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- All Subjects: Breast Cancer
- All Subjects: Diabetes
- Creators: Department of Chemistry and Biochemistry
- Resource Type: Text
Description
The purpose of this project was to identify proteins associated with the migration and invasion of non-transformed MCF10A mammary epithelial cells with ectopically expressed missense mutations in p53. Because of the prevalence of TP53 missense mutations in basal-like and triple-negative breast cancer tumors, understanding the effect of TP53 mutations on the phenotypic expression of human mammary epithelial cells may offer new therapeutic targets for those currently lacking in treatment options. As such, MCF10A mammary epithelial cells ectopically overexpressing structural mutations (G245S, H179R, R175H, Y163C, Y220C, and Y234C) and DNA-binding mutations (R248Q, R248W, R273C, and R273H) in the DNA-binding domain were selected for use in this project. Overexpression of p53 in the mutant cell lines was confirmed by western blot and q-PCR analysis targeting the V5 epitope tag present in the pLenti4 vector used to transduce TP53 into the mutant cell lines. Characterization of the invasion and migration phenotypes resulting from the overexpression of p53 in the mutant cell lines was achieved using transwell invasion and migration assays with Boyden chambers. Statistical analysis showed that three cell lines—DNA-contact mutants R248W and R273C and structural mutant Y220C—were consistently more migratory and invasive and demonstrated a relationship between the migration and invasion properties of the mutant cell lines. Two families of proteins were then explored: those involved in the Epithelial-Mesenchymal Transition (EMT) and matrix metalloproteinases (MMPs). Results of q-PCR and immunofluorescence analysis of epithelial marker E-cadherin and mesenchymal proteins Slug and Vimentin did not show a clear relationship between mRNA and protein expression levels with the migration and invasiveness phenotypes observed in the transwell studies. Results of western blotting, q-PCR, and zymography of MMP-2 and MMP-9 also did not show any consistent results indicating a definite relationship between MMPs and the overall invasiveness of the cells. Finally, two drugs were tested as possible treatments inhibiting invasiveness: ebselen and SBI-183. These drugs were tested on only the most invasive of the MCF10A p53 mutant cell lines (R248W, R273C, and Y220C). Results of invasion assay following 30 μM treatment with ebselen and SBI-183 showed that ebselen does not inhibit invasiveness; SBI-183, however, did inhibit invasiveness in all three cell lines tested. As such, SBI-183 will be an important compound to study in the future as a treatment that could potentially serve to benefit triple-negative or basal-like breast cancer patients who currently lack therapeutic treatment options.
ContributorsZhang, Kathie Q (Author) / LaBaer, Joshua (Thesis director) / Anderson, Karen (Committee member) / Gonzalez, Laura (Committee member) / Barrett, The Honors College (Contributor) / School of International Letters and Cultures (Contributor) / Department of Chemistry and Biochemistry (Contributor)
Created2015-05
Description
There has been an alarming rise in the prevalence of obesity which has been attributed to the paralleled rise in consumption of high-fat foods. It’s commonly accepted that high-fat diets can lead to increased weight gain, however not all fats have the same physiological action. This study primarily focuses on the effect of canola oil, a monounsaturated fat, on energy homeostasis and body composition when it’s given as a supplement to a high-fat diet composed of saturated fatty acid. Rodent models were divided into three dietary groups: 1) low-fat diet (LFD), 2) high-fat diet (HFD) and 3) canola oils supplemented HFD (HF+CAN). After 4 weeks of dietary intervention, samples of epididymal fat, perinephric fat, and liver were analyzed across the three groups to see if the changes in energy homeostasis could be explained by the cellular behavior and composition of these tissues. Interestingly, the supplement of canola oil appeared to reverse the deleterious effects of a saturated fat diet, reverting energy intake, body weight gain and adipose tissue sizes to that (if not lower than that) of the LFD group. The only exception to this effect was the liver: the livers remained larger and fattier than those of the HFD. This occurrence is possibly due to a decrease in free fatty acid uptake in the adipose tissues—resulting in smaller adipose tissue sizes—and increased fatty acid uptake in the liver. The mechanism by which this occurs has yet to be elucidated and will be the primary focus of upcoming studies on the effect of monounsaturated fat on other diets.
ContributorsZuo, Connie Wanda (Author) / Washo-Krupps, Delon (Thesis director) / Deviche, Pierre (Committee member) / Herman, Richard (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
Sickle Cell Disease (SCD) is a prevalent genetic disease in Africa, and specifically in Kenya. The lack of available relevant disease education and screening mean that most don't understand the importance of getting testing and many children die before they can get prophylactic care. This project was designed to address the lack of knowledge with supplemental educational materials to be partnered with an engineering capstone project that provides a low cost diagnostic test.
