目的: 探讨胃癌组织中 MAGE-1基因启动子 B′B区去甲基化状态及其与病理分级及临床分期的关系。方法: 取胃癌组织标本40例，另外取同患者相应的癌旁组织40例作为对照。采用分子生物学技术-甲基化敏感性内切酶酶切及 PCR扩增技术，研究了胃癌组织中MAGE-1启动子 B′B区的去甲基化状态。结果: 在所检测的胃癌组织标本中 MAGE-1基因启动子 B′B区去甲基化的发生率为25％(10／40)。而在癌旁组织中发生率为0，两者发生率的差别具有显著的统计学意义(P＜001)。在低分化腺癌中 MAGE-1基因的 B′B区去甲化发生率为50％(6／12)，中分化腺癌中发生率为18.7％(3／16)，高分化腺癌中发生率为8.3( 1／11)。其发生率的差异有统计学意义(P<0.05)。在早期胃癌组织中 B′B区的去甲基化的发生率为16.7％，在晚期胃癌组织中发生率为28.6％(P<0.05)，差别有统计学意义。结论: 胃癌组织中 MAGE-1基因启动子的 B′B区存在去甲基化。该区的去甲基化发生率与胃癌组织的病理分级以及与临床分期有关。

Objective:To study the methylation state within MAGE-1 B′B promoter in gastric carcinoma and the association between demethylation and pathological differentiation, the association between demethylation and clinical stage. Methods: Using methylation-sensitive restriction analysis followed by polymerase chain reaction (PCR)，we studied 80 specimen that were obtained from surgical samples (including 40 gastric carcinoma and 40 matched adjacent normal gastric mucosae)．Results: An demethylation state was identified in DNA from gastric carcinoma specimens．The demethvlation rate is 25％(10／40)．In contrast，no demethylation state was identified in DNA from matched adjacent normal gastric mucosae. The differences were Significant statistically. ln our study, the demethylation in poorly, moderately, and well differentiated glandulous-cell carcinoma were detected at frequencies of 50％,18.7% and 8.3％,respectively, The differences were significant statistically （P<0.05）． The demethylation rate in early, 1ate tumor stage was 16.7% and 286％，respectively. The differences were significant statistically(P<0.05). Conclusions: The demethylation in MAGE-1 B′B promoter is anomalous in gastric carcinoma, and maybe it is related to the expression of MAGE-1 gene in gastric carcinoma. The demethylation rate is related to the pathological and disease stages differentiation.

R392.1

黑龙江省重点攻关课题 (G0 0C190 40 1)资助