1.The Function And Mechanism Of Fibroblast-derived Insulin-like Growth Factor 2 Attenuating Anti-tumor Immunity By Promoting T Cell Exclusion 2.Feasibility Study Of Mirna Combined Signature As A Survival Prognostic Marker For Patients With Endometrial Can

CHAPTER Ⅰ:THE FUNCTION AND MECHANISM OF FIBROBLAST-DERIVED INSULIN-LIKE GROWTH FACTOR 2 ATTENUATING ANTI-TUMOR IMMUNITY BY PROMOTING T CELL EXCLUSIONBackground: The immune checkpoint blockade(ICB)monotherapy has a low response rate in a variety of tumors,among which the important reason is the low T cell infiltration.Previous studies have classified tumors into T cell excluded type and T cell inflamed type according to the spatial distribution of T cells.The main purpose of this study is to investigate the key reasons and methods of reversal of T cell infiltration in T cell excluded tumors.Methods: A total of 3549 samples of 7 tumors in TCGA database were analyzed.Based on the comparison of their immune exclusion scores,the gene insulin-like growth factor 2(IGF2)that is commonly expressed in excluded tumors was obtained.And according to the expression level of IGF2,we study the influence on immune cell infiltration.Using single-cell sequencing data analysis to explore the main origin of IGF2 in the tumor microenvironment.By knocking down Igf2 to study its effect on tumor cell and T cell functions.Using Western blot to detect the signal pathways involved in the regulation of Igf2.The IGF2 receptor inhibitor Linsitinib was selected to study its effect on tumor growth and T cell infiltration in vivo and in vitro,respectively.After establishing subcutaneous tumors,Linsitinib was administered by intragastric administration to detect changes in the composition of immune cells in the immune microenvironment by flow cytometry,and RNA sequencing was performed to understand the expression changes of related genes in tumor tissues.The levels of IGF2 protein in clinical tissues and blood samples were detected by immunohistochemistry and ELISA.A total of 142 patients with triple-negative breast cancer who had not received neoadjuvant chemotherapy were collected and followed up.Results: Compared with T cell inflamed tumors,IGF2 was highly expressed in T cell excluded tumors.Single-cell sequencing data and primary culture results indicate that IGF2 is mainly secreted by tumor-associated fibroblasts(CAFs).The autocrine IGF2 viaIGF1R/AKT/CXCL12 axis in CAFs prevented T cell infiltration.In murine models,IGF2 receptors blockade converted excluded tumor to inflamed tumor,and it promoted tumor regression in a T-cell dependent manner.In vitro,the IGF2/IGF1 R axis did not directly affect naive T cell priming,migration,and ovalbumin(OVA)-specific cytotoxicity,but it could significantly affect the inhibition of T cell migration by CAFs.The combination of IGF2 receptor blockade and anti-PD-1 synergistically amplified antitumor immunity.Finally,IGF2 in mouse plasma reflected the degree of tumor regression in anti-PD-1 therapy,and IGF2 in human plasma was correlated with T-cell exclusion.These data suggest that plasma IGF2 may be a biomarker for predicting and evaluating sensitivity to immunotherapy.Conclusion: IGF2 originated from CAFs regulates the secretion of CXCL12 via the PI3K/AKT pathway in the form of autocrine,thus forming a chemical barrier that prevents T cell infiltration.At the same time,IGF2 promotes the proliferation and differentiation of fibroblasts,which can form a physical barrier to hinder T cell infiltration.The IGF2 receptor blocker Linsitinib can transform the T cell exclusion phenotype,and in combination with anti-PD-1 therapy can play a synergistic role in enhancing anti-tumor immunity.IGF2 can potentially be used as a biomarker to predict immune exclusion and survival prognosis.CHAPTER Ⅱ:FEASIBILITY STUDY OF MIRNA COMBINED SIGNATURE AS A SURVIVAL PROGNOSTIC MARKER FOR PATIENTS WITH ENDOMETRIAL CANCERBackground: The micro RNAs(miRNAs)have been validated as prognostic markers in many cancers.The aim of this study was to identify new miRNA prognostic biomarkers in endometrial cancer(EC)and to develop an expression-based miRNA signature to provide survival risk prediction for EC patients.Methods: From the TCGA database,the miRNA datasets of EC and clinical information were downloaded in April 2018.Using univariate and multivariate Cox regression analyses to identify prognostic factors.Using the area under the curve(AUC)of receiver operating characteristic(ROC)curve to assess the sensitivity and specificity of the prognostic model.Results: 530 patients were randomly divided into training set and testing set.Among 561 differentially expressed miRNAs,4 miRNAs(miR-4758,miR-876,miR-142,miR-190b)were demonstrated to be predictive biomarkers of overall survival(OS)for EC patients in training set.Based on the risk score of the 4-miRNA model,patients in the training set were divided into high-risk and low-risk groups with significantly different OS.This 4-miRNA model was validated in testing and entire set.The AUC for the ROC curves in the entire set was 0.704.Meanwhile,multivariate Cox regression combined with other traditional clinical parameters indicated that the 4-miRNA model can be used as an independent OS prognostic factor.Functional enrichment analysis revealed that these miRNAs are involved in biological processes and pathways that are closely related to cancer.Conclusion: A robust 4-miRNA signature as an independent prognostic factor for OS in EC patients was established.