双向热循环消减-SELEX方法筛选肝癌血清核酸适配体

肝癌位于我国肿瘤死亡率第2位，生存率较低。目前用于肝癌早期诊断的临床检查及血清肿瘤标志物检测的特异性与敏感性均较低，不能满足肝癌早期诊断和治疗的需要。核酸适配体与靶标分子结合的灵敏度高、特异性强，有巨大的临床诊断和治疗应用前景。本文利用双向热循环消减指数富集的配基系统进化（systematic evolution of ligands by exponential enrichment, SELEX）技术，分别以肝癌血清和健康人血清为靶标，经过19轮筛选，获得了肝癌血清特异性核酸适配体序列1 000余条，以及健康人血清特异性核酸适配体序列1 000余条，并从中各挑取了1条高丰度适配体序列，分别命名为Tc1和Tn1。采取了50例肝癌病人血清和50例健康人血清，对适配体Tc1和Tn1与靶标血清的结合特异性进行了检测。结果显示，Tc1和Tn1对两种靶标血清的检出率分别为92%和94%。说明Tc1可特异性与肝癌血清结合，Tn1可特异性与健康人血清结合。肝癌血清特异性核酸适配体的筛选获得，将为建立基于核酸适配体的肝癌血清检测新方法奠定基础。

Screening of Serum Nucleic Acid Aptamers for Liver Cancer by Bidirectional Thermal Cycle Subtractive SELEX#br#

In China, liver cancer is the second in cancer mortality, and the survival rate is low. At present, the clinical examination for early diagnosis of liver cancer and the specificity and sensitivity of serum tumor markers are low, which can not meet the needs of early diagnosis and treatment of liver cancer. The binding of nucleic acid aptamers to target molecules has high sensitivity and specificity, and has a great prospect of clinical diagnosis and treatment. In this paper, we used the systemic evolution of ligands by the exponential enrichment (SELEX) technique to target liver cancer serum and healthy human serum, and obtained 19-round screening for liver cancer-specific nucleic acids. More than 1 000 aptamer sequences and more than 1 000 sequences of healthy human serum-specific nucleic acid aptamers were selected, and one high-abundance aptamer sequence was selected from each of them, named Tc1 and Tn1, respectively. 50 cases of liver cancer were taken. The binding specificity of the aptamers Tc1 and Tn1 to the target sera was tested in patient sera and 50 healthy human sera. The results showed that the detection rates of Tc1 and Tn1 for the two target sera were 92% and 94%, respectively. It is indicated that Tc1 can specifically bind to liver cancer serum, and Tn1 can specifically bind to healthy human serum. Screening of liver-specific serum-specific nucleic acid aptamers will lay the foundation for the establishment of a new method for the detection of liver cancer serum based on nucleic acid aptamers.