Loss of heterozygosity (LOH) on the long arm of chromosome 16 is frequently observed during the onset of breast cancer. Our laboratory has recently identified both ANKRD11 and FBXO31 as candidate tumour suppressor genes in the chromosome band 16q24.3, which is the smallest region of overlap for breast cancer LOH. This thesis focuses on the functional analysis of these two novel genes and implicates a role for them as breast cancer tumour suppressors. ANKRD11: a novel p53 coactivator involved in the rescue of mutant p53. The ability of p53 to act as a transcription factor is critical for its function as a tumour suppressor. Ankyrin repeat domain 11 (ANKRD11) was found to be a novel p53-interacting protein which enhanced the transcriptional activity of p53. ANKRD11 expression in breast cancer cell lines was shown to be down-regulated when compared to ANKRD11 expression in finite life-span HMECs and non-malignant immortalized breast epithelial cells. Restoration of ANKRD11 expression in MCF-7 (p53 wild-type) and MDA-MB-468 (p53[superscript R273H] mutant) cells suppressed the oncogenic properties of these breast cancer cell lines through enhancement of p21[superscript waf1] expression. ShRNA-mediated silencing of ANKRD11 reduced the ability of p53 to activate p21[superscript waf1] expression in response to DNA damage. ANKRD11 was shown to associate with the p53 acetyltransferase, P/CAF, and exogenous ANKRD11 expression increased the levels of acetylated p53. Exogenous ANKRD11 expression enhanced the DNA-binding properties of the p53[superscript R273H] mutant to the CDKN1A promoter, implicating a role for ANKRD11 in the restoration of mutant p53[superscript R273H] function. These findings demonstrate a role for ANKRD11 as a p53 coactivator and illustrate the potential of ANKRD11 in the restoration of mutant p53[superscript R273H] function. ANKRD11 has roles beyond that of p53 coactivation. This thesis also presents preliminary findings to suggest that ANKRD11 may be involved in the regulation of eukaryotic cell division. Furthermore, ANKRD11 was shown to function as an estrogen receptor coactivator. Taken together, these finding suggest that ANKRD11 is a multi-functional cancer-related protein. FBXO31: the 16q24.3 senescence gene. A BAC located in the 16q24.3 breast cancer loss of heterozygosity region was previously shown to restore cellular senescence when transferred into breast tumour cell lines. We have shown that FBXO31, although located just distal to this BAC, can induce cellular senescence in the breast cancer cell line MCF-7 and is the likely candidate senescence gene. Exogenous FBXO31 expression inhibited the oncogenic properties of the MCF-7 breast cancer cell line. In addition, compared to the relative expression in normal breast, levels of FBXO31 were down-regulated in breast tumour cell lines and primary tumours. FBXO31 protein levels were cell cycle regulated, with maximal expression from late G2 to early G1 phase. Ectopic expression of FBXO31 in the breast cancer cell line MDA-MB-468 resulted in the accumulation of cells at the G1 phase of the cell cycle. FBXO31 was also shown to be a component of a SCF ubiquitination complex. We propose that FBXO31 functions as a tumour suppressor by generating SCF[superscript FBXO31] complexes that target particular substrates, critical for the normal execution of the cell cycle, for ubiquitination and subsequent degradation. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1325445 / Thesis (Ph.D.) -- University of Adelaide, School of Medicine, Discipline of Medicine, 2008

