Matching Items (189)
Description
Cell-cell interactions in a microenvironment under stress conditions play a critical role in pathogenesis and pre-malignant progression. Hypoxia is a central factor in carcinogenesis, which induces selective pressure in this process. Understanding the role of intercellular communications and cellular adaptation to hypoxia can help discover new cancer biosignatures and more effective diagnostic and therapeutic strategies. This dissertation presents a study on transcriptomic and metabolic profiling of pre-malignant progression of Barrett's esophagus. It encompasses two methodology developments and experimental findings of two related studies. To integrate phenotype and genotype measurements, a minimally invasive method was developed for selectively retrieving single adherent cells from cell cultures. Selected single cells can be harvested by a combination of mechanical force and biochemical treatment after phenotype measurements and used for end-point assays. Furthermore, a method was developed for analyzing expression levels of ten genes in individual mammalian cells with high sensitivity and reproducibility without the need of pre-amplifying cDNA. It is inexpensive and compatible with most of commercially available RT-qPCR systems, which warrants a wide applicability of the method to gene expression analysis in single cells. In the first study, the effect of intercellular interactions was investigated between normal esophageal epithelial and dysplastic Barrett's esophagus cells on gene expression levels and cellular functions. As a result, gene expression levels in dysplastic cells were found to be affected to a significantly larger extent than in the normal esophageal epithelial cells. These differentially expressed genes are enriched in cellular movement, TGFβ and EGF signaling networks. Heterotypic interactions between normal and dysplastic cells can change cellular motility and inhibit proliferation in both normal and dysplastic cells. In the second study, alterations in gene transcription levels and metabolic phenotypes between hypoxia-adapted cells and age-matched normoxic controls representing four different stages of pre-malignant progression in Barrett's esophagus were investigated. Through differential gene expression analysis and mitochondrial membrane potential measurements, evidence of clonal evolution induced by hypoxia selection pressure in metaplastic and high-grade dysplastic cells was found. These discoveries on cell-cell interactions and hypoxia adaptations provide a deeper insight into the dynamic evolutionary process in pre-malignant progression of Barrett's esophagus.
ContributorsZeng, Jia (Author) / Meldrum, Deirdre R (Thesis advisor) / Kelbauskas, Laimonas (Committee member) / Barrett, Michael T (Committee member) / Bussey, Kimberly J (Committee member) / Zhang, Weiwen (Committee member) / Arizona State University (Publisher)
Created2014
Description
Cellular heterogeneity is a key factor in various cellular processes as well as in disease development, especially associated with immune response and cancer progression. Cell-to-cell variability is considered to be one of the major obstacles in early detection and successful treatment of cancer. Most present technologies are based on bulk cell analysis, which results in averaging out the results acquired from a group of cells and hence missing important information about individual cells and their behavior. Understanding the cellular behavior at the single-cell level can help in obtaining a complete profile of the cell and to get a more in-depth knowledge of cellular processes. For example, measuring transmembrane fluxes oxygen can provide a direct readout of the cell metabolism.
The goal of this thesis is to design, optimize and implement a device that can measure the oxygen consumption rate (OCR) of live single cells. A microfluidic device has been designed with the ability to rapidly seal and unseal microchambers containing individual cells and an extracellular optical oxygen sensor for measuring the OCR of live single cells. The device consists of two parts, one with the sensor in microwells (top half) and the other with channels and cells trapped in Pachinko-type micro-traps (bottom half). When the two parts of the device are placed together the wells enclose each cell. Oil is flown in through the channels of the device to produce isolated and sealed microchamber around each cell. Different fluids can be flowed in and out of the device, alternating with oil, to rapidly switch between sealed and unsealed microenvironment around each cell. A fluorescent ratiometric dual pH and oxygen sensor is placed in each well. The thesis focuses on measuring changes in the oxygen consumption rate of each cell within a well. Live and dead cells are identified using a fluorescent live/dead cell assay. Finally, the technology is designed to be scalable for high-throughput applications by controlling the flow rate of the system and increasing the cell array density.
The goal of this thesis is to design, optimize and implement a device that can measure the oxygen consumption rate (OCR) of live single cells. A microfluidic device has been designed with the ability to rapidly seal and unseal microchambers containing individual cells and an extracellular optical oxygen sensor for measuring the OCR of live single cells. The device consists of two parts, one with the sensor in microwells (top half) and the other with channels and cells trapped in Pachinko-type micro-traps (bottom half). When the two parts of the device are placed together the wells enclose each cell. Oil is flown in through the channels of the device to produce isolated and sealed microchamber around each cell. Different fluids can be flowed in and out of the device, alternating with oil, to rapidly switch between sealed and unsealed microenvironment around each cell. A fluorescent ratiometric dual pH and oxygen sensor is placed in each well. The thesis focuses on measuring changes in the oxygen consumption rate of each cell within a well. Live and dead cells are identified using a fluorescent live/dead cell assay. Finally, the technology is designed to be scalable for high-throughput applications by controlling the flow rate of the system and increasing the cell array density.
