不同级别胃黏膜上皮内肿瘤和胃癌组织sFas／mFasmRNA表达比的改变及意义

目的：研究Fas基因的两种拼接异构蛋白基因表达在胃黏膜瘤变形成与发展过程中的变化，在基因水平上探讨Fas系统的表达与胃上皮组织瘤变及免疫逃逸形成的关系，评估胃镜下活检的胃黏膜组织进行Fas基因检测的临床价值和意义。方法：采用半定量RT—PCR法，对胃镜下活检的30例正常胃黏膜组织，30例胃黏膜低级别上皮内肿瘤，20例高级别上皮内肿瘤和30例胃癌组织检测sFas／mFasmRNA表达比。结果：sFas／mFasmRNA表达比在正常胃黏膜组织为0．47±0．07，低级别上皮内肿瘤组织为0．55±0．05，高级别上皮内肿瘤组织为0．22±0．04，胃癌组织为0．19±0．03，正常胃黏膜上皮组织的sFas／mFasmRNA表达比低于低级别上皮内肿瘤（P〈0．01），低级别上皮内肿瘤sFas／mFasmRNA表达比明显高于高级别上皮内肿瘤组（P〈0．001），高级别上皮内肿瘤组表达明显高于胃癌（P〈0．001）。结论：正常胃黏膜及瘤变胃黏膜组织FasmRNA以可溶型FasmRNA（sFasmRNA）为主，伴少量的膜型FasmRNA（mFasmRNA），胃黏膜不同级别上皮内肿瘤和胃癌组织sFas／mFas表达比的强度各不相同，胃黏膜瘤变过程中的Fas基因表达形式具有可修饰性并伴有凋亡易感性的改变，胃镜下Fas基因表达形式的检测，有望指导临床在瘤变发生的早期，即免疫逃逸阶段这一基因水平上提早预知。

The Change and significance of expression ratio of sFas/mFas mRNA in different grades of gastric mucous intraepithelial tumor and gastric cancer tissue

Objective：To study the change of splicing isomerism protein gene expression in gastric mucous tumorgenesis, discuss the relation of Fas expression with gastric epithelium neoplasia and immunologic escape, and evaluate clinical value and significance of Fas gene detection in gastric mucous tissue through gastroscope biopsy. Methods： The expression ratio of sFas/mFas mRNA was examined by semiquantitative RT - PCR. Results： The expression ratio of sFas/mFas mRNA in normal gastric mucous tissue was 0.47 ± 0.07, in low grade intraepithelial tumor tissue was 0. 55 ± 0. 05, in high grade intraepithelial tumor tissue was 0.22 ±0.04, in gastric cancer tissue was 0.19 ±0.03. The expression ratio of sFas/mFas mRNA in normal gastric mucous tissue was lower than in low grade intraepithelial tumor tissue（ P 〈 0.01 ） ;The expression ratio of sFas/mFas mRNA in low grade intraepithelial tumor tissue was obviously higher than in high grade intraepithelial tumor tissue（P 〈 0.001 ） ;The expression ratio of sFas/mFas mRNA in high grade intraepithelial tumor tissue was obviously higher than in gastric cancer tissue（P 〈 0. 001 ）. Conclusion： Fas mRNA in normal and neoplasia gastric mucous tissue is mainly soluble Fas mRNA （sFas mRNA）, with slight membranous Fas mRNA （mFas mRNA）. The expression ratio of sFas/mFas mRNA in different grade intraepithelial tumor tissue and gastric cancer tissue is different from each other. The expression form of Fas gene in gastric mucous neoplasia has modifiability,with the change of apoptosis susceptibility. The detection of expression form of Fas gene under gastroscope is hopeful to instruct clinical earlier prediction in the gene level of immunologic escape in early stage of neoplasia.