染色体8p21区域胃癌相关EST的筛选

Screening of ESTs Associated With Gastric Carcinoma on Chromosome 8p21

目的筛选胃癌发病相关的表达序列标签,为克隆胃癌相关新基因奠定工作基础。方法在染色体8p21-22区域定位查找ESTs,经BLAST比对分析,筛选出符合条件的10个EST,选取其中4个进行引物设计;收集28例胃癌手术切除的新鲜标本,切取胃癌组织为实验组,远离癌组织(≥5 cm)的胃黏膜组织作为正常对照组,分别提取胃癌及正常胃黏膜组织总RNA,运用RT-PCR方法检测EST的表达水平,筛选出在胃癌和正常胃黏膜中表达差异的EST。结果RT-PCR结果显示:EST DA931869在正常胃黏膜组织中阳性表达率为89.28%(25/28),在胃癌组织中阳性表达率为46.43%(13/28),两者比较差异有显著性(P<0.05);其中高分化胃癌中阳性表达率83.33%(5/6),明显高于中分化胃癌57.14%(4/7)和低分化胃癌26.67%(4/15),差异均有显著性(P<0.05);无淋巴结转移胃癌阳性表达率60.00%(9/15)高于有淋巴结转移胃癌的阳性表达率30.77%(4/13),差异有显著性(P<0.05)。结论EST DA931869在胃癌组织中的阳性表达率低于正常胃黏膜组织,胃癌中该EST表达下调或缺失。

Objective To screen the ESTs associated with gastric carcinoma, which provided basis for further cloning and identifying novel genes associated with the development of gastric carcinoma. Methods ZEST markers on the chromosome 8p21 region were screened with the BLAST software and 10 ESTs were filtered out. We selected 4 ESTs to design primers. 28 cases of gastric cancer surgery samples were collected as cancer groups, corresponding normal gastric mucosa away from the cancer point as the positive control groups. All normal and cancer samples were pathologically diagnosed. The total RNA of samples was extracted out, with reverse transcription polymerase chain reaction （ RT - PCR ）, to screen the differential expression EST. Results The RT -PCR results showed that EST DA931869 expressed significantly different between gastric carcinoma and normal gastric mucosa by RT - PCR approach （ P 〈 0.05 ）. The positive expression rate of EST DA931869 was 89.28 % （ 25/28 ） in normal gastric mucosa, and 46.43 % （ 13/28 ） in gastric carcinoma, which reduced or absently expressed compared with that in normal gastric mucosa. The positive rate of EST DA931869 expressed in well - differentiated gastric carcinoma was 83.33% （ 5/6 ） , obviously higher than in moderately differentiated gastric carcinoma 57.14% （4/7 ） and in poor differentiated gastric carcinoma 26.67% （4/15 ） （ P 〈 0.05 ）. In addition, the positive rate of the EST expressed in lymphoid node metastasis - negative gastric carcinoma was 60.00% （9/15）, significantly higher than in lymphoid node metastasis - positive gastric carcinoma 30.77% （4/13） （ P 〈 0.05 ）. Conclusion DA931869 is downregulated in GC, suggesting it may play a role in GC carcinogenesis.