Triple-negative breast cancers (TNBCs) are highly refractive to current treatment strategies, and new multi-targeted treatments need to be elucidated. Combination therapy that includes targeting the murine double minute 2 (Mdm2) signaling axis offers a promising approach. Protein-protein interaction inhibitors such as Nutlin-3a block the binding of key signaling molecules such as p53, p73α, and E2F1 to the hydrophobic pocket of Mdm2 and can lead to activation of cell-death signaling pathways. Since clinical trials for TNBC are evaluating the DNA damaging agent carboplatin, the objective of this thesis was to evaluate the therapeutic potential and mechanism of action of combination carboplatin and Nutlin-3a to treat TNBC. In TNBC cell lines with a mutant p53 background, we determined if modulation of Mdm2 function in the context of carboplatin-mediated DNA damage resulted in a synergistic inhibition of cell growth. Several ratios of carboplatin:Nutlin-3a were strongly synergistic in increasing cell death, with combination indices of 0.5 and lower. Mechanistic studies indicated that drug sensitivity and Mdm2 expression were dependent on p73. Mdm2 localized to a larger degree in the chromatin fraction isolated from cells treated with the combination treatment consistent with observations by others that Mdm2 binds to the Mre11/Rad50/Nbs1 complex, inhibits the DNA damage response, and increases drug sensitivity. In vivo efficacy experiments were conducted in the TMD231 orthotopic mammary fat pad model in NOD.Cg-PrkdcscidIl2rgtm1Wjl/SzJ (NSG) mice. For assessment of baseline tumor burden and randomization, fluorescent imaging of E2-Crimson expressing TMD231 cells was performed. Following Nutlin-3a and carboplatin combination treatment, there was a statistically significant reduction in primary tumor volume as well as lung metastases with significantly increased probability of survival compared to Vehicle and single drug treatments (p<0.001). While there was a decrease in bone-marrow cellularity, this did not lead to bone-marrow aplasia, and body weights recovered to normal levels within 7 days post-treatment. The present studies demonstrate the promise of Mdm2 as a therapeutic target in combination with conventional therapy, increase our understanding of how to potentiate DNA damage in cancers, and may lead to new clinical therapies for triple-negative primary and metastatic breast cancer.

Indiana University-Purdue University Indianapolis (IUPUI) / Today we know that there are several different types of breast cancer. Accurate identification breast cancer subtype is extremely important in treating this disease effectively. Consequently the process of invtro development of drugs to treat this disease should be naturally subtype specific. Until now several studies have identified multiple breast cancer cell lines and these cell lines have served as invaluable invitro tumor models. However very few of these cell lines are classified as per their subtypes. In this thesis an effort is made to classify 59 of such breast cancer cell lines using genetic profile comparison approach. This approach is based on comparing characteristic features such as copy number and gene expression of a given cell line to those observed from the tissue samples of different breast subtypes. The tissue data for this comparison comes from The Cancer Genome Atlas (TCGA) while cell line data is taken from Cancer Cell Line Encyclopedia (CCLE).

Indiana University-Purdue University Indianapolis (IUPUI) / The biophysical microenvironment of the tumor site has significant impact on breast cancer progression and metastasis. The importance of altered mechanotransduction in cancerous tissue through the integrin-mediated signaling axis has been documented, yet its role in the regulation of cellular metabolism and the potential link between cellular energy and cell migration remain poorly understood. In this study, we investigated the role of mechanotransduction (via Src and FAK) in AMP-activated protein kinase (AMPK) activation in breast cancer cells in response to interstitial fluid flow. Additionally, we explored the involvement of AMPK in breast cancer cell migration. An in-vitro three-dimensional (3D) cell culture model utilizing collagen-Matrigel matrices was used. Interstitial fluid flow was applied to the 3D cell-matrix construct inside a flow chamber. The sub-cellular signaling activity of Src, FAK, and AMPK was visualized in real-time using fluorescent resonance energy transfer (FRET). We observed that breast cancer cells (MDA-MB-231) are more sensitive to interstitial fluid flow than normal epithelial cells (MCF-10A) in the regulation of FAK and Src. AMPK was activated in the mitochondria of MDA-MB-231 cells by interstitial fluid flow, but not in other subcellular domains (i.e., cytosol, plasma membrane, and nucleus). Subcellular AMPK in MCF-10A cells did not respond to interstitial fluid flow. The inhibition of FAK or Src abolished flow-induced AMPK activation in the mitochondria of MDA-MB-231 cells. We also observed that global AMPK activation reduced MDA-MB-231 cell migration. Interestingly, specific AMPK inhibition in the mitochondria reduced cell migration and blocked interstitial fluid flow-induced cell migration. Our results suggest the linkage of FAK/Src and mitochondria-specific AMPK in mechanotransduction and the dual role of AMPK in breast cancer cell migration depending on its subcellular activation. Therefore, subcellular AMPK activation may play an important and distinct role in cancer invasion and progression.

