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Title: The cytologic responses of normal beagle dogs utilizing the skin window technic
Creator: Drees, David T.
Date: 1966
Collection: Electronic Theses & Dissertations

Title: Cytology and seed set studies in the pansy, Viola tricolor Hortensis L
Creator: Emino, Everett Raymond, 1942-
Date: 1967
Collection: Electronic Theses & Dissertations

Title: On the isolation of basal bodies from Tetrahymena pyriformis
Creator: Linney, Elwood A.
Date: 1967
Collection: Electronic Theses & Dissertations

Title: Rat colon epithelial cells : isolation, cultivation, and benzo(a)pyrene metabolism
Creator: Skrypec, Daniel J.
Date: 1981
Collection: Electronic Theses & Dissertations

Title: Biochemical analysis of transformation-sensitive alterations in the substratum associated material of chicken embryo fibroblasts
Creator: Blenis, John
Date: 1983
Collection: Electronic Theses & Dissertations

Title: The cyanelle and the cyanelle genome of Cyanophora paradoxa
Creator: Wasmann, Catherine Clair
Date: 1985
Collection: Electronic Theses & Dissertations

Title: Jasmonate regulation of defense responses in tomato (Lycopersicon esculentum)
Creator: Liu, Guanghui
Date: 2004
Collection: Electronic Theses & Dissertations

Title: Biochemical analysis of the chloroplast division proteins FtsZ1 and FtsZ2
Creator: Olson, Bradley Jesse Stanford Carnahan
Date: 2008
Collection: Electronic Theses & Dissertations

Title: Detecting intracellular metabolites and the resulting cell function by merging microfluidic and microtitre plate technologies
Creator: Tolan, Nicole Villiere
Date: 2009
Collection: Electronic Theses & Dissertations

Title: Biomolecular engineering of siRNA therapeutics
Creator: Gredell, Joseph A.
Date: 2009
Collection: Electronic Theses & Dissertations

Title: In vivo analysis of Arabidopsis FtsZ isoforms
Creator: Schmitz, Aaron James
Date: 2011
Collection: Electronic Theses & Dissertations
Description: Chloroplasts are organelles derived from the ancient endosymbiosis between a cyanobacterium and a primitive eukaryote. These organelles are essential for algae and plants for their many functions, including photosynthesis, biosynthesis of a wide array of essential molecules, and reduction of sulfur and nitrogen. Chloroplasts cannot form de novo and their numbers are maintained through the process of binary fission. This division process requires several genes originally encoding bacterial...
Show moreChloroplasts are organelles derived from the ancient endosymbiosis between a cyanobacterium and a primitive eukaryote. These organelles are essential for algae and plants for their many functions, including photosynthesis, biosynthesis of a wide array of essential molecules, and reduction of sulfur and nitrogen. Chloroplasts cannot form de novo and their numbers are maintained through the process of binary fission. This division process requires several genes originally encoding bacterial cell division factors. FtsZ is one of these genes. FtsZ is present in most bacteria and encodes a cytoskeletal protein that is structurally similar to tubulin. FtsZ polymerizes into a ring structure (Z-ring) at mid-cell prior to cell division in bacteria and also forms a Z-ring within the stroma of chloroplasts and other plastids types in plants. However, in the green lineage FtsZ has split into two phylogenetically-distinct families called FtsZ1 and FtsZ2. Both families have been shown to colocalize to the Z-ring and interact with themselves and each other. Chloroplast division, like cell division in bacteria, is sensitive to small decreases or increases in FtsZ protein levels, which result in division defects and fewer, enlarged chloroplasts. Therefore, distinguishing the relationship between the encoded FtsZ protein isoforms based upon ftsZ null or overexpression mutants is not feasible. The focus of this work was to resolve the functional relationship and distinguishing features of FtsZ isoforms in Arabidopsis - our chloroplast division model. Stable transformation of Arabidopsis ftsZ mutants followed by careful examination of complemented chloroplast division defects and FtsZ protein levels was the predominant approach for these studies.FtsZ2-1 complemented chloroplast division defects of plants lacking FtsZ2-2, and vice versa, near the previously quantified protein levels expected for complete FtsZ2 substitution. Therefore, I conclude that the two AtFtsZ2 isoforms are functionally redundant. Subsequently, I determined that FtsZ1 cannot substitute for FtsZ2 protein, and vice versa, since chloroplast division defects remained. In a related study, though both FtsZ1 and FtsZ2 are required for maintenance of chloroplast numbers, the generation of fully viable Arabidopsis plants lacking FtsZ, yet maintaining one chloroplast per cell, indicated that an FtsZ-independent mode of chloroplast partitioning exists in higher plants.FtsZ1 and FtsZ2 proteins diverge significantly at their C-termini where only the FtsZ2 family has a conserved motif found in bacteria. This motif is critical for the interaction with Z-ring promoting factors in bacteria and with ARC6 in plants. By swapping the C-termini and substituting the resulting chimeric FtsZ proteins in vivo, I demonstrate that neither C-terminus fully defines the unique functions of FtsZ1 or FtsZ2. Though I also show that the C-termini are required for the full function of each FtsZ family, these results indicate that other regions contribute significantly to FtsZ function. Related experiments also indicate that ARC3, a negative regulator of Z-ring formation, interacts with FtsZ2 in addition to FtsZ1. Together these results have clarified FtsZ functional relationships and laid significant groundwork for future analyses of FtsZ and their regulators.