Loss of heterozygosity (LOH) on the long arm of chromosome 16 is frequently observed during the onset of breast cancer. Our laboratory has recently identified both ANKRD11 and FBXO31 as candidate tumour suppressor genes in the chromosome band 16q24.3, which is the smallest region of overlap for breast cancer LOH. This thesis focuses on the functional analysis of these two novel genes and implicates a role for them as breast cancer tumour suppressors. ANKRD11: a novel p53 coactivator involved in the rescue of mutant p53. The ability of p53 to act as a transcription factor is critical for its function as a tumour suppressor. Ankyrin repeat domain 11 (ANKRD11) was found to be a novel p53-interacting protein which enhanced the transcriptional activity of p53. ANKRD11 expression in breast cancer cell lines was shown to be down-regulated when compared to ANKRD11 expression in finite life-span HMECs and non-malignant immortalized breast epithelial cells. Restoration of ANKRD11 expression in MCF-7 (p53 wild-type) and MDA-MB-468 (p53[superscript R273H] mutant) cells suppressed the oncogenic properties of these breast cancer cell lines through enhancement of p21[superscript waf1] expression. ShRNA-mediated silencing of ANKRD11 reduced the ability of p53 to activate p21[superscript waf1] expression in response to DNA damage. ANKRD11 was shown to associate with the p53 acetyltransferase, P/CAF, and exogenous ANKRD11 expression increased the levels of acetylated p53. Exogenous ANKRD11 expression enhanced the DNA-binding properties of the p53[superscript R273H] mutant to the CDKN1A promoter, implicating a role for ANKRD11 in the restoration of mutant p53[superscript R273H] function. These findings demonstrate a role for ANKRD11 as a p53 coactivator and illustrate the potential of ANKRD11 in the restoration of mutant p53[superscript R273H] function. ANKRD11 has roles beyond that of p53 coactivation. This thesis also presents preliminary findings to suggest that ANKRD11 may be involved in the regulation of eukaryotic cell division. Furthermore, ANKRD11 was shown to function as an estrogen receptor coactivator. Taken together, these finding suggest that ANKRD11 is a multi-functional cancer-related protein. FBXO31: the 16q24.3 senescence gene. A BAC located in the 16q24.3 breast cancer loss of heterozygosity region was previously shown to restore cellular senescence when transferred into breast tumour cell lines. We have shown that FBXO31, although located just distal to this BAC, can induce cellular senescence in the breast cancer cell line MCF-7 and is the likely candidate senescence gene. Exogenous FBXO31 expression inhibited the oncogenic properties of the MCF-7 breast cancer cell line. In addition, compared to the relative expression in normal breast, levels of FBXO31 were down-regulated in breast tumour cell lines and primary tumours. FBXO31 protein levels were cell cycle regulated, with maximal expression from late G2 to early G1 phase. Ectopic expression of FBXO31 in the breast cancer cell line MDA-MB-468 resulted in the accumulation of cells at the G1 phase of the cell cycle. FBXO31 was also shown to be a component of a SCF ubiquitination complex. We propose that FBXO31 functions as a tumour suppressor by generating SCF[superscript FBXO31] complexes that target particular substrates, critical for the normal execution of the cell cycle, for ubiquitination and subsequent degradation. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1325445 / Thesis (Ph.D.) -- University of Adelaide, School of Medicine, Discipline of Medicine, 2008

<p>Breast cancer is the most common form of cancer which struck women around the world. When a human is exposed to threat or stress, e.g. breast cancer, different coping strategies are used in order to cope with the situation by the afflicted person. The aim of this literature study was to describe how women, who suffered from breast cancer, experienced coping with their situation. Scientific articles were found in the databases Medline (Pub Med) and Cinahl. A total of 14 articles were chosen regarding to the inclusion criteria and were assessed, analyzed and compiled. The result of the study showed that the women coped with their situation with different and varied strategies. These strategies were categorised in all ready known main categories: problem based, emotional, meaning based and religious coping. The sub categories that emerged under problem based were: seek and find support, educate oneself, have a positive attitude and remaining strategies, under emotional; avoidance and distraction, live a normal life, emotionally composed activities, the use of humour, have a passive attitude, under meaning based; acceptance, the will to survive, lean on hope, newfound meaning and personal development, under religious; faith and spirituality, the relationship to God, prayer for strength and support and remaining categories. Altogether the result displayed a variety of coping strategies that were different depending on the person and the unique situation and it is of great importance that medical staff possesses this knowledge in order to understand patients different ways to cope with their illness.