Fluorescent AuNPs-nucleic Acid Probe Targeting MicroRNA-155 For The Detection And Treatment Of Cancer Cell

To date,cancer still threatens the health of human seriously.The incidence of cancer in China is also extremely severe.It not only seriously threatens the life and health of the people;affects the quality of people' life,but also causes the loss of a large amount of labor in our country,which brings heavy weight to the national economy burden.This serious situation makes the prevention and treatment of cancer extremely important.However,because the cancer cells have a strong ability to metastasize,it has brought great difficulties to the prevention and treatment of cancer,at the same time,it has made early diagnosis,and timely and reasonable treatment become the key to cancer prevention and treatment.How to diagnose cancer more accurately and how to treat cancer more effectively have become important research directions for scientific researchers.In this dissertation,for intracellular micro RNA-155,two kinds of nanoprobes were designed and synthesized for visual detection and treatment of live cancer cells,which consisted of Au nanoparticle,DNA,fluorophore and aptamer.The details are as follows:First,a novel fluorescent nucleic acid probe was designed and synthesized.In the probe,the carrier is Au nanoparticle,and the anchor sequence of the recognition sequence is a continuous adenine nucleotide sequence.The detection principle of the probe is strands displacement.The detection signal is fluorescent signal.The probe can detect and analyze micro RNA-155 in cancer cells,and it can effectively distinguish cancer cells from normal cells by detecting cancer cells visually.The probe not only provides a convenient and sensitive method for the detection and analysis of micro RNA,but also provides a new research idea for the accurate detection of cancer cell?Secondly,on the basis of the research above,a novel fluorescent nucleic acid probe was designed and synthesized by connecting AS1411 aptamer with cancer cell killing effect to the 3' end of recognition sequence above probe via the disulfide bond.The new probe has synchronous effect on the diagnosis and treatment of cancer cells.After the probe was phagocytized by cancer cells,the AS1411 aptamer was released,because the disulfide bond was broken into sulfhydryl group by glutathione which is highly expressed in cancer cells.And then,the AS1411 aptamer entered into the nucleus and interacted with nucleolin to promote apoptosis of cancer cell,which could be used to treat cancer cell.At the same time,disulfide bond breaking exposes the recognition sequence of the probe,when the probe met the target micro RNA-155,a strand displacement reaction occurred,which generated the fluorescent signal to detect the cancer cell.In summary,the probe designed and prepared in this study not only can detect and analyze micro RNA-155 in cancer cells visually,but also has certain killing effect on cancer cells,which provides a new idea for early diagnosis and treatment of cancer.