众所周知，多食绿色蔬菜是能降低癌症发病率的，现在科学家已经有证据表明绿色蔬菜能帮助抵抗已经出现在肿瘤中的癌症。

美国研究人员发现，在深绿色蔬菜（又名十字花科蔬菜）中有一种混合物称为萝卜硫素，可以治疗癌症并有助于提高药效。

萝卜硫素在西兰花幼芽时期的含量最高，同时也存在于球芽甘蓝、羽衣甘蓝、菜花和卷心菜中。除了食用天然产品外，也可以购买花椰幼芽萃取物中的萝卜硫素作为膳食补充。

在德克萨斯州农工健康科学中心研究人员进行的一项研究中，有28名50岁以上的志愿者接受了对十字花科蔬菜饮食习惯的调查，他们都进行了常规结肠镜检查。

当研究人员检查志愿者结肠活组织切片检查时，他们发现那些多吃深绿色蔬菜的志愿者比那些少吃或不吃十字花科蔬菜的有较高水平的肿瘤抑制基因表达（名为p16）。

出乎研究人员意料的是，即便他们没有每天都吃蔬菜，因摄入蔬菜而获得的p16仍然存留。这很奇怪，因为萝卜硫素通常会在消化后不到24小时被清除体外。

“这暗示了一种可能，表观遗传机制是最初由萝卜硫素及其代谢产物激发的，下游机制可以一直持续，至少在短期内，甚至在化合物从体内排出之后。”研究人员之一Praveen Rajendran说。

这意味着吃十字花科蔬菜或服用萝卜硫素作为有效补充，也就是西兰花药丸，最终可能改变你的基因，帮助身体更好的抑制肿瘤生长。该研究结果已发表在《临床实验胚胎学》（Clinical Epigenetics）。

该研究团队在先前的研究已经发现，萝卜硫素能抑制结肠癌细胞和前列腺癌细胞，对人类意义重大。

Rajendran说：“我们的工作利用细胞基础、动物和人类研究提供了一个综合性的原理证明，萝卜硫素等膳食化合物可以成为化学防护。然而，我们还没准备好向所有人推荐摄入花椰幼芽萃取物（BSE）作为补给，而且非常值得再次重申营养学家常年建议的：多吃蔬菜。”（来源：科技世界网）

Nrf2 status affects tumor growth, HDAC3 gene promoter associations, and the response to sulforaphane in the colon

Abstract  Background  The dietary agent sulforaphane (SFN) has been reported to induce nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2)-dependent pathways as well as inhibiting histone deacetylase (HDAC) activity. The current investigation sought to examine the relationships between Nrf2 status and HDAC expression in preclinical and translational studies.  Results  Wild type (WT) and Nrf2-deficient (Nrf2 −/+ ) mice were treated with the colon carcinogen 1,2-dimethylhydrazine (DMH) followed by 400 ppm SFN in the diet (n = 35 mice/group). WT mice were more susceptible than Nrf2 −/+mice to tumor induction in the colon. Tumors from WT mice had higher HDAC levels globally and locally on genes such as cyclin-dependant kinase inhibitor 2a (Cdkn2a/p16) that were dysregulated during tumor development. The average tumor burden was reduced by SFN from 62.7 to 26.0 mm 3 in WT mice and from 14.6 to 11.7 mm 3 in Nrf2 −/+mice. The decreased antitumor activity of SFN in Nrf2 −/+mice coincided with attenuated Cdkn2a promoter interactions involving HDAC3. HDAC3 knockdown in human colon cancer cells recapitulated the effects of SFN on p16 induction. Human subjects given a broccoli sprout extract supplement (200 μmol SFN equivalents), or reporting more than five cruciferous vegetable servings per week, had increased p16 expression that was inversely associated with HDAC3 in circulating peripheral blood mononuclear cells (PBMCs) and in biopsies obtained during screening colonoscopy.

Conclusions  Nrf2 expression varies widely in both normal human colon and human colon cancers and likely contributes to the overall rate of tumor growth in the large intestine. It remains to be determined whether this influences global HDAC protein expression levels, as well as local HDAC interactions on genes dysregulated during human colon tumor development. If corroborated in future studies, Nrf2 status might serve as a biomarker of HDAC inhibitor efficacy in clinical trials using single agent or combination modalities to slow, halt, or regress the progression to later stages of solid tumors and hematological malignancies.

原文链接：http://www.clinicalepigeneticsjournal.com/content/pdf/s13148-015-0132-y.pdf