《英文文献/摘要翻译》站在时间尽头2012

13、Copy number alteration landscape

　　There are remarkable differences in the LOH between cancer types.
　　不同类型肿瘤之间的杂合性丢失有显著差异。

　　For instance, we observed LOH events on the 3p arm in 90% of kidney samples and LOH of the complete chromosome 10 in 72% of CNS tumours.
　　例如，我们在90%的肾脏样本中观察到3p臂上的杂合性丢失现象，在72%的中枢神经系统肿瘤中，观察到完整的10号染色体的杂合性丢失。

　　Furthermore, the mechanism for LOH in TP53 is highly specific to tumour type, with ovarian cancers exhibiting LOH of the full chromosome 17 in 75% of samples, whereas in prostate cancer this is nearly always caused by highly focal deletions.
　　此外，TP53的杂合性丢失机制与肿瘤类型高度相关，卵巢癌在75%的样本中显示出整个17号染色体杂合性丢失，反之对于前列腺癌，这几乎总是由高度局灶性缺失引起。

　　Unlike LOH events, homozygous deletions are nearly always restricted to small chromo regions.
　　与杂合性丢失现象不同，纯合子缺失几乎总是局限于较小的染色体区域。

　　Not a single example was found in which a complete autosomal arm was homozygously deleted.
　　没有发现一个完整的常染色体臂纯合缺失的例子。

　　Homozygous deletions of genes are also surprisingly rare: we found only a mean of 2.0 instances per tumour in which one or several consecutive genes are fully or partially homozygously deleted.
　　基因的纯合缺失也令人惊讶地罕见：我们发现平均每个肿瘤只有2.0例，其中一个或几个连续的基因完全或部分纯合缺失。

　　In 46% of these events, a putative TSG was deleted.
　　在这些现象中，有46%缺失了假定的肿瘤抑制基因。

　　Loss of chromosome Y is a special case and is deleted in 36% of all male tumour genomes but varies strongly between tumour types, from 5% deleted in CNS tumours to 68% deleted in biliary tumours.
　　Y染色体缺失是一种特例，在所有男性肿瘤基因组中有36%缺失，但在不同肿瘤类型之间存在极大差异，从中枢神经系统肿瘤的5%缺失到胆管肿瘤的68%。

　　An extreme form of copy number change can be caused by whole-genome duplication (WGD).
　　全基因组复制(WGD)可能导致拷贝数目的极端变化。

　　We found WGD events in 56% of all samples ranging from 15% in CNS to 80% in oesophageal tumours.
　　我们在56%的样本中发现了全基因组复制现象，从中枢神经系统概率的15%到食道肿瘤概率的80%。

　　This is much higher than previously reported for primary tumours and from panel-based sequencing analyses of advanced tumours.
　　这比之前报告的【原发性肿瘤和晚期肿瘤基于成组测序分析】的结果要高得多。