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Cancer rates vary between people, between cultures, and between tissue types, driven by clinically relevant distinctions in the risk factors that lead to different cancer types. Despite the importance of cancer location in human health, little is known about tissue-specific cancers in non-human animals. We can gain significant insight into

Cancer rates vary between people, between cultures, and between tissue types, driven by clinically relevant distinctions in the risk factors that lead to different cancer types. Despite the importance of cancer location in human health, little is known about tissue-specific cancers in non-human animals. We can gain significant insight into how evolutionary history has shaped mechanisms of cancer suppression by examining how life history traits impact cancer susceptibility across species. Here, we perform multi-level analysis to test how species-level life history strategies are associated with differences in neoplasia prevalence, and apply this to mammary neoplasia within mammals. We propose that the same patterns of cancer prevalence that have been reported across species will be maintained at the tissue-specific level. We used a combination of factor analysis and phylogenetic regression on 13 life history traits across 90 mammalian species to determine the correlation between a life history trait and how it relates to mammary neoplasia prevalence. The factor analysis presented ways to calculate quantifiable underlying factors that contribute to covariance of entangled life history variables. A greater risk of mammary neoplasia was found to be correlated most significantly with shorter gestation length. With this analysis, a framework is provided for how different life history modalities can influence cancer vulnerability. Additionally, statistical methods developed for this project present a framework for future comparative oncology studies and have the potential for many diverse applications.

ContributorsFox, Morgan Shane (Author) / Maley, Carlo C. (Thesis director) / Boddy, Amy (Committee member) / Compton, Zachary (Committee member) / School of Mathematical and Statistical Sciences (Contributor) / School of Molecular Sciences (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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The goal of this project was to design and create a genetic construct that would allow for <br/>tumor growth to be induced in the center of the wing imaginal disc of Drosophila larvae, the <br/>R85E08 domain, using a heat shock. The resulting transgene would be combined with other <br/>transgenes in

The goal of this project was to design and create a genetic construct that would allow for <br/>tumor growth to be induced in the center of the wing imaginal disc of Drosophila larvae, the <br/>R85E08 domain, using a heat shock. The resulting transgene would be combined with other <br/>transgenes in a single fly that would allow for simultaneous expression of the oncogene and, in <br/>the surrounding cells, other genes of interest. This system would help establish Drosophila as a <br/>more versatile and reliable model organism for cancer research. Furthermore, pilot studies were <br/>performed, using elements of the final proposed system, to determine if tumor growth is possible <br/>in the center of the disc, which oncogene produces the best results, and if oncogene expression <br/>induced later in development causes tumor growth. Three different candidate genes were <br/>investigated: RasV12, PvrACT, and Avli.

ContributorsSt Peter, John Daniel (Author) / Harris, Rob (Thesis director) / Varsani, Arvind (Committee member) / School of Molecular Sciences (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Lyme disease is a common tick-borne illness caused by the Gram-negative bacterium Borrelia burgdorferi. An outer membrane protein of Borrelia burgdorferi, P66, has been suggested as a possible target for Lyme disease treatments. However, a lack of structural information available for P66 has hindered attempts to design medications to target

Lyme disease is a common tick-borne illness caused by the Gram-negative bacterium Borrelia burgdorferi. An outer membrane protein of Borrelia burgdorferi, P66, has been suggested as a possible target for Lyme disease treatments. However, a lack of structural information available for P66 has hindered attempts to design medications to target the protein. Therefore, this study attempted to find methods for expressing and purifying P66 in quantities that can be used for structural studies. It was found that by using the PelB signal sequence, His-tagged P66 could be directed to the outer membrane of Escherichia coli, as confirmed by an anti-His Western blot. Further attempts to optimize P66 expression in the outer membrane were made, pending verification via Western blotting. The ability to direct P66 to the outer membrane using the PelB signal sequence is a promising first step in determining the overall structure of P66, but further work is needed before P66 is ready for large-scale purification for structural studies.

