PLACENTAL/UTERINE & PROSTATE EFFECTS OF ORGANOCHLORINES

我们研究的一个主要目标是识别人类生殖细胞系中基因表达的变化，这些变化是由原型Superfund化学物质介导的。我们的重点是开发体外模型，以重现与人类胎盘、子宫和前列腺的发育和功能有关的一些体内事件。在目前的供资期间，研究的重点是2，3，7，8-四氯二苯并-对二恶英(TCDD)、苯并(A)芘(BaP)、多氯联苯(PCb)同系物3，3‘，4，4，4’-四氯联苯(TCB)和2，2‘，4，4’，5，5‘-六氯联苯(HCB)，作为确定ah受体(AhR)依赖效应的原型。我们的假设是，TCDD、PCbs和BaP改变了旁分泌和自分泌生长调节网络，这些网络被认为对增殖、迁移/侵袭和激素反应具有重要作用。已经为每个基因产物建立了剂量-反应关系，以确定哪些终点是与细胞色素P450 CYPIA1诱导有关的最敏感的生物标记物。下一个供资期将侧重于评价多氯联苯同系物的影响，这些多氯联苯同系物与人类接触有关，可能既有依赖于阿赫里德的行动机制，也可能有独立的行动机制。第一个具体目的是确定TCDD、PCBS和BaP诱导人类子宫和胎盘细胞系中促炎细胞因子表达的机制，这些细胞因子可能是促进子宫疾病和胎盘发育受损的基础。第二个具体目的是通过细胞黏附分子与细胞外基质和细胞骨架微丝相互作用的变化来表征TCDD、多氯联苯和BaP对胎盘和子宫细胞迁移/侵袭活性的影响。第三个目的是研究前列腺素H合成酶(PGHS)-1和-2在BaP和多氯联苯化合物的代谢激活和毒性效应中的潜在作用。PGHS酶的结构性表达和诱导，可能为氧化应激诱导的基因表达改变和过氧化代谢提供了一条替代CYPIAI的途径。最终目的将调查人类前列腺细胞系是否成为增殖、迁移和生长因子基因表达变化的目标，这可能是促进前列腺疾病的机制。总之，这项研究将确定和验证暴露的敏感生物标志物，以及建立子宫、胎盘和前列腺功能改变的分子和细胞机制。

A primary goal of our research is the identification of alterations in gene expression in human reproductive cell lines which are mediated by prototype Superfund chemicals. Our focus is to develop in vitro models to reproduce some of the in vivo events involved in the development and function of human placenta, uterus and prostate. In the present funding period, studies have focused on 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), benzo(a)pyrene (BaP), and the polychlorinated biphenyl (PCB) congeners 3,3',4,4'-tetrachlorobiphenyl (TCB) and 2,2'4,4'5,5'- hexachlorobiphenyl (HCB) as prototypes for defining Ah receptor (AhR)- dependent effects. Our hypothesis is that TCDD, PCBs and BaP alter paracrine and autocrine growth regulatory networks which are recognized to be important for proliferation, migration/invasiveness and hormone responsiveness. Dose-response relationships have been established for each gene product to identify which endpoints are the most sensitive biomarkers in relationship to the induction of cytochrome P450 CYPIA1. The next funding period will focus on evaluation of the effects of PCB congeners which are relevant to human exposure and which may have both AhR-dependent and -independent mechanisms of action. The first Specific Aim is to identify mechanisms by which TCDD, PCBs and BaP induce the expression of the pro-inflammatory cytokines in human uterine and placental cell lines which may underlie the promotion of uterine disease and impaired placental development. The second Specific Aim is to characterize the effects of TCDD, PCBs and BaP on the migration/invasive activity of placental and uterine cells relative to changes in cell adhesion molecule interactions with extracellular matrix and cytoskeletal microfilaments. The Third Aim is to investigate the potential role of the enzymes prostaglandin H synthase (PGHS)-1 and -2 in the metabolic activation and toxic effects of BaP and PCB compounds. PGHS enzymes, constitutively expressed and induced, may provide an alternative pathway to CYPIAI for peroxidative metabolism and oxidative stress-induced alterations in gene expression. The final Aim will investigate whether human prostate cell lines are targets for changes in proliferation, migration and growth factor gene expression, which can be mechanisms for the promotion of prostate disease. In summary, this research will identify and validate sensitive biomarkers for exposure, as well as establish molecular and cellular mechanisms for altered uterine, placental and prostate function.