胃癌与癌前病变复制差错的研究及BAT-26的作用

目的:探讨胃癌及癌前病变组织中微卫 星不稳定性及复制差,在胃癌发生发展中的作 用,及BAT 26在评价组织复制差错情况中的作 用。方法:对包括BAT 26在内的5个微卫星位 点,采用PCR扩增、硝酸银染色法检测微卫星不 稳定性(microsatelliteinstability,MSI)情况。结 果:正常组、癌前病变组和胃癌组中MSI的发生 率分别为0、26.1%(12/46)和51.2%(21/41) 胃癌组明显高于正常组及癌前病变组,P<0.05 肠型胃癌复制差错阳性(replicationerror,RER+ 的发生率(40%)高于弥漫型胃癌(7.7%),P< 0.05。癌前病变组伴发胃癌的标本(癌旁组织 中MSI及RER+的发生率(81.8%,25%)均高于 不伴癌性标本(0.04%,0.04%),P<0.05。所有 的MSI H(RER+)组织均具有BAT 26的变异 MSI L及微卫星稳定(microsatellitesability,MSS 则无发生变化。结论:微卫星不稳定性在胃癌的 发生发展中具有一定作用;检测BAT 26变异可 确定组织中复制差错情况;检测组织中RER情况 可能成为预测肿瘤发生及生物学预后的重要内 容。

Replication error in gastric cancer and precancerous lesion and the function of BAT-26

OBJECTIVE:To study the MSI (microsatellite instability) and RER (replication error) status in gastric cancers and precancerous lesions,and to explore their actions in gastric carcinogenesis and the function of BAT-26 in deciding RER condition. METHODS: Five microsatellite loci including BAT-26 were used to examine the MSI status by PCR amplification and silver stanning. RESULTS: The incidences of MSI were 51.2%(12/40), 26.1%(12/46) and 0 in cancer, precancerous lesions and normal groups respectively. The frequency of MSI was much more higher in gastric cancer than the other two groups,P<0.05,and the frequency of RER + was significantly higher in intestinal type (40%) than diffuse type carcinomas (7.7%),P<0.05. The frequency of RER + was significantly higher in precancerous lesions with cancers than those without cancers,P<0.05. All of the MSI-H tissues were positive in BAT-26, but none in MSI-L and MSS. CONCLUSIONS: MSI takes effect on carcinogenesis and development of gastric cancer. Studying the conditions of BAT-26 can show RER status in tissue, and the RER conditions can be very important in the prognosis and/or prophylaxis of human tumors.