</p> / <p>Bröstcancer är den vanligaste cancerformen som drabbar kvinnor världen över. När människan utsätts för hot och påfrestningar, som t ex vid bröstcancer, används olika copingstrategier av de drabbade för att hantera situationen. Syftet med denna litteraturstudie var att beskriva hur kvinnor med bröstcancer upplever att de hanterade sin situation. Vetenskapliga artiklar söktes i databaserna Medline (Pub Med) och Cinahl. Utifrån fastställda inklusionskriterier valdes 14 artiklar ut, dessa värderades, analyserades och sammanställdes. Resultatet visade att kvinnorna hanterade sin situation med olika och varierande strategier. Dessa strategier kategoriserades i de kända huvudkategorierna: problembaserad, emotionell, meningsbaserad och religiös coping. De underkategorier som framkom under problembaserad var; söka och finna stöd, utbilda sig, ha en positiv attityd och övriga strategier, under emotionell; undvikande och distraktion, leva ett normalt liv, känslostillande aktiviteter, använda humor, ha en passiv attityd, under meningsbaserad; accepterande, viljan att överleva, förlita sig på hopp, nyfunnen mening och personlig utveckling, under religiös; tro och andlighet, relationen till Gud, böner för styrka och stöd och övriga strategier. Sammantaget visade resultatet på en mångfald av copingstrategier som var olika beroende på individ och situation och det är av stor vikt att vårdpersonal har vetskap om detta för att kunna förstå patienters olika sätt att hantera sin situation.</p>

Breast cancer is of a primary concern in women, although it can occur in men. It is the second leading cause of cancer related deaths amongst women, and it is estimated that roughly 39,840 women will die of this disease this year. Breast cancer occurs across all populations and ethnicities. When African-Americans (AA) present with breast cancer, they usually have poorly differentiated tumors, and are more likely to be diagnosed with an advanced stage tumor. When compared to Caucasian (Cau) women, African-American women also have higher breast cancer mortality. The causes of these differences are not yet definitively known, but it has been suggested that the disparities that are present between African-American and Caucasian women are due to a number of factors. A few which have been mentioned are differences in Body Mass Index (BMI), socioeconomic status, health care coverage, and the level of obtained education that exists between the two ethnic groups. Although these factors may account for a small percentage of the difference seen between the two ethnic groups, the underlying cause that may explain why African-American women are at a greater risk of developing aggressive breast cancer may be due to differences in gene expression. A focus of my research project is the comparison of genome-wide gene expression differences between African-American and Caucasian women. Preliminary results from the comparison of normal breast tissue (obtained from reduction mammoplasty) from Caucasian and African-American women suggest there are marked differences in gene expression patterns. Pathway analysis of differentially expressed genes shows that they are involved in protein folding and the immune response. I am currently expanding this study to include a comparison of 10 AA to 10 Cau normal breast samples. These samples are being LCM dissected to separately compare gene expression in epithelial and stromal tissue. Cross comparisons between ethnic groups and tissue types will provide an understanding of normally occurring differences between AA and Cau women, which may help to explain the observed cancer disparities. Data from the study of normal tissue will be compared to gene expression data from triple negative breast cancer (TNBC) patients from both ethnicities.

