细胞SELEX技术用于胰腺癌细胞特异性适配体的筛选及鉴定

细胞SELEX是目前常用的筛选细胞特异性适配体的技术。胰腺癌细胞特异性适配体在胰腺癌的诊断和治疗中有巨大的应用潜力。本研究拟通过该技术获得特异性识别胰腺癌PANC-1细胞的适配体，并对所筛选的适配体进行功能鉴定。本研究以胰腺癌PANC-1细胞为正筛细胞，正常胰腺导管上皮细胞HPDE6-C7为负筛细胞，通过磁珠法细胞SELEX技术进行筛选。经过12轮筛选，对筛选文库进行PCR扩增、质粒转染、单克隆挑选及测序，获得2条适配体Apt-5和Apt-12。流式细胞术检测发现，适配体Apt-5和Apt-12可特异性识别PANC-1细胞，其Kd值分别为8.27±2.10 nmol/L和8.88±2.51 nmol/L，Kd值均处于纳摩尔级别。通过RNA结构预测，2条适配体的二级结构均为茎-环结构。细胞免疫荧光验证了适配体的结合部位为细胞膜表面。本研究表明，通过磁珠法细胞SELEX技术，成功获得可特异性识别胰腺癌PANC-1细胞的适配体。该适配体有望成为胰腺癌诊断和治疗中的特异性分子靶向剂。

Screening and Identification of Specific Aptamer for Pancreatic Cancer Cells by Cell-SELEX

Aptamers have great potential in the diagnosis and treatment of pancreatic cancer. Cell-SELEX（systematic evolution of ligands by exponential enrichment）is a common technique for screening cell-specific aptamers. This study aims to screen DNA aptamers that can specifically recognize pancreatic cancer cell line PANC-1 based on Cell-SELEX analysis. In this study, PANC-1 cells were used as positive cells, meanwhile HPDE6-C7 cells were used as negative cells. After 12 rounds of selection, the ssDNA pool was PCR-amplified and cloned, and monoclonal colony was selected for sequence analysis by Sangon Biotech. Results showed that DNA aptamers Apt-5 and Apt-12 were obtained. Flow cytometry was used to verify the affinity of the DNA aptamers with PANC-1 cells. Their Kd values were 8.27±2.10 nmol/L and 8.88±2.51 nmol/L, respectively. This study showed that the DNA aptamers screened by Cell-SELEX can specifically bind to PANC-1 cells, which may be used for finding potential molecular targets for the diagnosis and treatment of pancreatic cancer.