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Title: Reprogramming to the nervous system : a computational and candidate gene approach
Creator: Alicea, Bradly John
Date: 2013
Collection: Electronic Theses & Dissertations
Description: The creation of stem-like cells, neuronal cells, and skeletal muscle fibers from a generic somatic precursor phenotype has many potential applications. These uses range from cell therapy to disease modeling. The enabling methodology for these applications is known as direct cellular reprogramming. While the biological underpinnings of cellular reprogramming go back to the work of Gurdon and other developmental biologists, the direct approach is a rather recent development. Therefore, our...
Show moreThe creation of stem-like cells, neuronal cells, and skeletal muscle fibers from a generic somatic precursor phenotype has many potential applications. These uses range from cell therapy to disease modeling. The enabling methodology for these applications is known as direct cellular reprogramming. While the biological underpinnings of cellular reprogramming go back to the work of Gurdon and other developmental biologists, the direct approach is a rather recent development. Therefore, our understanding of the reprogramming process is largely based on isolated findings and interesting results. A true synthesis, particularly from a systems perspective, is lacking. In this dissertation, I will attempt to build toward an intellectual synthesis of direct reprogramming by critically examining four types of phenotypic conversion that result in production of nervous system components: induced pluripotency (iPS), induced neuronal (iN), induced skeletal muscle (iSM), and induced cardiomyocyte (iCM). Since potential applications range from tools for basic science to disease modeling and bionic technologies, the need for a common context is essential.This intellectual synthesis will be defined through several research endeavors. The first investigation introduces a set of experiments in which multiple fibroblast cell lines are converted to two terminal phenotypes: iN and iSM. The efficiency and infectability of cells subjected to each reprogramming regimen are then compared both statistically and quantitatively. This set of experiments also resulted in the development of novel analytical methods for measuring reprogramming efficiency and infectability. The second investigation features a critical review and statistical analysis of iPS reprogramming, specifically when compared to indirect reprogramming (SCNT-ES) and related stem-like cells. The third investigation is a review and theoretical synthesis which stakes out new directions in our understanding of the direct reprogramming process, including recent computational modeling endeavors and results from the iPS, iN and induced cardiomyocyte (iCM) experiments. To further unify the outcomes of these studies, additional results related to Chapter 2 and directions for future research will be presented. The additional results will allow for further interpretation and insight into the role of diversity in direct reprogramming. These future directions include both experimental approaches (a technique called mechanism disruption) and computational approaches (preliminary results for an agent-based population-level approximation of direct reprogramming). The insights provided here will hopefully provide a framework for theoretical development and a guide for traditional biologists and systems biologists alike.
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Title: Peroxisome associated proteolytic processes in Arabidopsis
Creator: Kaur, Navneet
Date: 2013
Collection: Electronic Theses & Dissertations
Description: Peroxisomes are small single-membrane-bounded organelles that play key roles in development and metabolism in most eukaryotic organisms. Peroxisome functions encompass ß-oxidation of fatty acids, detoxification of hydrogen peroxide and the metabolism of a range of biochemical compounds including glyoxylate, glycolate, urate, polyamines, benzoate, phylloquinone, bile acids and plasmalogen to name a few, as well as synthesis of plant hormones such as jasmonic acid (JA) and indole-3-butyric acid...
