Medicine and Health Sciences Commons^™

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

Dissertations & 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 …

Lkb1 Deficient Non-Small Cell Lung Cancer Cells Are Vulnerable To Energy Stress Induced By Atp Depletion, Chao Yang

Dissertations & Theses (Open Access)

Lung cancer is the second most frequent cancer in United States, which represents about 13.5% of new cancer cases every year. It accounts for about 27.2% of all cancer related deaths, which is more than the sum of deaths caused by prancretic, breast and colorectal. On average, only about 16% of lung cancer patients survive beyond 5 years. LKB1 is the third most mutated gene in lung cancer. It has been shown that LKB1 is mutated in at least 15% to 30% of NSCLC. Tumor with LKB1 mutation is associated with poor differentiation, high metastasis and worse response to chemotherapy. …

Epidermal Growth Factor Receptor Induces Fyn Expression Via Up-Regulation Of P47phox In Glioblastoma Multiforme, Blake P. Johnson

Dissertations & Theses (Open Access)

Src family kinases (SFKs) are commonly over-expressed and/or activated in glioblastoma multiforme (GBM), where they serve as key mediators of GBM cell proliferation, survival, invasion and angiogenesis. Mechanisms of allosteric SFK activation are well described; however, the SFK Fyn is commonly up-regulated at the mRNA level in multiple human cancers, including GBM, where the mode of increased expression is poorly understood. Since activating mutations in the epidermal growth factor receptor (EGFR) are commonly occurring in GBM, we examined whether EGFR could induce Fyn expression. Here, we found that wild-type EGFR, and to a greater extent hyper-activating EGFR mutants, EGFRΔIII and …

Sustained Adrenergic Signaling Promotes Cervical Cancer Progression, Nouara C. Sadaoui

Dissertations & Theses (Open Access)

Background: Chronic stress and sustained adrenergic signaling are known to promote tumor progression. The underlying mechanisms behind this process are not well understood. We examined the effects of sustained adrenergic signaling on cervical cancer progression through increased expression of HPV oncogenes, E6 and E7.

Materials and Methods: ADRβ expression levels were examined in patient-derived cervical cancer samples. We used an orthotopic model of cervical cancer to investigate the effects of restraint stress on tumor growth and metastasis. We evaluated the in vivo effects of a β-blocker, propranolol, and HPV E6/E7 siRNA. In vitro, ADRβ positive cervical cancer cells were …

Large-Scale Identification Of Chemically Induced Mutations In Drosophila Melanogaster., Nele A Haelterman, Lichun Jiang, Yumei Li, Vafa Bayat, Hector Sandoval, Berrak Ugur, Kai Li Tan, Ke Zhang, Danqing Bei, Bo Xiong, Wu-Lin Charng, Theodore Busby, Adeel Jawaid, Gabriela David, Manish Jaiswal, Koen J T Venken, Shinya Yamamoto, Rui Chen, Hugo J Bellen

Faculty Publications

Forward genetic screens using chemical mutagens have been successful in defining the function of thousands of genes in eukaryotic model organisms. The main drawback of this strategy is the time-consuming identification of the molecular lesions causative of the phenotypes of interest. With whole-genome sequencing (WGS), it is now possible to sequence hundreds of strains, but determining which mutations are causative among thousands of polymorphisms remains challenging. We have sequenced 394 mutant strains, generated in a chemical mutagenesis screen, for essential genes on the Drosophila X chromosome and describe strategies to reduce the number of candidate mutations from an average of …

Roles For B-Raf Kinase In The Specific Regulation Of Α4Β1 Integrin In T Cells, Wells S. Brown

Dissertations & Theses (Open Access)

The regulation of integrin-mediated adhesion is of vital importance to adaptive and innate immunity. Integrins are versatile proteins and mediate T cell migration and trafficking by binding to ECM or other cells, as well as initiating intracellular signaling cascades promoting survival or activation. The mitogen activated-protein kinase (MAPK) pathway is known to be downstream from integrins and regulate survival, differentiation, and motility. However, secondary roles for canonical MAPK pathway members are being discovered. We show chemical inhibition of RAF by Sorafenib or shRNA-mediated knockdown of B-Raf reduces T cell resistance to shear stress to α4β1 integrin ligands vascular cell adhesion …

