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- All Subjects: Breast Cancer
- 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
The influenza virus is the main cause of thousands of deaths each year in the United States, and far more hospitalizations. Immunization has helped in protecting people from this virus and there are a number of therapeutics which have proven effective in aiding people infected with the virus. However, these therapeutics are subject to various limitations including increased resistance, limited supply, and significant side effects. A new therapeutic is needed which addresses these problems and protects people from the influenza virus. Synbodies, synthetic antibodies, may provide a means to achieve this goal. Our group has produced a synbody, the 5-5 synbody, which has been shown to bind to and inhibit the influenza virus. The direct pull down and western blot techniques were utilized to investigate how the synbody bound to the influenza virus. Our research showed that the 5-5 synbody bound to the influenza nucleoprotein (NP) with a KD of 102.9 ± 74.48 nM. It also showed that the synbody bound strongly to influenza viral extract from two different strains of the virus, the Puerto Rico (H1N1) and Sydney (H3N2) strains. This research demonstrated that the 5-5 synbody binds with high affinity to NP, which is important because influenza NP is highly conserved between various strains of the virus and plays an important role in the replication of the viral genome. It also demonstrated that this binding is conserved between various strains of the virus, indicating that the 5-5 synbody potentially could bind many different influenza strains. This synbody may have potential as a therapeutic in the future if it is able to demonstrate similar binding in vivo.
ContributorsKombe, Albert E. (Author) / Diehnelt, Chris (Thesis director) / Woodbury, Neal (Committee member) / Legutki, Bart (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor) / School of International Letters and Cultures (Contributor)
Created2014-05
Description
The influenza virus, also known as "the flu", is an infectious disease that has constantly affected the health of humanity. There is currently no known cure for Influenza. The Center for Innovations in Medicine at the Biodesign Institute located on campus at Arizona State University has been developing synbodies as a possible Influenza therapeutic. Specifically, at CIM, we have attempted to design these initial synbodies to target the entire Influenza virus and preliminary data leads us to believe that these synbodies target Nucleoprotein (NP). Given that the synbody targets NP, the penetration of cells via synbody should also occur. Then by Western Blot analysis we evaluated for the diminution of NP level in treated cells versus untreated cells. The focus of my honors thesis is to explore how synthetic antibodies can potentially inhibit replication of the Influenza (H1N1) A/Puerto Rico/8/34 strain so that a therapeutic can be developed. A high affinity synbody for Influenza can be utilized to test for inhibition of Influenza as shown by preliminary data. The 5-5-3819 synthetic antibody's internalization in live cells was visualized with Madin-Darby Kidney Cells under a Confocal Microscope. Then by Western Blot analysis we evaluated for the diminution of NP level in treated cells versus untreated cells. Expression of NP over 8 hours time was analyzed via Western Blot Analysis, which showed NP accumulation was retarded in synbody treated cells. The data obtained from my honors thesis and preliminary data provided suggest that the synthetic antibody penetrates live cells and targets NP. The results of my thesis presents valuable information that can be utilized by other researchers so that future experiments can be performed, eventually leading to the creation of a more effective therapeutic for influenza.
ContributorsHayden, Joel James (Author) / Diehnelt, Chris (Thesis director) / Johnston, Stephen (Committee member) / Legutki, Bart (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor) / Department of Chemistry and Biochemistry (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