Breast cancer (BC) is the second most common malignancy in the world and it accounts for 15% of female deaths due to cancer every year. The development of these tumours is regulated by the activities of the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). Tamoxifen (TAM) is frequently used to treat patients with ER+ BC; however, a recurring problem is the development of resistance and the mechanisms leading up to this event remain unclear. FAM84B is reported to be associated with the development of various cancers such as esophageal squamous cell carcinoma and prostate cancer. The function of the protein is unknown; however, insight towards its mechanism of action has been made through the discovery of its structural similarities with the H-Ras-like suppressor (HRASLS) subfamily of enzymes. We hypothesize that FAM84B upregulation enhances BC tumorigenesis and facilitates the development of TAM resistance in this disease. We observed that both overexpression and knockdown of FAM84B had little effects on cell proliferation; however, the latter reduced the ability of MCF7 cells to form isolated colonies. We performed similar analyses using a FAM84B mutant with deletion of its HRASLS domain and we observed that MCF7 cells expressing this protein showed higher rates of cell proliferation and increased ability to form isolated colonies compared to cells with baseline expression of wild-type FAM84B. These results suggest that FAM84B regulates BC cell proliferation through a complex manner. An analysis of patient-derived BC tissue revealed that FAM84B expression was associated with BC at early stages than later stages, which suggests a possible role of the protein in directing events associated with the early developmental stages of the disease. Additional analyses demonstrated that overexpression and knockdown of FAM84B had little impact on TAM-derived cytotoxicity of MCF7 cells. We observed higher expression of FAM84B in TAM-resistant MCF7 cells in comparison to TAM-sensitive cells, while TAM-resistant and TAM-sensitive xenograft tumours showed similar levels of FAM84B expression. This suggests that the contributions of FAM84B in BC tumorigenesis and resistance to TAM are complex; alternatively, FAM84B may not play a major role in either events. Future studies will be needed to clarify the effects of FAM84B on BC tumorigenesis and progression. / Dissertation / Master of Science (MSc) / Breast cancer (BC) is the second most common malignancy in the world and it accounts for 15% of female deaths due to cancer every year. Although hormonal therapy with tamoxifen (TAM) is a commonly used treatment for the disease, a recurring problem is that tumours eventually develop resistance to the drug. We are interested in investigating the role of FAM84B in BC tumorigenesis and the development of TAM resistance in these tumours. FAM84B has been shown to have higher expression in esophageal squamous cell carcinoma than in normal tissue and the protein was associated with increased tumour growth. Similar studies in prostate cancer have shown that FAM84B is associated with progression of the disease. The results of our analyses suggest that FAM84B may have a possible role in promoting events associated with enhancing the viability of MCF7 cells, leading to increased rates of growth and division. In addition, FAM84B may also function to direct events associated with the early developmental stages of BC. We did not, however, observe any impact of altered FAM84B expression on the development of TAM resistance in BC. Further research involving improved in vitro and in vivo studies, along with an examination of FAM84B’s impact on various oncogenic molecular signalling pathways, will help improve our understanding of the protein’s role in BC tumorigenesis.

A resistively loaded bowtie antenna, intended for applications in breast cancer detection, is adaptively modified through modelling and genetic optimization. The required wideband operating characteristic is achieved through manipulation of the resistive loading of the antenna structure, the number of wires, and their angular separation within the equivalent wire assembly. The results show an acceptable impedance bandwidth of 100.75%, with a challenge VSWR <; 2, over the interval from 3.3 GHz to 10.0 GHz. Feasibility studies were made on the antenna sensitivity for operation in a tissue-equivalent dielectric medium. The simulated and measured results are all in close agreement.

