应用噬菌体随机肽库筛选结肠癌患者血清中的肿瘤标记物的研究

目的用噬菌体随机呔库技术对结肠癌病人血清进行差异性筛选。以获得特异性的肿瘤标志物。方法用噬菌体随机十二肽库与结肠癌病人血清和正常人血清进行淘选．经过几轮吸附和洗脱得到重组噬菌体库。采用ELISA方法进行单克隆鉴定。挑选20个阳性范隆测序获得相同的序列：19B（GSMSRYVRWYIP）。人工合成小肽19B的寡核苷酸序列，并将其与原核表达载体PGEX-4T—I连接。转化大肠杆菌BI-21（DF3），诱导融合蛋白的表达。以Glutathione Sepharose 4B进行纯化。结果用纯化的蛋白包被抗原板检测24例正常人血清和24例结肠癌病人的血清．证实小肽在正常人血清和结肠癌病人血清间存在差异。结论小肽19B有可能作为检测结肠癌的生物标志物。

Random phage display librar select in the serum of colorectal cancer

Objective To get specific marker of cancer.Methods We screen a phage display 12-mer peptide library with the serum from colon cancer patients sequently.After several panning,we acquire a recombined phage library.After identifying single clone with ELISA,we got a positive clone 19B coding(GSMSRYVRWYTP) which can bind to the serum of colorectal cancer patient specially.The DNA encoding 19B was cloned and express as fusion protein GST-19B in E.coli strain BL-21(DE3).The purified GST-19B shows difference binding with the serum of patient and that of normal person.Results There is a difference between the tissue of liver cancer and that of normal.Conclusion 19B may be can be used as a molecular marker for colorectal cancer.