胰腺癌18号染色体和20号染色体的不稳定性

目的 检测胰腺癌细胞系基因组中18号染色体和20号染色体数目及结构的变化，探讨胰腺癌细胞染色体不稳定性的规律。方法 选择18号染色体和20号染色体的染色体涂染（chromosome painting）探针，用与我院实验室自建的中国人胰腺癌细胞系PC-1、PC-2、PC-4、PC-7和来源于ATCC的人胰腺癌细胞系PANC-1、ASPC-1、Miapaea、BXPC-3共8株细胞系进行双色荧光原位杂交，分析胰腺癌细胞基因组中18号染色体和20号染色体发生非整倍体的特点。结果 在8株胰腺癌细胞系中7株细胞系18号染色体为二倍体，1株为四倍体，2株有18号染色体长臂部分丢失，另有2株18号染色体与其他染色体发生重组：有3株细胞系20号染色体出现三倍体，其中2株同时有20号染色体重组发生，有3株细胞系20号染色体出现四倍体，其中1株伴有重组。结论 中国人胰腺癌细胞18号染色体长臂部分丢失，并有18号染色体与其他染色体的重组发生；20号染色体扩增和重组是高频发生事件，这些染色体的非整倍体与胰腺癌发生可能有着密切的关系。

Instability of chromosomes 18 and 20 in pancreatic carcinoma cell lines

Objective To detect the alterations of copy number and structure of chromosomes 18 and 20 and to determine the characteristics of chromosome instability in pancreatic carcinoma. Methods Double-color fluorescence in situ hybridization(FISH) was performed in 8 pancreatic carcinoma cell lines(four Chinese pancreatic carcinoma cell lines established in our laboratory,and other four cell lines came from ATCC) by using painting probes of chromosomes 18 and 20,and aneuploid patterns of chromosomes 18 and 20 in the genome of pancreatic carcinoma were analyzed. Results Diploids of chromosome 18 were detected in seven of the eight cell lines,and tetraploid was detected in the other one cell line.Partial loss of 18q presented in 2 cell lines,and recombination of chromosome 18 with other chromosomes were found in other 2 cell lines.Triploids of chromosome 20 were detected in 3 cell lines,and recombinations of chromosome 20 were found in two of them,tetraploids of chromosome 20 presented in 3 cell lines,and recombination was detected in one of them. Conclusions Partial loss of chromosome 18q and recombination of chromosome 18 with other chromosomes are specific in Chinese pancreatic carcinoma cell lines.Amplification and recombination of chromosome 20 are events of high frequency in pancreatic carcinoma.Aneuploid of chromosomes 18 and 20 may be associated with the carcinogenesis of pancreatic carcinoma.