Research on the DNA Recombinational Mutation and p53 Gene Mutation Correlating to the Development of Metastatic Potential in Human Cancer Cells

本研究的目的是探讨基于遗传不稳定性的DNA重组突变和p53基因突变在人类癌细胞转移潜能发展中的意义。对4例晚期结直肠癌行结肠切除术的患者外周血白细胞、肿瘤组织及正常结肠黏膜进行了检测。从材料中提取DNA，利用Southern杂交技术进行DNA指纹鉴定。hPc-1是一种多态小卫星探针，用于检测突变。对于p53基因突变，从7例患者中取样材料，准备使用单链构象多态性技术（SSCP）进行分析。外显子6的重点是检查突变的存在。与相应的Wbc和正常粘膜相比，4例癌标本未出现由重组和/或DNA滑移引起的额外条带。7个癌症样本也未显示出外显子6的任何突变。这些缺陷是由于样本（患者）数量不足造成的，也可能是由于对人体材料的分析方法不恰当。我们考虑了实验材料的积累和分析系统的修改。

The aim of this study was to investigate the significance of the DNA recombinational mutation based on the genetic instability and the p53 gene mutation in the development of metastatic potential in human cancer cells. Peripheral white blood cells (Wbc), tumor tissue and normal colonic mucosa were obtained from 4 patients undergoing colectomy for an advanced colorectal cancer. DNA were extracted from the materials and prepared to examine the DNA recombinational mutation with DNA fingerprinting by Southern hybridization technique. The hPc-1, a polymorphic minisatellite probe, was used to detect mutations. As to the p53 gene mutation, aterials were sampled from 7 patients and prepared for anlysis using th single strand confor-mation polymorphisms technique (SSCP) . The exon 6 was focused to examine the presence of mutation.The 4 cancer specimens exhibited no extra-bands resulting from recombination and/or DNA slippage as compared to the corresponding Wbc and normal mucosa. The 7 cancer specimens did not show any mutations either as to the exon 6. These nay resulted from inadequately small number of specimens (patients) and also, presumably, inappropriate analytic methodolgy for human materials. We consider the accumulation of subject materials and modification of assay systems.