Show morePeroxisomes are small single-membrane-bounded organelles that play key roles in development and metabolism in most eukaryotic organisms. Peroxisome functions encompass ß-oxidation of fatty acids, detoxification of hydrogen peroxide and the metabolism of a range of biochemical compounds including glyoxylate, glycolate, urate, polyamines, benzoate, phylloquinone, bile acids and plasmalogen to name a few, as well as synthesis of plant hormones such as jasmonic acid (JA) and indole-3-butyric acid (IBA). Peroxisomes exhibit great functional diversity largely because of a plastic proteome that varies greatly depending on the environmental condition, tissue type or developmental stage of the specific organism. Proteins in peroxisomes are imported by the actions of conserved machinery that includes several proteins known as peroxins that are important for peroxisome biogenesis. Proteins destined for the peroxisome matrix contain peroxisome targeting signal (PTS) enabling their recognition by cytosolic receptor proteins that transport them to the peroxisome. Although we have an increased understanding of how peroxisomal protein import is accomplished, we know little about how proteins in peroxisomes are degraded. In this research, I provide evidence that RING domains of three peroxisomal membrane proteins AtPEX2, AtPEX10 and AtPEX12 have E3 ligase activity. I further show that AtPEX2 specifically interacts with two homologous ubiquitin receptor proteins, DSK2a and DS2Kb that have been implicated as adapters linking ubiquitination and 26S proteasome-based degradation events. DSK2 amiRNA lines lacked obvious plant growth phenotypes and were not compromised in peroxisome functions, suggesting that functional redundancies exist among ubiquitin receptor proteins. My results indicate that Arabidopsis RING peroxins and DSK2s can together form a peroxisome membrane associated degradation system. I also explored the role of a predicted ovarian tumor-like cysteine protease (OCP1) in Arabidopsis. OCP1 was found to be a novel plant specific peroxisomal protein with a canonical C-terminal PTS1 and a novel N-terminal PTS2. Analysis of mutant lines revealed that OCP1 influences IBA metabolism in the peroxisome. Further, ocp1 mutants show retarded degradation of two transiently expressed seedling peroxisome enzymes, isocitrate lyase (ICL) and malate synthase (MS) suggesting that OCP1 has a role in the timely removal of ICL from seedling peroxisomes. In summary, these studies add significantly to our knowledge of proteolysis in plant peroxisomes and open up several avenues for future investigations that may have ramifications in agriculture and biomedical applications.
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Title: From skin to neurons : examining variations in reprogramming efficiency
Creator: Keaton, Sarah A.
Date: 2013
Collection: Electronic Theses & Dissertations
Description: Cellular reprogramming is a newly emerging field with promising clinical applications. The ability to generate non-dividing crucial cell types from rapidly proliferating cell types, the potential to heal diseased people who do not have many treatment options, being able to bypass immune rejection, and avoid invasive surgery has captured the media's attention. However, there have been disparities in the efficiency of reprogramming and these needs to be addressed before cellular reprogramming...
Show moreCellular reprogramming is a newly emerging field with promising clinical applications. The ability to generate non-dividing crucial cell types from rapidly proliferating cell types, the potential to heal diseased people who do not have many treatment options, being able to bypass immune rejection, and avoid invasive surgery has captured the media's attention. However, there have been disparities in the efficiency of reprogramming and these needs to be addressed before cellular reprogramming can be applicable in a clinical setting. To better understand the variations of cellular reprogramming, human and mouse fibroblasts were converted into induced neural cells in an attempt to unveil the impact of disease state, tissue origin and genetics. The experimental results indicate reprogramming efficiency was reproducible within a primary fibroblast line however there was a dramatic difference between lines even from an isogenic source. Testing a larger number of fibroblast lines, even lines with the identical genetic backgrounds and tissue origins, is likely the most direct means of improving reprogramming efficiency and enabling this procedure to be available for therapeutic use.
