胃癌候选抑癌基因Syk表达的意义

Expression of tyrosine kinase Syk and its clinicaI significance in gastric carcinoma

目的:探索酪氨酸激酶Syk(spleen tyrosine kinase,Syk) 基因的表达与胃癌生成及转移的关系. 方法:用半定量RT-PCR检测胃癌组织、正常胃组织61例Syk mRNA,p53的表达,同时用免疫组化方法检测Syk 的表达. 结果:所有正常胃组织都有Syk基因的表达,而61例胃癌组织中只有14例表达,正常胃组织Syk基因表达率显著高于胃癌组织(X2=72.3,P<0.05),且胃癌组织中Syk mRNA 含量比正常胃组织显著降低(t=2.1,P<0.05).31例有淋巴结转移的胃癌组织中,3例有Syk基因表达,30例无淋巴结转移的胃癌中有11例检测到Syk mRNA的表达,有淋巴结转移的胃癌Syk mRNA的表达率和表达水平显著降低(X2=4.85,P<0.05),且Syk mRNA表达与p53的表达呈正相关(X2=22.03,P<0.05). 结论:Syk基因的表达缺失与胃癌的生长及转移相关,呈p53依赖性.

AIM: To evaluate the effects of the Syk mRNA expression in human gastric carcinoma on tumor growth and metastasis, and the correlation of expression of the Syk gene with p53. METHODS: Using semi-RT-PCR technique, we detected specimens from 61 gastric carcinoma patients (tumor tissues, adjacent normal tissues) for their rate and level of Syk and p53 gene expression. Meanwhile, immunohis-tochemical staining was also used to detect Syk expression. RESULTS: All normal gastric tissues were detected the expression of the Syk gene. Unlike normal tissue, 47 out of 61 breast cancer tissue did not show any detectable Syk mRNA expression, and there were significant difference between the two groups (X2=72.3, P <0.05). The level of Syk mRNA in the primary gastric carcinoma tissues was significantly lower than that in the adjacent non-cancerous gastric tissues (t=2.1, P<0.05). Furthermore, only 3 gartric carcinoma tissues in 31 patients with lymph node metastasis had the Syk mRNA expression. The Syk mRNA expression was negatively correlated to lymph node metastasis (X2= 4.85, P <0.05). And the Syk expression was correlated to that of p53 (X2 =22.03, P <0.05). CONCLUSION: The expression of the Syk gene may play an important role in suppressing growth and metastasis in gastric cancer. Syk gene expression is repressed in a p53-dependent manner.