Isolation Of Exosomes And Their Regulation Of The Immune Microenvironment Of Ovarian Cance

Ovarian cancer is one of the most common malignant tumors in women,and its morbidity and mortality rank among the forefront of gynecological malignant tumors,which seriously threatens women’s health.Ovarian cancer is one of the most common malignant tumors in women,and its morbidity and mortality rank among the forefront of gynecological malignant tumors,which seriously threatens women’s health.The 5-year survival rate of early stage ovarian cancer patients can reach more than 90%through surgery combined with chemotherapy.However,the detection rate of existing screening methods for ovarian cancer is low,and most patients with ovarian cancer are already at an advanced stage when diagnosed,most of which are accompanied by the spread of cancer cells in the abdominal cavity or in the body,leading to a sharp increase in the difficulty of treatment and a decrease in the 5-year survival rate.Advanced ovarian cancer patients are prone to metastasis and recurrence,which may be related to the highly immunosuppressive microenvironment of ovarian cancer.First,tumor cells promote tumor occurrence,progression,and metastasis by inhibiting or inducing infiltrating immune cells within the tumor.Secondly,tumor cells also secrete exosomes to regulate intercellular information exchange and substance transfer,promoting tumor metastasis and recurrence.Exosomes are small vesicles secreted by cells that carry information about mother cells and participate in many physiological and pathological processes in the body.They are considered as potential biomarkers and have been used in the diagnosis of liver cancer,lung cancer and other major clinical diseases.However,how to obtain high purity exosomes is still an urgent problem to be solved.In addition,tumor exosomes play an indispensable role in the tumor immunosuppressive microenvironment.Therefore,it is crucial to study the mechanism of exosomes in the ovarian cancer microenvironment to improve the cure rate of ovarian cancer patients.Based on the above background,we have carried out the following work:Chapter 1: The current status of diagnosis and treatment of ovarian cancer,the methods of exosome isolation and the role of exosomes in the immune microenvironment of ovarian cancer were discussed.Chapter 2: Aiming at the low purity of exosome separation from ovarian cancer,we construct a new method to capture exosomes.The p HLIP-modified magnetic beads were synthesized and characterized by modifying low p H intercalation peptide(p HLIP)onto the surface of magnetic beads.Subsequently,the embedding properties of the material were investigated,and it was found that the p HLIP-modified magnetic beads could be embedded into the phospholipid bilayer of exosomes at low p H.Finally,we demonstrated that the new method can capture exosomes in the supernatant of cells by transmission electron microscopy,nanoflow,and western blotting,and the purity of the captured exosomes is better than that of the traditional overspeed centrifugation method.In this study,the separation method of exosomes was extended.Chapter 3: This chapter studies the effects of exosomes produced by the chemotherapy drug cisplatin on T cells in ovarian cancer cells.Firstly,exosomes were collected from the supernatant of ovarian cancer cells without drug treatment and from the supernatant of ovarian cancer cells treated with cisplatin.The results showed that chemotherapeutic drugs can promote the secretion of exosomes by ovarian cancer cells.In addition,the appearance and size of exosomes secreted by ovarian cancer cells remained consistent before and after treatment with chemotherapy drugs.Subsequently,the effects of two exosomes on T cell apoptosis and Treg cell differentiation were investigated.The results showed that exosomes produced by ovarian cancer cells treated with chemotherapy drugs did not induce T cell apoptosis,but promoted T cell differentiation into Treg cells.Chapter 4: In this chapter,we sequenced the mi RNA genome of exosomes produced by drug-free ovarian cancer cells and exosomes produced by chemotherapeutic drugs.By analyzing the differential gene expression of the two kinds of exosomes,we screened the potential mi RNAs in exosomes that promote the differentiation of T cells into Treg cells,and then acted these mi RNAs with T cells.The differentiation of T cells into Treg cells was studied to further determine the target mi RNA.Chapter 5: This chapter summarizes the new methods of exosome capture and the mechanism of exosome action in the tumor immunosuppressive microenvironment,and prospects our future research direction,hoping to further study the mechanism of mi RNA in exosomes on T cells,and provide new research ideas and better treatment for the poor prognosis of ovarian cancer patients.In order to improve the displacement measurement accuracy of the self-mixing interference,high accuracy phase measurement method is introduced into the SMI system.