Craanen M E, Blok P, Top B, Boerrigter L, Dekker W, Offerhaus G J, Tytgat G N, Rodenhuis S
Department of Gastroenterology, Academic Medical Centre, Amsterdam, The Netherlands.
Gut. 1995 Dec;37(6):758-62. doi: 10.1136/gut.37.6.758.
The aims of this study were to assess the prevalence and type of activating point mutations at codons 12, 13, and 61 of the Ki-, Ha-, and N-ras genes in a series of early gastric carcinomas in white patients and to correlate these ras gene mutations, if any, with the histological type (Lauren classification), the type of growth pattern, and with the Helicobacter pylori status. Haematoxylin and eosin and Giemsa stained sections from 45 formalin fixed, paraffin wax embedded early gastric carcinomas were used to assess the Lauren type, the type of growth pattern, and the antral H pylori status. DNA was extracted according to standard procedures. Mutations at codon 12 of the Ki-ras gene were examined with a polymerase chain reaction based restriction fragment length polymorphism (PCR-RFLP) method and dot blot hybridisation with allele-specific 32P-labelled oligodeoxynucleotide (ASO) probes. All other ras genes were analysed with specific PCR amplification and dot blot hybridisation with ASO probes. Mutations were detected by overnight autoradiography at -70 degrees C. Some 20 intestinal-type and 25 diffuse-type early gastric carcinomas were seen. According to growth pattern, there were 24 small mucosal type early gastric carcinomas, five superficial spreading type early gastric carcinomas, and 16 penetrating type early gastric carcinomas (four penetrating A type, 12 penetrating B type). H pylori was found in the antral mucosa of 28 early gastric carcinomas (62%). Activating ras gene mutations were not found. It was discovered that activating point mutations at codons 12, 13, and 61 of the Ki-, Ha-, and N-ras genes do not play a part in the development of early gastric carcinomas in white subjects, irrespective of Lauren type. Moreover, differences in biological behaviour between early carcinomas with different types of growth pattern are not related to these ras gene mutations. Finally, H pylori positive and H pylori negative gastric carcinomas cannot be discriminated on the basis of ras gene mutational analysis.
本研究旨在评估一系列白人患者早期胃癌中Ki-、Ha-和N-ras基因第12、13和61密码子激活点突变的发生率和类型，并将这些ras基因突变（若存在）与组织学类型（劳伦分类）、生长模式类型以及幽门螺杆菌状态相关联。采用苏木精-伊红染色和吉姆萨染色的45例经福尔马林固定、石蜡包埋的早期胃癌切片，用于评估劳伦类型、生长模式类型和胃窦部幽门螺杆菌状态。按照标准程序提取DNA。采用基于聚合酶链反应的限制性片段长度多态性（PCR-RFLP）方法及与等位基因特异性32P标记寡脱氧核苷酸（ASO）探针的斑点杂交，检测Ki-ras基因第12密码子的突变。所有其他ras基因均采用特异性PCR扩增及与ASO探针的斑点杂交进行分析。通过在-70℃过夜放射自显影检测突变。共观察到约20例肠型和25例弥漫型早期胃癌。根据生长模式，有24例小黏膜型早期胃癌、5例浅表扩散型早期胃癌和16例浸润型早期胃癌（4例浸润A型，12例浸润B型）。28例早期胃癌（62%）的胃窦黏膜中发现幽门螺杆菌。未发现激活的ras基因突变。研究发现，Ki-、Ha-和N-ras基因第12、13和61密码子的激活点突变在白人早期胃癌的发生中不起作用，与劳伦类型无关。此外，不同生长模式的早期癌之间生物学行为的差异与这些ras基因突变无关。最后，基于ras基因突变分析无法区分幽门螺杆菌阳性和阴性的胃癌。
