Wooster R, Cleton-Jansen A M, Collins N, Mangion J, Cornelis R S, Cooper C S, Gusterson B A, Ponder B A, von Deimling A, Wiestler O D
Section of Molecular Carcinogenesis, Haddow Laboratories, Sutton, Surrey, UK.
Nat Genet. 1994 Feb;6(2):152-6. doi: 10.1038/ng0294-152.
The allele sizes of polymorphic microsatellite repeats in DNA from human cancers were compared to normal DNA from the same patients. In 16 out of 196 paired samples (8%), we found evidence of an extra allele of a different size in the tumour which was not present in the normal DNA. Sequence analysis confirmed that the extra allele originates from the appropriate locus and that the size change is attributable to alteration in the number of repeat units. This form of instability was more common in tri- and tetranucleotide repeats than in dinucleotide repeats. In any single tumour sample only one repeat in the set examined was abnormal, the remainder showing identical patterns in normal and tumour DNA or evidence of allele loss. The pattern of instability in diverse types of cancer differs from that reported in colorectal neoplasms.
将人类癌症DNA中多态性微卫星重复序列的等位基因大小与同一患者的正常DNA进行了比较。在196对样本中的16对（8%）中，我们发现肿瘤中存在一个正常DNA中不存在的不同大小的额外等位基因的证据。序列分析证实，额外等位基因起源于适当的位点，并且大小变化归因于重复单元数量的改变。这种形式的不稳定性在三核苷酸和四核苷酸重复序列中比在二核苷酸重复序列中更常见。在任何单个肿瘤样本中，所检测的一组重复序列中只有一个是异常的，其余在正常和肿瘤DNA中显示相同的模式或等位基因缺失的证据。不同类型癌症中的不稳定性模式与结直肠肿瘤中报道的不同。
