The Role of Prolactin in the Etiology of Postmenopausal Breast Cancer

我们建议评估几种假设，检查催乳素在绝经后乳腺癌病因中的作用，这是建立在我们以前的研究结果，即催乳素水平与浸润性绝经后乳腺癌的风险呈正相关，特别是雌激素受体阳性肿瘤的风险增加。大量的体外和动物数据支持催乳素和催乳素受体在乳腺癌发展中的作用，特别是通过促进细胞增殖，增加细胞存活，改变细胞运动性和支持肿瘤血管化。分析将使用1976年开始的护士健康研究的数据进行，使用1989-1990年提供血液样本的女性（约33，000人），并重点关注乳腺癌病例的一个子集（约500人）我们既有血液样本又有肿瘤组织块。具体来说，我们将通过使用从白色血细胞中获得的生殖系DNA，研究遗传变异性对血液中催乳素浓度和乳腺癌风险的作用来扩展我们的发现。我们还将使用我们独特的基于人群的组织库，首次分析乳腺肿瘤中的催乳素受体状态是否改变催乳素浓度与乳腺癌风险之间的关联。此外，我们建议扩大有关催乳素水平和各种生活方式和其他乳腺癌风险因素之间的关系的信息，特别关注生殖因素，能量平衡和饮食的措施，早期生活暴露和乳腺癌家族史。这些分析将有助于我们更好地了解血浆中催乳素水平的调节，并提供有关这些因素如何改变乳腺癌风险的潜在机制信息。最后，我们建议对两种检测方法进行重要和必要的试点测试，这两种检测方法将提供在未来资助中将其作为生物标志物所需的初步数据。该应用程序的主要优势是前瞻性收集乳腺癌病例和问卷数据的可用性，存档的血浆和DNA样本，以及来自我们乳腺癌病例的肿瘤组织样本。建议的分析将提高我们对催乳素和催乳素受体在绝经后乳腺癌病因中的作用的理解。这可能会通过增加我们对乳腺癌如何发展的了解来影响公共卫生，从而更好地了解如何预防这种疾病。

We propose to evaluate several hypotheses examining the role of prolactin in postmenopausal breast cancer etiology, which build upon our previous findings that prolactin levels are positively associated with risk of invasive postmenopausal breast cancer, with a particularly increased risk for estrogen receptor positive tumors. Substantial in vitro and animal data support the role of prolactin and the prolactin receptor in breast cancer development, specifically by promoting cell proliferation, increasing cell survival, altering cellular motility, and supporting tumor vascularization. Analyses will be conducted using data from the Nurses' Health Study, which began in 1976, using women who provided a blood sample in 1989-1990 (approximately 33,000) and also focusing on a subset of breast cancer cases (approximately 500) for whom we have both a blood sample and tumor tissue blocks. Specifically we will extend our findings by examining the role of genetic variability with respect to both prolactin concentrations in the blood and breast cancer risk, using germline DNA obtained from white blood cells. We will also provide the first analysis examining whether prolactin receptor status in breast tumors modifies the association between prolactin concentrations and breast cancer risk, using our unique population-based tissue bank. In addition, we propose to expand information concerning the relationship between prolactin levels and various lifestyle and other breast cancer risk factors, particularly focusing on reproductive factors, measures of energy balance and diet, early life exposures, and family history of breast cancer. These analyses will help us to better understand the regulation of prolactin levels in plasma as well as provide potential mechanistic information on how these factors may modify risk of breast cancer. Finally we propose to conduct important and necessary pilot testing for two assays that will provide preliminary data needed to pursue these as biomarkers in a future grant. Major strengths of this application are the prospective collection of breast cancer cases and the availability of questionnaire data, archived plasma and DNA samples, and tumor tissue samples from our breast cancer cases. The proposed analyses will improve our understanding of the role of prolactin and the prolactin receptor in postmenopausal breast cancer etiology. This potentially may affect public health by increasing our understanding of how breast cancer develops, which in turn can lead to a better understanding of how to prevent this disease.