ContributorsRamirez, Christopher Nicholas (Author) / Fromme, Petra (Thesis director) / Hansen, Debra (Committee member) / Department of Physics (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description
Current studies in Multiple Myeloma suggest that patient tumors and cell lines cluster separately based on gene expression profiles. Hyperdiploid patients are also extremely underrepresented in established human myeloma cell lines (HMCLs). This suggests that the average HMCL model system does not accurately represent the average myeloma patient. To investigate

Current studies in Multiple Myeloma suggest that patient tumors and cell lines cluster separately based on gene expression profiles. Hyperdiploid patients are also extremely underrepresented in established human myeloma cell lines (HMCLs). This suggests that the average HMCL model system does not accurately represent the average myeloma patient. To investigate this question we performed a combined CNA and SNV evolutionary comparison between four myeloma tumors and their established HMCLs (JMW-1, VP-6, KAS-6/1-KAS-6/2 and KP-6). We identified copy number changes shared between the tumors and their cell lines (mean of 74 events - 59%), those unique to patients (mean of 21.25 events - 17%), and those only in the cell lines (mean of 30.75 events \u2014 24%). A relapse sample from the JMW-1 patient showed 58% similarity to the primary diagnostic tumor. These data suggest that, on the level of copy number abnormalities, HMCLs show equal levels of evolutionary divergence as that observed within patients. By exome sequencing, patient tumors were 71% similar to their representative HMCLs, with ~12.5% and ~16.5% of SNVs unique to the tumors and HMCLs respectively. The HMCLs studied appear highly representative of the patient from which they were derived, with most differences associated with an enrichment of sub-populations present in the primary tumor. Additionally, our analysis of the KP-6 aCGH data showed that the patient's hyperdiploid karyotype was maintained in its respective HMCL. This discovery confirms the establishment and validation of a novel and potentially clinically relevant hyperdiploid HMCL that could provide a major advance in our ability to understand the pathogenesis and progression of this prominent patient population.
ContributorsBenard, Brooks Avery (Author) / Keats, Jonathan (Thesis director) / Anderson, Karen (Committee member) / Jelinek, Diane (Committee member) / School of Molecular Sciences (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
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Description
Cancer is a disease that occurs in many and perhaps all multicellular organisms. Current research is looking at how different life history characteristics among species could influence cancer rates. Because somatic maintenance is an important component of a species' life history, we hypothesize the same ecological forces shaping the life

Cancer is a disease that occurs in many and perhaps all multicellular organisms. Current research is looking at how different life history characteristics among species could influence cancer rates. Because somatic maintenance is an important component of a species' life history, we hypothesize the same ecological forces shaping the life history of a species should also determine its cancer susceptibility. By looking at varying life histories, potential evolutionary trends could be used to explain differing cancer rates. Life history theory could be an important framework for understanding cancer vulnerabilities with different trade-offs between life history traits and cancer defenses. Birds have diverse life history strategies that could explain differences in cancer suppression. Peto's paradox is the observation that cancer rates do not typically increase with body size and longevity despite an increased number of cell divisions over the animal's lifetime that ought to be carcinogenic. Here we show how Peto’s paradox is negatively correlated for cancer within the clade, Aves. That is, larger, long-lived birds get more cancer than smaller, short-lived birds (p=0.0001; r2= 0.024). Sexual dimorphism in both plumage color and size differ among Aves species. We hypothesized that this could lead to a difference in cancer rates due to the amount of time and energy sexual dimorphism takes away from somatic maintenance. We tested for an association between a variety of life history traits and cancer, including reproductive potential, growth rate, incubation, mating systems, and sexual dimorphism in both color and size. We found male birds get less cancer than female birds (9.8% vs. 11.1%, p=0.0058).
ContributorsDolan, Jordyn Nicole (Author) / Maley, Carlo (Thesis director) / Harris, Valerie (Committee member) / Boddy, Amy (Committee member) / School of Molecular Sciences (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
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Description
All multicellular organisms are susceptible to developing cancer, but some organisms have varying sensitivities to the disease. One such organism is the Trichoplax adhaerens which has no documented case of cancer development. T. adhaerens cancer resistance was studied by observing physiological and morphological changes of the organism after radiation treatment.

