Department: Anatomy and Pathology
Research Cluster: Cancer Biology
Office: BBSC 336-V
Phone: (304) 696-3700
Oxidative Stress, Epigenetics and Chronic Disease |
Breast and Colon Cancer | Chemoprevention | Experimental Therapeutics |
Metabolism and Nutrition (Transsulfuration, Ethanol, Cholesterol, Lipid, and Iron Metabolism)
My research background is diverse. As an undergraduate student I conducted environmental studies in ecology and limnology while pursuing a natural science degree at a small college in a rural setting. For my graduate work at Boston University, I trained in microbiology, but my research involved manipulating cholesterol and lipid metabolism for therapeutic effect to inhibit the growth and metastasis of colon cancer, evaluated using syngeneic and immunocompromised mouse models. During my postdoctoral work I studied phase II enzyme induction and iron biology.
My laboratory’s overall goal is to study the role of oxidant stress in the etiology of chronic diseases such as cancer, atherosclerosis, and age related tissue degeneration. I am a member of the Cancer Biology Research Cluster.
Early work in my laboratory at Marshall led to the discovery of active transsulfuration in normal breast cells by one of my graduate students (Andrea Belalcázar). Transsulfuration is a biochemical pathway that ties one-carbon metabolism, which is important for generating methyl donors for key reactions involved in epigenetic control, with glutathione production, the principal cellular antioxidant, which plays a critical role in the cells’ defense against toxic stress. We are concentrating on this intriguing intersection between metabolism and epigenetics in pursuit of our overall goal of determining how oxidant stress may contribute to the etiology of chronic disease. We have three projects underway in the laboratory:
Project I explores the intersection of transsulfuration, oxidant stress and epigenetics in the context of breast tissue. Initial work in this area led to the novel finding that human mammary epithelial cells have an active transsulfuration pathway. This research was conducted by developing a novel methodologic approach using 35S-methionine treated primary human mammary epithelial cells, and autoradiography of simple thin layer chromatography coupled with fluorescent imaging. The pathway provides a potential link between oxidant stress and epigenetic reactions that involve methyl donation, such as DNA or histone methylation, which has several implications for breast cancer etiology. Our planned work in this area will involve determining the impact of oxidant stress on epigenetic control in normal breast cells using tissue culture models involving primary human breast epithelial cells and a transgenic mouse model with impaired transsulfuration activity. This work will also involve determining the impact of transsulfuration blockade on the generation of DNA methylation and DNA hydroxymethylation using next-gen methods.
Project II (funded by an R21 Grant) explores how iron and ethanol may interact to impact oxidant stress in murine tissues, and how this may in turn affect global epigenetic regulation. Our findings indicate that strategies to reduce the stresses derived from ethanol exposure for chronic drinkers that involve iron restriction may be of limited utility, as iron uptake in the liver increases to compensate for low dietary iron. The initial funded work in this area has been conducted and a manuscript is in revision for publication. Future work will involve using in vitro methods to follow up on our primary findings of alcohol’s impact in the liver, to determine its impact in the breast, which may provide a mechanistic basis for alcohol’s strong epidemiologic role as a risk factor for mammary cancer.
Project III involves using a genetic approach to reveal candidate genes that regulate the basal iron phenotype in mice, what I loosely term the “ferrostat”. Mice from more than 30 strains of mice have been sacrificed and their tissues harvested for iron phenotype evaluation. We are currently conducting endpoint assays that will enable us to separate the strains into iron phenotype categories. Using an in silico approach, genetic regions that are associated with different phenotypes will be determined and potential regulatory candidates identified.
Students in the Wilkinson Lab
|Table 1: Careers of Graduate Students who have worked in my laboratory|
|Andrea Belalcázar||Research Technician at Mylan, Inc.|
|Kristen McKee||Quality Control/Assurance Scientist at Calgon Carbon|
||Seeking lab tech position (recent graduate)|
Three master’s students have worked in my laboratory. These are listed in Table 1 above. Please note that two have moved on to successful research careers, and the third is in the process of finding a position in research. Of additional note is that the discovery of the transsulfuration pathway in mammary cells occurred due to the work of my first graduate student, Andrea Belalcázar. Her work, published in ISRN Biochemistry, forms the basis for the further exploration of the impact of this active pathway in the breast on epigenetic processes that may respond to oxidant stress in this application.
Research in my laboratory is also advanced by undergraduate students, and is associated with their advancement to high-quality science careers. These undergraduates are listed in Table 2 below. During the course of the work funded by my recent R21 award, many opportunities arose for undergraduate students to work in my laboratory. Coupled with other lab projects, much of this work was labor-intensive, involving pair feeding mice, colony management, genotyping, and developing endpoint assays. I found the students to generally be very high caliber lab workers who approached the work with a determination to learn and to advance the projects’ goals.
|Table 2: Careers of Undergraduate Students who have worked in my laboratory|
|Katherine N. Bush
||Master’s Student in Neuroscience program at University of South FL|
|Benjamin Crowder||Medical Student at West Virginia University|
|Katie Curry||Ph.D. Student at University of North Carolina|
|Rebekah Jamieson||Research Technician at Duke University|
||Medical Student at Marshall University|
||Medical Student at University of Louisville|
Jesse A. Thornton, Vincent E. Sollars, Monica A. Valentovic, Emine C. Koc, David L. Porter Kristen R. McKee, James T. Buchanan Jr., John G. Ball, Hayden M. Hedrick, Trevor B. Stone, and John Wilkinson IV. Ethanol liquid diets with normal methyl donor levels generate mild gross pathology and iron-dependent patterns of hepatic protein acetylation in C57BL/6 J mice. In revision for resubmission to PlosOne.
Andrea D. Belalcázar, John G. Ball, Leslie M. Frost, Monica A. Valentovic, and John Wilkinson IV. Transsulfuration is a significant source of sulfur for glutathione production in human mammary epithelial cells. ISRN Biochemistry 2013: Article ID 637897, 7 pages, 2013.
Wilkinson J. IV, Is there an etiologic role for dietary iron and red meat in breast cancer development? IN “Nutrition and Cancer: From Epidemiology to Biology” Claudio P.P. And R.M. Niles, Editors; Bentham E-Books (ISBN: 978-1-60805-506-7) (Review), 2012.
Jiao Y, Wilkinson J 4th, Di X, Wang W, Hatcher H, Kock ND, D’Agostino R Jr, Knovich MA, Torti FM, Torti SV. Curcumin, a cancer chemopreventive and chemotherapeutic agent, is a biologically active iron chelator. Blood. 113:462-9, 2009.
Wilkinson J. IV, Xiumin, D., Schönig, K., Buss, J.L., Kock, N.D., J. Mark Cline, Saunders, T.L., Bujard, H., Torti, S.V., and Torti, F.M. Tissue-specific expression of ferritin H regulates cellular iron homeostasis in vivo. Biochem J, 395:501-507, 2006.
Yan Jiao, John Wilkinson IV, E. Christine Pietsch, Joan L. Buss, Roy P. Planalp, Frank M. Torti, Suzy V. Torti. Iron chelation in the biological activity of curcumin. Free Rad. Biol. Med., 40:1152-60, 2006.