One of the leading causes of mortality for African-American women is breast cancer. The national breast cancer mortality rate for African-American women is 28.0 per 100,000. However, African-American women residing in Northwest Louisiana have a breast cancer mortality rate of 34.5 per 100,000 (American Cancer Society; National Cancer Institute; Landis, Murry, Boldern & Wingo, 1998). This is the fourth highest of all women living in the United States (Early Cancer Detection Program, Annual Report, 1999). Breast cancer mortality is correlated to the stage at diagnosis. The earlier breast cancer is diagnosed and treated, the more likely women can survive the disease (Davis, Axelrod, Osborne & Telang, 1997). African-American women are frequently diagnosed with breast cancer at an advanced stage (Phillips, Cohen, & Moses, 1999). The frequent advanced stage diagnosis may be due to African-American women breast cancer screening practices. When done correctly and as recommended, breast cancer screening can help women detect breast cancer at an early stage, when it is most treatable. Since African-American women residing in Northwest Louisiana have the fourth highest national mortality rate, and little is known about their compliance with the recommendations of the American Cancer Society regarding breast cancer screening, there is a need to identify these practices of African-American women in Northwest Louisiana.The purpose of this study was to examine the relationship between select variables and breast cancer screening practice. A questionnaire was used to gather information from a convenient sample of 273 African-American women recruited from two sites located in Northwest Louisiana -- Grambling State University and the Willis-Knighton Neighborhood Clinic. The questionnaire was used to gather information about: demographics, knowledge, and individual breast cancer risk factors (age of menarche, full term pregnancy, history of breast condition or disease, type of breast condition or disease, age when gave birth to first child, menopause, age menopause began). Andersen's theoretical framework served as the guiding theory for the study. The hypotheses were analyzed by the chi square test of independence and logistic regression.Results from the chi-square test of independence indicated that breast cancer screening is dependent upon age, education, income, age when gave birth to first child, menopause, and age menopause began. In contrast, breast cancer screening is independent of breast cancer knowledge, age of menarche, full term pregnancy, history of breast condition or disease, type of breast condition or disease, and family history of breast cancer. Logistic regression was used to predict the odds of breast cancer screening compliance by the women in this study. The analysis found that having an annual income of 25,000 - 39,999 as the strongest income predictor of non-compliance. Logistic regression analysis found that having a Master's degree was the strongest educational attainment predictor of non-compliance. / Ph. D.

Cancer is characterized by a deregulation of the cell cycle resulting in abnormal proliferation of cells that can bypass tightly regulated molecular checkpoints. Breast cancer is the most common cancer diagnosed in women, ~70% of cases displaying an estrogen receptor positive (ER+) phenotype. The aim of the present work was to generate a comprehensive overview of the biological mechanisms, molecular pathways and specific proteins involved in cell cycle progression in ER+ breast cancer cells. We focused on the G1-to-S phase transition of the cell cycle because major differences in cell proliferation mechanisms between normal and cancerous cells are observed at this point. We developed a large-scale proteomics strategy to enable the comparison of MCF-7 ER+ (cancer) and MCF-10A (non-tumorigenic) epithelial breast cells. Samples were analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS) followed by a label-free quantitation approach, i.e., spectral counting, for differential protein expression analysis. The study was divided into three distinct parts: 1) qualitative profiling of MCF-7 cells arrested in the G1-phase and released into the S-phase of the cell cycle, 2) differential expression profiling of MCF-7 cells in G1 and S, and 3) differential expression profiling of the G1-phases of MCF-7 and MCF-10A cells. The qualitative evaluation of MCF-7 proteomic data resulted in the identification of >2700 proteins (p-score<0.001). A large number of these proteins were involved in cell cycle relevant processes, being representative of all hallmarks of cancer. Differential expression analysis of the MCF-7 G1 and S-phases resulted in the identification of >250 proteins with roles in DNA repair, transcription, translation, chromatin maintenance and signaling. The MCF-7/MCF-10 comparison revealed that major cellular processes that require DNA access, such as the ones identified in the MCF-7 analysis, are up-regulated in the nucleus of MCF-7 cells during starvation, possibly allowing these cancerous cells to bypass the restriction point. Several proliferative and anti-proliferative markers were identified in both MCF-7 and MCF-10A cells. / Ph. D.

