Matching Items (95)
Description
The majority of chronic myeloid leukemia (CML) and some of acute lymphocytic leukemia (ALL) cases are associated with possessing the BCR-Abl fusion protein from an oncogenic translocation, resulting in a constantly active form of Abl and rapid proliferation. CML and ALL cells that possess the BCR-Abl fusion protein are known as Philadelphia chromosome positive (Ph+). Currently, Imatinib (selective Abl inhibitor) is used as therapy against CML and ALL. However, some patients may have malignancies which show resistance to Imatinib. Previous work displays that the transformation of progenitor B cells with the v-Abl oncogene of Abelson murine leukemia virus results in cell cycle progression, rapid proliferation, and potentially malignant transformation while preventing any further differentiation. Progenitor B cells transformed with the temperature-sensitive form of the v-Abl oncogene have served as a model to study cellular response to Imatinib treatment. After some manipulation, very few cells were forced to progress to malignancy, forming tumor in vivo. These cells were no long sensitive to v-Abl inactivation, resembling the Imatinib resistant ALL. Autophagy is the process by which proteins and organelles are broken-down and recycled within the eukaryotic cell and has been hypothesized to play a part in cancer cell survival and drug-resistance. LC3 processing is a widely accepted marker of autophagy induction and progression. It has also been shown that Imatinib treatment of Ph+ leukemia can induce autophagy. In this study, we examined the autophagy induction in response to v-Abl inactivation in a Ph+-B-ALL cell model that shows resistance to Imatinib. In particular, we wonder whether the tumor cell line resistant to v-Abl inactivation may acquire a high level of autophagy to become resistant to apoptosis induced by v-Abl inactivation, and thus become addicted to autophagy. Indeed, this tumor cell line displays a high basal levels of LC3 I and II expression, regardless of v-Abl activity. We further demonstrated that inhibition of the autophagy pathway enhances the tumor line's sensitivity to Imatinib, resulting in cell cycle arrest and massive apoptosis. The combination of autophagy and Abl inhibitions may serve as an effective therapy for BCR-Abl positive CML.
ContributorsArkus, Nohea (Author) / Chang, Yung (Thesis advisor) / Kusumi, Kenro (Committee member) / Lake, Douglas (Committee member) / Jacobs, Bertram (Committee member) / Arizona State University (Publisher)
Created2011
Description
Cancer is one of the most serious global diseases. We have focused on cancer immunoprevention. My thesis projects include developing a prophylactic primary and metastatic cancer vaccines, early cancer detection and investigation of genes involved in tumor development. These studies were focused on frame-shift (FS) antigens. The FS antigens are generated by genomic mutations or abnormal RNA processing, which cause a portion of a normal protein to be translated out of frame. The concept of the prophylactic cancer vaccine is to develop a general cancer vaccine that could prevent healthy people from developing different types of cancer. We have discovered a set of cancer specific FS antigens. One of the FS candidates, structural maintenance of chromosomes protein 1A (SMC1A) FS, could start to accumulate at early stages of tumor and be specifically exposed to the immune system by tumor cells. Prophylactic immunization with SMC1A-FS could significantly inhibit primary tumor development in different murine tumor models and also has the potential to inhibit tumor metastasis. The SMC1A-FS transcript was detected in the plasma of the 4T1/BALB/c mouse tumor model. The tumor size was correlated with the transcript ratio of the SMC1A-FS verses the WT in plasma, which could be measured by regular RT-PCR. This unique cancer biomarker has a practical potential for a large population cancer screen, as well as clinical tumor monitoring. With a set of mimotope peptides, antibodies against SMC1A-FS peptide were detected in different cancer patients, including breast cancer, pancreas cancer and lung cancer with a 53.8%, 56.5% and 12.5% positive rate respectively. This suggested that the FS antibody could be a biomarker for early cancer detection. The characterization of SMC1A suggested that: First, the deficiency of the SMC1A is common in different tumors and able to promote tumor initiation and development; second, the FS truncated protein may have nucleolus function in normal cells. Mis-control of this protein may promote tumor development. In summary, we developed a systematic general cancer prevention strategy through the variety immunological and molecular methods. The results gathered suggest the SMC1A-FS may be useful for the detection and prevention of cancer.