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Title: Dietary manipulation of natural killer cell biology through refeeding of previously calorically restricted mice
Creator: Clinthorne, Jonathan F.
Date: 2013
Collection: Electronic Theses & Dissertations
Description: The dynamic role of natural killer (NK) cells in immunology has been demonstrated in numerous fashions, proving they are much more than "natural killers". However, NK cells are perhaps still the least well understood lymphocyte, due to their relatively low abundance and the limited transgenic models available for study. An innate immune cell that plays a critical role in providing early immunity against viral infections and cancers, NK cells are becoming increasingly recognized for shaping...
Show moreThe dynamic role of natural killer (NK) cells in immunology has been demonstrated in numerous fashions, proving they are much more than "natural killers". However, NK cells are perhaps still the least well understood lymphocyte, due to their relatively low abundance and the limited transgenic models available for study. An innate immune cell that plays a critical role in providing early immunity against viral infections and cancers, NK cells are becoming increasingly recognized for shaping and directing immune responses. Accounting for approximately 5-25% of peripheral blood mononuclear cells in humans and 5-10% of lymphocytes in murine circulation, NK cells have very similar functional attributes in both species, making mice an ideal model system for the study of NK cell biology. Studies in mice have revealed the critical importance of NK cells in providing tumor surveillance as well as early protection from viral infections. Preclinical studies have underscored the utility of using NK cells as an immunotherapeutic technique to combat various cancers, while NK cell function is often associated with positive or negative outcomes in various disease states. Furthermore, various lifestyle factors have been found to positively or negatively influence NK cell function. Among these lifestyle factors, diet has gained notoriety as being capable of influencing the homeostasis and function of NK cells. However, the mechanisms by which diet influences NK cells are not fully understood, highlighting the need for a better understanding of the molecular and cellular mechanisms by which diet influences NK cell development. Thus, our laboratory has extensively studied the effects of the restriction of energy intake, or caloric restriction (CR) on NK cell function and biology at the organismal, cellular, and molecular level. Here we describe a series of experiments investigating the role of energy intake on immunity to influenza virus, with a focus on NK cells. We describe a series of studies that identify the specific changes to NK cells induced by CR, both beneficial and potentially damaging. In these experiments we show that CR results in fewer NK cells with a mature phenotype, and that expression of transcription factors critical for NK cell maturation are reduced by CR. We also demonstrate that thymic derived NK cells are present in normal numbers in CR mice and have enhanced function. In a series of experiments demonstrating the intricate relationship between immunity and metabolism we show how refeeding of CR mice restores NK cell homeostasis and function, both before, and during influenza infection. Using in vitro techniques combined with ex vivo analysis of metabolic signaling pathways, we provide potential mechanisms by which CR impairs NK cell maturation. These studies serve to highlight the critical role of optimal nutrition in maintaining NK cell homeostasis and function. To our knowledge, this dissertation is the first data presented that clearly details the effects of CR on NK cell development and homeostasis, as well as the molecular and biochemical pathways mediating this effect.
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Title: Engineering of the small cytosolic retinoid binding proteins into pH-sensing probes and novel fluorescent protein tags
Creator: Berbasova, Tetyana
Date: 2014
Collection: Electronic Theses & Dissertations
Description: Reprogramming the biological systems to perform a process other than that dictated by nature illustrates the power of the modern synthetic biology. Protein engineering represents one of the research areas in this field. Crystal structure guided mutagenesis studies allow for a rational protein redesign. Utilizing this de novo approach, Cellular Retinoic Acid Binding Protein II (CRABPII) has been reengineered into a Schiff base forming protein. The reaction is performed deep inside the protein...