ER+ breast cancer raises a significant diagnostic challenge since resistance invariably develops to the current endocrine therapies. 70% of breast cancers are ER+, which results from the overexpression of estrogen receptor. ER mediates strong anti-inflammatory signaling in ER+ tissues. Once activated with estradiol (E2), ER inhibits inflammatory gene expression via protein-protein interactions that block NF-kappa B transcriptional activity. Importantly, NF-kappa B is a primary mediator of resistance in many cancers, including breast cancer. All current endocrine suppressive treatments block this palliative signaling pathway, along with the desired proliferative pathway. Thus, there is a significant unmet clinical need for novel endocrine treatments for breast cancer that can ameliorate patient outcome in resistant populations, be less prone to resistance development, retain anti-inflammatory action, and cause fewer side effects. Following the hypothesis driven approach, the work described here introduces structural analogs of an innovative ligand scaffold, 5,6-bis-(4-hydroxyphenyl)-7-oxabicyclo[2.2.1]hept-5-ene-2-sulfonic acid phenyl ester, termed OBHS, which reduces gene activation through ligand-induced shifts in helices 8 and 11, thereby indirectly modulating helix 12 of ER (hence, indirect antagonists). This new class of ligands with a bicyclic hydrophobic core retains strong anti-inflammatory effects while dialing out the proliferative effects of E2 (similar to Selective Estrogen Receptor Modulators, SERMS), and could potentially replace the current endocrine therapies of breast cancer. In this work, we carried out rational design and syntheses of two series of OBHS analogs, namely OBHS-A (for acetamido derivatives), and OBHS-P (for propargyl derivatives), while we explored a synthetic methodology for a third series of OBHS compounds. Many analogs from the OBHS-A series exhibited high binding affinity. For example, the exo diastereomer of 2.11a, 2.11b, 2.11c, 2.11d, and 2.11e exhibited Relative Binding Affinities (RBAs) of 22.6%, 10.5%, 19.5%, 12.1%, and 14.4%, respectively. As observed before, endo OBHS compounds exhibited lower binding affinities than exo compounds. The RBA values with acetamide, and isobutyramide (i.e. short hydrophobic chains) were very comparable to each other. However, unexpectedly the propionamide compound showed lower binding affinity than butyramide. Nevertheless, we consider OBHS analogs with RBA values greater than 1% (Kd = 20 nM) to be very potent. This data is only the first step in a battery of assays that will be conducted eventually on these compounds. In particular, our emphasis is in ascertaining and improving the NF-kappa B mediated anti-inflammatory property, where these compounds have shown promising activity in conjunction with their anti-proliferative activity. / Master of Science

Bioimpedance is the term given to the complex impedance value that is characteristic of the resistance that biological cells offer to the flow of electric current. The objective of this study is to analyze the differences in the bioimpedance of highly metastatic MDA-MB-231 and normal MCF 10A breast epithelial cells and use this information to detect a very small number of breast cancer cells present in a background of normal breast cells and other cells that are typically present in a human biopsy sample.To accomplish this, a bioimpedance sensor with flat gold microelectrodes on a silicon substrate was designed and fabricated. Suberoylanilide hydroxamic acid (SAHA), an FDA-approved anti-cancer agent was used to improve the sensitivity of the bioimpedance sensor towards cancer cells by selectively modifying their cytoarchitecture. / Master of Science

The research presented in this thesis aims to uncover the intricate manner in which BRCA1 interacts with RNAP II during mRNA production utilizing a unique microchip system developed in our lab. We were first able to prove the effectiveness of our tunable system using a breast cancer model of patient derived triple negative breast cancer (TNBC) cells. Here we switched out different mammalian antibodies and collected images of the same structure from different angles. This served many purposes: (1) it proved the system could be tuned for specific uses; (2) it demonstrated that all subunits were present in the complex; (3) it eliminated the need for the tilt function allowing for a less intensive computational procedure. In the BRCA1 wild type cell line we were able to incorporate into our 3D reconstruction, atomic models of the BRCA1-BARD1 heterodimer and the RNAP II core in regions of major unoccupied density. Other areas of minor missing density were overlaid with a short strand of DNA and ubiquitin moieties, which proved agreement with Co-IPs. Next we sought to compare the wild type structure with a BRCA1 mutant variety. Using these techniques, we determined the 3D structure of the mutated complex. After further analysis slight differences were detected between the two complexes, especially in the placement of the atomic models. Overall we were able to determine structural abnormalities that occur when a mutation is present in BRCA1 that may have future applications for targetable therapy in TNBC patients. Moreover, by using TNBC as the disease model, we have created a platform that can be used to evaluate other human diseases due to the tunable nature of our microchip system. / Master of Science

