| Gastric cancer(GC) is one of the most common malignancies in China. It is now widely accepted that most GC arise from a process described as the cellula epithelialis-carcinoma sequence and the development of cancer is caused by the accumulation of genetic alternations. Genetic instability may play an important role in the accumulation of genetic alternations. Genetic instability include chromosomal instability and microsatellite instability. In the most of GC, chromosomal instability(CIN) appears to result in gains and losses of genetic materials.Characterization of CIN may lead to new insight into the development and progression of GC. The aims of this study is to identify recurrent chromosomal alterations in gastric carcinogenesis of Chinese.Methods:20GC were from Chinese patients. All tumor specimens were histopathologically proven to be GC .The procedures are followings: (1). extraction of genomic DNA:Genomic DNA was extracted from tumor specimens by proteinase K/sodium dodecyl sulfate digestion followed by phenol/chloroform/ alcohol extraction. Normal reference DNA was prepared from peripheral blood lymphocytes of healthy donors.(2).labling probes: 1μg of DNA from tumor and normal reference DNA were labled with Spectrum Green-dUTP and Spectrum Red-dUTP respectively by nick translation.(3)hybridization: 500 ng of each labled probe was used for hybridization with a slide containing nomal metaphase cells. After hybridization, the slide was counterstained with DAIP.(4)digital image analysis:the hybridized metaphase chromosomes were analyzed using a digital image analysis system containing a microscope equipped with a CCD camera. Four to six metaphase cells were analyzed to generate...
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