ContributorsShawver, Jamie Christine (Author) / Caplan, Michael (Thesis director) / Snyder, Jan (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor) / Harrington Bioengineering Program (Contributor)
Created2014-05
Description
The focus of this project was to look at alternative treatments for endocrine resistant breast cancer (ERBC), which are breast cancers that have become resistant to hormone therapies such as Tamoxifen or aromatase inhibitors. The first part of this project involves investigating the relationship between histone de-acetylase inhibitor Vorinostat and Tamoxifen in MCF7 G11 cells, Tamoxifen resistant sub-clones, according to the PSOC Time grant. The second part involves targeting the androgen receptor (AR) in MCF7 sub-clones with AR antagonists, Bicalutamide and MDV3100, and investigating the possible usage of AR as a biomarker, due to over-expression of AR in ERBC, in accordance with the Mayo ASU Seed Grant.
The synergistic effects between Vorinostat and Tamoxifen observed through a phase II study on breast cancer patients resistant to hormone therapy may involve more than the modulation of ER-alpha to reverse Tamoxifen resistance in ERBC cells. RT-qPCR of genes expressed in Tamoxifen resistant cells, trefoil factor 1(TFF1) and v-myc avian myelocytomatosis viral oncogene homolog (MYC), were evaluated along with ESR1 and Diablo as a control. MYC was observed to have increased expression in the treated cells, whereas the other genes had a decrease in their expression levels after the cells were treated for 3 days with Vorinostat IC30 of 1 µM. As for targeting the AR, MCF7 Tamoxifen sensitive and resistant cells were not affected by the AR antagonists to determine an IC50. The cell viability for all MCF7 sub-clones only decreased for high concentrations of 5.56 µM - 50 µM in Bicalutamide and 16.67 µM – 50 µM of MDV1300. Furthermore, hormone depletion of MCF7 G11 Tamoxifen resistant sub-clones did not show a great response to DHT stimulation or the AR antagonists. In the RT-qPCR, the MCF7 G11 cells showed an increase in mRNA expression for ER, AR, and PR after 4 hours of treatment with estradiol. As for the DHT treatment, ER, AR, PR, and PSA had a minimal increase in the fold change, but the fold change in AR was less than in the estradiol treatment. The Mayo Clinic will investigate the possible usage of AR as a biomarker through immunohistochemistry.
The synergistic effects between Vorinostat and Tamoxifen observed through a phase II study on breast cancer patients resistant to hormone therapy may involve more than the modulation of ER-alpha to reverse Tamoxifen resistance in ERBC cells. RT-qPCR of genes expressed in Tamoxifen resistant cells, trefoil factor 1(TFF1) and v-myc avian myelocytomatosis viral oncogene homolog (MYC), were evaluated along with ESR1 and Diablo as a control. MYC was observed to have increased expression in the treated cells, whereas the other genes had a decrease in their expression levels after the cells were treated for 3 days with Vorinostat IC30 of 1 µM. As for targeting the AR, MCF7 Tamoxifen sensitive and resistant cells were not affected by the AR antagonists to determine an IC50. The cell viability for all MCF7 sub-clones only decreased for high concentrations of 5.56 µM - 50 µM in Bicalutamide and 16.67 µM – 50 µM of MDV1300. Furthermore, hormone depletion of MCF7 G11 Tamoxifen resistant sub-clones did not show a great response to DHT stimulation or the AR antagonists. In the RT-qPCR, the MCF7 G11 cells showed an increase in mRNA expression for ER, AR, and PR after 4 hours of treatment with estradiol. As for the DHT treatment, ER, AR, PR, and PSA had a minimal increase in the fold change, but the fold change in AR was less than in the estradiol treatment. The Mayo Clinic will investigate the possible usage of AR as a biomarker through immunohistochemistry.
ContributorsVorachitti, Merica (Author) / LaBaer, Joshua (Thesis director) / Anderson, Karen (Committee member) / Gonzalez, Laura (Committee member) / Barrett, The Honors College (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Department of Chemistry and Biochemistry (Contributor)
Created2014-05
Description
The pathogenesis of type 1 diabetes (T1D) is still not fully understood in the scientific community. Evidence has shown that viral infections are one of the important environmental factors associated with the disease development. Seven of the top T1D related viruses were selected to study the prevalence of viral humoral response in T1D patients using our innovative protein array platform called Nucleic Acid Programmable Protein Array (NAPPA). In this study, each viral gene was individually captured using various PCR based techniques, cloned into a protein expression vector, and assembled as the first version of T1D viral protein array. Humoral responses of IgG, IgA, and IgM were examined. Although each class of immunoglobulin generated a wide-range of reactivity, responses to various viral proteins from different proteins were observed. In summary, we captured most of the T1D related viral genes, established viral protein expression on the protein array, and displayed the serum response on the viral protein array. The successful progress will help to fulfill the long term goal of testing the viral infection hypothesis in T1D development.
ContributorsDavis, Amy Darlene (Author) / LaBaer, Joshua (Thesis director) / Qiu, Ji (Committee member) / Desi, Paul (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor)
Created2013-05