Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 7 uppsatser.

Wang Ya-ping. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 111-120). / CONTENT / ACKNOWLEDGMENT / ABSTRACT / Chapter Chapter 1. --- Introduction / Chapter Chapter 2. --- Review of relevant literature / Chapter 2.1 --- Mammary structure and embryology / Chapter 2.2 --- Pathology of breast cancer / Chapter 2.3 --- Risk factors in breast cancer / Chapter 2.4 --- Prognostic factors in breast cancer / Chapter 2.5 --- Treatment of breast cancer / Chapter 2.6 --- Breast cancer research by flow cytometry / Chapter 2.7 --- c-erbB-2 oncogene research in breast cancer / Chapter 2.8 --- Tables and figures of chapter2 / Chapter Chapter 3. --- Materials and methods / Chapter 3.1 --- Flow cytometry assay of breast cancer tissue / Chapter 3.1.1 --- Sample collection / Chapter 3.1.2 --- Sample preparation for flow cytometric assay / Chapter 3.1.3 --- DNA content assay by flow cytometry / Chapter 3.1.4 --- Solutions for flow cytometric analysis / Chapter 3.2 --- c-erbB-2 and EGF receptor protein detection by immunohistochemical methods / Chapter 3.2.1 --- Preparation of sections / Chapter 3.2.2 --- Methods of staining / Chapter 3.2.3 --- Methods of analysis / Chapter 3.2.4 --- Confirmation of expression of c-erbB-2 protein by immunoblotting method / Chapter 3.2.5 --- Solutions for immunohistochemical and immunoblotting methods / Chapter 3.3 --- Clinical data from 346 breast cancer patients and method of analysis / Chapter 3.4 --- Tables and figures of chapter3 / Chapter Chapter 4. --- Results / Chapter 4.1 --- Results of flow cytometric analysis / Chapter 4.1.1 --- Tumour characteristics of 94 breast cancer patients / Chapter 4.1.2 --- Survival analysis by results of flow cytometry / Chapter 4.2 --- Results of immunohistochemical assay of c-erbB-2 and EGFr / Chapter 4.2.1 --- C-erbB-2 and EGFr expression in breast cancer / Chapter 4.2.2 --- The distribution of c-erbB-2 and EGFr expression in breast cancer / Chapter 4.2.3 --- Analysis of clinical outcome by c-erbB-2 and EGFr expression / Chapter 4.3 --- Clinical data of 346 patients with breast cancer / Chapter 4.3.1 --- Patients' characteristics / Chapter 4.3.2 --- Analysis of clinical data and outcome / Chapter 4.3.3 --- Analysis of clinical outcome according to histopathological characteristics of breast tumour / Chapter 4.3.4 --- Types of operation and clinical outcome / Chapter 4.3.5 --- Postoperative adjuvant therapy and clinical outcome / Chapter 4.3.6 --- Results from statistical analysis by Cox-regression / Chapter 4.4 --- Tables figures of chapter4 / Chapter Chapter 5. --- Discussion and conclusion / Chapter 5.1 --- Flow cytometric analysis of paraffin-embedded breast cancer tissue / Chapter 5.1.1 --- Evaluation of DNA flow cytometric results / Chapter 5.1.2 --- Correlation between tumor DNA aneuploidy or cell subpopulation and clinical outcome / Chapter 5.1.3 --- Correlation between S-phase fraction of breast tumour and clinical outcome / Chapter 5.1.4 --- Observation of high proportion of DNA hypoaneuploidy in this study / Chapter 5.2 --- c-erbB-2 oncogene overexpression in breast cancer / Chapter 5.2.1 --- c-erbB-2 oncoprotein expression in other studies / Chapter 5.2.2 --- Correlation between c-erbB-2 oncoprotein expression status and breast cancer pathogenesis / Chapter 5.3 --- Evaluation of EGFr expression in breast cancer / Chapter 5.4 --- Analysis of clinical data / Chapter 5.4.1 --- Clinical characteristics of patients with breast cancer / Chapter 5.4.2 --- Clinical characteristics of breast cancer and clinical outcome / Chapter 5.4.3 --- Clinical outcome by types of postoperative treatment / Chapter 5.5 --- Prognostic factors / Chapter 5.5.1 --- Our observations in comparison to other studies / Chapter 5.5.2 --- Prognostic factors for clinical application / Chapter 5.6 --- Tables and figures of chapter5 / References:

Breast cancer is a very heterogeneous disease. This heterogeneity can be observed at many levels, including gene expression, chromosomal aberrations, and disease pathology. A clear understanding of these differences is important since they impact upon treatment efficacy and clinical outcome. Recent studies have demonstrated that the tumour microenvironment also plays a critical role in cancer initiation and progression. Genomic technologies have been used to gain a better understanding of the impact of gene expression heterogeneity on breast cancer, and have identified gene expression signatures associated with clinical outcome, histopathological breast cancer subtypes, and a variety of cancer-related pathways and processes. However, little work has been done in this context to examine the role of the tumour microenvironment in determining breast cancer outcome, or in defining breast cancer heterogeneity. Additionally, little is known about gene expression in histologically normal tissue adjacent to breast tumour, if this is influenced by the tumour, and how this compares with non-tumour-bearing breast tissue. By applying laser--capture microdissection and gene expression profiling to clinical breast cancer specimens the research presented in this thesis addresses these questions. / We have generated gene expression profiles of morphologically normal epithelial and stromal tissue, isolated using laser capture microdissection, from patients with breast cancer or undergoing breast reduction mammoplasty. We determined that morphologically normal epithelium and stroma exhibited distinct expression profiles, but molecular signatures that distinguished breast reduction tissue from tumour-adjacent normal tissue were absent. Stroma isolated from morphologically normal ducts adjacent to tumour tissue contained two distinct expression profiles that correlated with stromal cellularity, and shared similarities with soft tissue tumors with favourable outcome. Adjacent normal epithelium and stroma from breast cancer patients showed no significant association between expression profiles and standard clinical characteristics, but did cluster ER/PR/HER2-negative breast cancers with basal-like subtype expression profiles with poor prognosis. Our data reveal that morphologically normal tissue adjacent to breast carcinomas has not undergone significant gene expression changes when compared to breast reduction tissue, and provide an important gene expression data set for comparative studies of tumour expression profiles. / We compared gene expression profiles of tumour stroma from primary breast tumors and derived signatures strongly associated with clinical outcome. We present a new stroma-derived prognostic predictor (SDPP) that stratifies disease outcome independently of standard clinical prognostic factors and published expression-based predictors. The SDPP predicts outcome in several published whole tumour--derived expression data sets, identifies poor-outcome individuals from multiple clinical subtypes, including lymph node--negative tumors, and shows increased accuracy with respect to previously published predictors, especially for HER2-positive tumors. Prognostic power increases substantially when the predictor is combined with existing outcome predictors. Genes represented in the SDPP reveal the strong prognostic capacity of differential immune responses as well as angiogenic and hypoxic responses, highlighting the importance of stromal biology in tumour progression. / We show that gene expression in the breast tumour microenvironment is highly heterogeneous, identifying at least six different classes of tumour stroma with distinct expression patterns and distinct biological processes. Two of these classes recapitulate the processes identified in the stroma-derived prognostic predictor, while the others are new classes of stroma associated with distinct clinical outcomes. One of these is associated with matrix remodelling and is strongly associated with the basal molecular subtype of breast cancer. The remainder are independent of the previously published molecular subtypes of breast cancer. Additionally, based on independent data from over 800 tumors, the combinations of stroma classes and breast cancer subtypes identify new subgroups of breast tumors that show better discrimination between good and poor outcome individuals than the molecular breast cancer subtypes or the stroma classes alone, suggesting a novel classification scheme for breast cancer. This research demonstrates an important role for the tumour microenvironment in defining breast cancer heterogeneity, with a consequent impact upon clinical outcome. Novel therapies could be targeted at the processes that define the stroma classes suggesting new avenues for individualized treatment.

The Ras signaling cascade is a vital component in the processes that mediate cell survival, growth, differentiation and transformation through activation of MAP kinase (mitogen-activated protein kinase). The recent discovery of a new scaffold of the Ras signaling pathway, Kinase Suppressor of Ras (KSR), is found to be a positive effector of Ras signaling which further contributes to proliferation and transformation in the ERK/MAPK pathway. This thesis describes the roles of Ras and Kinase Suppressor of Ras 1 (KSR-1) in regulating the expression of tumor promoting genes such as urokinase plasminogen activator (uPA) in the development and progression of breast cancer in vitro and in vivo. Ras and KSR increase the proliferative capacity and migration of MDAMB-231 human breast cancer cells in vitro. In contrast, Ras and KSR decrease the invasiveness of MDA-MB-231 human breast cancer cells in vitro. Furthermore, uPA gene expression levels do not correlate with uPA protein expression levels suggesting a possible mutation induced by KSR and/or Ras. In vivo studies reveal that Ras and KSR increase tumor volume in mice, as well as more advanced osteolytic bone metastases. Collectively, these results indicate that Ras and KSR play significant roles in breast cancer development and metastasis.