Tumour initiation and progression is thought to be driven by a small population of tumor initiating cells (TICs) or cancer stem cells (CSCs), which have the capacity to migrate and cause metastases and contribute to tumour relapse. These cells possess properties that are similar to those of normal tissue stem cells, which include the capacity to undergo self-renewal as well as the capacity to give rise to more differentiated progenitor cells, which comprise the bulk of the tumour cell population. Thus far, the clinical significance of these cells in breast cancers has not been extensively explored with regard to their relationship with tumour pathology or patient survival. In this thesis we evaluate the presence of these cells in terms of clinicopathological tumour characteristics and patient outcome, as well as assess potential markers of breast CSCs for prognostic significance. Through the quantification of breast CSCs in primary breast tumours using in vivo xenografts assays we show that their presence correlates with aggressive tumour characteristics. In addition, we propose that markers of breast CSCs may differ based on the molecular subtype of the tumour, and that these markers have prognostic significance in patients. / Thesis / Master of Science (MSc)

Indiana University-Purdue University Indianapolis (IUPUI) / Current evidence shows that sleep-wake disturbances are a persistent problem in women surviving breast cancer. The purpose of this study was to refine the knowledge regarding the incidence, prevalence, and predictive factors of sleep-wake disturbances in breast cancer survivors (BCS) compared to age-matched women without breast cancer (WWBC). The cross-sectional, convenience-sample consisted of secondary data from BCS and WWBC who were recruited by two parent quality of life studies. Subjects were matched within +/- 5 years of age. The sample consisted of 246 BCS and 246 WWBC who were a mean age of 48 years old (SD=8.50), Caucasian (70%), employed (69%), married or partnered (76%), postmenopausal (59%), with a college education (56%), and with at least one concurrent medical problem (95%). Results showed that BCS had more prevalent sleep-wake disturbances (65%) compared to WWBC (55%). The poorest sleepers were BCS, women with hot flashes, poor physical functioning, depressive symptoms, or with moderate or high levels of distress related to a life event. BCS had higher PSQI scores indicating poorer sleep quality and higher sleep disturbances compared to WWBC. Predictors of the severity of poor sleep quality and sleep disturbances were BCS, women with higher number of co-morbidities, women with hot flashes, lower levels of physical functioning, higher depressive symptoms, and greater impact of a life event. Disease and treatment related factors did not predict poor sleep or sleep quality in BCS. Sleep disturbances are a problem in long-term BCS. Knowledge of contributing factors provides useful information during clinical evaluations and treatment of BCS reporting poor sleep. Additional research is needed to determine the impact of poor sleep on quality of life and develop/test effective interventions for long-term BCS.

