breast tumor cells. In contrast, IRS2 facilitates glycolysis, invasion, and metastasis. To determine the mechanistic basis for IRS2-dependent functions, we investigated unique structural features of IRS2 that are required for invasion. Our studies revealed that the ability of IRS2 to promote invasion is dependent upon upstream insulin-like growth factor 1 receptor (IGF-1R)/insulin receptor (IR) activation and the recruitment and activation of phosphatidylinositol 3-kinase (PI3K ...


Cell Clustering Mediated By The Adhesion Protein Pvrl4 Is Necessary For Alpha6beta4 Integrin-Promoted Ferroptosis Resistance In Matrix-Detached Cells, Caitlin W. Brown, John J. Amante, Arthur M. Mercurio Jun 2018

Cell Clustering Mediated By The Adhesion Protein Pvrl4 Is Necessary For Alpha6beta4 Integrin-Promoted Ferroptosis Resistance In Matrix-Detached Cells, Caitlin W. Brown, John J. Amante, Arthur M. Mercurio

University of Massachusetts Medical School Faculty Publications

Ferroptosis is an iron-dependent form of programmed cell death characterized by the accumulation of lipid-targeting reactive oxygen species that kill cells by damaging their plasma membrane. The lipid-repair enzyme glutathione peroxidase 4 (GPX4) protects against this oxidative damage and enables cells to resist ferroptosis. Recent work has revealed that matrix-detached carcinoma cells can be susceptible to ferroptosis and that they can evade this fate through the signaling properties of the alpha6beta4 integrin, which sustains GPX4 expression. Although these findings on ferroptosis are provocative, they differ from those in previous studies indicating that matrix-detached cells are prone to apoptosis, via a ...


Imp3 Stabilization Of Wnt5b Mrna Facilitates Taz Activation In Breast Cancer, Sanjoy Samanta, Santosh Guru, Ameer L. Elaimy, John J. Amante, Jianhong Ou, Jun Yu, Lihua Julie Zhu, Arthur M. Mercurio May 2018

Imp3 Stabilization Of Wnt5b Mrna Facilitates Taz Activation In Breast Cancer, Sanjoy Samanta, Santosh Guru, Ameer L. Elaimy, John J. Amante, Jianhong Ou, Jun Yu, Lihua Julie Zhu, Arthur M. Mercurio

Open Access Articles

Insulin-like growth factor-2 mRNA-binding protein 3 (IMP3) is an oncofetal protein associated with many aggressive cancers and implicated in the function of breast cancer stem cells (CSCs). The mechanisms involved, however, are poorly understood. We observed that IMP3 facilitates the activation of TAZ, a transcriptional co-activator of Hippo signaling that is necessary for the function of breast CSCs. The mechanism by which IMP3 activates TAZ involves both mRNA stability and transcriptional regulation. IMP3 stabilizes the mRNA of an alternative WNT ligand (WNT5B) indirectly by repressing miR145-5p, which targets WNT5B, resulting in TAZ activation by alternative WNT signaling. IMP3 also facilitates ...


Deciphering The Roles Of Δnp63 In Regulating Epithelial To Mesenchymal Transition, Cancer Progression And Metastasis, Ngoc Bui May 2018

Deciphering The Roles Of Δnp63 In Regulating Epithelial To Mesenchymal Transition, Cancer Progression And Metastasis, Ngoc Bui

UT GSBS Dissertations and Theses (Open Access)

p63 is a member of the p53 family, a well-known tumor suppressor which is considered the guardian of the genome. The TP63 gene encodes multiple isoforms that can be categorized into two main isoforms, TAp63 and ΔNp63, which are expressed in different cellular compartments and have distinct functions in many biological processes. While the Flores laboratory identified TAp63 as a tumor and metastasis suppressor, the precise roles of ΔNp63 isoforms in tumorigenesis and metastasis remain elusive. ΔNp63 is the predominant p63 isoform expressed in the epidermis and plays essential roles in regulating epidermal development and homeostasis. Utilizing a ΔNp63-conditional ...


