肿瘤抑素抗血管活性相关肽的表达及活性研究

目的利用大肠杆菌表达系统表达肿瘤抑素抗血管活性相关肽-21肽,检测其生物学活性。方法人工合成21肽基因序列(肿瘤抑素75～95位氨基酸),克隆到表达载体pTYB2上,转化大肠杆菌BL-21(DE_3),酶切和测序鉴定后,用IPTG诱导表达融合蛋白。经几丁质亲和层析柱纯化21肽。通过MTT实验,细胞生长曲线测定,小鼠肝癌转移瘤模型的大体抑瘤实验及组织病理学切片研究其活性。结果获得的可溶性21肽对人脐静脉内皮细胞的生长具有抑制作用。小鼠肝癌转移瘤模型的大体抑瘤实验抑瘤率达42.86%。组织病理学切片结果可见H22小鼠肝癌细胞死亡,血管数量减少。结论经初步检测获得具有抗血管活性的21肽,为进一步研究肿瘤抑素的作用机制和肿瘤的临床治疗奠定了基础。

Study on Expression and Biological Activity of Anti-angiogenic Peptide of Tumstatin

Objective To express anti-angiogenic peptide of tumstatin-21 peptide in E. Coli and determine its biological activity. Method The DNA sequence encoding 21 peptide (75-95 amino acid of tumstatin) was designed, artificially synthesized and cloned into expression vector pTYB2. Then the recombinant plasmid was transformed into E. Coli BL-21 (DE3). After sequencing and restriction, fusion protein was expressed under induction by IPTG. The soluble 21 peptide was purified by using chitin affinity chromatography. Through MTT assay, cell growth curve, the effect of the ascetic transferent H22 hepatoma in mice and histopathology, the biological activity of the 21 peptide was studied. Results The soluble 21 peptide inhibited proliferation of human umbilical veil endothelial cells (HUVEC). The tumor inhibition rate of ascetic fluid transfevent H22 hepatoma in mice was 42. 86%. Histopathological examination showed that hepatoma cells of mice died and the number of blood vessels decreased. Conclusions The 21 peptide of tumstatin with anti-angiogenic activity is obtained, which provides a foundation for further study of its mechanism of action and clinical application.