A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Medicine in Diagnostic Radiology Johannesburg, 2019 / INTRODUCTION Breast cancer is one of the leading causes of cancer deaths worldwide. Triple negative breast Cancer (TNBC) is an aggressive subtype, commonly described as presenting at a younger age, in women of African descent and in low socioeconomic groups. Commonly it demonstrates benign imaging features making diagnosis a challenge. Early detection and treatment is imperative. AIM To determine the common imaging features of TNBC in South Africa. METHOD A retrospective study was conducted at a tertiary institution in South Africa. the study population included all biopsy proven TNBC patients presenting between 01/01/2012 – 30/06/2016. All the initial mammograms were re-read by three independent radiologists using a data collection sheet. Illegible or incomplete reports were excluded from the study. RESULTS In our population, TNBC commonly presented in African women with an average age of 54.2 and range 25-95 years, with 47% being pre-menopausal. Typical mammographic features were an oval (27%) or irregular (27%) shaped mass with well circumscribed margins (33%). Our lesions were much larger than those reported in the literature (1). Global asymmetry and architectural distortion were commonly associated features. On ultrasound, the lesions were mostly irregularly shaped (56%) with spiculated borders (29%) and hypoechoic (80%) with axillary adenopathy (81%). CONCLUSION The majority of our patient population presented with a clinically palpable mass, that was larger and had more aggressive features than usually described in the literature. This can be attributed to delayed presentation, due to numerous factors. In order to improving the detection rate and reduce mortality, education and screening programs play a major role. / E.K. 2019

No description available.

<p> Being the second most important cause of death in women, breast cancer attracted great interest from many research groups in different fields developing techniques to prevent, detect or cure it. Due to the fact that this disease can be treated if it is detected in early stages, many projects in this field have focused on early breast cancer detection. Modern imaging technologies have helped in the detection of this cancer but they still have high false positive or negative rates indicating a great need for more research in early breast cancer detection.</p> <p> In 2002 the Federal Communication Commission allowed usage of 3.1 - 10.6 GHz frequency range for short-range medical and personal applications, and this has stimulated much research on one of the most interesting technologies for medical imaging. With the aid of advances in complementary metal-oxide-semiconductor technology as well as wireless communications, this imaging technology has steadily grow, and now, it has it has many attractive characteristics that makes it a perfect substitute for conventional imaging systems.</p> <p> This thesis reports on the design of some key circuits for an ultra-wideband transceiver architecture that can be used for medical imaging and especially for breast cancer detection. In this work, we concentrated on the receiver and two of its major blocks, namely, a low noise amplifier and a mixer are designed, simulated, fabricated and tested. Both of these circuits are designed in 0 .13 μm technology and Cadence tools are used for simulation and layout. </p> <p> First, a low noise amplifier is designed based on a common-source configuration with inductive degeneration and a third order Chebyshev input matching network. Using precise zero-pole analysis, two inductors have been added to the main architecture of amplifier to improve its gain bandwidth product. The designed circuit shows a very good performance in terms of all of design parameters. Voltage gain with a peak value of 18.6 dB and very acceptable flatness is achieved. Also the noise figure of this circuit had an average of 4.7dB and a minimum value of 3.3dB. Input and output impedance matching shows very satisfying performance for the whole range of 3.1 to 10.6 GHz. Moreover, linearity of the circuit shows a very good performance compared with other works with IIP3 of -0.996 dBm. Finally, all of these specifications are achieved while consuming only 4.01 mW and occupying 1.3 mm2 of chip area.</p> <p> Second, an ultra-wideband mixer is designed to work as a multiplier in this configuration, and to perform a critical function in correlation block. The mixer is designed for both super- and sub-threshold modes of MOSFET operation, and in both modes, it shows very acceptable performance. While super-threshold mixer shows much better characteristics in terms of gain, noise and linearity, the very low power consumption of sub-threshold circuit along with its reasonable performance in terms of gain, noise and linearity makes both circuits excellent designs for niche applications. Excellent conversion gain of 22.54dB is achieved for super-threshold circuit together with minimum noise figure of 7.4 dB and IIP3 of 2.67 dBm, while consuming 6.67 mW and having excellent input impedance matching all over the bandwidth. On the other hand, the sub-threshold circuit dissipates only 623 μW, with 13.44 dB of conversion gain and minimum noise figure of 7.67 and IIP3 of -7.47 dBm. This circuit has excellent input matching all over the UWB frequency range.</p> / Thesis / Master of Applied Science (MASc)