Breast cancer is a devastating disease that affects thousands of women every year influencing their psychological and physical well-being for many years after being diagnosed. The goal of the current study was to determine if there are distinct trajectories of functioning among breast cancer patients in the domains of negative psychological adjustment, positive psychological adjustment, and physical adjustment. This was accomplished using growth mixture modeling. Another goal of this study was to determine whether demographic, medical, and psychosocial variables were able to distinguish among the trajectories. The study combined women from two samples spanning 10 years providing a sample size of 376 women diagnosed and treated for breast cancer. These women were recruited to participate in a 10-week cognitive behavioral stress management intervention and were either randomized to the 10-week experimental condition or a one-day control group. It was hypothesized that distinct trajectories would emerge for each of the domains and that psychosocial variables (i.e., social support, benefit finding, and emotional approach coping) would distinguish among the trajectories. This study was able to statistically identify multiple classes or trajectories of adjustment, consistent with findings reported by Helgeson and colleagues (2004) and Donovan and colleagues (2007). It is difficult to say, however, whether these classes differ in clinically significant ways. The present study also provides a cautionary note to researchers who intend to use growth mixture modeling to identify different trajectories of functioning and the limitations associated with this statistical technique. First, it is important to start this process with strong empirical or theoretical support for the possibility of different classes or trajectories. Without this foundation it becomes difficult to justify why a certain number of classes were chosen. Another limitation of this statistical approach is that there is not a standard method for determining the best number of classes. There are conflicting opinions among researchers in the field about the best fit index to use when the multiple fit indices do not converge. A serious issue related to this is the fact that classes are used for interpreting results and drawing conclusions and inferences. Therefore, clinicians using GMM must be careful when deciding on the number of classes and the clinical inferences drawn from these analyses. Further research needs to be conducted validating these statistical techniques.

Background: The synthetic insecticide DDT (dichlorodiphenyltrichloroethane) has been speculated to increase breast cancer risk due to its environmental persistence, levels of bioaccumulation in breast adipose tissue, and endocrine disrupting actions. Epidemiological studies have had inconsistent findings, however a study in MMTV-neu mice determined that localized, developmental exposure to the reported anti-androgen p,p' DDE accelerated mammary tumor development. This study tested the potential cancer-promoting actions of p,p' DDE, the most prevalent and persistent DDT metabolite. &lt;br&gt;Objectives: To identify and characterize the expression of p,p' DDE -regulated genes to determine how developmental exposure may influence mammary tissue to promote tumor formation. Methods: For localized delivery, ELVAX 40P pellets containing various doses of p,p' DDE, hydroxyflutamide (another anti-androgen), and mixtures of p,p' DDE with other congeners like o,p' DDE and p,p' DDT were implanted into the mammary fatpads of prepubertal female mice. p,p' DDE-regulated genes were identified by microarray analysis and analyzed by real time RT-PCR. &lt;br&gt;Results: Lipid-adjusted levels of p,p' DDE in mammary adipose tissue and serum in young mice were within the ranges of human exposure. p,p' DDE significantly upregulated casein gamma (csn1s2a ), keratin 18 (krt18) and interferon-induced protein 44 (ifi44) genes in mammary tissue. These genes were similarly, but not significantly regulated by hydroxyflutamide. The dose of p,p' DDE that caused early tumor onset in a previous study resulted in unique expression for all three genes and concentrations of p,p' DDE also influenced gene responses for the mixtures. However, no qualitative changes were observed in gland morphology. Significant upregulation of transforming growth factor beta (tgfb1) and downregulation of interleukin 10 (il10) in splenic leukocytes indicated that localized delivery of p,p' DDE to the mammary gland also influences systemic immune responses. Significant upregulation of il10 by p,p' DDE and hydroxyflutamide suggest that some of p,p' DDE actions may be through its anti-androgenic activity. &lt;br&gt;Conclusions: Relevant human exposure levels of p,p' DDE induce significant increases in expression of csn1s2a, krt18 and ifi44. This activity as well as those induced by other doses, ratios and hydroxyflutamide suggest p,p' DDE actions may involve anti-androgenic activity and influence local and systemic effects in a HER2+ breast cancer mouse model. / Mylan School of Pharmacy and the Graduate School of Pharmaceutical Sciences / Pharmacology-Toxicology / PhD / Dissertation

MicroRNAs (miRNAs) play a vital role in differentiation, proliferation and tumorigenesis by binding to messenger RNAs (mRNA) and inhibiting translation. To initiate an investigation into the identification of miRNAs in the domestic dog, an emerging model for human disease, a comparison of the human and canine genetic databases was conducted. The bioinformatics work revealed significant conservation of miRNA genes between the two species. Proof of principle experiments, including serial dilutions and sequencing, were performed to verify that primers made to amplify human mature miRNAs can be used to amplify canine miRNAs, providing that the mature sequences are conserved. TaqMan® Real-time RT-PCR, a sensitive and specific method, was used to isolate the first miRNA mature products from canine tissues. The expression levels of miR-17-3p, miR-17-5p, miR-18, miR-19a, miR-19b, miR-20, and miR-92 were evaluated in five canine tissues (heart, lung, brain, kidney, and liver). Because miRNAs have been found to act as both tumor suppressors and oncogenes in several different cancers, expression patterns of ten miRNAs (miR-15a, miR-16, miR-17-5p, miR-21, miR-29b, miR-125b, miR-145, miR-155, miR-181b, let-7f) known to be associated with human breast cancer were compared between malignant canine mammary tumors (n=6) and normal canine mammary tissue (n=10). Resulting data revealed miR-29b and miR-21 to have a statistically significant (p<0.05) up-regulation in cancerous samples. Overall expression patterns showed nine of the ten miRNAs follow the same pattern of expression in the domestic dog as the human, while the miR-145 expression does not show a difference between the normal and cancerous samples.