Nanoparticle Delivery Of Mir-34a Eradicates Long-Term-Cultured Breast Cancer Stem Cells Via Targeting C22orf28 Directly, Xiaoti Lin, Weiyu Chen, Fengqin Wei, Binhua P. Zhou, Mien-Chie Hung, Xiaoming Xie Oct 2017

Nanoparticle Delivery Of Mir-34a Eradicates Long-Term-Cultured Breast Cancer Stem Cells Via Targeting C22orf28 Directly, Xiaoti Lin, Weiyu Chen, Fengqin Wei, Binhua P. Zhou, Mien-Chie Hung, Xiaoming Xie

Molecular and Cellular Biochemistry Faculty Publications

Rationale: Cancer stem cells (CSCs) have been implicated as the seeds of therapeutic resistance and metastasis, due to their unique abilities of self-renew, wide differentiation potentials and resistance to most conventional therapies. It is a proactive strategy for cancer therapy to eradicate CSCs. Methods: Tumor tissue-derived breast CSCs (BCSC), including XM322 and XM607, were isolated by fluorescence-activated cell sorting (FACS); while cell line-derived BCSC, including MDA-MB-231.SC and MCF-7.SC, were purified by magnetic-activated cell sorting (MACS). Analyses of microRNA and mRNA expression array profiles were performed in multiple breast cell lines. The mentioned nanoparticles were constructed following the standard ...


The Effect Of Target-Specific Biomolecules In Breast Cancer, Mohannad Garoub Jun 2017

The Effect Of Target-Specific Biomolecules In Breast Cancer, Mohannad Garoub

FIU Electronic Theses and Dissertations

Cancer is the second leading cause of mortality in the United States and the World, therefore, early effective prevention, diagnosis, and therapy is needed. Estrogens play a major role in the initiation and progression of breast cancer. Elevated lifetime exposure to estrogens is associated with an increased risk of developing breast cancer. Estrogens through influencing mitochondria contribute to estrogen induced breast carcinogenesis; however, the exact mitochondrial mechanisms underlying the estrogen carcinogenic effect in breast tissue are not clearly understood. For this dissertation, the mitotoxic and cytotoxic effects of triphenylphosphonium cation (TPP) and Origanum majorana organic extract (OME) as well as ...


The Brg1 Atpase Of Human Swi/Snf Chromatin Remodeling Enzymes As A Driver Of Cancer, Qiong Wu, Jane B. Lian, Janet L. Stein, Gary S. Stein, Jeffrey A. Nickerson, Anthony N. Imbalzano Jun 2017

The Brg1 Atpase Of Human Swi/Snf Chromatin Remodeling Enzymes As A Driver Of Cancer, Qiong Wu, Jane B. Lian, Janet L. Stein, Gary S. Stein, Jeffrey A. Nickerson, Anthony N. Imbalzano

Pediatric Publications and Presentations

Mammalian SWI/SNF enzymes are ATP-dependent remodelers of chromatin structure. These multisubunit enzymes are heterogeneous in composition; there are two catalytic ATPase subunits, BRM and BRG1, that are mutually exclusive, and additional subunits are incorporated in a combinatorial manner. Recent findings indicate that approximately 20% of human cancers contain mutations in SWI/SNF enzyme subunits, leading to the conclusion that the enzyme subunits are critical tumor suppressors. However, overexpression of specific subunits without apparent mutation is emerging as an alternative mechanism by which cellular transformation may occur. Here we highlight recent evidence linking elevated expression of the BRG1 ATPase to ...


Differential Involvement Of The Microtubule Cytoskeleton In Insulin Receptor Substrate 1 (Irs-1) And Irs-2 Signaling To Akt Determines The Response To Microtubule Disruption In Breast Carcinoma Cells, Jose Mercado-Matos, Jennifer L. Clark, Andrew J. Piper, Jenny Janusis, Leslie M. Shaw May 2017

Differential Involvement Of The Microtubule Cytoskeleton In Insulin Receptor Substrate 1 (Irs-1) And Irs-2 Signaling To Akt Determines The Response To Microtubule Disruption In Breast Carcinoma Cells, Jose Mercado-Matos, Jennifer L. Clark, Andrew J. Piper, Jenny Janusis, Leslie M. Shaw

UMass Metabolic Network Publications

The insulin receptor substrate (IRS) proteins serve as essential signaling intermediates for the activation of PI3K by both the insulin-like growth factor 1 receptor (IGF-1R) and its close family member, the insulin receptor (IR). Although IRS-1 and IRS-2 share significant homology, they regulate distinct cellular responses downstream of these receptors and play divergent roles in breast cancer. To investigate the mechanism by which signaling through IRS-1 and IRS-2 results in differential outcomes, we assessed the involvement of the microtubule cytoskeleton in IRS-dependent signaling. Treatment with drugs that either stabilize or disrupt microtubules reveal that an intact microtubule cytoskeleton contributes to ...


