Matching Items (7)
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Description

Cancer is a disease acquired through mutations which leads to uncontrolled cell division and destruction of normal tissue within the body. Recent increases in available cross-species data of cancer in mammals, reptiles, birds, and other vertebrates has revealed that the prevalence of cancers varies widely across species. Life-history theory suggests

Cancer is a disease acquired through mutations which leads to uncontrolled cell division and destruction of normal tissue within the body. Recent increases in available cross-species data of cancer in mammals, reptiles, birds, and other vertebrates has revealed that the prevalence of cancers varies widely across species. Life-history theory suggests that there could be traits that potentially explain some of that variation. We are particularly interested in species that get very little cancer. How are they preventing cancer and can we learn from them how to prevent cancer in humans? Comparative oncology focuses on the analysis of cancer prevalence and traits in different non-human species and allows researchers to apply their findings to humans with the goal of improving and advancing cancer treatment. We incorporate the predictions that animals with larger bodies have evolved better cancer suppression mechanisms than animals with small bodies. Ruminants in the past were larger in size than modern day ruminants and they may have retained cancer defenses from their large ancestors. The strong cancer defenses and small body size combined may explain the low prevalence of cancer in Ruminants. This paper aims to evaluate the presence of benign and malignant neoplasia prevalence across multiple ruminant species following a time of dramatic decrease in body size across the clade. Our aim is to illuminate the potential impact that these shifts in body size had on their cancer prevalence as well as test the statistical power of other key life history variables to predict cancer prevalence.

ContributorsAustin, Shannon Ruth (Author) / Maley, Carlo (Thesis director) / Boddy, Amy (Committee member) / Compton, Zachary (Committee member) / Historical, Philosophical & Religious Studies (Contributor) / Historical, Philosophical & Religious Studies, Sch (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

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
Description
Cancer is a problem of multicellularity, making it a problem across all species. This pervasiveness has led to much research into the defense and the pathology of the disease. Previously, studies have been limited in sample size, taxonomic breadth, and comparative methods to explain and understand the data available. Here,

Cancer is a problem of multicellularity, making it a problem across all species. This pervasiveness has led to much research into the defense and the pathology of the disease. Previously, studies have been limited in sample size, taxonomic breadth, and comparative methods to explain and understand the data available. Here, we have access to life history and cancer risk data of 17,563 individuals for 327 species, spanning across three monophyletic clades: Amphibians, Sauropsids, and Mammals. Comparative biology’s approach to cross-species cancer prevalence is crucial to the identification of species that are uniquely resistant to cancer as well as stratifying risk across a phylogeny based on the life history framework. Using the life history framework, alongside a multitude of life history data, was able to find that neoplasia prevalence increases with adult weight and longevity, but decreases with gestation time. It was also discovered that malignancy prevalence decreases with gestation time. Gestation and adult weight are also both significant predictors of neoplasia and malignancy prevalence when controlling for the other. On an evolutionary scale, cancer risk appears to be best described by sudden shifts in cancer prevalence followed by stabilizing selection of that trait. The understanding of increases and decreases of cancer risk across species could create better insight on human’s own cancer risk, as well as disease prevention in humans.
ContributorsMellon, Walker (Author) / Maley, Carlo (Thesis director) / Compton, Zachary (Committee member) / Mallo, Diego (Committee member) / Barrett, The Honors College (Contributor) / Department of Information Systems (Contributor) / Department of Economics (Contributor)
Created2022-12
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Description

Cooperative cellular phenotypes are universal across multicellular life. Division of labor, regulated proliferation, and controlled cell death are essential in the maintenance of a multicellular body. Breakdowns in these cooperative phenotypes are foundational in understanding the initiation and progression of neoplastic diseases, such as cancer. Cooperative cellular phenotypes are straightforward

Cooperative cellular phenotypes are universal across multicellular life. Division of labor, regulated proliferation, and controlled cell death are essential in the maintenance of a multicellular body. Breakdowns in these cooperative phenotypes are foundational in understanding the initiation and progression of neoplastic diseases, such as cancer. Cooperative cellular phenotypes are straightforward to characterize in extant species but the selective pressures that drove their emergence at the transition(s) to multicellularity have yet to be fully characterized. Here we seek to understand how a dynamic environment shaped the emergence of two mechanisms of regulated cell survival: apoptosis and senescence. We developed an agent-based model to test the time to extinction or stability in each of these phenotypes across three levels of stochastic environments.

