美国科学家在１４日出版的英国《自然遗传学》杂志上发表文章说，他们在线虫体内发现具有“防癌延寿”双重功效的基因。
据美国媒体报道，美国加利福尼亚大学旧金山分校生物学家辛西娅·凯尼恩领导的研究小组发现，一种体型极小、生命周期仅为３天的秀丽隐杆线虫体内的ＤＡＦ－２基因发生变异后，这些线虫寿命比正常情况延长１倍。
科学家对７３４个受到ＤＡＦ－２影响的基因进行筛选后发现，其中２９种基因能促进或抑制癌细胞的生长。这２９种基因中，又有一半的基因同时对线虫寿命发挥影响。当ＤＡＦ－２变异后，促进癌细胞生长的基因就不能正常表达了，只有抑制癌细胞的基因还在表达，结果线虫的寿命延长了。
凯尼恩说，过去有一种普遍看法是，能够“延寿”的基因同时也促进癌细胞的生长，“但我们通过本次研究发现，一些能‘延寿’的基因其实也抑制癌细胞的生长，而一些促进癌细胞生长的基因反而加速生命体的衰老”。
凯尼恩认为，人体内也存在类似线虫体内的“防癌延寿”基因，他们的这项研究有利于帮助找到既能延长人类寿命、又使人类免患癌症的方法。（新华网）
原始出处：
Nature Genetics
Published online: 14 October 2007 | doi:10.1038/ng.2007.1
DAF-16/FOXO targets genes that regulate tumor growth in Caenorhabditis elegans
Julie Pinkston-Gosse1 & Cynthia Kenyon1
Cancer is an age-related disease, and inhibiting insulin/insulin-like growth factor 1 (IGF-1) signaling extends lifespan and increases tumor resistance in C. elegans and mammals. To investigate how the insulin/IGF-1 pathway couples these two processes, we analyzed putative transcriptional targets of the C. elegans FOXO transcription factor DAF-16, which promotes both longevity and tumor resistance. Twenty-nine of 734 genes tested influenced germline-tumor cell proliferation or p53-dependent apoptosis. About half of these genes also affected normal aging, thereby linking these two processes mechanistically. Many of these 29 genes are orthologs of known human tumor suppressors or oncogenes, suggesting that others may be as well. Our findings implicate nuclear-pore modification in p53-dependent cell death, because inhibiting nuclear-pore genes that are upregulated by DAF-16 blocks p53-dependent cell death in the tumor, but not normal, p53-independent, germline cell death.
Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, California 94158, USA.
Correspondence to: Cynthia Kenyon1 e-mail: ckenyon@biochem.ucsf.edu