All multicellular organisms are susceptible to developing cancer, but some organisms have varying sensitivities to the disease. One such organism is the Trichoplax adhaerens which has no documented case of cancer development. T. adhaerens cancer resistance was studied by observing physiological and morphological changes of the organism after radiation treatment. Preliminary experiments suggested that this organism is able to survive exposure to 160 gray radiation treatment almost as well as untreated organisms. The T. adhaerens have two genes, TriadG6402 and TriadG5479, similar to the human genes TP53 and MDM2 respectively. TP53 and MDM2 are the two main genes associated with apoptosis in humans: an important cell regulatory checkpoint involved in cancer prevention. PCR analysis, done after radiation treatment, showed an overexpression of the ortholog gene MDM2 in the T. adhaerens. This may suggest that T. adhaerens block apoptosis from occurring and that their ortholog gene is involved in DNA repair. It is significant to study the gene expression of TriadG6402 and TriadG54791 in T. adhaerens because these genes are well conserved in humans. Future studies of these genes in the T. adhaerens can be used to understand the evolution of the function of these genes in more complex organisms and be used for human cancer prevention.
ContributorsKulkarni, Arathi (Author) / Fortunato, Angelo (Thesis director) / Maley, Carlo (Committee member) / Department of Economics (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
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Description
Tumor-stroma interactions significantly influence cancer cell metastasis and disease progression. These interactions partly comprise crosstalk between tumor and stromal fibroblasts, but the key molecular mechanisms within the crosstalk governing cancer invasion are still unclear. Here we develop a 3D in vitro organotypic microfluidic to model tumor-stroma interaction by mimicking the

Tumor-stroma interactions significantly influence cancer cell metastasis and disease progression. These interactions partly comprise crosstalk between tumor and stromal fibroblasts, but the key molecular mechanisms within the crosstalk governing cancer invasion are still unclear. Here we develop a 3D in vitro organotypic microfluidic to model tumor-stroma interaction by mimicking the spatial organization of the tumor microenvironment on a chip. We co-culture breast cancer and patient-derived fibroblast cells in 3D tumor and stroma regions respectively and combine functional assessments, including cancer cell migration, with transcriptome profiling to unveil the molecular influence of tumor-stroma crosstalk on invasion. This led to the observation that cancer associated fibroblasts enhanced invasion in 3D by inducing the expression of a novel gene of interest, GPNMB, in breast cancer cells resulting in increased migration speed. Importantly, knockdown of GPNMB blunted the influence of CAFs on enhancing cancer invasion. Overall, these results demonstrate the ability of our model to recapitulate patient specific tumor microenvironment to investigate cellular and molecular consequences of tumor-stroma interactions.
ContributorsBarrientos, Eric Salvador (Author) / Nikkhah, Mehdi (Thesis director) / Veldhuizen, Jaime (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
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Description
Trichoplax adhaerens (Placozoa) is the simplest multicellular animal to be described. This organism lacks nervous tissue, muscle tissue and organs, and is composed of only five cell types organized into three layers. Placozoa are gaining popularity as a model organism due to their simple make-up and completely sequenced genome. The

