Flaxseed and its lignan and oil components: Mechanisms of biological effect

我的研究计划的长期目标是阐明亚麻籽及其主要成分，植物雌激素木脂素和富含α-亚麻酸（ALA）的油发挥其生物学效应的细胞和分子机制，但本提案的主要焦点是ALA。我们以前的研究表明，富含ALA的亚麻籽油可以降低癌细胞的生长速度，但变化的程度取决于雌激素环境，无论细胞是雌激素受体（ER）阳性还是阴性，以及没有，低或过表达HER 2（一种生长因子受体），以及它们是否与其他生物活性化合物或也与HER 2结合的药理学药物相互作用。 对这些条件下作用机制的基础知识有限，可能导致对脂肪酸的生物反应不一致。因此，我建议对不同水平的ALA对差异表达ER和HER 2的几种细胞系模型的影响进行基础研究，单独或与能够降低HER 2表达和活性的化合物（如曲妥珠单抗（赫赛汀））组合。 使用体外方法，这些细胞系将用单独或与曲妥珠单抗组合的各种水平的ALA处理，并且将在一系列实验中测量和关联以下内容：（a）细胞增殖和凋亡（程序性细胞死亡），（B）ER、HER 2和参与导致细胞生长的细胞信号传导的分子的蛋白质和基因表达，（c）微小RNA，（d）脂肪酸合酶和磷酸酶以及张力蛋白同源物表达，（e）脂质过氧化，以及（f）可能导致受体和细胞信号分子变化的细胞膜脂质。研究结果将为控制具有不同水平ER和HER 2的细胞生长提供潜在靶点，并为营养学家和食品科学家提供关于使用亚麻籽及其富含ALA的油作为功能性食品的指导。

The long term goal of my research program is to elucidate the cellular and molecular mechanisms whereby flaxseed and its major components, the phytoestrogen lignan and alpha- linolenic acid (ALA)-rich oil, exert their biological effects but the main focus of this proposal is ALA. Our previous studies have shown that ALA-rich flaxseed oil can reduce the growth rate of cancer cells but the extent of change depends on the estrogen environment, whether the cells are estrogen receptor (ER) positive or negative and with no, low or overexpressed HER2 (a type of growth factor receptor), and whether they interact with other bioactive compounds or pharmacologic agents that also bind to HER2. Limited fundamental knowledge on the mechanisms of the effect under those conditions may have contributed to the inconsistencies in biological response to fatty acids. I therefore propose to do basic research on the effect of various levels of ALA on several cell line models that differentially express ER and HER2, alone or in combination with compounds that are able to reduce the expression and activity of HER2 such as trastuzumab (herceptin). Using in vitro methods, those cell lines will be treated with various levels of ALA, alone or combined with trastuzumab, and the following will be measured and correlated in a series of experiments: (a) cell proliferation and apoptosis (programmed cell death), (b) protein and gene expressions of ER, HER2 and molecules involved in cell signalling that leads to cell growth, (c) microRNA, (d) fatty acid synthase and phosphatase and tensin homologue expressions, (e) lipid peroxidation, and (f) cell membrane lipids that may have led to changes in receptor and cell signalling molecules. Results will provide insight into potential targets for controlling the growth of cells with various levels of ER and HER2 and will also provide guidance to nutritionists and food scientists regarding the use of flaxseed and its ALA-rich oil as functional foods.