PEDF, VEGF and Leptin in Serum, EDTA-Plasma, and Platelet Poor Plasma

描述（由申请人提供）： 在美国，大约30%的成年人肥胖。超重和肥胖与几种癌症的发病率和/或死亡率有关。此外，越来越多的证据表明，肥胖的测量与癌症的诊断、预后和生存期有关。然而，这些关联背后的生物学机制尚不清楚。一种假说认为肥胖可能在血管生成中起重要作用。瘦素和血管内皮生长因子（VEGF），两种由脂肪组织产生的蛋白质，刺激血管生成，而色素上皮衍生因子（PEDF），也由脂肪组织产生，抑制血管生成。虽然肥胖和循环瘦素之间的关联已经很好地建立，但VEGF和PEDF与超重或肥胖以及与瘦素的关联还没有很好地理解。重要的是，循环VEGF和PEDF的测量可能被血小板源性PEDF和VEGF混淆。对于拟议的试点研究，我们将招募100名年龄在21- 50岁之间的健康男性和女性，他们愿意完成简短的社会人口统计学和健康问卷，测量他们的身高和体重，并在禁食10小时后提供血液样本，两小时后吃清淡，健康的零食。基于采集的样本和数据，我们将比较从血清、EDTA血浆或贫血小板血浆管采集的样本中以及空腹和非空腹状态下的循环瘦素、PEDF和VEGF水平。此外，我们将开始探索PEDF、VEGF、BMI和瘦素水平之间的复杂关联。这项研究的结果将使我们能够建立适当的血液收集方法来测量瘦素，PEDF和VEGF，并提供有关血液生物标志物和肥胖之间的关联程度的初步数据。我们的长期目标是研究肥胖与癌症风险和预后的关系是否由瘦素、PEDF和/或VEGF介导。

DESCRIPTION (provided by applicant): In the United States, approximately 30% of adults are obese. Overweight and obesity are associated with the incidence and/or mortality of several cancers. Moreover, there is a growing body of evidence suggesting that measures of obesity are associated with the stage at diagnosis, prognosis and survival of cancer. However, the biological mechanisms underlying these associations are unclear. One hypothesis suggests that obesity might play an important role in angiogenesis. Leptin and vascular endothelial growth factor (VEGF), two proteins produced from adipose tissue, stimulate angiogenesis whereas pigment epithelium-derived factor (PEDF), also produced from adipose tissue, inhibits angiogenesis. Although an association between obesity and circulating leptin is well established there the associations of VEGF and PEDF with overweight or obesity and with leptin are not well understood. Importantly, the measurement of circulating VEGF and PEDF could be confounded by platelet-derived PEDF and VEGF. For the proposed pilot study, we will recruit 100 healthy men and women, aged 21- 50 years who are willing to complete a short sociodemographic and health questionnaire, have their height and weight measured, and who will provide blood samples after a 10 hour fast and two hours later after eating a light, healthful snack. Based on the samples and data collected, we will compare circulating leptin, PEDF and VEGF levels in sample collected from serum, EDTA plasma or platelet poor plasma tubes and between the fasted and non-fasted state. In addition, we will begin to explore the complex associations among PEDF, VEGF, BMI and leptin levels. Results of this study will allow us to establish appropriate blood collection methods for measurement of leptin, PEDF and VEGF, and provide pilot data on the magnitude of associations between the blood biomarkers and obesity. Our long-term goal is to study whether the associations of obesity with cancer risk and prognosis are mediated by leptin, PEDF, and/or VEGF.