Show moreReprogramming the biological systems to perform a process other than that dictated by nature illustrates the power of the modern synthetic biology. Protein engineering represents one of the research areas in this field. Crystal structure guided mutagenesis studies allow for a rational protein redesign. Utilizing this de novo approach, Cellular Retinoic Acid Binding Protein II (CRABPII) has been reengineered into a Schiff base forming protein. The reaction is performed deep inside the protein cavity and fascilitates a complete ligand closure from the aqueous media.An initial aim of this project was to design a functioning rhodopsin mimic from CRABPII for the wavelength regulation studies. The strategy combined the principles we learned in the earlier work on CRABPII and human Cellular Retinol Binding Protein II (hCRBPII). The rational modifications of the CRABPII binding cavity provides the effective charge delocalization along the protein-embedded all- trans-retinal-PSB that leads to the regulation of absorption. Reengineered CRABPII is capable of spanning the visible spectrum in the range of 474 - 640 nm. Additionally, CRABPII mutants exhibit an extraordinary range of the iminiumpKa values, ranging from 1.8 to 8.1. The latter phenomena allowed for thechromophoric pH-probe design utilizing the protein-bound chromophoric aldehyde, an isoform of Vitamin A. Moreover, the fusion of the two selected pigments provides a ratiometric protein based pH-sensor.The aldehydes other than retinal might yield alternative pH-sensing ligands with the engineered CRABPII and hCRBPII mutants. With fluorescence being the most widely used detection method in biology, fluorescent and fluorogenic retinal analogs are the primary targets in the ligand redesign. Synthetic julolidine retinal analog meets most of the criteria for an effective fluorogenic probe with pH- sensing properties upon PSB formation. In the protein-bound form this chromophore accounts for the imine-iminium equilibrium with changes in fluorescence intensity. Only iminium yields a light emitting pigment. Moreover, the wavelength shift in response to the pH changes provided the platform for a single protein ratiometric pH-probe design. This pH-dependent shift of absorption is a result of the more effective charge delocalization along the chromophore after protonation of the anionic carboxylate residue in the iminium region.Merocyanine retinal analog shows bright fluorescence and penetrates cells easily. These are valuable criteria for live-cell imaging applications. Optimization of the reaction half-life between hCRBPII mutants and merocyanine retinal analog provided an hCRBPII-tag with instantaneous red fluorescence. Designed method comprises a unique fluorescence recovery after the photobleaching when the cells are treated again with merocyanine.
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Title: The roles of C/EBPbeta and c-Jun in transcription of the gene encoding the murine progesterone receptor
Creator: Do, Han Ngoc
Date: 2014
Collection: Electronic Theses & Dissertations
Description: Progesterone (P) and its receptor, the progesterone receptor (PR), are important for mammary gland development. Moreover, P/PR signaling also contributes to mammary tumorigenesis. Thus, studying the mechanism of PR expression is important in breast cancer research. C/EBPB-deficient mice and mice blocked for AP-1 activity show similar defects in mammary gland development as do PRB-deficient mice, especially during pregnancy, suggesting that these transcription factors might act in the same...
Show moreProgesterone (P) and its receptor, the progesterone receptor (PR), are important for mammary gland development. Moreover, P/PR signaling also contributes to mammary tumorigenesis. Thus, studying the mechanism of PR expression is important in breast cancer research. C/EBPB-deficient mice and mice blocked for AP-1 activity show similar defects in mammary gland development as do PRB-deficient mice, especially during pregnancy, suggesting that these transcription factors might act in the same pathway or may regulate overlapping sets of downstream target genes. An overall decrease in PR observed in sexually mature wild type mice fails to occur in C/EBPB-deficient mice, while no alterations in C/EBPB expression are observed in PR-deficient mice. Moreover, AP-1 has been found to regulate PR expression. These observations suggest that C/EBPB and AP-1 act upstream of PR. This leads us to study the possibility that C/EBPB and AP-1 are required for PR expression.We examined whether C/EBPB participated in the transcriptional regulation of PR expression in the mammary gland. Transient co-transfection of a PR promoter-reporter construct with expression vectors that individually express C/EBPB isoforms (LAP1, LAP2, or LIP) into a mouse mammary carcinoma cell line revealed that all C/EBPB isoforms, surprisingly including LIP (the shortest isoform lacking transactivation domains), can transactivate the PR promoter. Importantly, we found that LIP, in particular, robustly synergizes with an AP-1 member, c-Jun, to drive PR transcription. Consistent with significant roles for C/EBPB and c-Jun in PR expression, knockdown experiments showed that endogenous levels of C/EBPB and c-Jun expression were sufficient to drive the PR promoter-reporter. Additionally, overexpression of LIP elevated PR protein expression from the intact endogenous gene encoding PR. Furthermore, in vivo immunofluorescence studies showed that C/EBPB and PRA expression are mutually exclusive in the mammary epithelium, while PRB is only expressed in cells that express C/EBPB. This suggests an important role for C/EBPB in PRB expression during pregnancy. Then, we studied the mechanism by which LIP and c-Jun synergistically activate the PR promoter. We demonstrated in the reporter assay that the integrity of C/EBP- and AP-1-binding sites was required for the respective C/EBPB; and c-Jun activities on the PR promoter. Moreover, we showed in ChIP assay that efficient promoter occupancy of both LIP and c-Jun and their synergistic transactivation of the PR promoter required at least one C/EBP- and one AP-1-binding site. In addition, as indicating in the sequential ChIP assay, C/EBPB and c-Jun simultaneously occupied PR promoter. This leads us to propose a model where the synergy of C/EBPB and c-Jun in transactivation of the PR promoter is dependent on the two factors mutually stabilizing their recruitment to the PR promoter. Collectively, our data suggest a critical role for C/EBPB, particularly LIP, in PRB expression.
