Katsura K, Sugihara H, Nakai S, Fujita S
Department of Pathology, Kyoto Prefectural University of Medicine, Japan.
Cancer Genet Cytogenet. 1996 Sep;90(2):146-53. doi: 10.1016/s0165-4608(96)00066-0.
To trace the sequence of numerical chromosomal aberrations during tumor progression of colorectal tumors, we studied intratumoral heterogeneity of chromosomal copy number by a combined fluorescence in situ hybridization (FISH) and ploidy analysis. We used six formalin-fixed paraffin-embedded tumors of which the mucosal lesions were preserved. Nuclear suspensions were made from the tumor tissues that were scraped from several small regions in 100 micron thick sections. Copy number of chromosomes 1, 7, 17, and 18 were examined by FISH with centromeric repetitive probes. DNA ploidy was monitored by cytofluorometry, and was correlated to the chromosomal copy number on the smear slides of identical nuclear suspension from each tumor portion. All the tumors examined included the DNA-diploid regions in the mucosa, where cancer cells commonly showed monosomy 18 and/or trisomy 7. These chromosomal changes may be quite common early events before the occurrence of DNA-aneuploidy in the development of colorectal tumors. Three out of the 6 tumors included near-tetraploid (3.6-4.1C) cells in deeper invasive regions. Chromosomal constitution of DNA-aneuploid cells was suggested to derive from that of DNA-diploid cells through ploidy duplication with or without additional loss or gain of chromosomes.
为了追踪结直肠癌肿瘤进展过程中染色体数目异常的序列，我们通过荧光原位杂交（FISH）和倍性分析相结合的方法研究了肿瘤内染色体拷贝数的异质性。我们使用了6个福尔马林固定石蜡包埋的肿瘤，其黏膜病变得以保留。从100微米厚切片的几个小区域刮取的肿瘤组织制成核悬液。使用着丝粒重复探针通过FISH检测1、7、17和18号染色体的拷贝数。通过细胞荧光测定法监测DNA倍性，并将其与来自每个肿瘤部分的相同核悬液涂片上的染色体拷贝数相关联。所有检测的肿瘤在黏膜中都包含DNA二倍体区域，其中癌细胞通常表现为18号染色体单体和/或7号染色体三体。这些染色体变化可能是结直肠癌发生过程中DNA非整倍体出现之前相当常见的早期事件。6个肿瘤中有3个在更深的浸润区域包含近四倍体（3.6 - 4.1C）细胞。DNA非整倍体细胞的染色体组成被认为是通过倍性加倍从DNA二倍体细胞衍生而来，可能伴有或不伴有额外的染色体丢失或增加。
