Matching Items (100)
Description
The long-term survival of patients with glioblastoma multiforme is compromised by the tumor's proclivity for local invasion into the surrounding normal brain. These invasive cells escape surgery and display resistance to chemotherapeutic- and radiation-induced apoptosis. We have previously shown that tumor necrosis factor-like weak inducer of apoptosis (TWEAK), a member of the tumor necrosis factor superfamily, can stimulate glioma cell invasion and survival via binding to the fibroblast growth factor-inducible 14 (Fn14) receptor and subsequent activation of the Rac1/NF-kappaB pathway. In addition, we have reported previously that Fn14 is expressed at high levels in migrating glioma cells in vitro and invading glioma cells in vivo. Here we demonstrate that TWEAK can act as a chemotactic factor for glioma cells, a potential process to drive cell invasion into the surrounding brain tissue. Specifically, we detected a chemotactic migration of glioma cells to the concentration gradient of TWEAK. Since Src family kinases (SFK) have been implicated in chemotaxis, we next determined whether TWEAK:Fn14 engagement activated these cytoplasmic tyrosine kinases. Our data shows that TWEAK stimulation of glioma cells results in a rapid phosphorylation of the SFK member Lyn as determined by multiplex Luminex assay and verified by immunoprecipitation. Immunodepletion of Lyn by siRNA oligonucleotides suppressed the chemoattractive effect of TWEAK on glioma cells. We hypothesize that TWEAK secretion by cells present in the glioma microenvironment induce invasion of glioma cells into the brain parenchyma. Understanding the function and signaling of the TWEAK-Fn14 ligand-receptor system may lead to development of novel therapies to therapeutically target invasive glioma cells.
ContributorsJameson, Nathan Meade (Author) / Anderson, Karen (Thesis director) / Lake, Douglas (Committee member) / Tran, Nhan (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2013-05
Description
Sports related concussions, or mild traumatic brain injuries (mTBI), have recently increased in prevalence, and thus gained a great deal of recognition from the public and the media. While the acute symptoms associated with concussions are well known, which include headaches, dizziness, vomiting, and fatigue, recent research has indicated that there can be severe chronic consequences of multiple conditions. Most notably, a disease called Chronic Traumatic Encephalopathy (CTE) has been linked to multiple mTBIs, which produces symptoms similar to Alzheimer's disease and dementia, in addition to personality changes, increased suicidality, and in some cases death. This knowledge has led the NFL to take steps to protect their players, and increase both the understanding and awareness of the problems associated with multiple concussions. This comes with many problems, however, as players and fans alike are quick to resist any type of change to the rules or policies present in football, in fear that it may damage the integrity of the game. The NFL is thus forced into a difficult position, and must balance public opinion and player safety. There are things that can be done, however, that do not threaten the game itself, such as investing in concussion research and safety equipment design that will more effectively protect the brain from concussions.
ContributorsAiello, Mimi Elizabeth (Author) / Olive, M. Foster (Thesis director) / Bimonte-Nelson, Heather (Committee member) / Camp, Bryan (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor)
Created2013-05
Description
Oropharyngeal cancer (OPC) is the world's sixth most common cancer and in many cases is associated with infection with human papillomavirus (HPV) type 16. Antibodies (Abs) to HPV16 viral antigens are potential diagnostic biomarkers of HPV-associated OPC (HPV OPC). A custom multiplexed bead array assay was used to detect Abs to HPV16 antigens E1, CE2, NE2, E4, E5, E6, E7, L1, and L2. Following extensive optimization of the assay, these genes were expressed as GST-fusion proteins and captured onto anti-GST magnetic beads. Serum was obtained from 256 OPC patients at the time of diagnosis and from 78 healthy controls. The median fluorescent intensity (MFI) was determined for each antigen and ratios of MFI to control GST-fusion protein were determined for each serum sample. Cutoff values were set as the mean + 3 SD of the MFIs of healthy controls and p-values were calculated using Wilcoxon unpaired and Fisher's exact test. Results of this experiment showed that HPV16 E1, CE2, NE2, E4, E6, and E7 Ab levels were elevated in OPC patients compared to controls (p<0.001), as were Ab levels to L1 (p = 0.013) and L2 (p = 0.023), per Fischer's exact test. Abs to CE2, NE2, E6, and E7 were identified as a potential biomarker panel for early detection of HPV OPC. For the 111 patients with known HPV+ tumors as measured by tumor PCR of E6 and/or E7, this assay had a sensitivity of 90% and specificity of 87% (AUC = 0.96). From these results, we conclude that custom bead array assays can be used to detect HPV16 Abs in patient sera, and we have identified a 4-Ab biomarker panel for the early detection of HPV OPC.
