SEREX技术筛选EID3及其表达的实验研究

Cloning and expression of the gene encoding a novel colon cancer associated antigen-EID3

[目的]新的大肠癌相关性抗原EID3的基因克隆及其诊断价值研究.[方法]利用大肠癌病人体内血清中所含的对肿瘤抗原产生的特异性抗体筛选睾丸组织cDNA噬菌体表达文库和大肠癌组织cDNA噬菌体表达文库(SEREX),并用RT-PCR技术研究EID3 mRNA在正常组织和大肠癌传代细胞表达.[结果]睾丸组织cDNA噬菌体表达文库筛选得到了可以诱导大肠癌病人抗体免疫应答的新抗原EID3基因(Gen-bank NM_001008394.1).它们定位于染色体19q13.2,EID3含1个外显子.通过RT-PCR分析发现,EID3基因在43例大肠癌传代细胞株中,39例阳性,阳性率为90.7%.在正常组织中,除睾丸组织外不表达或有极低水平转录.[结论]EID3 mRNA表达检测用于诊断大肠癌,可能具有高特异性和高敏感性的特点.EID3蛋白被首次发现在大肠癌病人中能够诱导机体的抗体免疫应答,为一个新的大肠癌相关性抗原分子.其功能可能与抑制细胞的恶性增殖相关,并可进一步研究其用于治疗和诊断大肠癌的可行性.

[ Objective] To clone the gene encoding a novel colon cancer associated antigen-EID3, and to investigate its mRNA expression pattern in normal tissue and colon cancer cell lines. [ Methods ] Screening on testis cDNA library and colon cancer eDNA library with the serum of patient with colon cancer, and investigating EID3 mRNA expression pattern in normal tissue and colon cancer cell lines by RT-PCR technique. [ Results]The gene encoding EID3 is located on chromosome 19q13.2 ,with one exon,the restglts of RT-PCR indicated that 39 out of 43 colon cancer ceil lines were positive（90. 7% ）, and the EID3 mRNA expression in normal tissue was exclusively positive in testis, other normal tissues were negative or very weak. [ Conclusion ] EID3 mRNA detection can be used in diagnosis of colon cancer with the possibility of high sensitivity and high specificity. It was the first time to discover that the EID3 protein can initiate humoral immune response in colon cancer patient. The function of EID3 may be associated with the inhibition of malignant cellular proliferation. It is necessary to further investigate the possibility of using EID3 in diagnosis and therapy of the patient with colon cancer.