ContributorsRodrigues, Meryl (Author) / Meldrum, Deirdre (Thesis advisor) / Kelbauskas, Laimonas (Committee member) / LaBelle, Jeffrey (Committee member) / Arizona State University (Publisher)
Created2014
Description
A series of mitochondria targeting probes was synthesized for the purpose of exploring the feasibility of a mitochondria targeting fluorescent sensor. Of the probes, the probe with a two carbon spacer showed the best co-localization from staining with the established MitoTracker Red® FM, indicating a potential development of the probe into mitochondria targeting sensor. However, cytotoxicity was observed for the probe with a six carbon spacer. Three additional mitochondria targeting fluorescent probes of longer spacer groups were synthesized, but the cytotoxicity was not observed to be as high as that of the probe with a two carbon spacer. The cytotoxicity was characterized to be that of caspase dependent cell death. To screen for a possible effect on apoptosis due to the mitochondrial probe, three fluorescent fusion proteins binding the anti-apoptotic proteins were designed and expressed. Each purified fusion protein was then incubated with the cytotoxic mitochondrial probe, and the mixture was isolated by running an affinity column. The fluorescence analysis of eluted fractions showed preliminary data of possible interaction between the protein and the mitochondrial probe.
ContributorsLee, Fred (Author) / Meldrum, Deirdre R. (Thesis director) / Tian, Yanqing (Committee member) / Zhang, Liqiang (Committee member) / Barrett, The Honors College (Contributor) / Chemical Engineering Program (Contributor) / Department of Chemistry and Biochemistry (Contributor)
Created2014-12
Description
An in-depth analysis of Homeview Realty and Homeview Financial was conducted. A marketing plan for both companies was prepared for this project. Homeview Realty and Homeview Financial are in the midst of dynamic industries. The landscape of doing business in the real estate and mortgage industries are constantly changing and evolving. Thus, it is vital for Homeview Realty and Homeview Financial to constantly be knowledgeable in these fields. With this dynamic aspect, the landscape for marketing has also changed; it became digital in nature. Thus, it is important to analyze Homeview Realty and Homeview Financial currently and create a live marketing plan that can be updated when needed. With a marketing plan in hand, Homeview will be able understand its business model, mission, goals, and objectives and in turn be able to create marketing campaigns compatible with the companies objectives and strategic directions.
ContributorsCrowley, Rachel Victoria (Author) / Ostrom, Lonnie (Thesis director) / Montoya, Detra (Committee member) / Mirshak, Paul (Committee member) / Barrett, The Honors College (Contributor) / Department of Marketing (Contributor) / Department of Supply Chain Management (Contributor) / Department of Chemistry and Biochemistry (Contributor) / Department of Finance (Contributor) / School of Accountancy (Contributor)
Created2014-05
Description
Repeating tiles made of DNA were used to try to form an indefinitely large structure. Both the tiles and structure were 2D. Two different patterns were tested, one corrugated and one not. Corrugation means that the tiles alternated between facing up and facing down, canceling out any curvature to the tile and creating a slightly corrugated but largely 2D pattern. Annealing methods were also experimented with. Annealing the structure in two, separate steps as opposed to one was tested. Another experiment was comparing cyclic versus linear annealing. A linear decrease in temperatures defines the linear annealing, and a cyclic method involved a linear drop to a certain temperature, followed by a slight increase in temperature and cooling back down again. This cycle is done several times before it continues linear cool down. It was seen that both corrugated and non-corrugated structures could be made. In both cases tiles that make up a larger section of the overall pattern were more successful. This is especially important for the non-corrugated pattern. Linear and 2step annealing methods seem to yield the best results.
ContributorsHunt, Ashley Elizabeth (Author) / Yan, Liu (Thesis director) / Yan, Hao (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor)
Created2015-05
Description
Lung cancer is the leading cause of cancer-related deaths in the US. Low-dose computed tomography (LDCT) scans are speculated to reduce lung cancer mortality. However LDCT scans impose multiple risks including false-negative results, false- positive results, overdiagnosis, and cancer due to repeated exposure to radiation. Immunosignaturing is a new method proposed to screen and detect lung cancer, eliminating the risks associated with LDCT scans. Known and blinded primary blood sera from participants with lung cancer and no cancer were run on peptide microarrays and analyzed. Immunosignatures for each known sample collectively indicated 120 peptides unique to lung cancer and non-cancer participants. These 120 peptides were used to determine the status of the blinded samples. Verification of the results from Vanderbilt is pending.
