Recent Student Research Posters

Rebecca LeVan ‘08
Major: Biochemistry
Hometown: Waverly, Iowa

iRoles of Leptin and Adiponectin in Liver of TGF ą + Mice
Faculty Sponsors: Dr. Margot Clearly and Dr. Soner Dogan, Hormel Institute, University of Minnesota. Past studies have looked at transgenic mouse mammary tumor virustransforming growth factor ą (MMTVTGF- ą) female mice placed in three different caloric consumption groups: (1) Ad libitum-fed (AL) (2) Chronic Caloric Restricted (CCR) (3) Intermittent Caloric Restricted (ICR). This study also suggested that ObR and ObRb (Leptin receptors) have a role in early phase of mammary tumor development due to the finding that ObR and ObRbs expression level was higher in the mammary fat pad tissue in AL mice than ICR and CCR mice (Cleary, 2007). Knowing that AL group showed the most tumor occurrence, the study was based on sixteen mice of the AL caloric. The mice were tested and half came back mammary tumor positive. These mice then had their mammary tumor tissue and mammary fat pad tissue tested for different protein expression levels. The study focused on whether Leptin and/or Adiponectin and their receptor levels in the liver change based on the presences of mammary tumors, with the hypothesis that Leptin would show an increase in protein expression levels in mammary tumor positive mice and Adiponectin would show an increase in protein expression levels in mammary tumor negative mice. The current study in the liver tissues of Ad-libitum fed mice showed that there was a significant difference between ObRb (receptor of Leptin) total protein expression levels with mammary tumor positive mice having both increased (not opposite). Leptin, ObR (receptor of Leptin), Adiponectin, Adipo R1 (receptor of Adiponectin) and Adipo R2 (receptor of Adiponectin) showed no significant difference between mammary tumor positive and negative. Adipo R1 molecular weight in the liver showed to be 55 kDa which is different than other studies have shown in the mammary fat pad and the mammary tumor tissue. This will be further studied.

Mark Schultz ‘08
Majors: Biochemistry, Biochemistry/Biology
Hometown: Waverly, Iowa

DNA Damage Causes TTF2 to Enter the Nucleus of Cervical Cancer Cells Faculty Sponsor: Dr. David H. Price, professor of biochemistry, University of Iowa Interdisciplinary Summer Undergraduate Research Program This past summer, I was assigned a project working on Transcription Termination Factor-2 (TTF2). DNA damage causes TTF2 to travel from the cytoplasm to the nucleus in promotion of DNA repair. The lab has been trying to elucidate just how TTF2 is able to move around in the cell. I examined whether various proteins inhibited TTF2 trafficking and found one protein that did not allow TTF2 to enter the nucleus. I presented my work at the Summer Undergraduate Research Conference at the end of the summer.

Jennifer Starner ‘08
Major: Chemistry
Hometown: Brooklyn Park, Minn.

IgG Purification Methods Utilizing Specialized Affinity Chromatography
Faculty Sponsor: Dr. Robert Carlson, RECEPTORS LLC and professor of chemistry, University of Minnesota. For the past two summers, I was a significant member of a research team and was involved in various product development projects. I designed and tested an immunoassay for tetrachloroethylene, an environmental toxin. The results of this project were formally presented to the company. I also participated in a group research project which focused on designing affinity chromatography methods for IgG purification. IgG purification has great pharmaceutical implications. I personally created miniature chromatography columns using micorcentrifuge tubes and the company’s specialized support mediums. These miniature columns, along with dot blots, allowed us to effectively and efficiently test the various support mediums and determine which supports were successful at IgG purification. They also allowed us to conduct high throughput screening of possible elution buffers.

Jessica Viner ‘08
Major: Biochemistry
Hometown: Eldridge, Iowa

Determining the Molecular Link Between HPV and Protein Tyrosine Phosphatase in Oncogenesis
Faculty Sponsor: Dr. Ernesto Fuentes, University of Iowa Department of Biochemistry Summer Undergraduate Research Program HPV 16 is a type of HPV that causes cancer in tonsilar epithelial cells. A protein thought to be involved in the development of tonsilar epithelial carcinoma is ProteinTyrosinePhosphatase-Basophil like. PTP-BL has 5 PDZ domains that are believed to bind to the oncoprotein E6 that is transcribed via HPV 16. My job this summer was to isolate and analyze PDZ domains from PTP-BL. Specifically, I designed restriction enzymes for each domain and used PCR to replicate the DNA for each domain, purified the domains using columns, and conducted the fluorescence assay to determine the binding properties of the separate domains with E6.

John Welch ‘08
Majors: Biochemistry/Biology/Chemistry
Hometown: Shellsburg, Iowa

Surface Feature Analyses of Biocements from Pectinaria gouldii and Phragmatopoma lapidos
Faculty Sponsor: Dr. Maria Dean, assistant professor of chemistry and Dr. Thomas Tauer, assistant professor of biology, Coe College Presented at the 42nd Midwest Regional Meeting of the American Chemical Society By using surface microscopies such as atomic force microscopies (AFM), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS), I was able to gain information about the physical characteristics of the biocements produced by each annelid. By analyzing the data, I was able to determine what differences existed in the physical characteristics and elemental composition of the biocements.

Kim Chaffin ‘09
Major: Biology/Biochemistry
Hometown: Milford, Iowa

Kyle Huegel ‘09
Major: Biochemistry
Hometown: Charles City, Iowa

Tim McKenna ‘08
Major: Biology
Hometown: Cedar Falls, Iowa

Jessica Viner ‘09
Major: Biochemistry
Hometown: Eldridge, Iowa

LPA regulation of cell surface associated proteases in ovarian cancer cells
Faculty Sponsor: Dr. Shawn Ellerbroek, assistant professor of chemistry/biochemistry
Published in the 2008 American Association of Cancer Research Annual Meeting Proceedings Lysophosphatidic acid (LPA) contributions to ovarian cancer progression are postulated to involve stimulation of cell surface associated proteolysis. We analyzed the effects of LPA on the expression and cell surface association of two proteolytic enzymes linked with ovarian cancer progression. LPA significantly increased the density of OVCA 429 and OVCA 433 ovarian cancer cell cultures at or below concentrations normally found in ascites fluids (0.1 uM), whereas its stimulation of uPA activity in culture medium required the elevated concentrations (20-80 uM) often found in the ascites of ovarian cancer patients. Inhibitor studies demonstrated that OVCA 433, but not OVCA 429, cellular release of uPA activity required p42/44 MAPK signaling. Conversely, inhibition of p38 MAPK signaling in OVCA 433 cells stimulated the release of uPA activity in a dose-dependent fashion. LPA treatment (80 uM) significantly stimulated the binding of uPA activity to the surface of both OVCA 429 and OVCA 433 cells. LPA treatment increased the expression of MMP-9 over MMP-2 in conditioned media, but did not stimulate detectable binding of MMP-9 to the cell surface. Over expression of MMP-9 in control cells was sufficient to drive cell surface association of a proteolytically processed MMP-9 species that was not observed in conditioned media. Future studies will evaluate the functional consequence of enhanced cell surface proteolysis on ovarian cancer cell invasive activity.