| Background and objective:Gastric cancer is one of the most common and poorly prognosis malignancies. This tumor has bad diagnosis effect at early stage, it always becomes later period when people form a correct diagnosis on it. Currently, comprehensive treatments combined with surgery were the main way to therapy gastric cancer. Also there were some progress in chemoradiotherapy, but due to the high distant metastasis ratio and the rebellious neoplasma growth, the survival rate didn’t have obvious enhance. For the past few years, looking for and study the inhibitory molecules that took part in the tumor evasion had become the new reasearch direction to therapy gastric cancer. ILT3belongs to the Ig-like receptors family, and it has inhibitory function. It displays long cytoplasmic tails that contains immunoreceptor tyrosine-based inhibitory motifs (ITIM), which transducer inhibitory signal by recruiting protein tyrosine phosphatase SHP-1and SHP-2. It was already demonstrated that, ILT3was mainly expressed on DC and macrophage and it had important inhibitory function in transplantation and autoimmunity diseases. Recently, we have found that ILT3is expressed in pancreatic cancer cells and ovarian carcinoma cells of laying hens, the expression of ILT3has some relationship with the development of cancer and tumor evasion, But the function and mechanism about ILT3expressed in peripheral and T cell subsets are still unknown. In this test, we will examine the expression of ILT3in gastric cancer and the relationship between ILT3and development and progression of gastric cancer this test could provide assistance to the further diagnose and treatment of gastric cancer.Method:1. Clinical experiment:The group of experiments included a group of patients with gastric cancer and a group of healthy controls. The group of patients which had made a definite diagnose of gastric cancer came from the department of general surgery of QiLu hospital; the group of healthy control came from physical examination center. Real time fluorescent quantitative PCR was used to investigate the expression of ILT3mRNA and analyze the relationship between the clinicopathoiogical features and biological behavior; at the same time, flow cytometry was used to detect the expression of ILT3on T cell subsets in peripheral blood of patients with gastric cancer and healthy controls, and analyse its function in development and progression of gastric cancer and clinical diagnose.2. Experiment in vitro:(1) After separate PBMC from peripheral blood of healthy people, IL-10(50,100,200ng/L) was used to stimulate these cells for8h,12h,24h. Real time fluorescent quantitative PCR and flow cytometry was used to investigate the alteration of ILT3expression in mRNA and protein level before and after medication respectively.(2) PBMC treated with or without IL-10(50ng/L) for24h were co-incubated with SGC-7901or BGC-823cells, and then the cytolytic activity of PBMC against SGC-7901or BGC-823was determined with CCK-8assayResults:1. clinical trials:1. The results of RT-PCR showed that, the expression of ILT3mRNA (8.465+0.674) in PBMC of gastric cancer patients was significant higher than that in healthy controls (6.234±0.556), and the expression level of ILT3in PBMC had relationship with infiltration degree and differentiation stage. Moreover, the size of cancer, gender, age and lymph node metastases had no relationship with it. In addition, the expression of ILT3mRNA of patients with poorly differentiated stage was significantly higher than that in patients with high differentiated stage (t=4.802; P<0.01); the expression of ILT3mRNA of patients with deep infiltrated degree was significantly higher than that in patients with no infiltration (t=5.971; P<0.01)2. ROC curve was used to estimate the diagnostic value of ILT3in gastric cancer, the sensibility was0.933, the specificity was0.675, the area under the curve was0.760(P <0.05)3. The analysis result of flow cytometry showed that, the protein level of ILT3in CD3+CD4+and CD3+CD81ow cells was remarkably higher than healthy controls. Among that, the percentage of positive cells in CD3+CD4+and CD3+CD8low T cell subsets (29.93%±1.269%and75.53±2.200%) in patients with gastric cancer was significantly higher than those in healthy controls(7.671±1.032%and12.83±0.940%).Experiment in vitro:1. IL-10up-regulated the expression of ILT3mRNA on PBMC, and the degrees of up-regulation were related to drug concentration and reaction time. mRNA level of ILT3was raised significantly on PBMC which dealed with IL-10(50ng/L) for24h (P <0.05),and with the passage of time, the expression of ILT3mRNA was obviously rised. The expression of ILT3PBMC which dealed with IL-10(100,200ng/L) had no statistical significance.2.IL-10up-regulated the expression of ILT3protein in T cell subsets, among that, after dealed PBMC with IL-10(50ng/L) for24h, the expression of ILT3protein was significantly up-regulated in CD3+CD4+and CD3+CD8lowT cell subsets.3. Because of the expression of ILT3was up-regulation, the ability of PBMC coped with IL-10(50ng/L) for24h to kill the target cells decreased markedly.Conclusions:1. ILT3is expressed in the peripheral blood of both gastric cancer patients and healthy controls, but the expression in gastric cancer patients is significant increased, and it is related to the cell differentiation and infiltration degree.2.The expression of ILT3in CD3+CD4+and CD3+CD8low T cell subset of gastric cancer cells was significant higher than that in controls, those reminded that ILT3may induce T cell differentiation and participate in tumor immune evasion.3. IL-10could up-regulate the expression of ILT3in PBMC and T cell subset and took part in the regulation of killing activity of PBMC via ILT3. In addition, the range of the up-regulation of ILT3was related to the density of IL-10. These results could provide reference value to the research which about the mechanism of action of ILT3in gastric cancer and the clinical diagnose and treatment of gastric cancer.In conclusion, the inhibition receptor ILT3plays an important role in the development and progression of gastric cancer. Those ideas could bring new expect to the diagnose and treatment of gastric cancer. |
PDF Full Text Request