Abstract：
Polyunsaturated fatty acids (PUFAs), notably omega-3 (n-3) and omega-6 (n-6), have received much attention owing to their multifaceted effects not only in the management of diverse pathological conditions but also in the maintenance of overall health of an individual. A disproportionately high n-6 to n-3 ratio contributes to the development of various disorders including cancer, which ranks as a leading cause of death worldwide with profound social and economic burden. Epidemiological studies and clinical trials combined with the animal and cell culture models have demonstrated the beneficial effects of n-3 PUFAs in reducing the risk of various cancer types including breast, prostate and colon cancer. The anti-cancer actions of n-3 PUFAs are mainly attributed to their role in the modulation of a wide array of cellular processes including membrane dynamics, apoptosis, inflammation, angiogenesis, oxidative stress, gene expression and signal transduction pathways. On the contrary, n-6 PUFAs have been shown to exert pro-tumor actions; however, the inconsistent findings and controversial data emphasize upon the need to further investigation. Nevertheless, one of the biggest challenges in future is to optimize the n-6 to n-3 ratio despite the genetic predisposition, age, gender and disease severity. Moreover, a better understanding of the potential risks and benefits as well as the cellular and molecular mechanisms of the basic actions of these PUFAs is required to explore their role as adjuvants in cancer therapy. All these aspects will be reviewed in this chapter.
摘要：
多不饱和脂肪酸（PUFA），特别是omega-3（n-3）和omega-6（n-6），由于其多方面的影响，不仅在管理各种病理状况方面，而且在维持个人整体健康方面也受到了广泛的关注。不成比例的高n-6与n-3比率有助于各种疾病的发展，包括癌症。它是世界范围内死亡的主要原因，具有深刻的社会和经济负担。流行病学研究和临床试验结合动物和细胞培养模型已经证明了n-3PUFA在降低包括乳腺癌在内的各种癌症风险方面的有益作用。前列腺癌和结肠癌.n-3PUFA的抗癌作用主要归因于它们在调节广泛的细胞过程中的作用，包括膜动力学。凋亡，炎症,血管生成,氧化应激，基因表达和信号转导途径。相反,n-6PUFA已被证明具有促肿瘤作用；然而，不一致的发现和有争议的数据强调了进一步调查的必要性。然而，未来最大的挑战之一是优化n-6与n-3的比例，尽管有遗传倾向，年龄,性别和疾病严重程度。此外，需要更好地了解这些PUFA的潜在风险和益处以及基本作用的细胞和分子机制,以探索其在癌症治疗中作为佐剂的作用.所有这些方面都将在本章中进行回顾。
