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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

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
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Description
Vaccines against the arthropod-borne dengue virus (DENV) are still commercially nonexistent. A subunit immunization strategy may be of value, especially if a safe viral vector acts as a biologically active adjuvant. The DENV envelope protein (E), the main target for neutralizing immune responses, has three conformational domains. The immunoglobulin-like and

Vaccines against the arthropod-borne dengue virus (DENV) are still commercially nonexistent. A subunit immunization strategy may be of value, especially if a safe viral vector acts as a biologically active adjuvant. The DENV envelope protein (E), the main target for neutralizing immune responses, has three conformational domains. The immunoglobulin-like and independently folding domain III (DIII) contains epitopes that elicit highly specific neutralizing antibodies. The hepatitis B small surface antigen (HBsAg, S) was used as a scaffold to display DENV 2 DIII on a virus-like particle (VLP). A measles virus (MV) was engineered to vector HBsAg and the hybrid glycoprotein DIII-HBsAg in two different loci (DIII-S). Despite the relatively deleterious effect on replication caused by the insertion of two transcription cassettes, the recombinant virus MVvac2(DIII-S,S)P induced the secretion of DIII-S hybrid VLP with a similar sucrose density as HBsAg particles (1.10-1.12g/ml) and peaked at 48 h post-infection producing 1.3x106 TCID50/ml infectious MV units in vitro. A second recombinant virus, MVvac2(DIII-S)N, was engineered to vector only the hybrid DIII-S. However, it did not induce the secretion of hybrid HBsAg particles in the supernatant of infected cells. The immunogenicity of the recombinant viruses was tested in a MV-susceptible small animal model, the experimental group which received two 105 TCID50 I.P. doses of MVvac2(DIII-S,S)P in a 28 day interval developed a robust immune response against MV (1:1280), HBsAg (787 mIU/ml) and DENV2 (Log10 neutralization index of 1.2) on average. In summary, it is possible to display DENV E DIII on hybrid HBsAg particles vectored by MV that elicit an immune response. This forms the basis for a potential vaccine platform against DENV.
ContributorsHarahap, Indira (Author) / Reyes del Valle, Jorge (Thesis advisor) / Hogue, Brenda G (Thesis advisor) / Lake, Douglas (Committee member) / Mason, Hugh (Committee member) / Arizona State University (Publisher)
Created2015
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Description
Despite the approval of a Dengue virus (DV) vaccine in five endemic countries, dengue prevention would benefit from an immunization strategy highly immunogenic in young infants and not curtailed by viral interference. Problematically, infants younger than 9 year of age, whom are particularly prone to Dengue severe infection and death,

Despite the approval of a Dengue virus (DV) vaccine in five endemic countries, dengue prevention would benefit from an immunization strategy highly immunogenic in young infants and not curtailed by viral interference. Problematically, infants younger than 9 year of age, whom are particularly prone to Dengue severe infection and death, cannot be immunized using current approved DV vaccine. The most important issues documented so far are the lack of efficiency and enhancement of the disease in young seronegative recipients, as well as uneven protection against the four DV serotypes. Based on data from clinical trials that showed enhanced performance of dengue vaccines when the host has previous anti-flaviviral immunity, I proposed here an attractive solution to complement the current vaccine: a recombinant measles vaccine vectoring dengue protective antigens to be administered to young infants. I hypothesized that recombinant measles virus expressing Dengue 2 and 4 antigens would successfully induce neutralizing responses against DV2 and 4 and the vaccine cocktail of this recombinant measles can prime anti-flaviviral neutralizing immunity. For this dissertation, I generated and performed preclinical immune assessment for four novel Measles-Dengue (MV-DV) vaccine candidates. I generated four MVs expressing the pre membrane (prM) and full length or truncated (90%) forms of the major envelope (E) from DV2 and DV4. Two virus, MVvac2-DV2(prME)N and MVvac2-DV4(prME), expressed high levels of membrane associated full-length E, while the other two viruses, MVvac2-DV2(prMEsol)N and MVvac2-DV4(prMEsol)N, expressed and secreted truncated, soluble E protein to its extracellular environment. The last two vectored vaccines proved superior anti-dengue neutralizing responses comparing to its corresponding full length vectors. Remarkably, when MVvac2-DV2/4(prMEsol)N recombinant vaccines were combined, the vaccine cocktail was able to prime cross-neutralizing responses against DV 1 and the relatively distant 17D yellow fever virus attenuated strain. Thus, I identify a promising DV vaccination strategy, MVvac2-DV2/4(prMEsol)N, which can prime broad neutralizing immune responses by using only two of the four available DV serotypes. The current MV immunization scheme can be advantageus to prime broad anti-flaviviral neutralizing immunity status, which will be majorly boosted by subsequent chimeric Dengue vaccine approaches.
ContributorsAbdelgalel, Rowida (Author) / Reyes del Valle, Jorge (Thesis advisor) / Mason, Hugh (Thesis advisor) / Lake, Douglas (Committee member) / Stout, Valerie (Committee member) / Frasch, Wayne (Committee member) / Arizona State University (Publisher)
Created2016
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Description
Cancer researchers have traditionally used a handful of markers to understand the origin of tumors and to predict therapeutic response. Additionally, performing machine learning activities on disparate data sources of varying quality is fraught with inherent bias. The Caris Life Sciences Molecular Database (CMD) is an immense resource

