Activation of the transcription factor signal transducer and activator of transcription 5b (STAT5b) is a key event in the development of asthma. The potent ability of small interfering RNA (siRNA) to inhibit the expression of STAT5b mRNA has provided a new class of therapeutics for asthma. However, efficient delivery of siRNAs remains a key obstacle to their successful application. A targeted intracellular delivery approach for siRNA to specific cell types would be highly desirable.
To screen the nucleic acid aptamers of the EB virus-positive nasopharyngeal carcinoma cells, we used SELEX technology and synthesized in vitro a 78-nucleotide random DNA library. We used normal nasopharyngeal epithelial cells and EB virus-positive low differentiated nasopharyngeal carcinoma cells as target to conduct 10 cycles of screening, cloning, sequencing, and identification of the aptamers.