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Title: Impact of ploidy on morphological variation in Arizona phlox, Phlox amabilis (Polemoniaceae)
Creator: Chansler, Matthew Thomas
Date: 2015
Collection: Electronic Theses & Dissertations
Description: Polyploidy is an important factor in the evolution and ecology of flowering plants. A better understanding of the kind and degree of morphological differentiation among ploidy levels within a species can help explain further how polyploidy affects biodiversity. How widespread is the impact of ploidy across the phenotype of a species? Which aspects of morphology vary, and do they vary consistently? How does ploidy relate to overall morphological diversity? Do ploidy levels have detectable...
Show morePolyploidy is an important factor in the evolution and ecology of flowering plants. A better understanding of the kind and degree of morphological differentiation among ploidy levels within a species can help explain further how polyploidy affects biodiversity. How widespread is the impact of ploidy across the phenotype of a species? Which aspects of morphology vary, and do they vary consistently? How does ploidy relate to overall morphological diversity? Do ploidy levels have detectable phenotypic profiles? Finally, are there morphological differences between populations, potentially due to environment or evolutionary changes since formation apparent in natural populations? I assessed morphological variation within Arizona phlox, Phlox amabilis. This species of conservation concern is endemic to Arizona, and prior work has detected diploid, tetraploid, and hexaploid populations. I sampled 11 populations of P. amabilis, covering a large portion of the species’ range. A wide array of morphological features, including characters that described cell size, overall habit, leaf dimensions, and floral dimensions, were measured for up to 25 plants at each population. Significant differences were detected in 15 out of 27 characters using mixed GLM. A large amount of overall morphological variation is explained by the differences between ploidy levels, and each ploidy level can be described by a specific multivariate phenotype with 95% accuracy. Finally, although overall structuring was influenced by ploidy, differences among populations still contributed a high degree of variation in the morphospace of Phlox amabilis. This morphological assessment will be integrated with ecological and genetic data to build a more complete understanding of the interplay between these factors and ploidy in Phlox amabilis.
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Title: Therapeutically targeting autophagy in non-small cell lung cancer
Creator: Yco, Lisette Pangilinan
Date: 2019
Collection: Electronic Theses & Dissertations
Description: Autophagy is a conserved catabolic pathway which sequesters intracellular components in lysosomes to recycle macromolecules for cell maintenance. The role of autophagy in tumor cells is dynamic and depends on many factors including tumor types, tumor stages, and activity of several tumor suppressors and oncogenes. In this thesis, I wanted to improve our understanding of the unique relationship of autophagy with tumor suppressor p53 and oncogenic KRAS in cancer cells, particularly in NSCLC....
