Genomics：非编码序列L1与癌症发生相关

Tlexander

英国研究人员日前报告说，人类基因组中一些“垃圾DNA”产生的物质与乳腺癌等癌症存在相关性，这项发现有助于研发新的癌症治疗方法。& y/ k9 Y5 _) X; X& g

6 J$ @- [4 a- V7 J0 \3 m, N英国诺丁汉大学等机构研究人员在美国《基因组学》杂志上报告说，他们发现人类基因组中名为L1的DNA序列会导致生成一些反常产物，而这些产物多见于乳腺癌细胞中。
- o2 t7 b0 _* |" e$ u0 e, e5 _Genomics December 2009 doi:10.1016/j.ygeno.2009.08.013  
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Isolation of cancer-specific chimeric transcripts induced by hypomethylation of the LINE-1 antisense promoter' N) o* P5 `( ]8 B  _& v. J7 C" z
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Hazel A. Cruickshanksa, b and Cristina Tufarelli, a, b,
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/ |2 J- m/ ?& ]- S5 faWolfson Centre for Stem Cells, Tissue Engineering and Modelling (STEM), Centre for Biomolecular Sciences, University of Nottingham, Nottingham, NG7 2RD, UK
9 c5 Q1 K; X0 N4 t9 H1 MbDepartment of Genetics, University of Leicester, Leicester, LE1 7RH, UK
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The antisense promoter of human LINE-1 (L1) retroelements can direct transcription of adjacent unique genomic sequences generating chimeric RNAs, which can perturb transcription of neighbouring genes. As L1 elements constitute 17% of the human genome, chimeric transcription is potentially widespread, but the extent to which this occurs is largely unknown. Using a genome-wide screen we have isolated novel chimeric transcripts that are unique to breast cancer cell lines, primary tumours and colon cancer cells. Expression of the cancer-specific chimeric transcripts can be induced in non-malignant breast epithelial cells by the demethylating drug 5-azacytidine. These findings indicate that loss of L1 methylation in cancer cells is linked to the expression of L1-chimeric transcripts which may therefore constitute a useful set of markers of malignancy.