A NOVEL ENDOCRINE DISRUPTING AGENT AND BREAST CANCER

描述（由申请人提供）：玉米芯垫料和食物中的内分泌干扰剂（ED）阻断大鼠雄性和雌性的性行为和性循环，刺激乳腺癌和前列腺癌细胞增殖。这些药物在HPLC中分离成两个组分（峰I-CM和峰II-CM）。峰I-CM中的促丝剂（THF-diols）被鉴定为9，(12)-氧- 10,10,13 -二羟基硬脂酸和10，(13)-氧- 9,12 -二羟基硬脂酸的异构体混合物，可阻断雄性和雌性的性行为和环性。峰II-CM （LTX-diols）中的有丝分裂因子被鉴定为白质毒素二醇（LTX-diol）和异白质毒素二醇（iLTX-diol）的异构体混合物，将在提议的研究中被评估为ed。本研究的目的是确定最具生物活性的合成thf -二醇和ltx -二醇异构体，确定它们在调节内分泌功能和乳腺癌细胞增殖中的相互作用的性质，并确定这些化合物在这些系统中调节的特定生化位点。最活跃的thf -二醇和ltx -二醇异构体将被分离并分别鉴定（Specific Aim 1），并确定它们是否加和或协同刺激乳腺癌细胞增殖（细胞周期转变和凋亡），并改变男性和女性的性行为和周期（Specific Aim 2）。给予“ED”剂量化合物的大鼠的组织和血液中thf -二醇和/或ltx -二醇异构体的浓度将通过GC/MS进行定量，并研究ltx -二醇是否为大鼠thf -二醇的前体（具体目标3）。将评估thf -二醇和ltx -二醇异构体在体外或体内（裸鼠）通过调节磷脂酶A2 （PoA）、环氧合酶（COX）、脂氧合酶（LOX）和芳香化酶，促进二甲苯并(a)蒽（DMBA）诱导的大鼠乳腺肿瘤（Specific Aim 4），以及雌激素受体（ER）阳性（MCF-7）或ER阴性（MDA-MB-231细胞）乳腺癌细胞增殖（细胞周期转变和凋亡）的能力（Specific Aim 5）。已知白质毒素会影响NO的释放，LTX-diol和THFdiol异构体可能通过破坏控制LHRH释放的一氧化氮（NO）依赖途径来抑制女性性行为（前倾）。这将被评估（具体目标6）。如果thf -二醇和ltx -二醇通过控制LHRH释放和脂肪生成产物来影响内分泌和细胞调节途径，那么它们可能对实验动物的行为和生殖反应以及癌症生长速率产生重大影响。在过去的十年里，亚油酸已经取代了我们饮食中的硬脂酸。作为亚油酸的代谢物，thf -二醇和ltx -二醇的摄入增加可能会影响人体健康和发育。所提出的研究是确定这些化合物的作用机制的目标途径的关键一步。

DESCRIPTION (provided by applicant): Endocrine disruptive (ED) agents in ground corncob bedding and foods block male and female sexual behavior and cyclicity in the rat and stimulate breast and prostate cancer cell proliferation. These agents separate into two components (Peak I-CM and Peak II-CM) during HPLC. The mitogenic agents in Peak I-CM (THF-diols) were identified as an isomeric mixture of 9, (12)-oxy-10, 13-dihydroxystearic acid and 10, (13)-oxy-9, 12-dihydroxystearic acids which block male and female sexual behavior and cyclicity. The mitogenic agents in Peak II-CM (LTX-diols) were identified as an isomeric mixture of leukotoxin-diol (LTX-diol) and isoleukotoxin-diol (iLTX-diol) that will be assessed as EDs in the proposed studies. The objectives of the proposed research are to identify the most biologically active synthetic THF-diol and LTX-diol isomers, define the nature of their interaction in modulating endocrine function and breast cancer cell proliferation and define specific biochemical sites regulated by these compounds in these systems. The most active THF-diol and LTX-diol isomer will be isolated and identified separately (Specific Aim 1) and whether they act additively or synergistically to stimulate breast cancer cell proliferation (cell cycle transition and apoptosis) and modify male and female sexual behavior and cyclicity will be determined (Specific Aim 2). The concentrations of THF-diol and/or LTX-diol isomers in tissues and blood from rats given "ED" doses of the compounds will be quantified by GC/MS and whether LTX-diols are precursors to THF-diols in rats will be studied (Specific Aim 3). The abilities of THF-diol and LTX-diol isomers to promote dimethylbenz(a)anthracene (DMBA)-induced mammary tumors in rats (Specific Aim 4), and to stimulate the proliferation (cell cycle transition and apoptosis) of estrogen receptor (ER) positive (MCF-7) or ER-negative (MDA-MB-231 cells) breast cancer cells in vitro or in vivo (in nude mice) by modulating phospholipase A2 (PoA), cyclooxygenase (COX), lipoxygenase (LOX) and aromatase will be evaluated (Specific Aim 5). Leukotoxins are known to affect NO release and it is possible that LTX-diol and THFdiol isomers inhibit female sexual behavior (Lordosis) by disrupting nitric oxide (NO) dependent pathways controlling LHRH release. This will be evaluated (Specific Aim 6). If THF-diols and LTX-diols impact endocrine and cell regulatory pathways by controlling LHRH release and lipogenic products that control cell proliferation, they likely have a major impact on behavioral and reproductive response profiles and cancer growth rates in experimental animals. Over the last decade, linoleic acid has replaced stearic acid in our diet. As metabolites of linoleic acid, increased intake of THF-diols and LTX-diols may influence human health and development. The proposed studies represent a critical step in defining target pathways for ultimately determining the mechanism of action of these compounds.