Selection And Characterization Of DNA Aptamers Against Glioblastoma Multiforme Cell Line T98G

Research objective: To select aptamers that can specifically recognize glioblastoma multiforme cell line T98 G by using cell-based Systematic Evolution of Ligands by EXponential enrichment(cell-SELEX).These aptamers can be applied to imaging of glioma cells at the molecular level,identifying biomarkers for glioma and realizing the rapid sensitive detection.Such tools will be beneficial to early diagnosis of glioma,molecular diagnosis,further guiding the glioma individualized treatment and prognosis evaluation.Research method: The initial DNA library containing 80 bp total length was designed and chemically synthesized.Human glioblastoma multiforme cell line T98 G was used as the target cell and human normal astroglia cell line SVGp12 for counter selection.Aptamers with high specificity and affinity to T98 G cells can be evolved by cellSELEX including monitoring the selected screening process,cloning sequencing and characterization of aptamers.Research result: We generated three target-specific aptamers against human glioblastoma multiforme cell line T98 G after 8 rounds selection.Two aptamers named WYZ-41 and WYZ-50 were characterized.Two aptamers named WYZ-41 a and WYZ-50 a with higher affinity and dissociation constant(Kd)were obtained by truncating generated aptamers.Both aptamers can distinguish different glioma cell lines and tumor cell lines origined from other organizations.Preliminary experiments confirmed that targets of two aptamers were likely to be membrane protein on the cell surface or substance related to the protein.By laser confocal microscopy,it was observed that aptamers bound to the surface of target cells while control cells did not.Conclusion: Aptamers named WYZ-41 a and WYZ-50 a can bind to target cells T98 G with high specificity and affinity,and the binding site was determined to be membrane protein on the cell surface.The generated aptamers can have great application potential in applications including identification of specific glioblastoma multiforme biomarkers,molecular imaging and targeted drug delivery.