在中国人胃癌组织DNA中发现癌基因Ha-ras等位基因缺失

Loss of Ha-ras Alleles in DNA from Gastric Carcinoma Tissue of Chinese Individuals

本文应用c-Ha-ras-1为探针,与13个中国人胃癌患者癌组织和癌旁正常组织DNA经BamHI酶切后进行Southern印迹杂交。结果发现1例6.3kb/7.8kb杂合子患者在癌组织中丢失了6.3kb Ha-ras等位基因。在另一个胃癌杂合子患者家系的限制性片段长度多态性(restriction fragment length polymorphisms,RFLP)分析中,发现患者的1个女儿也丢失了1个Ha-ras 7.4kb的等位基因。这一现象可能是有丝分裂不分离或重组事件造成的,它提示Ha-ras在胃癌中的激活除点突变外还有另外的途径。

In this study, a human c-Ha-ras-1 6 kilobase recombinant clone (EcoRI fragment) was used as a probe. DNA from 15 gastric carcinoma patients heterozygous for the Ha-ras locus contained two Ha-ras-related BamHI restriction fragments. Southern blotting results showed similar patterns of allelic restriction fragments between gastric carcinoma and normal gastric tissue DNA in 12 cases. But one heterozygous patient (6.3kb/7.8kb) lost a 6.3kb allelic restriction fragment in the gastric carcinoma tissue. We also examined the RFLPs of the Ha-ras oncogene in one pedigree of a heterozygous gastric carcinoma patient. The results showed that one daughter had lost one Ha-ras allele in WBC DNA. This Ha-ras allele loss may have resulted from a mitotic nondisjunction or a mitotic recombination event.