ContributorsShen, Luhui (Author) / Johnston, Stephen Albert (Thesis advisor) / Chang, Yung (Committee member) / Miller, Laurence (Committee member) / Sykes, Kathryn (Committee member) / Jacobs, Bertram (Committee member) / Arizona State University (Publisher)
Created2012
Description
Over the past decade, several high-value proteins have been produced using plant-based transient expression systems. However, these studies exposed some limitations that must be overcome to allow plant expression systems to reach their full potential. These limitations are the low level of recombinant protein accumulation achieved in some cases, and lack of efficient co-expression vectors for the production of multi-protein complexes. This study report that tobacco Extensin (Ext) gene 3' untranslated region (UTR) can be broadly used to enhance recombinant protein expression in plants. Extensin is the hydroxyproline-rich glycoprotein that constitutes the major protein component of cell walls. Using transient expression, it was found that the Ext 3' UTR increases recombinant protein expression up to 13.5- and 6-fold in non-replicating and replicating vector systems, respectively, compared to previously established terminators. Enhanced protein accumulation was correlated with increased mRNA levels associated with reduction in read-through transcription. Regions of Ext 3' UTR essential for maximum gene expression included a poly-purine sequence used as a major poly-adenylation site. Furthermore, modified bean yellow dwarf virus (BeYDV)-based vectors designed to allow co-expression of multiple recombinant genes were constructed and tested for their performance in driving transient expression in plants. Robust co-expression and assembly of heavy and light chains of the anti-Ebola virus monoclonal antibody 6D8, as well as E. coli heat-labile toxin (LT) were achieved with the modified vectors. The simultaneous co-expression of three fluoroproteins using the single replicon, triple cassette is demonstrated by confocal microscopy. In conclusion, this study provides an excellent tool for rapid, cost-effective, large-scale manufacturing of recombinant proteins for use in medicine and industry.
ContributorsRosenthal, Sun Hee (Author) / Mason, Hugh (Thesis advisor) / Mor, Tsafrir (Committee member) / Chang, Yung (Committee member) / Arntzen, Charles (Committee member) / Arizona State University (Publisher)
Created2012
Description
Recombinant protein expression is essential to biotechnology and molecular medicine, but facile methods for obtaining significant quantities of folded and functional protein in mammalian cell culture have been lacking. Here I describe a novel 37-nucleotide in vitro selected sequence that promotes unusually high transgene expression in a vaccinia driven cytoplasmic expression system. Vectors carrying this sequence in a monocistronic reporter plasmid produce >1,000-fold more protein than equivalent vectors with conventional vaccinia promoters. Initial mechanistic studies indicate that high protein expression results from dual activity that impacts both transcription and translation. I suggest that this motif represents a powerful new tool in vaccinia-based protein expression and vaccine development technology.
ContributorsFlores, Julia Anne (Author) / Chaput, John C (Thesis advisor) / Jacobs, Bertram (Committee member) / LaBaer, Joshua (Committee member) / Arizona State University (Publisher)
Created2012
Description
Human Immunodeficiency Virus type 1 (HIV-1) causes millions of deaths every year, but a protective vaccine remains elusive. A promising vaccine strategy is to use virus-like particles (VLPs) for HIV-1. To this end, HIV-1 VLPs were produced in Nicotiana benthamiana plants that were stably expressing the HIV-1 Gag protein and transiently expressing a truncated form of gp41. These VLPs were tested to determine their inherent adjuvant effects due to their production in plants in order to dissect the previously observed stimulating activity of these VLPs in a prime-boost vaccine approach. THP1 human monocytes were differentiated using PMA or IL-4 and GM-CSF to form macrophages and dendritic cells, respectively. These cells were treated with purified VLPs or control samples to determine the individual adjuvant effects of the plant, bacterial, and VLP components in the purified VLP samples. It was postulated that the PMA-differentiated THP1 cells were not induced to become macrophages due to the lack of CD11b+ cells in the sample and the lack of increased TNFα expression in response to LPS treatment. It was also determined that the VLPs have inherent adjuvant properties to dendritic cells due to bacterial and VLP components, but not due to plant components.
ContributorsDickey, Rebekah Marie (Author) / Mor, Tsafrir (Thesis director) / Blattman, Joseph (Committee member) / Meador, Lydia (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
The Intercellular Adhesion Molecule-1 (ICAM-1, known as CD54) is a cell surface type I transmembrane glycoprotein with a molecular weight of 85 to 110 kDa. The primary function of ICAM-1 is to provide adhesion between endothelial cells and leukocytes after injury or stress. ICAM-1 is used as a receptor for various pathogens such as rhinoviruses, coxsackievirus A21 and the malaria parasite Plasmodium falciparum. ICAM-1 contains five immunoglobulin (Ig) domains in its long N-terminal extracellular region, a hydrophobic transmembrane domain, and a small C-terminal cytoplasmic domain. The Ig domains 1-2 and Ig domains 3-4-5 have been crystallized separately and their structure solved, however the full ICAM-1 structure has not been solved. Because ICAM-1 appears to be important for the mediation of cell-to-cell communication in physiological and pathological conditions, gaining a structural understanding of the full-length membrane anchored ICAM-1 is desirable. In this context, we have transiently expressed a plant-optimized gene encoding human ICAM-1 in Nicotiana benthamiana plants using the MagnICON expression system. The plant produced ICAM-1 is forming aggregates according to previous data. Thus, the current extraction and purification protocols have been altered to include TCEP, a reducing agent. The protein was purified using TALON metal affinity resin and partially characterized using various biochemical techniques. Our results show that there is a reduction in aggregation formation with the use of TCEP.
