Experimental And Clinical Study On Myeloid Derived Suppressor Cell Induced By Autophagosomes(TRAP) Derived From Malignant Pleural Effusion In Adenocarcinoma Of Lung

Experimental and clinical study on myeloid derived suppressor cell induced by autophagosomes(TRAP)derived from malignant pleural effusion in adenocarcinoma of lung.In recent years,autophagy has become a hot topic about cancer all over the world.As is known to everyone,autophagy is an important pathway to maintain the balance of nutrition and homeostasis involving degradation of different kinds of proteins and organelles.Numbers of experiments demonstrate that autophagy plays an important role both in the process of physiological and pathological conditions.What is more,autophagy is considered to be related with many kinds of diseases,such as inflammation,trauma and cancer.It should be emphasized that autophagy is involved in growth and progression of tumor.However,the mechanism of how autophagy works remains unknown,requiring further investigation.Myeloid-derived suppressor cells(MDSC)origin from immune regulation and response of immune system during pathological conditions.MDSC are a large heterogeneity population of immature myeloid cells(IMC),consisting of the progenitors of macrophages,neutrophils and dendritic cells.And it has been reported that MDSC promote tumor progression by suppressing immune system.In tumor-bearing conditions,the differentiation and activation of immature myeloid cells are suppressed and accumulate.The expansion and activation of these immature cells results in the upregulated expression of series of immune suppressive factors.Recently,it has been demonstrated that MDSC mediate inhibition of antitumor immune response through many different mechanisms,including secretion of immunosuppressive mediators and so on.Previous studies have discovered that autophagosomes can be released by tumor cells cultured in vitro.And autophagosomes derived from tumor cells can induce MDSC in tumor-bearing mice both in vivo and in vitro.It has been found that MDSC can inhibit the proliferation and activation of T cell in vivo,demonstrating that MDSC can suppress immune system.With the development of lung adenocarcinoma,pleural effusion is a common clinical phenomenon.In the advanced stage of lung cancer,antitumor therapy has become less effective.It is difficult to control the progression of tumor and multiple kinds of infection come one after another like bacteria,virus and fungus due to inhibition of immune system.With the progression of tumor,hypoxia is an important future of tumor cells.It is assumed that the level of autophagy in lung cancer will increase.Therefore,we guess that autophagosomes may exist in malignant effusion and it can induce the production of MDSC.Due to easy availability of malignant effusion,we take it as research object to explore whether our assumption is true.Objectives:1.To analyze the existence and expression level of MDSC derived from malignant effusions of lung adenocarcinoma patients.2.To study and discuss the effect of TRAP derived from malignant effusions on the activation of MDSC.Methods:1.Analysis and detection of existence and expression level on MDSC derived from malignant effusions of lung adenocarcinoma patients and peripheral blood..1.1 We collect 18 malignant effusions samples from patients of Nanjing Chest Hospital.Then analyze the existence and expression level of MDSC by flow cytometry.1.2 Analyze the expression level of MDSC derived from peripheral blood of lung cancer patients by floe cytometry.2.Experiments on the effect of TRAP derived from malignant effusions on the activation of MDSC.2.1 Deal with the malignant effusions samples to obtain autophagosome.After that,using Western Blot to identify autophagosome.2.2 Collect umbilical cord blood monocyte,then incubate TRAP and monocyte in vitro for 72 hours.Finally,analyze the activation and expression of MDSC via flow cytometry.Results:1.Expression of MDSC in peripheral blood and malignant effusions of lung adenocarcinoma patients both upregulate.And level of MDSC is related to the progression and prognosis of patients.2.Malignant effusions of lung adenocarcinoma contain aotophagosomes.3.TRAP derived from malignant effusions of lung adenocarcinoma can activate and upregulate the expression of MDSC.