胃癌及肠化生组织微卫星不稳定性研究

Microsatellite instability in gastric carcinoma and intestinal metaplasia

目的 研究微卫星不稳定性 (MSI)在胃癌发生、发展中的作用。方法 使用聚合酶链反应 简单序列长度多态性 (PCR SSCP)的方法 ,检测 36例活检和手术切除胃癌标本及 30例肠化生标本的MSI。结果 36例胃癌中 ,有 15例检出 1个以上位点MSI ,总阳性率为 41.7% ;中 高分化腺癌MSI检出率为 6 6 .7% (10 / 15例 ) ,显著高于低分化腺癌的 2 6 .3% (5 / 19例 ,P <0 .0 5 ) ;肠型胃癌MSI阳性率为6 4.7% (11/ 17例 )显著高于弥漫型胃癌的 2 2 .2 % (4 / 18例 ,P <0 .0 5 ) ;MSI与胃癌大小、发生部位、分期及幽门螺杆菌 (Hp)感染无显著相关。 3例早期胃癌MSI均阳性 ,30例肠化生标本中有 9例检出MSI,阳性率为 30 .0 %。Ⅰ、Ⅱ、Ⅲ型肠化生MSI阳性率分别为 2 5 .0 % (2 / 8例 )、2 5 .0 % (3/ 12例 )、40 .0 % (4 /10例 )。三者间差异无显著性。结论 MSI是胃癌多步骤发生过程中的早期分子标志 ,在胃癌的发生过程中可能起重要作用。

Objective To investigate the role of microsatellite instability(MSI) in the carcinogenesis and development of gastric cancer (GC). Methods MSI was examined in 36 gastric cancer specimens obtained endoscopically and during surgery and in 30 intestinal metaplasia specimens using PCR SSCP methods. Results MSI was detected in 15 of 36 GC and 9 of 30 intestinal metaplasia specimens at one or more loci. MSI was positive in all three cases of early GC. The incidence of MSI in well differenciated GC was significantly higher than that in poorly differentiated GC (66.7% vs 26.3%, P <0.05). The frequency of MSI in intestinal type of GC was significantly higher than that in diffused type (64.7% vs 22.2%, P <0.05). No significant correlation was found between MSI and tumor size, location, stage and Helicobacter pylori infect ion. MSI was detected in 2 of 8(25.0%) type Ⅰ, 3 of 12(25.0%) type Ⅱ, and 4 of 10(40.0%) type Ⅲ intestinal metaplasia respectively. There was no significent difference among the three types. Conclusions MSI is an early molecular marker in the multistep cascade of gastric carcinogenesis and may play an important role in the development of GC.