Dos Santos N R, Van Kessel A G
Department of Human Genetics, University Hospital Nijmegen, The Netherlands.
Anticancer Res. 1999 Nov-Dec;19(6A):4697-714.
The occurrence of chromosomal abnormalities is a common theme in carcinogenesis. A large proportion of tumours which have been characterized at the cytogenetic level carries numerical and/or structural aberrations. Numerical alterations may include acquisition or loss of specific chromosomes or dramatic changes in overall ploidy levels. Structural aberrations may include DNA amplifications or deletions, inversions and translocations. Many chromosomal alterations occur in a non-random fashion and may be subdivided in to primary and secondary, according to their timing of occurrence. Primary chromosomal abnormalities usually occur at the early stages of tumourigenesis and are often encountered as sole cytogenetic abnormalities. Secondary chromosomal abnormalities are usually associated with more advanced stages of tumour development. In recent years several chromosomal abnormalities could be correlated with specific gene alterations, thus providing insights into the molecular mechanisms underlying tumourigenesis. The biological consequences imparted by other chromosomal changes such as numerical changes are, however, less clear. By using recently developed molecular techniques for chromosome characterization, so-called molecular cytogenetics, our perception on cancer cytogenetics is rapidly changing through the disclosure of hitherto unknown (specific) chromosomal abnormalities.
染色体异常的发生是致癌过程中的一个常见现象。在细胞遗传学水平上已得到特征描述的大部分肿瘤都存在数目和/或结构畸变。数目改变可能包括特定染色体的获得或丢失，或整体倍性水平的显著变化。结构畸变可能包括DNA扩增或缺失、倒位和易位。许多染色体改变以非随机方式发生，根据其发生时间可分为原发性和继发性。原发性染色体异常通常发生在肿瘤发生的早期阶段，并且常常作为唯一的细胞遗传学异常出现。继发性染色体异常通常与肿瘤发展的更晚期阶段相关。近年来，一些染色体异常与特定基因改变相关，从而为肿瘤发生的分子机制提供了见解。然而，其他染色体变化（如数目变化）所带来的生物学后果尚不清楚。通过使用最近开发的用于染色体特征描述的分子技术，即所谓的分子细胞遗传学，我们对癌症细胞遗传学的认识正通过揭示迄今未知的（特定）染色体异常而迅速改变。
