美国和泰国科学家近日研究发现，孕妇饮用被砷（Arsenic）污染的水会改变胎儿某几种基因的活性水平，这会增加他们后来一生中患癌症的风险。这一发现再次提醒人们，特别是孕妇，谨防饮用水被砷污染。相关论文11月23日发表于《PLoS遗传学》（PLoS Genetics）上。
砷污染水源是个世界性的问题，主要来自自然沉积和工业活动。世界卫生组织（WHO）的饮用水砷含量标准为不超过0.01毫克／升，但在有些地区，比如孟加拉国，饮用水砷含量远远高于这一安全标准。过高的砷含量会导致一系列疾病，近来有研究表明，孕妇饮用被砷污染的水会增加胎儿出生后患癌症的风险，但其中的机制并没有弄清。
在最新的研究中，由泰国朱拉蓬研究所（Chulabhorn Research Institute）的环境毒物学家Panida Navasumrit领导的研究小组重点关注了泰国Ron Pibul地区的水源情况。该区域由于矿业的影响，饮用水砷含量达到了世界卫生组织标准的50倍之高。研究人员采集了该地区新生儿和其母亲的血液和指甲样本，来自美国麻省理工学院的分子生物学家Leona Samson对这些样本进行了分析。通过与曼谷地区11个新生儿（这些新生儿的母亲在怀孕期间未饮用被砷污染的水）样本的比较，Samson发现，有11种基因的表达水平在这两种新生儿中存在显著不同。
Samson表示，这些基因在细胞生长、凋亡及炎症中都发挥着作用。虽然尚不清楚砷导致癌症的具体机制，不过由于慢性炎症与胃癌有关，所以有可能是砷诱导的炎症反应在其中起了作用。
美国国立癌症研究所与国立环境卫生研究所的毒物学家Michael Waalkes说，此次发现为研究环境污染物对胎儿的影响开辟了潜在的新方法。他同时表示，基因的“预言”能力是微弱的，而且由于此次实验的特定设计，我们并不能说其它的污染物就不是问题。（科学网 梅进/编译）
原始出处:
Received: July 4, 2007; Accepted: October 4, 2007; Published: November 23, 2007
Activation of Inflammation/NF-κB Signaling in Infants Born to Arsenic-Exposed Mothers
Rebecca C. Fry1,2, Panida Navasumrit3, Chandni Valiathan1,2, J. Peter Svensson1,2, Bradley J. Hogan1,2, Manlin Luo1,2, Sanchita Bhattacharya1,2¤, Krittinee Kandjanapa3, Sumitra Soontararuks3, Sumontha Nookabkaew3, Chulabhorn Mahidol3, Mathuros Ruchirawat3*, Leona D. Samson1,2*
1 Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America, 2 Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America, 3 Chulabhorn Research Institute, Bangkok, Thailand
The long-term health outcome of prenatal exposure to arsenic has been associated with increased mortality in human populations. In this study, the extent to which maternal arsenic exposure impacts gene expression in the newborn was addressed. We monitored gene expression profiles in a population of newborns whose mothers experienced varying levels of arsenic exposure during pregnancy. Through the application of machine learning–based two-class prediction algorithms, we identified expression signatures from babies born to arsenic-unexposed and -exposed mothers that were highly predictive of prenatal arsenic exposure in a subsequent test population. Furthermore, 11 transcripts were identified that captured the maximal predictive capacity to classify prenatal arsenic exposure. Network analysis of the arsenic-modulated transcripts identified the activation of extensive molecular networks that are indicative of stress, inflammation, metal exposure, and apoptosis in the newborn. Exposure to arsenic is an important health hazard both in the United States and around the world, and is associated with increased risk for several types of cancer and other chronic diseases. These studies clearly demonstrate the robust impact of a mother's arsenic consumption on fetal gene expression as evidenced by transcript levels in newborn cord blood.
全文链接：http://genetics.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pgen.0030207