ContributorsGoulder, Alison Leigh (Author) / Anderson, Karen (Thesis director) / Lake, Douglas (Committee member) / Cheng, Julia (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2013-05
Description
Cancer is one of the leading causes of death in the world and represents a tremendous burden on patients, families and societies. S. Typhimurium strains are specifically attracted to compounds produced by cancer cells and could overcome the traditional therapeutic barrier. However, a major problem with using live attenuated Salmonella as anti-cancer agents is their toxicity at the dose required for therapeutic efficacy, but reducing the dose results in diminished efficacy. In this project, we explored novel means to reduce the toxicity of the recombinant attenuated Salmonella by genetically engineering those virulence factors to facilitate maximal colonization of tumor tissues and reduced fitness in normal tissues. We have constructed two sets of Salmonella strains. In the first set, each targeted gene was knocked out by deletion of the gene. In the second set, the predicted promoter region of each gene was replaced with a rhamnose-regulated promoter, which will cease the synthesis of these genes in vivo, a rhamnose-free environment.
ContributorsBenson, Lee Samuel (Author) / Kong, Wei (Thesis director) / Martin, Thomas (Committee member) / Lake, Douglas (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor) / Center for Infectious Diseases and Vaccinology (Contributor) / School of Life Sciences (Contributor)
Created2013-05
Description
An introduction to neuroscientific thought aimed at an audience that is not educated in biology. Meant to be readable and easily understood by anyone with a high school education. The first section is completed in its entirety, with outlines for the proposed final sections to be completed over the next few years.
ContributorsNelson, Nicholas Alan (Author) / Olive, M. Foster (Thesis director) / Brewer, Gene (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor) / School of Life Sciences (Contributor) / School of Historical, Philosophical and Religious Studies (Contributor)
Created2014-05
DescriptionA novel and unconventional approach for delivering a eukaryotic apoptosis factor, TNF-related apoptosis-inducing ligand (TRAIL), to cancer cells within and around necrotizing tumors by utilizing a S. Typhimurium purine requiring auxotroph as a biological vector to develop two anticancer therapies with multiple modality and broad economic feasibility.
ContributorsKoons, Andrew (Author) / Curtiss, Roy (Thesis director) / Lake, Douglas (Committee member) / Janthakahalli, Nagaraj Vinay (Committee member) / Barrett, The Honors College (Contributor)
Created2013-12
ContributorsChandler, N. Kayla (Author) / Neisewander, Janet (Thesis director) / Sanabria, Federico (Committee member) / Olive, M. Foster (Committee member) / Barrett, The Honors College (Contributor) / College of Liberal Arts and Sciences (Contributor)
Created2013-05
Description
While the entire human genome has been sequenced, the understanding of its functional elements remains unclear. The Encyclopedia of DNA Elements (ENCODE) project analyzed 1% of the human genome and found that the majority of the human genome is transcribed, including non-protein coding regions. The hypothesis is that some of the "non-coding" sequences are translated into peptides and small proteins. Using mass spectrometry numerous peptides derived from the ENCODE transcriptome were identified. Peptides and small proteins were also found from non-coding regions of the 1% of the human genome that the ENCODE did not find transcripts for. A large portion of these peptides mapped to the intronic regions of known genes, thus it is suspected that they may be undiscovered exons present in alternative spliceoforms of certain genes. Further studies proved the existence of polyadenylated RNAs coding for these peptides. Although their functional significance has not been determined, I anticipate the findings will lead to the discovery of new splice variants of known genes and possibly new transcriptional and translational mechanisms.
