大肠癌的细胞遗传学研究

A cytogenic study on colorectal carcinoma.

目的研究大肠癌的发生机理，期望发现与大肠癌发生有关的染色体脆性位点，以指导大肠癌高危人群的筛查和防治。方法对２０例大肠癌手术切除瘤组织及４例大肠癌细胞系进行了细胞遗传学研究。结果发现癌细胞多为异倍体，染色体数目以亚二倍体居多，常见１３号染色体增多及１７、１号染色体丢失；结构畸变较常累及１号染色体，以１ｑ２１，１ｐ１３区的裂隙、断裂、末端丢失最为常见。对比大肠癌细胞染色体高度非随机断裂点与脆性位点和目前所确认的癌基因位点，发现三者同位或毗邻的位点为１ｑ２１。结论１ｑ２１可能与大肠癌的发生有关，并对大肠癌高危人群的筛查和防治有一定的指导意义。

Objective To study the cytogenesis of colorectal carcinoma and to look for colorectal carcinoma related chromosomal fragility sites which could facilitate screening of high risk colorectal carcinoma patients.Methods 20 cases of surgically resected colorectal carcinomas and 4 cell lines were analysed cytogenetically. Results Most of the tumor cells were heteroploid, the chromosome number was predominately hypodiploid. Karyotypic analysis demonstrated an increase of chromosome 13, and loss of chromosome 17 and chromosome 1 appeared frequently. The most frequently found structural abnormalities in colorectal carcinoma were breakpoint lq21 and 1p13. Highly non random cancer chromosome breakpoints and fragile sites were compared with the oncogene locus and found that their locus or neighboring locus was 1q21. Conclusion The results suggest that breakpoint 1q21 may be related to tumorgenesis and may be useful in screening and preventing colorectal carcinoma.