LIGHT DURING DARKNESS AND BREAST CANCER PROGRESSION

描述（由申请人提供）：本研究的长期目标是 确定黑暗中的光线是否是乳腺癌的危险因素 进展工业化国家的人们接触到的 夜间的人工照明和乳腺癌的发病率正在增加。 松果体激素褪黑激素，抑制实验人类乳房 癌症生长，是在黑暗中产生的;光存在于黑暗中 抑制褪黑激素的合成要检验的假设是： 适当的强度、持续时间、时间和波长， 黑暗，刺激乳腺癌的进展，通过褪黑激素抑制和 从而解除对肿瘤亚油酸（LA）摄取和代谢的抑制。的 第一个目的是测量裸体女性暴露的剂量反应效应 大鼠，携带组织分离的雌激素受体（ER）+和孕激素受体 (PgR)+ MCF-7人乳腺癌异种移植物，呈不同强度的白色 黑暗中的光对肿瘤生长的褪黑素抑制作用 代谢及相关生长信号转导分子的表达 (i.e., ER和PgR、褪黑激素受体和cAMP）。第二个目标是确定 暴露于携带MCF-7异种移植物的裸鼠的剂量反应效应， 与携带ER/PgR-MDA-MB-231人乳腺癌的那些相比 不同强度白色光照射对褪黑素抑制的影响 与肿瘤生长有关。第三个目标是确定褪黑激素是否 替换将防止白色光暴露的刺激作用 黑暗对肿瘤生长、LA代谢及相关蛋白表达的影响 肿瘤生长信号转导分子。第四个目标将考验 黑暗中光照时间和时机对肿瘤的影响 生长和生长信号转导事件。这项研究可能会导致 阐释"夜灯"与膳食脂肪摄入量的关系 乳腺癌进展的危险因素和新的预防措施 通过改变室内照明来降低乳腺癌风险 和膳食脂肪摄入与褪黑激素补充。

DESCRIPTION (provided by applicant): The long-term goal of this research is to determine if light, present during darkness, is a risk factor for breast cancer progression. People in industrialized nations are being exposed to more artificial light during the night and the rate of breast cancer is increasing. The pineal gland hormone melatonin, which inhibits experimental human breast cancer growth, is produced during darkness; light present during darkness suppresses melatonin synthesis. The hypothesis to be tested is: Light, of the appropriate intensity, duration, timing and wavelength, present during darkness, stimulates breast cancer progression via melatonin suppression and a resultant disinhibition of tumor linoleic acid (LA) uptake and metabolism. The first aim is to measure the dose-response effects of exposure of nude female rats, bearing tissue-isolated estrogen receptor (ER)+ and progesterone receptor (PgR)+ MCF-7 human breast cancer xenografts, to different intensities of white light during darkness, on melatonin suppression in relation to tumor growth, LA metabolism and the expression of related growth signal transduction molecules (i.e., ER and PgR, melatonin receptor and cAMP). The second aim is to determine the dose-response effects of exposure of nude rats bearing MCF-7 xenografis in comparison with those bearing ER/PgR- MDA-MB-23 1 human breast cancer xenografts to different intensities of white light on melatonin suppression in relation to tumor growth. The third aim is to determine whether melatonin replacement will prevent the stimulative of effects of white light exposure during darkness on tumor growth, LA metabolism and the expression of related tumor growth signal transduction molecules. The fourth aim will test the effects of the duration and timing of light exposure during darkness on tumor growth and growth signal transduction events. This research may lead to the elucidation of "light-at-night" in conjunction with dietary fat intake as a new risk factor for breast cancer progression and to novel preventative measures for lowering breast cancer risk by combining modifications of indoor lighting and dietary fat intake with melatonin supplementation.