Remvikos Y, Vogt N, Muleris M, Salmon R J, Malfoy B, Dutrillaux B
CNRS URA 620, Institut Curie, Paris, France.
Genes Chromosomes Cancer. 1995 Apr;12(4):272-6. doi: 10.1002/gcc.2870120406.
The DNA-repeat [(CA)n] instability of colorectal cancer cells was studied relative to our previously defined classification based on chromosome alterations. Of the 23 tumors analyzed, 13 belonged to the "monosomic" type (MT) characterized by simultaneous loss of chromosome 18 and chromosome arm 17p, and many structural rearrangements, 7 to the "trisomic" type (TT) with many chromosome gains but few rearrangements, and 3 had a normal karyotype (NT). (CA)n repeat sequences were examined on chromosomes 2, 5, 11, 13, 18, and 20. We found sequence alterations in 12 tumors at 1 or several loci, 9 of which (1/13 MT, 5/7 TT, and 3/3 NT) exhibited a typical shift in allele size defined as microsatellite instability. Furthermore, a single alteration was observed for the MT tumor, whereas one NT tumor displayed instability on two and all the other tumors on three or more loci. These results suggest an inverse relationship between the occurrence of chromosome structural rearrangements and microsatellite instability, providing another argument for the subdivision of colorectal cancers into groups of distinct oncogenic pathways.
我们根据先前基于染色体改变所定义的分类，对结肠癌细胞的DNA重复序列[(CA)n]不稳定性进行了研究。在分析的23个肿瘤中，13个属于“单体型”（MT），其特征为18号染色体和17号染色体短臂同时缺失，且存在许多结构重排；7个属于“三体型”（TT），有许多染色体增加但重排较少；3个具有正常核型（NT）。对2号、5号、11号、13号、18号和20号染色体上的(CA)n重复序列进行了检测。我们在12个肿瘤的1个或多个位点发现了序列改变，其中9个（1/13 MT、5/7 TT和3/3 NT）表现出等位基因大小的典型改变，定义为微卫星不稳定性。此外，MT肿瘤仅观察到一处改变，而1个NT肿瘤在两个位点表现出不稳定性，其他所有肿瘤在三个或更多位点表现出不稳定性。这些结果表明染色体结构重排的发生与微卫星不稳定性之间存在负相关关系，为将结肠癌细分为不同致癌途径的组提供了另一个依据。