Strategies To Sensitize Bladder Cancer Cells To Small Molecule Inhibitors Targeting The Pi3k Pathway, Giovanni Nitti

Dissertations & Theses (Open Access)

After many years of cancer research, it is well accepted by the scientific community that the future cure for this disease lies in a personalized therapeutic approach. Anticipating therapeutic outcome based on the genetic signature of a tumor has become the new paradigm. The PI3K pathway represents an ideal target for bladder cancer, as many of the key proteins of this pathway are altered or mutated in this particular type of cancer. Several small molecule inhibitors have been developed to target this pathway, but their efficacy has been shown to be heterogeneous among different cell lines and mostly cytostatic but …

Mapping The Human Vasculature By In Vivo Phage Display, Julianna Bronk

Dissertations & Theses (Open Access)

In vivo phage display screenings by intravenous injection of a random phage-displayed peptide library allow for the selection of peptides that localize to specific vascular beds. At the University of Texas MD Anderson Cancer Center, we have had the opportunity to perform phage display screenings in cancer patients in order to select for cancer specific targets directly in humans. These targets serve to define biochemical diversity of endothelial cell surfaces and can be validated and explored towards the design of vascular-targeted pharmacology. In the most recent patient screen, samples were recovered from hepatocellular carcinoma (HCC) as well as 26 additional …

Cd56-Specific T Cells: Using Genetically Engineered T Cells To Redirect Specificity To A T Cell Expressed Antigen, Denise L. Crossland

Dissertations & Theses (Open Access)

The CD56 antigen is expressed on several deadly malignancies currently lacking long-term efficacious therapies. Chimeric antigen receptor (CAR) based immunotherapies have shown both safety and efficacy and even a curative ability in clinical trials, laying the foundation for applying CARs to new targets. Using T cells to target a T cell expressed antigen, such as CD56, seems counterintuitive in that the T cells would be susceptible to self-targeting a.k.a. fratricide. However, we expand CD56-specific CAR⁺ T cells that co-express the CD56 antigen. Since other CARs targeting T cell expressed antigens are hypothesized to be undergoing fratricide, such as the …

Imbalance Between Neutrophil Elastase And Elafin Promotes Breast Cancer Growth And Progression, Joseph Anthony Caruso

Dissertations & Theses (Open Access)

Elafin, an endogenous serine protease inhibitor, is a critical component of the epithelial barrier against neutrophil elastase (NE) activity. The central hypothesis examined in this dissertation was that elafin has tumor suppressive properties in breast cancer. In support of this hypothesis, immunohistochemical (IHC) analysis revealed that elafin was downregulated in the majority of invasive breast tumors and a subset of pre-invasive ductal carcinoma in situ (DCIS) compared to elafin expression in the normal mammary epithelium. To understand the role of elafin in the mammary epithelium and the impetus for its downregulation during breast tumorigenesis, primary and immortalized human mammary epithelial …

Diabetes And Obesity Induce Transcriptomic And Metabolomic Changes Enhancing Pancreatic Cancer Aggressiveness, Guermarie Velázquez Torres

Dissertations & Theses (Open Access)

Pancreatic cancer is one of the most aggressive types of cancer, with poor prognosis that lacks effective diagnostic markers and therapies. It is expected that in 2014 the incidence and the mortality of pancreatic cancer in the United States will be 46,420 and 39,590 respectively. Diabetes and obesity are modifiable risk factors associated with accelerated pancreatic carcinogenesis and tumor progression, but the biological mechanisms are not completely understood. The purpose of this study is to demonstrate direct evidence for the mechanisms mediating these epidemiologic phenomena. Our hypothesis is that obesity and diabetes mellitus type 2 (DM2) accelerate pancreatic cancer and …

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

Dissertations & 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 …

Modulated Functions Of The Fanconi Anemia Core Complex, Yaling Huang

Dissertations & Theses (Open Access)

Cells derived from Fanconi anemia (FA) patients are characterized by hypersensitivity to DNA interstrand crosslinks (ICLs), suggesting that FA genes play a role in ICL repair. Fanconi anemia core complex (including A, B, C, E, F, G, L, FAAP20, and FAAP100) activates the Fanconi pathway by providing the essential E3 ligase activity for FANCD2 mono-ubiquitination. Previous studies suggested the existence of three protein-protein interaction groups. However, the functions of most FA core complex protein are still limited to their presence in the complex. How the spatially-defined FANCD2 ubiquitination is accomplished by the core complex remains unknown.