Cancer researchers have traditionally used a handful of markers to understand the origin of tumors and to predict therapeutic response. Additionally, performing machine learning activities on disparate data sources of varying quality is fraught with inherent bias. The Caris Life Sciences Molecular Database (CMD) is an immense resource for discovery as it contains over 215,000 molecular profiles of tumors with consistently gathered clinical grade molecular data along with immense amounts of clinical outcomes data. This resource was leveraged to generate two artificial intelligence algorithms aiding in diagnosis and one for therapy selection.

The Molecular Disease Classifier (MDC) was trained on 34,352 cases and tested on 15,473 unambiguously diagnosed cases. The MDC predicted the correct tumor type out of thirteen possibilities in the labeled data set with sensitivity, specificity, PPV, and NPV of 90.5%, 99.2%, 90.5% and 99.2% respectively when considering up to 5 predictions for a case.

The availability of whole transcriptome data in the CMD prompted its inclusion into a new platform called MI GPSai (MI Genomic Prevalence Score). The algorithm trained on genomic data from 34,352 cases and genomic and transcriptomic data from 23,137 cases and was validated on 19,555 cases. MI GPSai can predict the correct tumor type out of 21 possibilities on 93% of cases with 94% accuracy. When considering the top two predictions for a case, the accuracy increases to 97%.

Finally, a 67 gene molecular signature predictive of efficacy of oxaliplatin-based chemotherapy in patients with metastatic colorectal cancer was developed - FOLFOXai. The signature was predictive of survival in an independent real-world evidence (RWE) dataset of 412 patients who had received FOLFOX/BV in 1st line and inversely predictive of survival in RWE data from 55 patients who had received 1st line FOLFIRI. Blinded analysis of TRIBE2 samples confirmed that FOLFOXai was predictive of OS in both oxaliplatin-containing arms (FOLFOX HR=0.629, p=0.04 and FOLFOXIRI HR=0.483, p=0.02).
ContributorsAbraham, Jim (Author) / Spetzler, David (Thesis advisor) / Frasch, Wayne (Thesis advisor) / Lake, Douglas (Committee member) / Compton, Carolyn (Committee member) / Arizona State University (Publisher)
Created2020
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Description
Quiescin Sulfhydryl Oxidase 1 (QSOX1) generates disulfide bonds in its client substrates via oxidation of free thiols. Localized to the Golgi and secreted, QSOX1 helps to fold proteins into their active form. Early work with QSOX1 in cancer began with the identification of a peptide from the long form of