Show moreAutophagy is a conserved catabolic pathway which sequesters intracellular components in lysosomes to recycle macromolecules for cell maintenance. The role of autophagy in tumor cells is dynamic and depends on many factors including tumor types, tumor stages, and activity of several tumor suppressors and oncogenes. In this thesis, I wanted to improve our understanding of the unique relationship of autophagy with tumor suppressor p53 and oncogenic KRAS in cancer cells, particularly in NSCLC. First, I demonstrated that stabilized nuclear wild-type p53 through HDM2 inhibition with MK-8242 or nutlin-3a could induce autophagy in tumor cells through transactivation of several autophagy-related genes (DRAM, FOXO3A, SESN2, and MRCKα) and autophagy core genes (ATG4A and ULK1). In addition, I found that inhibiting of KRAS G12C signaling and suppressing mTORC1 activity by selective KRAS G12C inhibitor, ARS-853, could drive autophagy response in KRAS G12C NSCLC cell lines. Since autophagy could also promote survival under stress induced by several anticancer agents, I designed a combination study using newly reported selective ULK1 inhibitor, ULK-101, with ARS-853 in KRAS mutant NSCLC. Autophagy inhibition with ULK-101 dramatically enhanced the ability of selective KRAS G12C inhibitor to impair the viability of KRAS G12C NSCLC. Together, my study provided evidence that autophagy serves as a survival pathway in tumor cells and that future assessment of small molecule that target autophagy core proteins may be potential cancer therapeutic option in p53 wild-type and KRAS G12C NSCLC.
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Title: SULFATED AND SIALYLATED N-ACETYL-LACTOSAMINE AS BIOMARKER OF SUBPOPULATIONS OF PANCREATIC DUCTAL ADENOCARCINOMAS
Creator: Hsueh, Peter Yiping
Date: 2019
Collection: Electronic Theses & Dissertations
Description: The sialyl Lewis A (sLeA) glycan forms the basis of the CA19-9 blood test and is the current biomarker for pancreatic ductal adenocarcinoma (PDAC). However, it is not elevated in approximately 25% of PDAC patients and it also has difficulties in diagnosing early-stage PDAC. My overarching goal was focusing on improving precision of overall PDAC diagnostics. I hypothesized that other glycans within the Lewis blood group family besides sLeA are aberrantly increased in the subpopulation of PDAC...
Show moreThe sialyl Lewis A (sLeA) glycan forms the basis of the CA19-9 blood test and is the current biomarker for pancreatic ductal adenocarcinoma (PDAC). However, it is not elevated in approximately 25% of PDAC patients and it also has difficulties in diagnosing early-stage PDAC. My overarching goal was focusing on improving precision of overall PDAC diagnostics. I hypothesized that other glycans within the Lewis blood group family besides sLeA are aberrantly increased in the subpopulation of PDAC patients who do not secret sLeA into their blood. To test the hypothesis, two specific approaches were implemented in this study: 1) Profile an isomer of sLeA, named sialyl-Lewis X (sLeX), and glycans with fucosylated motifs in the plasma of sLeA-low PDAC patients using antibody and lectin microarray method; and 2) Test the sulfated and sialylated glycans derived from type 2 N-acetyl-lactosamine precursor in subpopulations of PDACs using a novel on-chip analysis method.In the first approach, I profiled the levels of multiple glycans and glycosylated mucins in plasma from two cohorts of 200 and 116 test subjects with PDACs and non-malignant disease patients. From these screens, I found significant increases in two categories of glycans: sialyl Lewis X variants, presented both in sulfated and non-sulfated forms, and the sialylated type 1 N-acetyl-lactosamine. These glycans are increased in distinct groups of PDAC patients and contribute to the improved accuracy of a biomarker panel.Thus, I concluded that detecting other glycans within the Lewis blood-group besides sLeA has the potential to improve diagnoses of PDAC patients.To further elucidate the structural nuances of sialyl Lewis X variants from initial screen, I developed a new assay called On-chip Glycan Modification and Probing and a complementary computational algorithm to accurately analyze novel sulfated and sialylated glycans from plasma of pancreatic cancer patients. In detailed structural information, I observed strong evidences of sulfated and sialylated type 2 N-acetyl-lactosamine glycans overexpressed in plasma of PDAC patients and pancreatic cancer cell lines, but not in the plasma of healthy people. In addition, the sulfated and sialylated type 2 N-acetyl-lactosamine glycans presented on a specific mucin, MUC5AC, was statistically associated (p < 0.001) with short time-to-progression of PDAC patients, but CA19-9 test was not. I concluded sulfated and sialylated type 2 N-acetyl-lactosamine glycans presented on MUC5AC were new serological biomarkers that could improve precision of current practices for diagnosis and prognosis of PDACs patients.
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