Thesis (M.A.)--Indiana University, 2010. / Title from screen (viewed on February 26, 2010). Department of Sociology, Indiana University-Purdue University Indianapolis (IUPUI). Advisor(s): Lynn Blinn-Pike, Carrie E. Foote, Betsy Fife. Includes vitae. Includes bibliographical references (leaves 100-105).

Obesity is a known risk factor for postmenopausal breast cancer, and is associated with worse disease prognosis in pre- and postmenopausal women. Adjuvant hormonal therapies improve disease prognosis in obese women, but many still recur. Given that obesity induces inflammation and increases levels of cyclooxygenase-2 (COX-2) enzyme, resulting in tumor proliferation, this retrospective study investigated if women on anti-inflammatory drugs would have improved disease outcomes by reduced production of prostaglandins by COX-2 pathway. Four hundred and forty women treated for invasive breast cancer in San Antonio clinics were included. Cases were classified as NSAID users if notes included daily use of aspirin, ibuprofen, celecoxib or another COX-2 inhibitor; patients were categorized as NSAID nonusers if they were not taking any NSAIDs, or if they used COX-2 drugs for pain as needed rather than daily. Patients on NSAIDs were more likely to be older, be slightly more obese and postmenopausal. NSAID and NSAID nonusers did not statistically significantly differ in regards to BMI categories, tumor stage, hormone receptor status, type of invasive tumor, ethnicity/race and type of surgery. NSAID users had significantly less recurrence rates compared to nonusers (p=0.05). Further, time to disease progression was delayed by almost 28 months in patients who were NSAIDs users. Although this trend was non-significant statistically due to low number of total recurrences, it is promising in the clinical setting. In a logistic regression model using NSAID use, BMI categories and hormonal therapy drug as independent variables to predict recurrence, use of NSAID was only statistically significant in the univariate model. Overweight women were more likely to develop recurrence than normal weight when holding NSAID use and endocrine therapy constant. Obese women had increase recurrence risk, but the trend was not statistically significant. Females using aromatase inhibitors were less likely to recur than those on tamoxifen. The results of this exploratory study had limited power to determine multiple modulating factors, but because they suggest a major clinical benefit, further analyses in a larger sample size are needed to confirm these findings. / text

Breast cancer is the most common cancer in women in most part of the world. Although there are multiple risk factors which have been reported to be related to breast factors, by far one of the highest risk of breast cancer is the inheritance of the BRCA1 and BRCA2 cancer susceptibility genes. The lifetime risk of breast cancer can be as high as 60-80% for BRCA mutation carriers. As the breast cancer epidemiology and genetic predisposition is increasingly understood, it transpires that ethnic differences exist. Although variations of genetic factors may play a role, the reasons for these differences remain unclear. Most published data are Caucasian based and there are limited publications on hereditary breast cancer in Asians available to date. This thesis hypothesizes that due to the known differences in genetic predisposition in different ethnic groups, it is likely that the mutation spectrum of BRCA mutations and breast cancer characteristics of Hong Kong Chinese, a relatively unexplored cohort, will differ to that of Caucasians. Moreover, the ancestors of local Hong Kong population migrated from Mainland China of which majority were from Southern China. They then remained in Hong Kong and populated and hence similar to smaller countries such as Iceland and Poland where founder mutations are identified, it is likely that a founder mutation will be present. Lastly due to different cultural differences and availability of screening facilities, management options of those found to carry the BRCA mutation may differ to that of other countries. The aims of this study are as follows 1) Perform a comprehensive genetic and phenotypic analysis using Full Gene Sequencing and Multiplex ligation-dependent probe amplification (MLPA) testing of Hong Kong Chinese cohort or breast cancer patients/families who are clinically high risk and to develop a registry to collect data related to this study. 2) To identify the spectrum of BRCA mutation in Hong Kong. 3) To report, any novel mutations, founder mutations, large rearrangements and deletions (using MLPA) if any are found. 4) If founder mutations are present, to develop a fasting and cheaper technique so that rapid screening can be offered. 5) To identify the choice of management in this high risk cohort. A total of 451 clinically high-risk breast and /or ovarian cancer patients from 1 March 2007 to 28 February 2011 were recruited. Based on sequencing results, 59 (13.1%) deleterious BRCA gene mutations were identified: 24 (41%) were in BRCA1 and 35 (59%) in BRCA2. Of the 59 deleterious mutations, 22 (37%) were novel mutations, 8 were BRCA1 and 14 were BRCA2 mutations. Eight recurrent mutations were identified of which four were proven to be founder mutations. These results showed that both BRCA1 and BRCA2 mutations account for a substantial proportion of hereditary breast/ovarian cancer in Sothern Chinese population. By using MLPA, four patients with large genomic rearrangement were identified and one of whom has a de novo BRCA1 mutation encompassing exons 1 to 12 deletion. Such mutations are rare and this de novo mutation has not been previously reported. Moreover another novel BRCA2 variant of unknown significance (c.7806-9T>G), a splice-site intronic mutation, was recharacterized to be pathogenic due to clinical suspicion based on its co-segregation. High Resolution Melting Technique in performing rapid screening for the founder mutations was developed and tested on a further cohort confirming the possibility of the use of founder mutations screening technique in future. Finally, concerning the management choice of BRCA mutation carriers undertaken in Chinese, BRCA mutation carriers in our cohort are more likely to choose intensive surveillance as an option of risk management rather than prophylactic interventions. In summary, this study provides valuable information on mutation spectrum of BRCA1 and BRCA2 in Southern Chinese population. Identifications founder mutations and knowledge of its prevalence in this Chinese population provides important information both to genetic counselling and risk assessment as well as to development of a cost-effective screening strategy. Furthermore, our study on the choice of management of mutation carriers allows us to have a baseline for development of future studies of psychological impact of genetic testing and management related to genetic testing, so that these high risk families can be better supported. / published_or_final_version / Surgery / Doctoral / Doctor of Philosophy