the majority of patients with early breast cancer receive some form of systemic adjuvant therapy (chemo-, endocrine, and/or targeted therapy). Despite the increase in adjuvant therapy prescription, little progress has been made with respect to assisting oncologists to determine which breast cancer patients, particularly those deemed at “lower risk” of relapse, require chemotherapy or other systemic therapy and which women can safely be treated with loco-regional treatment alone. For these reasons, the identification of prognostic and predictive markers that will assist the clinician in selecting the most suitable form of medical therapy has become very high priority as well as a real challenge in translational research. Unfortunately, several problems have hampered the identification and/or clinical usefulness of prognostic and predictive markers. In Chapter 1, we sought to address some of the specific questions regarding prognosis: - Are gene expression signatures robust and reproducible? - Do the different gene signatures have similar prognostic performance? Are they concordant in their prediction for the individual patient? - What is the role of individual genes in a signature and what is their biological interpretation? - What is the relationship between the molecular classification defined by cluster analysis and the different prognostic signatures? Through the following specific aims: 1. Independent validation study of a prognostic gene signature derived from microarray technology, to demonstrate its reproducibility, robustness and clinical utility compared with classical breast cancer prognostic factors in an appropriate validation cohort (Chapter 1A); 2. Independent comparison of three prognostic gene signatures (Chapter 1B); 3. Characterization of the biological foundation of the different prognostic signatures and refinement of our knowledge regarding breast cancer prognosis according to the molecular subgroups defined by ER and HER2 through a meta-analysis of publicly available gene expression data (Chapter 1C). In Chapter 2, we sought to address some specific questions regarding the prediction of response for the most commonly given breast cancer treatments: - What is the importance of proliferation genes in predicting clinical outcome in patients treated with endocrine therapy? - What is the value of TOP2A in predicting the efficacy of anthracycline therapy? - Can we identify a list of genes associated with response to anthracyline therapy? - What is the best method and cutoff to determine HER2-positive patients eligible for trastuzumab therapy? Would an alternative quantitative method for HER2 expression and homodimerization discriminate patients with significantly different probabilities of clinical outcome following treatment with trastuzumab? Through the following specific aims: 1. Investigation of molecular markers of response to endocrine therapy in hormono-sensitive patients (Chapter 2A); 2. Prospective evaluation of the predictive value of TOP2A and identification of genes associated with response in a cohort of patients treated with anthracyclines (Chapter 2B); 3. Investigation of the best method to select patients who should be treated by trastuzumab-based therapy and evaluation of a new technique to quantitatively assess HER2 expression (Chapter 2C).