ContributorsDanesh, Dafna (Author) / Maley, Carlo (Thesis director) / Aktipis, Athena (Committee member) / Compton, Zachary (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2021-12
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Description
Cancer rates vary significantly across tissue type and location in humans, 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. A comparison of cancer prevalence across

Cancer rates vary significantly across tissue type and location in humans, 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. A comparison of cancer prevalence across the tree of life can give insight into how evolutionary history has shaped various mechanisms of cancer suppression. Here, we explore whether species-level life history strategies are associated with differences in mammary neoplasia rates across 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 phylogenetic regression on 15 life history traits across 112 mammalian species to determine the correlation between a life history trait and how it relates to mammary neoplasia prevalence. A greater risk of mammary neoplasia was found in the characteristics associated with fast life history organisms and a lower risk of mammary neoplasia was found in the characteristics associated with slow life history organisms. With this analysis, a framework is provided for how different life history modalities can influence cancer vulnerability.
ContributorsMajhail, Komal Kaur (Co-author) / Majhail, Komal (Co-author) / Maley, Carlo (Thesis director) / Boddy, Amy (Committee member) / Compton, Zachary (Committee member) / College of Health Solutions (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
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Description

Public education and involvement with evolutionary theory has long been limited by both the complexity of the subject and societal pushback. Furthermore, effective and engaging evolution education has become an elusive feat that often fails to reflect the types of questions that evolution research attempts to address. Here, we explore

Public education and involvement with evolutionary theory has long been limited by both the complexity of the subject and societal pushback. Furthermore, effective and engaging evolution education has become an elusive feat that often fails to reflect the types of questions that evolution research attempts to address. Here, we explore the best methods to present scientific research using interactive educational models to facilitate the learning experience of the audience most effectively. By creating artistic and game-play oriented models, it becomes possible to simplify the multifaceted aspects of evolution research such that it enables a larger, more inclusive, audience to better comprehend these complexities. In allowing the public to engage with highly interactive education materials, the full spectrum of the scientific process, from hypothesis construction to experimental testing, can be experienced and understood. Providing information about current cancer evolution research in a way that is easy to access and understand and accompanying it with an interactive model that reflects this information and reinforces learning shows that research platforms can be translated into interactive teaching tools that make understanding evolutionary theory more accessible.

ContributorsSilva, Yasmin (Author) / Maley, Carlo (Thesis director) / Compton, Zachary (Committee member) / Baciu, Cristina (Committee member) / Barrett, The Honors College (Contributor) / School of International Letters and Cultures (Contributor) / School of Life Sciences (Contributor)
Created2022-05
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Description

Cancers of the reproductive tissues make up a significant portion of the cancer burden and mortality experienced by humans. Humans experience several proximal causative carcinogens that explain a portion of cancer risk, but an evolutionary viewpoint can provide a unique lens into the ultimate causes of reproductive cancer vulnerabilities. A

Cancers of the reproductive tissues make up a significant portion of the cancer burden and mortality experienced by humans. Humans experience several proximal causative carcinogens that explain a portion of cancer risk, but an evolutionary viewpoint can provide a unique lens into the ultimate causes of reproductive cancer vulnerabilities. A life history framework allows us to make predictions on cancer prevalence based on a species’ tempo of reproduction. Moreover, certain variations in the susceptibility and prevalence of cancer may emerge due to evolutionary trade-offs between reproduction and somatic maintenance. For example, such trade-offs could involve the demand for rapid proliferation of cells in reproductive tissues that arises with reproductive events. In this study, I compiled reproductive cancer prevalence for 158 mammalian species and modeled the predictive power of 13 life history traits on the patterns of cancer prevalence we observed, such as Peto’s Paradox or slow-fast life history strategies. We predicted that fast-life history strategists will exhibit higher neoplasia prevalence risk due to reproductive trade-offs. Furthering this analytical framework can aid in predicting cancer rates and stratifying cancer risk across the tree of life.

ContributorsDarapu, Harshini (Author) / Maley, Carlo (Thesis director) / Boddy, Amy (Committee member) / Compton, Zachary (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2022-05