Rna-Sequencing Reveals Direct Targets Of Tumor Suppressor Mir-203 In Human Mammary Epithelial Cells, Alexander P. Boardman, Victoria E. Pedanou, Tessa M. Simone, Michael R. Green May 2017

Rna-Sequencing Reveals Direct Targets Of Tumor Suppressor Mir-203 In Human Mammary Epithelial Cells, Alexander P. Boardman, Victoria E. Pedanou, Tessa M. Simone, Michael R. Green

Senior Scholars Program

Background: Breast cancer is the leading cause of cancer-related mortality in women worldwide. Since a significant portion of cases present with or progress to metastatic disease, furthering our understanding of metastasis is critical to develop better treatments. Epithelial cells maintain contact with the extracellular matrix (ECM) predominantly via integrin engagement, a process required for tissue integrity and barrier function. In non-transformed cells, loss of ECM adhesion promotes a specialized form of programmed cell death, anoikis. In order for efficient metastasis to occur, breast tumor cells must evade anoikis. miR-203, known to be down-regulated in several cancers, was found by our ...


Runx1 And Breast Cancer, Jose Mercado-Matos, Asia N. Matthew-Onabanjo, Leslie M. Shaw Apr 2017

Runx1 And Breast Cancer, Jose Mercado-Matos, Asia N. Matthew-Onabanjo, Leslie M. Shaw

UMass Metabolic Network Publications

News on: Runx1 stabilizes the mammary epithelial cell phenotype and prevents epithelial to mesenchymal transition, by Hong et al. Oncotarget. 2017; 8:17610-27. doi: 10.18632/oncotarget.15381.


Mammalian Swi/Snf Enzymes And The Epigenetics Of Tumor Cell Metabolic Reprogramming, Jeffrey A. Nickerson, Qiong Wu, Anthony N. Imbalzano Apr 2017

Mammalian Swi/Snf Enzymes And The Epigenetics Of Tumor Cell Metabolic Reprogramming, Jeffrey A. Nickerson, Qiong Wu, Anthony N. Imbalzano

UMass Metabolic Network Publications

Tumor cells reprogram their metabolism to survive and grow in a challenging microenvironment. Some of this reprogramming is performed by epigenetic mechanisms. Epigenetics is in turn affected by metabolism; chromatin modifying enzymes are dependent on substrates that are also key metabolic intermediates. We have shown that the chromatin remodeling enzyme Brahma-related gene 1 (BRG1), an epigenetic regulator, is necessary for rapid breast cancer cell proliferation. The mechanism for this requirement is the BRG1-dependent transcription of key lipogenic enzymes and regulators. Reduction in lipid synthesis lowers proliferation rates, which can be restored by palmitate supplementation. This work has established BRG1 as ...


Investigating The Roles Of Δnp63 As A Suppressor Of Migration, Invasion, And Metastasis, Ramon E. Flores Gonzalez Aug 2016

Investigating The Roles Of Δnp63 As A Suppressor Of Migration, Invasion, And Metastasis, Ramon E. Flores Gonzalez

UT GSBS Dissertations and Theses (Open Access)

Cancer is one of the leading causes of death and disease in the world. Considerable resources are spent to study and understand cancer, with the hope of developing new treatments and eventually cures that will help millions of people. Efforts to understand cancer are hindered by its inherent complexity and instability. Nonetheless, understanding the basics of tumor development and progression are the key to focused on studying the role of ΔNp63 in cancer, a p53 family member known to be involved in epithelial development, microRNA biogenesis, and stem cell maintenance. Using the strength of in vivo mouse models, we found ...


