Bioinformatics Analysis Of Aptamer Targeting Human Bladder Cancer Cell And Its Property Study

Bladder cancer is the most common urinary system malignant tumor,which can be divided into non-muscular invasive bladder cancer and muscular invasive bladder cancer.Among them,non-muscular invasive bladder cancer has a high recurrence rate,while muscular invasive bladder cancer is high ly malignant and easy to metastasize,which is an important cause of death in patients with bladder cancer.At present,the main detection method for bladder cancer is invasive examination based on cystoscopy.This method is prone to complications,high me dical costs,and long-term monitoring is not possible,which limits the early diagnosis of bladder cancer.In terms of treatment,surgical resection,radiotherapy and chemotherapy,immunotherapy,and targeted therapy are still difficult to meet clinical re quirements,with a high recurrence rate and a low survival rate for advanced patients.Therefore,searching for ideal tumor markers and developing new molecular probes for detecting bladder cancer are of great significance to the diagnosis and treatment of bladder cancer.Aptamers are single-stranded oligonucleotides that can bind to the target with high specificity and high affinity,which are obtained by SELEX technology.Aptamers have a wide range of clinical applications and can be used in the fields of disease marker discovery,in vivo and in vitro diagnosis,and targeted therapy.Therefore,rapid and efficient screening of targeted nucleic acid aptamers is a key link in the development of this field.In recent years,virtual screening technology based on mathematical calculations can screen high-affinity aptamers through sequence structure prediction and molecular docking.The introduction of this technology can simplify screening procedures,shorten screening cycles,and optimize aptamer functions,which plays a significant role in the development of aptamers.In order to obtain aptamers that could target human bladder cancer,this study used the CELL-SELEX technology,human bladder cancer cell T24 were used as the positive selection cell and human bladder epithelial immortalized cell SV-HUC-1were used as the negative selection cell.After 11 rounds of selection experiments,an enriched library was obtained.The enriched library was sequenced by high-throughput sequencing,then we used bioinformatics me thods to analyze the sequences distribution of the sequencing data,then we clarified the trend of sequences enrichment in the selection process;through cluster analysis,we determined the dominant families and dominant sequences,and select three candida te aptamers,cyl-1,cyl-2 and cyl-3.Our data demonstrated that aptamers cyl-1 and cyl-3 could specifically bind to human bladder cancer cells T24,and not SV-HUC-1 negative selection cells,which successfully confirmed the accuracy of our bioinformatics analysis results.Subsequently,we investigated the related properties of the two aptamers.Both aptamers can specifically bind to T24 cells.Based on the simulation prediction of the secondary structure,we optimized the truncated aptamer cyl-3 to obtain the truncated aptamer cyl-3d,which also had a strong binding force to the target cells.Through target type identification,we found that the target of aptamer was a protein.In summary,we obtained three aptamers that could identify human bladder cancer T24 cells with high affinity through screening and bioinformatics analysis,providing possible molecular tools for the diagnosis and treatment of bladder cancer,and also promoting the further application of bioinformatics analysis in the field of aptamers.