Miles C P
Br J Cancer. 1974 Jul;30(1):73-85. doi: 10.1038/bjc.1974.115.
Chromosome changes in human cancer cells appear to evolve by non-random losses and/or gains of particular homologues or groups. It is probable that some of the apparent losses or gains actually represent formation of new chromosome structures, which are then classified as markers or are misclassified as normal homologues. In many cancers these changes appear to continue at a high rate throughout the life of the cancer (so that in some cancers almost every cell will exhibit a different karyotype). In other cancers the rate of change may be slow or arrested so that all cells will have the same abnormal karyotype. One very common step in karyotype evolution is doubling of the entire chromosome complement (2n → 4n or more commonly, S → 2S where S is the stemline number). The 2S cells tend to replace the original stemline. Homologues which have larger amounts of concentrated blocks of heterochromatin (i.e. late replicating DNA) seem more apt to be lost.
人类癌细胞中的染色体变化似乎是通过特定同源染色体或染色体组的非随机丢失和/或增加而演变的。很可能一些明显的丢失或增加实际上代表了新染色体结构的形成，这些新结构随后被归类为标记物或被错误地归类为正常同源染色体。在许多癌症中，这些变化在癌症的整个生命周期中似乎都以很高的速率持续发生（以至于在某些癌症中，几乎每个细胞都会表现出不同的核型）。在其他癌症中，变化速率可能很慢或停止，以至于所有细胞都将具有相同的异常核型。核型进化中一个非常常见的步骤是整个染色体组加倍（2n → 4n，或更常见的是，S → 2S，其中S是干系数）。2S细胞倾向于取代原来的干系。具有大量浓缩异染色质块（即晚复制DNA）的同源染色体似乎更容易丢失。