<P> Breast cancer has affected many women around the world throughout history. In order to recognize and treat the early signs of breast cancer, obtaining high quality images is crucial. A variety of imaging modalities are available for use in breast imaging, including conventional mammography and newer optical imaging techniques. One such optical imaging system is the ComfortScan™, which uses red light to image the breast and was the focus of this study. The objectives include investigating whether performing a large scale clinical trial with the ComfortScan TM would be warranted to further patient care and diagnostics for breast imaging, and determining whether the ComfortScan ™ would achieve better correlation to biopsy than mammography alone. An additional goal was to investigate whether the ComfortScan TM system would be beneficial as a mainstream method for a radiologist to diagnose breast cancer risk. </p> <p> The preliminary study with 19 patients demonstrated that there was no difference in diagnostic information between the near-infrared (NIR) image and mammography (p>O.OS). Anecdotal evidence suggests cases where mammography disagreed with biopsy, whereas ComfortScan TM agreed, though these were not statistically significant. Based on these encouraging results, a large scale clinical trial was launched to investigate the potential of widespread use of the ComfortScan ™. The large scale trial included 126 NIR images and found difference in diagnostic information between NIR and mammography (p<O.OS). Mammography agreed with biopsy in 18/33 and the ComfortScan™ system agreed with biopsy in 25/33 cases. The sensitivity and specificity for the ComfortScan™ system was 83% and 67%, respectively. The sensitivity and specificity of mammography was 94% and 13%, respectively. This study included a variety of women with varying ages and BIRADS scores, and demonstrated the effective clinical use of a portable, non-ionizing, inexpensive imaging modality, indicating that the ComfortScan ™ system could likely be successful as a mainstream adjunct to mammography. </p> <p> The potential of using polyvinyl alcohol cryogel (PVA-C) as a breast tissue mimic was investigated and PV A -C was then used to validate the mode of action of the ComfortScan TM system. Two experimental methods reported the absorption coefficients and reduced scattering coefficients of PV A-C. Using a double integrating sphere, the values were J.la = 0.012 ± 0.002 mm-1 and J.ls' = 1.5 ± 0.2 mm-1 and using steady-state spatially resolved diffuse reflectance, the values were J.la = 0.017 ± 0.005 mm-1 and J.ls' = 1.3 ± 0.2 mm-1 at 640 nm. These values are comparable to typical absorption coefficients for tissue reported by others. </p> <p> The mode of action suggested by DOBI (Dynamic Optical Breast Imaging) Medical for the ComfortScan ™ system is that under compression a malignant tumour will highly attenuate light, due to a partial collapse in the tumourous vasculature, resulting in an increased deoxygenation of blood over time. Using a PV A-C breast mimicking phantom, it was shown that by deoxygenating horse blood in a cavity, there was an increase in the attenuation of 640 nm light as compared with the surrounding phantom material; which suggests that the colour representative of malignancies on the ComfortScan ™ is caused by deoxygenating blood. Further evidence suggests that the ComfortS can TM system is not recognizing a total collapse of the vasculature and subsequent void of blood from the tumour as the trigger for malignant detection. The mode of action suggested by DOBI Medical is supported by our findings. </p> / Thesis / Doctor of Philosophy (PhD)

Breast cancer (BC) is the second most commonly occurring malignant disease in women and one of the leading causes of cancer-related death worldwide, globally accounting for almost half-a-million deaths per year. In Canada, BC is the second leading cause of death in women preceded only by lung cancer. Invasion and metastasis are the most common causes of mortality in patients with BC. Studies show that extracellular vesicles (EVs) play an important role in immune system evasion, invasion and metastasis. Studies have shown a significant elevation of EVs in the serum of cancer patients compared to healthy subjects. Furthermore, elevated secretion of EVs has been correlated with cancer malignancy. Therefore, it has been suggested that EVs may be an important non-invasive diagnostic and prognostic tool for cancer. Herein our in vitro studies show that ER-α is secreted via EVs from MCF-7 cells. Furthermore, our mass spectrometry (MS)-based proteomic study showed that the proteomic profile of EVs from the plasma of BC patients differs from that of healthy subjects. In addition, we have also shown that vesicular abundance of proteins associated with tumour malignancy, such as tissue factor (TF), plasminogen activator inhibitor (PAI-1), a disintegrin and metalloproteinase 12 (ADAM12) and β-Catenin is different between primary tumour and metastatic disease. / Thesis / Master of Science (MSc)