Jab1 Negatively Regulates Pten And Promotes Resistance To Trastuzumab In Her2-Positive Breast Cancer, Thuy T. Vu Dec 2014

Jab1 Negatively Regulates Pten And Promotes Resistance To Trastuzumab In Her2-Positive Breast Cancer, Thuy T. Vu

UT GSBS Dissertations and Theses (Open Access)

HER2-positive breast cancer, which is characterized by the over-expression of the HER2 onco-protein, accounts for approximately 20% of all breast cancer cases. Trastuzumab (Herceptin), the first targeted therapy approved for HER2-positive disease, potently prevents the activation of signaling pathways downstream of HER2 and significantly improves patients’ outcomes. However, resistance to trastuzumab is inevitable; such resistance can occur through reduced expression of PTEN protein.

Jab1 is over-expressed in 50% of primary cancers and 90% of metastatic tumors. Our lab previously showed that depletion of Jab1 in combination with trastuzumab treatment up-regulated PTEN in mouse xenografts refractory to trastuzumab. PTEN was not ...


The Regulation Of Microrna Biogenesis By Ribosome-Interacting Proteins, Brian Pickering May 2014

The Regulation Of Microrna Biogenesis By Ribosome-Interacting Proteins, Brian Pickering

UT GSBS Dissertations and Theses (Open Access)

MicroRNA (miRNA) are small, non-coding RNAs that affect gene expression through degradation of complementary mRNA targets or inhibition of translation. As they affect approximately 50% of all cellular processes, miRNA are tightly regulated by the cell through transcriptional and post-transcriptional mechanisms. Transcribed miRNA are capped and polyadenylated (referred to as pri-miRNA) which are cleaved by Drosha and DGCR8 to generate 60-90 nucleotide precursor miRNA. The precursors are cleaved again by Dicer and loaded into the RNA-induced silencing complex (RISC) of which Argonaute 2 is the functional component. Many of the proteins involved in miRNA biogenesis share a common role in ...


Requirements Of Rab5 Activity In Highly Invasive Breast Cancer Cell Lines, Nicole Porther, M Alejandro Barbieri Dec 2013

Requirements Of Rab5 Activity In Highly Invasive Breast Cancer Cell Lines, Nicole Porther, M Alejandro Barbieri

Nicole Porther

Rab5 expression in cancer has been associated with the disease progression and prognosis. We have previously shown that growth factor-directed cell invasion and migration was dependent on Rab5 activation in non-invasive breast cancer cells. However, hardly any data is available regarding the role of Rab5 in invasive cells in the presence of growth factor.  In our present study, we report that the invasive and migratory properties of the highly invasive breast cancer cell line, MDAMB-231, were abrogated in cells expressing the inactive (GDP-bound) form of Rab5 irrespective of growth factor stimulation; while the invasive potential of breast cancer cell lines ...


Proteomic And Biochemical Studies Of Estrogen-Mediated Signaling And Novel Estrogen Receptor-Interacting Proteins In Breast Cancer Cells, Zhenqi Zhou Aug 2013

Proteomic And Biochemical Studies Of Estrogen-Mediated Signaling And Novel Estrogen Receptor-Interacting Proteins In Breast Cancer Cells, Zhenqi Zhou

Theses and Dissertations

Estrogen plays essential roles in the growth, development, and homeostasis of a number of tissues, and can also be linked to the growth of breast cancer. The biological activities of estrogen are mediated by estrogen receptors (ERs) ERá and ERâ, and also orphan G-protein-coupled receptor 30 (GPR30). In order to identify novel proteins that are involved in ER-mediated actions of estrogen, we used mass spectrometry-based quantitative proteomic methods to systematically profile global protein expression in responses to E2 (17â-estradiol) stimulation in human breast cancer cell, and identify and characterize cellular novel proteins that are associated with ERs in breast cancer ...


In Vivo Investigations Of Polymer Conjugates As Therapeutics, Elizabeth M. Henchey Jan 2011

In Vivo Investigations Of Polymer Conjugates As Therapeutics, Elizabeth M. Henchey

Masters Theses 1911 - February 2014

Polymer conjugates offer a way to introduce materials into the body that would normally be rejected or cause toxicity. Two polymers are investigated in vivo for uses in chemotherapeutic delivery, protein therapeutics, and DNA transfection. A novel polymer, polyMPC, has the ability to increase doxorubicin loading and its solubility, and is conjugated in a way to release its payload in a low pH environment. Through its conjugation, blood clearance time of doxorubicin is increased, and thus tumor exposure to the drug is increased with a single administration. It can be administered at ten times the concentration of free doxorubicin, and ...


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 ...