Department of Medicine, Weill Cornell Medical College, 525 East 68th St, Room F-206, New York, New York 10065, USA.
Cancer Prev Res (Phila). 2013 Sep;6(9):886-97. doi: 10.1158/1940-6207.CAPR-13-0140. Epub 2013 Jul 23.
In postmenopausal women, obesity is a risk factor for the development of hormone receptor-positive breast cancer driven by estrogen. After menopause, aromatization of androgen precursors in adipose tissue is a major synthetic source of estrogen. Recently, in mouse models and women, we identified an obesity-inflammation-aromatase axis. This obesity-induced inflammation is characterized by crown-like structures (CLS) consisting of dead adipocytes encircled by macrophages in breast white adipose tissue. CLS occur in association with NF-κB activation, elevated levels of proinflammatory mediators, and increased aromatase expression. Saturated fatty acids released from adipocytes have been linked to obesity-related white adipose tissue inflammation. Here we found that stearic acid, a prototypic saturated fatty acid, stimulated Akt-dependent activation of NF-κB resulting in increased levels of proinflammatory mediators [TNF-α, interleukin (IL)-1β, COX-2] in macrophages leading, in turn, to the induction of aromatase. Several polyphenols (resveratrol, curcumin, epigallocatechin gallate) blocked these inductive effects of stearic acid. Zyflamend, a widely used polyherbal preparation that contains numerous polyphenols, possessed similar suppressive effects. In a mouse model of obesity, treatment with Zyflamend suppressed levels of phospho-Akt, NF-κB binding activity, proinflammatory mediators, and aromatase in the mammary gland. Collectively, these results suggest that targeting the activation of NF-κB is a promising approach for reducing levels of proinflammatory mediators and aromatase in inflamed mouse mammary tissue. Further investigation in obese women is warranted.
在绝经后妇女中,肥胖是由雌激素驱动的激素受体阳性乳腺癌的发病因素。绝经后,脂肪组织中雄激素前体的芳香化作用是雌激素的主要合成来源。最近,在小鼠模型和女性中,我们发现了一个肥胖-炎症-芳香酶轴。这种肥胖引起的炎症的特征是由巨噬细胞包围的死脂肪细胞组成的冠状结构(CLS)存在于乳腺白色脂肪组织中。CLS 与 NF-κB 激活、促炎介质水平升高和芳香酶表达增加有关。从脂肪细胞释放的饱和脂肪酸与肥胖相关的白色脂肪组织炎症有关。在这里,我们发现硬脂酸,一种典型的饱和脂肪酸,刺激 Akt 依赖性 NF-κB 激活,导致巨噬细胞中促炎介质[TNF-α、白细胞介素(IL)-1β、COX-2]水平升高,进而诱导芳香酶。几种多酚(白藜芦醇、姜黄素、表没食子儿茶素没食子酸酯)阻断了硬脂酸的这些诱导作用。Zyflamend 是一种广泛使用的多草药制剂,含有许多多酚,具有类似的抑制作用。在肥胖小鼠模型中,Zyflamend 治疗可抑制乳腺中磷酸化 Akt、NF-κB 结合活性、促炎介质和芳香酶的水平。总的来说,这些结果表明,靶向 NF-κB 的激活是减少炎症性小鼠乳腺组织中促炎介质和芳香酶水平的一种有前途的方法。在肥胖女性中进一步研究是必要的。