ContributorsPatel, Heeral (Author) / Mor, Tsafrir (Thesis director) / Mason, Hugh (Committee member) / Kannan, Latha (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
Variants of human butyrylcholinesterase (BChE) have been designed to have high cocaine hydrolytic activity. These variants have potential pharmacological applications toward treating cocaine overdose and addiction. These enzymes must be stable in the human body over fairly long periods of time in order to be effective at treating cocaine addiction. Recombinantly expressed BChE, however, tends to be in monomer or dimer oligomeric forms, which are far less stable than the tetramer form of the enzyme. When BChE is transiently expressed in Nicotiana benthamiana, it is produced mainly as monomers and dimers. However, when the protein is expressed through stable transformation, it produces much greater proportions of tetramers. Tetramerization of WT human plasma derived BChE is facilitated by the binding of a proline rich peptide. In this thesis, I investigated if a putative plant-derived analog of the mammalian proline-rich attachment domain caused stably expressed cocaine hydrolase variants of human BChE to undergo tetramerization. I also examined if co-expression of peptides with known proline-rich attachment domains further shifted the monomer-tetramer ratio toward the tetramer.
ContributorsKendle, Robert Player (Author) / Mor, Tsafrir (Thesis director) / Mason, Hugh (Committee member) / Larrimore, Kathy (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
Vaccinia virus (VV) is a prototype virus of the Orthopox viruses. The large dsDNA virus composed of 200kbp genome contains approximately 200 genes and replicates entirely in the cytosol. Since its use as a live vaccine against smallpox that leads to the successful eradication of smallpox, Vaccinia has been intensely studied as a vaccine vector since the large genome allows for the insertion of multiple genes. It is also studied as a molecular tool for gene therapy and gene functional study. Despite its success as a live vaccine, the vaccination causes some mild to serious bur rare adverse events in vaccinees such as generalized Vaccinia and encepharitis. Therefore, identification of virulence genes and removal of these genes to create a safer vaccine remain an important tasks. In this study, the author seeks to elucidate the possible relationship between immune evading proteins E3 and B19. VV did not allow double deletions of E3 and B19, indicating the existence of a relationship between the two genes.
ContributorsBarclay, Shizuka (Author) / Jacobs, Bertram (Thesis director) / Ugarova, Tatiana (Committee member) / Kibler, Karen (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
In the United States, a dispute has arisen over the safety and need for vaccination, particularly in regard to compulsory vaccination laws. New outlets and social media sites publish countless reports about the dangers of vaccines or of known adverse reactions as well as imagined or unproven worries. Individuals' rights to choose to get vaccinated or allow their children to be vaccinated comes to direct conflict with measures needed to protect communities from preventable viral diseases. The controversy surrounding vaccines is not new, nor necessarily are the fundamental reasons for skepticism. Looking back through the history of vaccines as a medical tool, the evolution of the controversy can be observed taking place with each new historical context, scientific development, and social conditions. Despite scientific research and assurances of vaccine safety, opposition and unease about vaccination appear to take Looking individually at the development and distribution of the smallpox (variola virus), polio (poliovirus) and human papilloma virus(HPV) vaccines, concerns regarding the violation of personal rights, safety of vaccines themselves, and social stigmas and connotations surrounding vaccines can be seen to evolve and change. Due to the way doubt can manifest in different ways over time, it may be impossible to fully end the vaccine debate. However, nderstanding the sociological factors behind anti-vaccine sentiment may allow healthcare professionals to work with concerned people with a particular care to address these visceral and sometimes irrational fears surrounding vaccination.
ContributorsStevens, Luke Christian (Author) / Jacobs, Bertram (Thesis director) / Washo-Krupps, Delon (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor) / School of Life Sciences (Contributor)
Created2014-05
Description
Utilizing a compilation of existing literature, theory and current praxis, a clear case for instituting a needle exchange in Maricopa County is visible.. Research on HIV rates are consulted to establish a foundation for understanding the value of needle exchange programs nationally and in Maricopa County. Case studies on existing needle exchange efficacy are also used to support the proposal and outline the success of needle exchanges in reducing rates of infection.
ContributorsGuntermann, Christel Young Shin (Author) / Jacobs, Bertram (Thesis director) / Jackson, Danielle (Committee member) / Taylor, Emily (Committee member) / Barrett, The Honors College (Contributor) / T. Denny Sanford School of Social and Family Dynamics (Contributor) / School of Community Resources and Development (Contributor)
Created2013-05