Quiescin Sulfhydryl Oxidase 1 (QSOX1) generates disulfide bonds in its client substrates via oxidation of free thiols. Localized to the Golgi and secreted, QSOX1 helps to fold proteins into their active form. Early work with QSOX1 in cancer began with the identification of a peptide from the long form of QSOX1 in plasma from patients with pancreatic ductal adenocarcinoma. Subsequent work confirmed the overexpression of QSOX1 in numerous cancers in addition to pancreatic, including those originating in the breast, lung, brain, and kidney. For my work, I decided to answer the question, “How does inhibition of QSOX1 effect the cancer phenotype?” To answer this I sought to fulfill the following goals A) determine the overexpression parameters of QSOX1 in cancer, B) identify QSOX1 small molecule inhibitors and their effect on the cancer phenotype, and C) determine potential biological effects of QSOX1 in cancer. Antibodies raised against rQSOX1 or a peptide from QSOX1-L were used to probe cancer cells of various origins for QSOX1 expression. High-throughput screening was utilized to identify 3-methoxy-n-[4(1pyrrolidinyl)phenyl]benzamide (SBI-183) as a lead inhibitor of QSOX1 enzymatic activity. Characterization of SBI-183 activity on various tumor cell lines revealed inhibition of viability and invasion in vitro, and inhibition of growth, invasion, and metastasis in vivo, a phenotype that was consistent with QSOX1 shKnockdown cells. Subsequent work identified 3,4,5-trimethoxy-N-[4-(1-pyrrolidinyl)phenyl]benzamide (SPX-009) as an SBI-183 analog with stronger inhibition of QSOX1 enzymatic activity, resulting in a more potent reduction in tumor invasion in vitro. Additional work with QSOX1 shKnockdown and Knockout (KO) cell lines confirmed current literature that QSOX1 is biologically active in modulation of the ECM. These results provide evidence for the master regulatory role of QSOX1 in cancer, making it an attractive chemotherapeutic target. Additionally, the small molecules identified here may prove to be useful probes in further elucidation of QSOX1 tumor biology and biomarker discovery.
ContributorsFifield, Amber (Author) / Lake, Douglas (Thesis advisor) / Ho, Thai (Committee member) / Rawls, Jeffery (Committee member) / Borges, Chad (Committee member) / Arizona State University (Publisher)
Created2020
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Description
Acute Myeloid Leukemia (AML) is a disease that occurs when genomic changes alter expression of key genes in myeloid blood cells. These changes cause them to resume an undifferentiated state, proliferate, and maintain growth throughout the body. AML is commonly treated with chemotherapy, but recent efforts to reduce therapy toxicity

Acute Myeloid Leukemia (AML) is a disease that occurs when genomic changes alter expression of key genes in myeloid blood cells. These changes cause them to resume an undifferentiated state, proliferate, and maintain growth throughout the body. AML is commonly treated with chemotherapy, but recent efforts to reduce therapy toxicity have focused on drugs that specifically target and inhibit protein products of the cancer’s aberrantly expressed genes. This method has proved difficult for some proteins because of structural challenges or mutations that confer resistance to therapy. One potential method of targeted therapy that circumvents these issues is the use of small molecules that stabilize DNA secondary structures called G-quadruplexes. G-quadruplexes are present in the promoter region of many potential oncogenes and have regulatory roles in their transcription. This study analyzes the therapeutic potential of the compound GQC-05 in AML. This compound was shown in vitro to bind and stabilize the regulatory G-quadruplex in the MYC oncogene, which is commonly misregulated in AML. Through qPCR and western blot analysis, a GQC-05 mediated downregulation of MYC mRNA and protein was observed in AML cell lines with high MYC expression. In addition, GQC-05 is able to reduce cell viability through induction of apoptosis in sensitive AML cell lines. Concurrent treatment of AML cell lines with GQC-05 and the MYC inhibitor (+)JQ1 showed an antagonistic effect, indicating potential competition in the silencing of MYC. However, GQC-05 is not able to reduce MYC expression significantly enough to induce apoptosis in less sensitive AML cell lines. This resistance may be due to the cells’ lack of dependence on other potential GQC-05 targets that may help upregulate MYC or stabilize its protein product. Three such genes identified by RNA-seq analysis of GQC-05 treated cells are NOTCH1, PIM1, and RHOU. These results indicate that the use of small molecules to target the MYC promoter G-quadruplex is a viable potential therapy for AML. They also support a novel mechanism for targeting other potentially key genetic drivers in AML and lay the groundwork for advances in treatment of other cancers driven by G-quadruplex regulated oncogenes.
ContributorsTurnidge, Megan (Author) / Lake, Douglas (Thesis advisor) / Kim, Suwon (Committee member) / Azorsa, David (Committee member) / Arizona State University (Publisher)
Created2017