A Novel Circulating 4-miRNA Prognostic Model in Diffuse Large B-Cell Lymphoma: Role of MDSCs and Th17 Cells on Lymphoma Progression

Background: MicroRNAs (miRNAs) have been emerging as prognostic biomarkers in diffuse large B-cell lymphoma (DLBCL). The aim of this study is to translate these findings into clinical prediction on lymphoma progression. Methods: Using genome-wide miRNA expression in serum samples of 20 patients with DLBCL at diagnosis, remission and at relapse, candidate miRNAs were identified to establish circulating prognostic model. DNA- and RNA-sequencing were performed on tumor samples to detect genetic mutations and signaling pathway dysregulation. Mechanism of action of miRNAs on oncogenic signaling and tumor microenvironment was analyzed in vitro and in vivo. Findings: A novel circulating 4-miRNA prognostic model (miR21, miR130b, miR155, and miR28) significantly predicted clinical outcome of DLBCL, independent on International Prognostic Index in the training cohort [n=279, HR=2.83 (95%CI 2.14-3.51), P<0.001] and in the validation cohort [n=225, NCT01852435, HR=2.71 (95%CI 1.91-3.50), P<0.001]. DNA-sequencing data showed no significant difference of tumor mutation burden between low-risk and high-risk groups of the 4-miRNA model. RNA-sequencing data showed that 4-miRNA model correlated with aberrant Ras signaling transduction. In B-lymphoma cells, modulation of the 4 miRNAs regulated IGF1 and JUN expression, resulting in alterations in MDSCs and Th17 cells. Clinically, comparing with low-risk group of the 4-miRNA model, high-risk group presented Ras signaling activation, increased MDSCs and Th17 cells, and immunosuppressive status in DLBCL. Interpretations: The easy-to-use circulating 4-miRNA prognostic model was effective to predict relapse and survival in DLBCL. Tumor microenvironment contributes to the underlying mechanism of the 4-miRNA model on DLBCL progression. Funding: This study was supported, in part, by research funding from the National Natural Science Foundation of China (81520108003, 81830007, 81670176, 81700191 and 81900193), Chang Jiang Scholars Program,Shanghai Municipal Education Commission Gaofeng Clinical Medicine Grant Support (20152206 and 20152208), Shanghai Sailing Program (19YF1430900), Clinical Research Plan of Shanghai hospital development center (SHDC, 16CR2017A), Multicenter Clinical Research Project by Shanghai Jiao Tong University School of Medicine (DLY201601), Multicenter Hematology-Oncology Programs Evaluation System (M-HOPES), Collaborative Innovation Center of Systems Biomedicine, and the Samuel Waxman Cancer Research Foundation. Declaration of Interests: All authors declare no potential conflict of interest. Ethics Approval Statement: The study was approved by the Institutional Review Boards of all M-HOPES centers with informed consent obtained from all patients in accordance with the Declaration of Helsinki.