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Several diseases, including cancer, have been associated with high membrane type-1 matrix metalloproteinase (MT1-MMP) expression levels. MT1-MMP together with a non-membrane-bound, soluble MMP, MMP-2, also associated with many other biological functions, have been implicated in breast cancer progression, invasion and metastasis, and poor prognosis. Researchers who ran early clinical trials that employed broad-spectrum MMP inhibitors (MMPIs) lacked understanding of the intricate physiological and patho-physiological roles that MMPs play in tissues. In addition, structural similarities between MMPs hamper selective inhibition. Selective inhibition of MT1-MMP is of particular interest as MT1-MMP is overexpressed in target cancer cells relative to normal cells and is key in signalling for invasion. The inhibition profiles of two structurally similar synthetic pyrimidine-class MMPIs, with increased bioavailability and stability compared to hydroxamates tested in earlier clinical trials, TF 17-2 and TF 22d, were assessed. TF 17-2 and TF 22d were applied to a normal MCF-10A breast epithelial cell line and its premalignant H-ras(V12)-transfected MCF-10AneoT derivative to assess their efficacy for inhibiting MT1-MMP-mediated normal and premalignant cell migration, and indirectly, invasion. Both inhibitors form a co-ordination complex with the zinc ion of the catalytic site of MT1-MMP and MMP-2 with greater affinity for MT1-MMP. The computational molecular docking package, AutoDock Vina, was used for in silico predictions of binding affinities that could potentially substitute for in vitro kinetic assays when assessing inhibitor potential for inhibiting target MMPs. The binding of the two MMPIs was assessed using AutoDock Vina and compared to established kinetic data. The AutoDock Vina program was found to be an unreliable predictor for assessing relative efficacy of inhibition. During in vitro applications, analysis of the induction of apoptosis and metabolic effects were assessed using flow cytometry and the MTS assay, respectively. These showed no significant toxicity. Effects of inhibitors on collective and single cell migration in the normal and premalignant cell model, assessed using time lapse live cell imaging, cell morphology and labelling for vinculin and F-actin (for focal adhesions, FAs) showed that the TF 17-2 and TF 22d inhibitors reduced the collective cell migration of MCF-10A cells in scratch assays. Live-cell analysis of single cell migration, however, showed that TF 22d increased cell migration rates, and reduced the size of FAs and actin stability in MCF-10AneoT cells, resulting in a predominently rounded cell morphology in the premalignant cell line. TF 17-2, on the other hand was seen to be a relatively selective inhibitor of premalignant cell migration and resulted in MCF-10AneoT cells re-establishing larger focal - v - adhesions due to more stable F-actin networks resembling those of the non-transfected MCF-10A cell line, but reduced MCF-10AneoT cell migration most markedly. FA size and velocity of movement seemed inversely related in the normal and premalignant cells. The results of the current study suggest that, TF 17-2 seemed to have the greater therapeutic potential than TF 22d for inducing phenotype reversion, inhibition of dissemination, invasion and metastasis. Three promising selective pharmacological actions of TF 17-2 on the premalignant MCF10AneoT cell line include the suppression of proliferation, induction of increased in metabolic activity (possibly indicating cell stress) and a decrease in premalignant cell migration. A lack of cytotoxicity, however, suggests that TF 17-2 would need to be administered with an ancillary chemotherapeutic agent. This study showed that MMPIs directed against MT1-MMP, may still represent an effective strategy for inhibiting the migration of premalignant cells expressing high levels of MT1-MMP, and suggests further studies on this topic may be profitable. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2013.