ContributorsNguyen, Geneva Trieu (Author) / Woodbury, Neal (Thesis director) / Zhao, Zhan-Gong (Committee member) / Stafford, Phillip (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor) / Department of Psychology (Contributor)
Created2015-05
Description
The purpose of this project was to identify proteins associated with the migration and invasion of non-transformed MCF10A mammary epithelial cells with ectopically expressed missense mutations in p53. Because of the prevalence of TP53 missense mutations in basal-like and triple-negative breast cancer tumors, understanding the effect of TP53 mutations on the phenotypic expression of human mammary epithelial cells may offer new therapeutic targets for those currently lacking in treatment options. As such, MCF10A mammary epithelial cells ectopically overexpressing structural mutations (G245S, H179R, R175H, Y163C, Y220C, and Y234C) and DNA-binding mutations (R248Q, R248W, R273C, and R273H) in the DNA-binding domain were selected for use in this project. Overexpression of p53 in the mutant cell lines was confirmed by western blot and q-PCR analysis targeting the V5 epitope tag present in the pLenti4 vector used to transduce TP53 into the mutant cell lines. Characterization of the invasion and migration phenotypes resulting from the overexpression of p53 in the mutant cell lines was achieved using transwell invasion and migration assays with Boyden chambers. Statistical analysis showed that three cell lines—DNA-contact mutants R248W and R273C and structural mutant Y220C—were consistently more migratory and invasive and demonstrated a relationship between the migration and invasion properties of the mutant cell lines. Two families of proteins were then explored: those involved in the Epithelial-Mesenchymal Transition (EMT) and matrix metalloproteinases (MMPs). Results of q-PCR and immunofluorescence analysis of epithelial marker E-cadherin and mesenchymal proteins Slug and Vimentin did not show a clear relationship between mRNA and protein expression levels with the migration and invasiveness phenotypes observed in the transwell studies. Results of western blotting, q-PCR, and zymography of MMP-2 and MMP-9 also did not show any consistent results indicating a definite relationship between MMPs and the overall invasiveness of the cells. Finally, two drugs were tested as possible treatments inhibiting invasiveness: ebselen and SBI-183. These drugs were tested on only the most invasive of the MCF10A p53 mutant cell lines (R248W, R273C, and Y220C). Results of invasion assay following 30 μM treatment with ebselen and SBI-183 showed that ebselen does not inhibit invasiveness; SBI-183, however, did inhibit invasiveness in all three cell lines tested. As such, SBI-183 will be an important compound to study in the future as a treatment that could potentially serve to benefit triple-negative or basal-like breast cancer patients who currently lack therapeutic treatment options.
ContributorsZhang, Kathie Q (Author) / LaBaer, Joshua (Thesis director) / Anderson, Karen (Committee member) / Gonzalez, Laura (Committee member) / Barrett, The Honors College (Contributor) / School of International Letters and Cultures (Contributor) / Department of Chemistry and Biochemistry (Contributor)
Created2015-05
Description
This study assessed the effects of running an eating prevention program on body image satisfaction/behavior and the leadership skills of collegiate women. The sample included a group of 43 undergraduate women who voluntarily chose to become peer-educators in the eating prevention program called the Body Project. Self-report questionnaires evaluating both the preoccupation with personal body image and general leadership skills were distributed and collected electronically. The results were analyzed to determine that being a peer leader in the Body project did not increase eating disorder symptoms but actually decreased the symptoms. It was also determined that being a peer educator had no effect on leadership skills. Therefore, being a peer leader is beneficial for reducing eating disorder symptoms, but not for advancing leadership skills.
ContributorsCamiliere, Taylor Marie (Author) / Perez, Marisol (Thesis director) / Cavanaugh Toft, Carolyn (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor) / Department of Psychology (Contributor)
Created2015-05
Description
Smartphone-based healthcare. It's becoming more real as technology advances, adding value to healthcare and opening the doors to more personalized medicine. The Medical Pal is a smartphone application that can track symptoms and analyze trends in the severity of those symptoms, alerting healthcare providers when there is a significant increase in the symptom severity. This is especially directed to the palliative patient, whose care is focused on managing symptoms and providing comfort. The HIPAA-compliant server used for the smartphone application was Catalyze.io and 40 Mayo Clinic Arizona palliative patients were surveyed on their smartphone usage to test the acceptance of this app in a clinical setting. A trial involving 9 simulated patients was conducted over a two week period to test the functionality of the app. A majority of surveyed patients (85%) expressed favor for the idea of a mobile ESAS, and the app was functioning, with the capability of displaying patient data on a healthcare provider's account. This project is intentionally a door-opener to an open field of opportunity for mobile health, symptom observation, and improvements in healthcare delivery.
ContributorsDao, Lelan Diep (Author) / Cortese, Denis (Thesis director) / Lipinski, Christopher (Committee member) / Fitch, Tom (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor)
Created2015-05
Description
The field of art conservation has evolved parallel to scientific advancements and in response to changing social conditions. Methods have expanded from dusting the surface of a work to bombarding an image with x-rays in an effort to fulfill the ultimate goal of restoration: to return a piece of art to the state originally created by the artist. The process has become much easier and more complex with the introduction of analytical equipment that shifted the focus of the field away from maintenance towards academic study. This work illustrates the changes the field and demonstrates the application of scientific techniques to specific works.
ContributorsSanders, Hailey Jane (Author) / Fahlman, Besty (Thesis director) / Codell, Julie (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor)
Created2015-05