DataSheet3_High-expression of the innate-immune related gene UNC93B1 predicts inferior outcomes in acute myeloid leukemia.PDF

Acute myeloid leukemia (AML) is a heterogeneous hematological malignancy with dismal prognosis. Identification of better biomarkers remained a priority to improve established stratification and guide therapeutic decisions. Therefore, we extracted the RNA sequence data and clinical characteristics of AML from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression database (GTEx) to identify the key factors for prognosis. We found UNC93B1 was highly expressed in AML patients and significantly linked to poor clinical features (p < 0.05). We further validated the high expression of UNC93B1 in another independent AML cohort from GEO datasets (p < 0.001) and performed quantitative PCR of patient samples to confirm the overexpression of UNC93B1 in AML (p < 0.005). Moreover, we discovered high level of UNC93B1 was an independent prognostic factor for poorer outcome both in univariate analysis and multivariate regression (p < 0.001). Then we built a nomogram model based on UNC93B1 expression, age, FAB subtype and cytogenetic risk, the concordance index of which for predicting overall survival was 0.729 (p < 0.001). Time-dependent ROC analysis for predicting survival outcome at different time points by UNC93B1 showed the cumulative 2-year survival rate was 43.7%, and 5-year survival rate was 21.9%. The differentially expressed genes (DEGs) between two groups divided by UNC93B1 expression level were enriched in innate immune signaling and metabolic process pathway. Protein–protein interaction (PPI) network indicated four hub genes (S100A9, CCR1, MRC1 and CD1C) interacted with UNC93B1, three of which were also significantly linked to inferior outcome. Furthermore, we discovered high UNC93B1 tended to be infiltrated by innate immune cells, including Macrophages, Dendritic cells, Neutrophils, Eosinophils, and NK CD56dim cells. We also found UNC93B1 had a significantly positive correlation with CD14, CD68 and almost all Toll-like receptors. Finally, we revealed negatively correlated expression of UNC93B1 and BCL2 in AML and conjectured that high-UNC93B1 monocytic AML is more resistant to venetoclax. And we found high MCL-1 expression compensated for BCL-2 loss, thus, we proposed MCL-1 inhibitor might overcome the resistance of venetoclax in AML. Altogether, our findings demonstrated the utility of UNC93B1 as a powerful poor prognostic predictor and alternative therapeutic target.

急性髓系白血病（Acute myeloid leukemia, AML）是一类异质性血液系统恶性肿瘤，预后极差。挖掘更优的生物标志物仍是优化现有分层策略、指导治疗决策的核心要务。为此，本研究从癌症基因组图谱（The Cancer Genome Atlas, TCGA）及基因型-组织表达数据库（Genotype-Tissue Expression, GTEx）中提取AML患者的RNA测序数据与临床特征，以筛选预后相关关键因子。研究发现UNC93B1在AML患者中呈高表达，且与不良临床特征显著相关（p < 0.05）。本研究进一步在另一项来自GEO数据集的独立AML队列中验证了UNC93B1的高表达（p < 0.001），并通过患者样本的定量聚合酶链反应（quantitative PCR, qPCR）证实了UNC93B1在AML中的过表达（p < 0.005）。此外，单因素与多因素回归分析均显示，UNC93B1高表达是不良预后的独立危险因素（p < 0.001）。随后，本研究基于UNC93B1表达水平、年龄、FAB分型及细胞遗传学风险构建列线图（nomogram）模型，该模型预测总生存期的一致性指数（concordance index, C-index）为0.729（p < 0.001）。基于UNC93B1表达水平的时间依赖性受试者工作特征曲线（time-dependent receiver operating characteristic, time-dependent ROC）分析显示，其预测的2年累积生存率为43.7%，5年累积生存率为21.9%。按UNC93B1表达水平分组得到的差异表达基因（differentially expressed genes, DEGs）富集于先天免疫信号通路与代谢过程。蛋白质-蛋白质相互作用（protein–protein interaction, PPI）网络显示，S100A9、CCR1、MRC1及CD1C这4个枢纽基因可与UNC93B1发生相互作用，其中3个基因同样与不良预后显著相关。进一步分析发现，UNC93B1高表达样本的先天免疫细胞浸润水平更高，包括巨噬细胞、树突状细胞、中性粒细胞、嗜酸性粒细胞及NK CD56dim细胞。本研究还发现，UNC93B1的表达与CD14、CD68及几乎所有Toll样受体均呈显著正相关。此外，本研究证实AML中UNC93B1与BCL2的表达呈负相关，并推测高表达UNC93B1的单核细胞亚型AML对维奈克拉（venetoclax）更易产生耐药性。同时发现MCL-1的高表达可代偿BCL2的功能缺失，因此提出MCL-1抑制剂或可克服AML对维奈克拉的耐药性。综上，本研究结果证实UNC93B1可作为极具潜力的不良预后预测因子与潜在治疗靶点。