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Breast cancer is the most commonly diagnosed cancer in women. Despite recent advances in screening and early detection, breast cancer continues to result in a high incidence of morbidity and mortality. In its late stage the majority of patients exhibit signs of destructive skeletal metastasis. This complication is promoted by the production of growth factors by tumor cells which can induce tumor cell proliferation via their interaction with their respective receptors to initiate the vicious cycle of bone resorption. Inhibition of growth factors signaling through their receptors can therefore serve as a useful therapeutic approach to block bone metastasis. / The biological characteristics of cancer cells along with the targeting properties of immune system offer a novel approach in the treatment of breast cancer. Directed against HER-2/nue oncogene, the recombinant humanized monoclonal antibody, Trastuzumab (Herceptin), has shown significant clinical benefits for the treatment of HER-2 positive metastatic breast cancer. / In the present study, the effects of Herceptin and its molecular mechanism of action in abrogating the development and progression of osteolytic bone metastasis is investigated in an experimental mouse model of skeletal metastasis using human breast cancer cells BT-474 which are known to express high levels of HER-2. Treatment of BT-474 cells with Herceptin caused a dose dependent decrease in cell proliferation. In in vivo studies BT-474 cells were injected by into the left ventricle of female BALB/c nu/nu mice. Intraperitoneal infusion of Herceptin from the day of tumor cell inoculation or at the time of radiologically detectable skeletal metastasis either slowed the development or prevented the progression of skeletal metastasis as compared to control groups of animals receiving non-specific IgG. Bone histological analysis of long bones showed the ability of Herceptin to reduce the ratio of tumor volume to bone volume as well as mitotic index when Herceptin treatment was initiated from the day of tumor cell inoculation. Immunohistochemical analysis of long bones showed a significantly lower level of activated (phosphorylated) MAPK in bones of Herceptin treated animals. These studies demonstrate the ability of Herceptin to inhibit the development and abrogate the progression of skeletal metastasis associated with breast cancer by blocking the HER-2 mediated signaling pathways.

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O tratamento sistêmico é extremamente importante na abordagem clínica do câncer de mama. O presente estudo teve a finalidade de avaliar se a quimioterapia sistêmica é capaz de produzir instabilidade genética representada por instabilidade de microssatélites (MSI) e perda de heterozigosidade (LOH) na fração mononuclear do sangue periférico de pacientes portadoras de câncer de mama. Foram estudadas 119 amostras de sangue, obtidas seqüencialmente antes, durante e após a quimioterapia. Das 30 pacientes avaliadas, 27 apresentaram MSI em pelo menos uma das amostras estudadas e 6 desenvolveram LOH. Uma importante correlação foi obtida entre o número de eventos de MSI por amostra e quimioterápicos com agentes alquilantes (p < 0,0001). Entretanto, quando as amostras foram de pacientes em radioterapia, observou-se um menor número de eventos de MSI por amostra (p=0,038). Concluímos que o tratamento sistêmico pode induzir MSI e LOH em células mononucleares do sangue periférico de pacientes em tratamento quimioterápico com agentes alquilantes / Systemic chemotherapy is an important part of treatment for breast cancer. We conduced the present study to evaluate whether systemic chemotherapy could produce microsatellite instability (MSI) in the peripheral blood mononuclear cell fraction of breast cancer patients. We studied 119 sequential blood samples from 30 previously untreated breast cancer patients before, during and after chemotherapy. In 27 out of 30 patients we observed MSI in at least one sample, and six patients had loss of heterozygosity (LOH). We found a significant correlation between the number of MSI events per sample and chemotherapy with alkylating agents (p < 0.0001). However, when the samples were obtained in patients with radiotherapy we observed low MSI events per samples (p = 0.038). We concluded that systemic chemotherapy may induce MSI and LOH in peripheral blood mononuclear cells from breast cancer patients receiving alkylating agents

O tratamento sistêmico é extremamente importante na abordagem clínica do câncer de mama. O presente estudo teve a finalidade de avaliar se a quimioterapia sistêmica é capaz de produzir instabilidade genética representada por instabilidade de microssatélites (MSI) e perda de heterozigosidade (LOH) na fração mononuclear do sangue periférico de pacientes portadoras de câncer de mama. Foram estudadas 119 amostras de sangue, obtidas seqüencialmente antes, durante e após a quimioterapia. Das 30 pacientes avaliadas, 27 apresentaram MSI em pelo menos uma das amostras estudadas e 6 desenvolveram LOH. Uma importante correlação foi obtida entre o número de eventos de MSI por amostra e quimioterápicos com agentes alquilantes (p < 0,0001). Entretanto, quando as amostras foram de pacientes em radioterapia, observou-se um menor número de eventos de MSI por amostra (p=0,038). Concluímos que o tratamento sistêmico pode induzir MSI e LOH em células mononucleares do sangue periférico de pacientes em tratamento quimioterápico com agentes alquilantes / Systemic chemotherapy is an important part of treatment for breast cancer. We conduced the present study to evaluate whether systemic chemotherapy could produce microsatellite instability (MSI) in the peripheral blood mononuclear cell fraction of breast cancer patients. We studied 119 sequential blood samples from 30 previously untreated breast cancer patients before, during and after chemotherapy. In 27 out of 30 patients we observed MSI in at least one sample, and six patients had loss of heterozygosity (LOH). We found a significant correlation between the number of MSI events per sample and chemotherapy with alkylating agents (p < 0.0001). However, when the samples were obtained in patients with radiotherapy we observed low MSI events per samples (p = 0.038). We concluded that systemic chemotherapy may induce MSI and LOH in peripheral blood mononuclear cells from breast cancer patients receiving alkylating agents