Yes / Breast cancer is a leading cause of cancer-related deaths. Anemia is common in breast cancer patients and can be treated with blood transfusions or with recombinant erythropoietin (EPO) to stimulate red blood cell production. Clinical studies have indicated decreased survival in some groups of cancer patients treated with EPO. Numerous tumor cells express the EPO receptor (EPOR), posing a risk that EPO treatment would enhance tumor growth, but the mechanisms involved in breast tumor progression are poorly understood. Here, we have examined the functional role of the EPO-EPOR axis in preclinical models of breast cancer. EPO induced the activation of PI3K/AKT and MAPK pathways in human breast cancer cell lines. EPOR knockdown abrogated human tumor cell growth, induced apoptosis through Bim, reduced invasiveness, and caused downregulation of MYC expression. EPO-induced MYC expression is mediated through the PI3K/AKT and MAPK pathways, and overexpression of MYC partially rescued loss of cell proliferation caused by EPOR downregulation. In a xenotransplantation model, designed to simulate recombinant EPO therapy in breast cancer patients, knockdown of EPOR markedly reduced tumor growth. Thus, our experiments in vitro and in vivo demonstrate that functional EPOR signaling is essential for the tumor-promoting effects of EPO and underline the importance of the EPO-EPOR axis in breast tumor progression. / Cancer Research UK - C10141/A9977 (TRL, MET, KKC). European Commission FP7 (EpoCan) 282551 (TRL, KBM); Invest NI RD0914223 (TRL, KBM).

Electrokinetics is a family of effects that induces motion of a liquid or a particle within a liquid in response to an external electric field. Using the intrinsic electrical properties of bacteria and of breast cancer cells, electrokinetics can be used to manipulate these particles for two different types of applications: tissue engineering and breast cancer detection. The first application studied the effects of electric fields on bacteria cells as well as calcium ions to potentially create a meniscus scaffold with hydroxyapatite ends for anchoring. In response to the electric field, calcium ions were able to deposit locally and simultaneously with cellulose growth. Bacteria cells were also studied to determine their response under an AC field. At low frequencies, bacteria demonstrated controlled movement caused by electroosmosis and dielectrophoresis with a net motion caused by a dielectrophoretic force. In the second application, the separation capabilities of different stages of breast cancer cells from the same cell line were tested using contactless dielectrophoretic (cDEP) devices. The electric field gradients in cDEP devices were altered to optimize selectivity and to determine an estimated membrane capacitance for each. From the results, the membrane capacitance of the early to intermediate stages proved to be very similar; however, late stage breast cancer cells have potential in being separated from early and intermediate stages. / Master of Science

<p dir="ltr">Metastatic breast cancer (MBC) and consequent dormancy present a significant clinical challenge due to recurrence and relapse. It is thus pivotal to understand the mechanisms which can reawaken the dormant cancer cells into a proliferative phenotype, and to develop effective therapeutic strategies to eradicate the minimal residual disease. Fibroblast Growth Factor Receptor 1 (FGFR1) is a receptor tyrosine kinase (RTK) which is amplified in MBC and plays a key role in cancer cell plasticity. Interestingly, while dormant cancer cells also exhibit high FGFR1 expression levels; still, mere FGFR1 alone is insufficient to drive proliferation without FGF2 ligand induced receptor activation. In accordance with previous data, we report elevated levels of FGF2 in serum of mice with diet induced obesity (DIO), thereby indicating a potential link between obesity and dormancy breakage. We demonstrate that serum from obese animals, exogenous FGF2 stimulation, or constitutive stimulation through autocrine and paracrine FGF2 is sufficient to induce proliferation and drive pulmonary outgrowth of the dormant D2OR model. Additionally, blockade of FGFR signaling via FGFR kinase inhibitors prevented ligand induced outgrowth of the D2OR model. Importantly, FGFR1 overexpression in normal mammary epithelial cells also requires FGF2 signaling to induce transformation suggesting that mere FGFR1 amplification alone is not a driving event.</p><p dir="ltr">Despite elevated FGFR1 expression levels in dormant and metastatic breast cancer, FGFR kinase inhibitors have been unsuccessful in inducing a significant therapeutic response in FGFR1-amplified setting, potentially due to the inability of targeting the kinase-independent functions of FGFR1. In our study, we explored the use of G-quadruplex (G4) stabilizers as epigenetic therapeutics to limit FGFR1 expression, thus targeting both kinase-dependent and independent functions of the receptor. Our findings demonstrate that, in contrast to the FDA approved FGFR-kinase inhibitors, G4 stabilizers significantly reduce the viability of dormant cells in 3D culture models. Additionally, the G4 stabilizers effectively suppressed the expression of other oncogenes such as PDGFR and MYC, which is advantageous given the heterogeneous nature of dormant and MBC cells. The results from our findings suggest that FGF2:FGFR1 signaling acts as a key molecular mechanism in modulating dormancy and breast cancer progression. Additionally, G4 stabilizers hold promise as a novel therapeutic approach to target and eliminate dormant breast cancer cells, potentially reducing the risk of relapse and improving long-term patient outcomes.</p>