昨日，记者从华西医院获悉：从我市川大华西医院走出去的访美女教授肖翠英作为第一作者在今年3月出版的国际著名权威学术杂志《细胞》上发表了最新研究结果，认为遗传性乳腺癌病因与X染色体失活无关。该颠覆性观点的提出不仅震惊世界，而且也为治疗乳腺癌带来新的希望。
“该观点的提出，为如何治疗乳腺癌确立了新的方向”，国内著名遗传学家、华西医院教授张思仲告诉记者。据张教授介绍，乳腺癌是严重威胁女性健康的肿瘤，它是女性中最常见的癌症之一，其致死率仅次于肺癌，占女性癌症死亡原因的第二位。在乳腺癌的发病中，遗传因素起了重要作用：经过专家对我国乳腺癌患者统计显示，10% 患者为遗传性，40% 的患者为家族性，并且90%的乳腺癌合并卵巢癌是由乳腺癌易感基因BRCA1突变造成。
目前医学的传统观点认为，乳腺癌系X染色体失去活性所致。但川大华西医院访问学者肖翠英等根据她们在美国国立卫生研究院和加州大学旧金山分校的最新研究结果，提出了自己的不同观点，认为乳腺癌与X染色体无关；而且还发现常用化疗药物合并染色体异常抑制剂可以有效杀伤BRCA1突变的乳腺癌细胞。该发现随后在国际著名的权威学术杂志《细胞》上发表，并震惊整个医学界，从而给乳腺癌的治疗带来了新的希望。
据悉，肖翠英是华西医院医学遗传研究室的教授，2004年到美国国立卫生研究院和加州大学旧金山分校作访问学者，期满后，因她正在进行的研究工作尚未完结且有重要发现，故特地向华西医院申请延长访问研究时间，经医院同意后继续在美国从事研究，最近在《细胞》以第一作者位置发表的学术论文是她在美国研究所取得的重要成绩。
部分英文原文：
Copyright © 2007 Cell Press. All rights reserved.
Cell, Vol 128, 977-989, 09 March 2007
Matters Arising
The XIST Noncoding RNA Functions Independently of BRCA1 in X Inactivation
Cuiying Xiao,1,7 Judith A. Sharp,2,7 Misako Kawahara,3 Albert R. Davalos,3 Michael J. Difilippantonio,4 Ying Hu,5 Wenmei Li,1 Liu Cao,1 Ken Buetow,5 Thomas Ried,4 Brian P. Chadwick,6 Chu-Xia Deng,1, and Barbara Panning2,
1 Genetics of Development and Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, 10/9N105, National Institutes of Health, Bethesda, MD 20892, USA
2 Department of Biochemistry and Biophysics, University of California, San Francisco, 600 16th Street, San Francisco, CA 94158, USA
3 Life Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
4 Section of Cancer Genomics, Genetics Branch/CCR, National Cancer Institute, National Institutes of Health, Room 1408, 50 South Drive, Bethesda, MD 20892, USA
5 NCI Center for Bioinformatics, Laboratory of Population Genetics, National Cancer Institute, National Institutes of Health, Room 116, 8424 Helgerman Court, Bethesda, MD 20892, USA
6 Department of Cell Biology, Duke University Medical Center, Institute for Genome Sciences and Policy, Durham, NC 27710, USA
Corresponding author
Chu-Xia Deng
chuxiad@bdg10.niddk.nih.gov
Corresponding author
Barbara Panning
bpanning@biochem.ucsf.edu
Summary
Females with germline mutations in BRCA1 are predisposed to develop breast and ovarian cancers. A previous report indicated that BRCA1 colocalizes with and is necessary for the correct localization of XIST, a noncoding RNA that coats the inactive X chromosome (Xi) to mediate formation of facultative heterochromatin. A model emerged from this study suggesting that loss of BRCA1 in female cells could reactivate genes on the Xi through loss of the XIST RNA. However, our independent studies of BRCA1 and XIST RNA revealed little evidence to support this model. We report that BRCA1 is not enriched on XIST RNA-coated chromatin of the Xi. Neither mutation nor depletion of BRCA1 causes significant changes in XIST RNA localization or X-linked gene expression. Together, these results do not support a role for BRCA1 in promoting XIST RNA localization to the Xi or regulating XIST-dependent functions in maintaining the stability of facultative heterochromatin
英文全文链接：http://www.cell.com/content/article/fulltext?uid=PIIS0092867407001791