To elucidate the roles …

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

Dissertations & 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 …

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

Dissertations & 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, …

The Association Between The Il-1 Pathway, Isaac C. Wun

Dissertations & Theses (Open Access)

Cutaneous malignant melanoma (CMM) is a potentially lethal malignancy that warrants attention and further research, as it is known to that there is an increasing rate of incidence in theUnited States, and it is also known that exposure to UV light is its most crucial risk factor, and family history of melanoma is also an important risk factor. Melanoma is an aggressive and lethal cancer in humans. There are an estimated new 132,000 melanoma cases annually worldwide, and the trend has doubled in the past 20 years. However, attempts to treat melanoma have encountered considerable resistance and remained ineffective. The …

Regulation Of Mammary Gland Development And Tumorigenesis By 14-3-3 Zeta, Sumaiyah Rehman

Dissertations & Theses (Open Access)

Signaling pathways that play critical roles in organ development are often aberrantly regulated during cancer initiation and progression. 14-3-3z is overexpressed in more than 40% of breast cancers and is associated with poor patient prognosis. Therefore, the function of 14-3-3z in cancer and normal mammary gland development was investigated utilizing multiple in vivo and in vitro approaches. 14-3-3z is a chaperone protein that interacts with a multitude of oncogenes and tumor suppressor genes, thereby functioning as a critical node in multiple oncogenic signaling networks. Mammary gland-specific 14-3-3z transgenic mouse models showed that 14-3-3z overexpression was sufficient to induce mammary tumorigenesis. …

Role Of Talin1 Phosphorylation In Beta1 Integrin Activation And Prostate Cancer Metastasis, Jung-Kang Jin

Dissertations & Theses (Open Access)

Talins are adaptor proteins that regulate focal adhesion signaling by conjugating integrins to the cytoskeleton. Talins directly bind and activate integrins but the mechanism by which this occurs is unknown. As integrin activation and overexpression of talins promote prostate cancer metastasis, understanding the mechanism by which talins activate integrins will better elucidate their roles in Prostate cancer metastasis. Phosphorylation of talins on serine 425 has been associated with β1 integrin functions. Work in this dissertation tested the hypothesis that increased talin1 S425 phosphorylation was required for β1 integrin activation and promotion of prostate cancer metastasis.

I first used shRNA to …

Anti-Insulin Resistance Treatments Suppress Her2+ Breast Cancer Growth Via Altering Metabolism, Ping-Chieh Chou

Dissertations & Theses (Open Access)

Epidemiological studies have identified that type 2 diabetes mellitus (DM2) is a significant risk factor for carcinogenesis and cancer death, including breast cancer. Our previous finding in patients showed that anti-insulin resistance treatments are associated with improved HER2⁺ breast cancer survival of diabetic women. However, there were no transgenic mouse models to study the correlation and explain the detailed mechanism. We generated a mouse model of HER2⁺ breast cancer with DM2 by crossing leptin receptor point mutation (Lepr ^db/+) and MMTV-ErbB2 (neu) mice. The MMTV-ErbB2/Lepr ^db/db mice had a poor survival rate compared …

Characterization Of Ftsa-Ftsn Interaction During Escherichia Coli Cell Division, Kimberly.Busiek@Gmail.Com K. Busiek

Dissertations & Theses (Open Access)

Division of a bacterial cell into two equal daughter cells requires precise assembly and constriction of the division machinery, or divisome. The Escherichia coli divisome includes nearly a dozen essential cell division proteins that assemble at midcell between segregating sister chromosomes. FtsZ, a homolog of eukaryotic tubulin, is the first essential cell division protein to localize at midcell where it polymerizes into a ring-shaped scaffold (Z ring). Establishment of the Z ring is required for recruitment of downstream cell division proteins including FtsA, a cytoplasmic protein that tethers the Z ring to the inner membrane. Following localization of FtsA and …