Trichoplax adhaerens (Placozoa) is the simplest multicellular animal to be described. This organism lacks nervous tissue, muscle tissue and organs, and is composed of only five cell types organized into three layers. Placozoa are gaining popularity as a model organism due to their simple make-up and completely sequenced genome. The complete sequencing of this organism’s genome has revealed the presence of important genes in cancer such as TP53 and MDM2 genes. Along with the presence of these genes, there are also additional pathways commonly deregulated in cancer that are well conserved in this organism. T. adhaerens are able to survive exposure to 160Gy and even 240Gy of X-ray radiation. Though small dark bodies form within the main body, they tend to extrude those masses, and continue to reproduce afterwards. After exposure to both grades of radiation, there was a greater increase in the apparent population size of the treated population than the control population. There was also a greater decrease in surface area of the organisms exposed to 160Gy than the control organisms. This increase in population and decrease in surface area of the treated organisms could be due to the extruded bodies. We hypothesize that the observed extrusion is a novel cancer defense mechanism for ridding the animal of damaged or mutated cells. This hypothesis should be tested through longitudinal observation and genetic analysis of the extruded bodies.
ContributorsYi, Avalon (Author) / Fortunato, Angelo (Thesis director) / Maley, Carlo (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-12
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Description
Enzyme Replacement Therapy (ERT) is a treatment often used for patients with disorders that affect the production of various enzymes within the body, such as Cystic Fibrosis and Fabry Disease. ERT involves the use of artificially-produced enzymes, which can be derived from humans, pigs, and bacteria. Generally, enzymes derived from

Enzyme Replacement Therapy (ERT) is a treatment often used for patients with disorders that affect the production of various enzymes within the body, such as Cystic Fibrosis and Fabry Disease. ERT involves the use of artificially-produced enzymes, which can be derived from humans, pigs, and bacteria. Generally, enzymes derived from porcine and bacterial sources are much less expensive and more accessible than those derived from a human source. This, and the ethical implications that porcine enzymes carry, make the decision of choosing treatment simple to some and complex to others. Ethically, human-derived enzymes are often considered more ethical, while not conflicting with religious beliefs and practices as porcine-derived enzymes do.
In order to further compare porcine and human-derived enzymes, a determination of the enzyme effectiveness was done via digestion simulation. The digestion for both the human and porcine-derived enzymes consisted of three steps: oral, gastric, and intestinal. After the digestion, the absorbance for each enzyme class as well as a dilution curve of the formula used was read and recorded. Using the standard dilution curve and the absorbance values for each unknown, the formula and thus enzyme concentration that was lost through the reaction was able to be calculated.
The effectiveness of both the human and porcine enzymes, determined by the percent of formula lost, was 18.2% and 19.7%, respectively, with an error of 0.6% from the spectrophotometer, and an error of about 10% from the scale used for measuring the enzymes. This error was likely due to the small mass required of the enzymes and can be prevented in the future by performing the experiment at a larger scale.
ContributorsBlevins, Brianna R (Author) / Martin, Thomas (Thesis director) / McILwraith, Heide (Committee member) / College of Integrative Sciences and Arts (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
With cancer rates increasing and affecting more people every year, I felt it was important to educate the younger generation about the potential factors that could put them at risk of receiving a cancer diagnosis later in life. I thought that this was important to do because most students, especially

With cancer rates increasing and affecting more people every year, I felt it was important to educate the younger generation about the potential factors that could put them at risk of receiving a cancer diagnosis later in life. I thought that this was important to do because most students, especially in rural communities, are not taught the factors that increase your risk of getting cancer in the future. This leads to students not having the tools to think about the repercussions that their actions can have in their distant future in regard to their risk of getting cancer. I went to six schools throughout the valley and the White Mountains of Arizona with differing education levels and demographics to provide them with prevention strategies that they could implement into their daily lives to reduce their risk of getting cancer in the future. Some of the schools had curriculums that included cancer and some of the factors that increase your risk, while others never mention what is happening biologically when a person has cancer. I introduced factors such as no smoking or tobacco use, diet, exercise, sunscreen use, avoiding alcohol, and getting screened regularly. While at each school, I discussed the importance of creating these healthy habits while they are young because cancer is a disease that comes from the accumulation of mutations that can begin occurring in their bodies even now. After my presentation, 98.6% of the 305 students who viewed my presentation felt like they had learned something from the presentation and were almost all willing to implement at least one of the changes into their daily lives.
ContributorsGoforth, Michelle Nicole (Author) / Compton, Carolyn (Thesis director) / Lake, Douglas (Committee member) / Popova, Laura (Committee member) / Dean, W.P. Carey School of Business (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05