Breast cancer is the most common cancer in female population worldwide. In addition to mutations, the breast tumor microenvironment especially the tumor cell - stroma interactions through extracellular matrix components and multiple growth factors have been shown to promote tumor progression. Among those, increases in both TGF-β (transforming growth factor beta) activities and periostin expression were associated with tumor cell survival, proliferation and metastasis. TGF-β role in breast cancer progression including its ability to promote periostin expression has been extensively studied. In contrast, the role of periostin in cancer progression remains to be fully understood. Thus, the present study aimed to determine whether TGF-β and periostin have effect on each other’s expressions in breast tumor and stroma cells using in vitro cell models. Through Western blot analyses and ELISAs, the periostin and TGF-β expressions of both stroma and tumor cells were analyzed following TGF-β and periostin treatments, respectively. The results indicate that TGF-β treatments led to significant increase in periostin expression in fibroblasts (p<0.05). In addition, periostin was differentially expressed by human breast cancer cells following TGF-β1 treatment. The TGF-β activities involved activation of pSMAD2 in both L929 fibroblasts and MCF10A mammary cells. Taken together, all experimental data indicate that within the breast tumor TGF-β and periostin likely participate in a regulation loop. Whether this putative regulation loop is critical to metastasis remains to be determined. Should periostin play a critical role in breast cancer progression, it could become a specific target in the preventive and/or therapeutic development of breast cancer patients.

Skewed somatic X inactivation (XCI), X-linked gene overexpression and abnormal X content have been associated with breast and ovarian cancer. Partial or complete reactivation of the inactive X in females may be a step in breast and ovarian cancer progression, leading to overexpression of some tumour enhancing gene. Markers of an X reactivation event were examined: X gene dosage, expression, and methylation in 8 ovarian cancer cell lines. Another marker of an X reactivation event, skewed XCI, was assayed in peripheral blood DNA from 106 breast and/or ovarian cancer patients (52 BRCA1 mutation carriers, 24 BRCA2 mutation carriers, 30 non-mutation carriers), 147 age-matched population controls. Combined RNA/DNA FISH was used to quantify the number of inactive Xs compared to total number of Xs. Five cell lines had increased X content. Three cell lines localized XIST to the presumptive inactive X; however the numbers of inactive Xs were variable. Expression levels of 8 X-linked genes were assessed by real-time PCR. Expression was inconsistent between different genes and among cell lines, ranging from a 2 to 300-fold increase compared to a control. Overall, expression was greatly increased for genes subject to inactivation but not increased in genes that escape inactivation for most ovarian cancer cell lines. Methylation at AR and FMR1 was quantified by a real-time PCR based assay and SNuPE respectively. Methylation was lower than expected for 7 of 8 ovarian cancer cell lines at AR or FMR1, while three cell lines had low or no methylation for both genes. Skewed XCI was evaluated using a methylation-based PCR assay at AR. There was no significant increase in skewing above 90% for any cancer group assayed. In addition, two markers of X reactivation were assayed in two low passage cultures of normal ovarian surface epithelium from BRCA1 mutation positive breast cancer patients. One sample did not localize XIST to the inactive X and three of five genes subject to inactivation were overexpressed. In summary, there is evidence for loss of X silencing or gain of active X content in ovarian cancer cell lines and normal ovarian surface epithelium from BRCA1 mutation carriers.

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