In the past decades our knowledge concerning breast cancer progression from ductal carcinoma in situ (DCIS) to invasive cancer has grown rapidly. However, molecular factors driving the progression are still largely unknown. In the first study, we investigated tumor evolution in breast cancer by analyzing TP53 mutation status in tumors from various stages of the disease. Presence of the same TP53 mutations in both DCIS and invasive components from the same tumor indicates same cellular origin. The role of mutant TP53 in the progression of breast cancer is less clear and may vary between subtypes. In the second study, we studied the prognosis of basal-like DCIS in a large population-based cohort. Basal-like DCIS was associated with about doubled but not statistically significant risk for local recurrence compared with the other molecular subtypes. Molecular subtype was a better prognostic parameter than histopathological grade. In the third study, we studied markers in primary DCIS in relation to type of recurrence. Interestingly, recurrences after an ER-/HER2+, ER negative or EGFR positive primary DCIS were more often of the in situ type. The molecular subtype ER+/HER2+, FOXA1 positivity and FOXC1 positivity were risk factors for any recurrence. In the fourth study, we proposed a histological classification system for a new entity: neoductgenesis. We also evaluated histologic criteria for neoductgenesis. According to our criteria, good agreements among pathologists were achieved. Neoductgenesis was related to more aggressive tumor biology and to mammographic features. The result indicates potential benefits for women earlier considered having pure DCIS but later diagnosed as breast carcinoma with neoductgenesis, suggesting a need to develop appropriate treatment regiments. Our findings have to be repeated and the relation to prognosis warrants further studies.

Breast cancer is the most common form of cancer which struck women around the world. When a human is exposed to threat or stress, e.g. breast cancer, different coping strategies are used in order to cope with the situation by the afflicted person. The aim of this literature study was to describe how women, who suffered from breast cancer, experienced coping with their situation. Scientific articles were found in the databases Medline (Pub Med) and Cinahl. A total of 14 articles were chosen regarding to the inclusion criteria and were assessed, analyzed and compiled. The result of the study showed that the women coped with their situation with different and varied strategies. These strategies were categorised in all ready known main categories: problem based, emotional, meaning based and religious coping. The sub categories that emerged under problem based were: seek and find support, educate oneself, have a positive attitude and remaining strategies, under emotional; avoidance and distraction, live a normal life, emotionally composed activities, the use of humour, have a passive attitude, under meaning based; acceptance, the will to survive, lean on hope, newfound meaning and personal development, under religious; faith and spirituality, the relationship to God, prayer for strength and support and remaining categories. Altogether the result displayed a variety of coping strategies that were different depending on the person and the unique situation and it is of great importance that medical staff possesses this knowledge in order to understand patients different ways to cope with their illness. / Bröstcancer är den vanligaste cancerformen som drabbar kvinnor världen över. När människan utsätts för hot och påfrestningar, som t ex vid bröstcancer, används olika copingstrategier av de drabbade för att hantera situationen. Syftet med denna litteraturstudie var att beskriva hur kvinnor med bröstcancer upplever att de hanterade sin situation. Vetenskapliga artiklar söktes i databaserna Medline (Pub Med) och Cinahl. Utifrån fastställda inklusionskriterier valdes 14 artiklar ut, dessa värderades, analyserades och sammanställdes. Resultatet visade att kvinnorna hanterade sin situation med olika och varierande strategier. Dessa strategier kategoriserades i de kända huvudkategorierna: problembaserad, emotionell, meningsbaserad och religiös coping. De underkategorier som framkom under problembaserad var; söka och finna stöd, utbilda sig, ha en positiv attityd och övriga strategier, under emotionell; undvikande och distraktion, leva ett normalt liv, känslostillande aktiviteter, använda humor, ha en passiv attityd, under meningsbaserad; accepterande, viljan att överleva, förlita sig på hopp, nyfunnen mening och personlig utveckling, under religiös; tro och andlighet, relationen till Gud, böner för styrka och stöd och övriga strategier. Sammantaget visade resultatet på en mångfald av copingstrategier som var olika beroende på individ och situation och det är av stor vikt att vårdpersonal har vetskap om detta för att kunna förstå patienters olika sätt att hantera sin situation.