ContributorsWang, Lulu (Author) / Lake, Douglas (Thesis advisor) / Chang, Yung (Committee member) / Touchman, Jeffery (Committee member) / Arizona State University (Publisher)
Created2010
Description
Host organisms have evolved multiple mechanisms to defend against a viral infection and likewise viruses have evolved multiple methods to subvert the host's anti-viral immune response. Vaccinia virus (VACV) is known to contain numerous proteins involved in blocking the cellular anti-viral immune response. The VACV E3L protein is important for inhibiting the anti-viral immune response and deletions within this gene lead to a severe attenuation. In particular, VACV containing N-terminal truncations in E3L are attenuated in animal models and fail to replicate in murine JC cells. Monkeypox virus (MPXV) F3L protein is a homologue of the VACV E3L protein, however it is predicted to contain a 37 amino acid N-terminal truncation. Despite containing an N-terminal truncation in the E3L homologue, MPXV is able to inhibit the anti-viral immune response similar to wild-type VACV and able to replicate in JC cells. This suggests that MPXV has evolved another mechanism(s) to counteract host defenses and promote replication in JC cells. MPXV produces less dsRNA than VACV during the course of an infection, which may explain why MPXV posses a phenotype similar to VACV, despite containing a truncated E3L homologue. The development of oncolytic viruses as a therapy for cancer has gained interest in recent years. Oncolytic viruses selectively replicate in and destroy cancerous cells and leave normal cells unharmed. Many tumors possess dysregulated anti-viral signaling pathways, since these pathways can also regulate cell growth. Creating a mutation in the N-terminus of the VACV-E3L protein generates an oncolytic VACV that depends on dysregulated anti-viral signaling pathways for replication allowing for direct targeting of the cancerous cells. VACV-E3Ldel54N selectively replicates in numerous cancer cells lines and not in the normal cell lines. Additionally, VACV-E3Ldel54N is safe and effective in causing tumor regression in a xenograph mouse model. Lastly, VACV-E3Ldel54N was capable of spreading from the treated tumors to the untreated tumors in both a xenograph and syngeneic mouse model. These data suggest that VACV-E3Ldel54N could be an effective oncolytic virus for the treatment of cancer.
ContributorsArndt, William D (Author) / Jacobs, Bertram (Thesis advisor) / Curtiss Iii, Roy (Committee member) / Chang, Yung (Committee member) / Lake, Douglas (Committee member) / Arizona State University (Publisher)
Created2010
Description
Major Depressive Disorder (MDD) affects over 300 million people worldwide, with the hippocampus showing decreased volume and activity in patients with MDD. The current study investigated whether a novel preclinical model of depression, unpredictable intermittent restraint (UIR), would decrease hippocampal neuronal dendritic complexity. Adult Sprague Dawley rats (24 male, 24 female) were equally divided into 4 groups: control males (CON-M), UIR males (UIR-M), control females (CON-F) and UIR females (UIR-F). UIR groups received restraint and shaking on an orbital shaker on a randomized schedule for 30 or 60 minutes/day for two to six days in a row for 26 days (21 total UIR days) before behavioral testing commenced. UIR continued and was interspersed between behavioral test days. At the end of behavioral testing, brains were processed. The behavior is published and not part of my honor’s thesis; my contribution involved quantifying and analyzing neurons in the hippocampus. Several neuronal types are found in the CA3 subregion of the hippocampus and I focused on short shaft (SS) neurons, which show different sensitivities to stress than the more common long shaft (LS) variety. Brains sections were mounted to slides and Golgi stained. SS neurons were drawn using a microscope with camera lucida attachment and quantified using the number of bifurcations and dendritic intersections as metrics for dendritic complexity in the apical and basal areas separately. The hypothesis that SS neurons in the CA3 region of the hippocampus would exhibit apical dendritic simplification in both sexes after UIR was not supported by our findings. In contrast, following UIR, SS apical dendrites were more complex in both sexes compared to controls. Although unexpected, we believe that the UIR paradigm was an effective stressor, robust enough to illicit neuronal adaptations. It appears that the time from the end of UIR to when the brain tissue was collected, or the post-stress recovery period, and/or repeated behavioral testing may have played a role in the observed increased neuronal complexity. Future studies are needed to parse out these potential effects.
ContributorsAcuna, Amanda Marie (Author) / Conrad, Cheryl (Thesis director) / Corbin, William (Committee member) / Olive, M. Foster (Committee member) / School of Life Sciences (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2020-12