Next generation sequencing of small non-coding RNAs of T-PLL patients and normal T-cell fractions

T cell prolymphocytic leukemia (T-PLL) is mostly characterized by aberrant expansion of small to medium sized pro-lymphocytes with a mature post-thymic phenotype, high aggressiveness of the disease and poor prognosis. However, T-PLL is more heterogeneous with a wide-range of clinical, morphological, and molecular features, which occasionally impedes the diagnosis. We hypothesized that T-PLL consists of phenotypic and genotypic subgroups that may explain the heterogeneity of the disease. We found that T-PLL does not show a clear skewing in T cell receptor alpha (TRA), TRB gene usage and CDR3 stereotypy. In addition, multi-dimensional immuno-phenotyping and gene expression profiling did not reveal clear T-PLL subgroups. However, based on miRNA expression profiles, T-PLL samples did clearly cluster in subgroups. We identified 35 miRNAs that were aberrantly expressed in T-PLL with miR-200c/141 as the most differentially expressed cluster. High miR-200c/141 expression was significantly correlated with increased white blood cell counts and poor survival. Furthermore, we found that overexpression of miR-200c/141 in T-PLL correlated with downregulation of their targets ZEB2 and TGFßR3, indicating that the TGFß pathway is affected. Our results thus highlight the emerging role for aberrantly expressed oncogenic miRNAs in T-PLL, thereby paving the way for new therapeutic targets in this disease. Overall design: small non-coding RNA seq of T-PLL patients compared to normal T cell fractions

T细胞前淋巴细胞白血病（T cell prolymphocytic leukemia, T-PLL）以携带成熟胸腺后表型的中小型前淋巴细胞异常扩增、疾病高侵袭性及不良预后为核心特征。然而T-PLL具有显著异质性，其临床、形态学与分子特征分布范围广泛，偶尔会对诊断造成阻碍。我们提出假说：T-PLL可分为表型与基因型亚型，这或可解释该疾病的异质性。研究发现，T-PLL在T细胞受体α（T cell receptor alpha, TRA）、TRB基因使用偏好以及CDR3刻板性方面均未表现出明显的偏向性。此外，多维度免疫表型分析与基因表达谱分析未发现明确的T-PLL亚型。但基于微小RNA（microRNA, miRNA）表达谱，T-PLL样本可清晰聚类为不同亚型。我们共鉴定出35个在T-PLL中异常表达的miRNA，其中miR-200c/141为差异表达最显著的miRNA簇。高表达miR-200c/141与白细胞计数升高及不良生存结局显著相关。进一步研究显示，T-PLL中miR-200c/141过表达与其靶基因ZEB2和转化生长因子β受体3（transforming growth factor beta receptor 3, TGFβR3）的下调存在关联，提示转化生长因子β（transforming growth factor beta, TGF-β）通路受到调控影响。综上，本研究凸显了异常表达的致癌性miRNA在T-PLL发病机制中的重要作用，为该疾病的新型治疗靶点开发铺平了道路。整体实验设计：对T-PLL患者的小非编码RNA测序数据与正常T细胞组分进行对比分析。