T-cell receptor architecture and clonal tiding provide insight into the transformation trajectory of peripheral T-cell lymphomas.

While T cell lymphomas are classified as mature neoplasms, emerging evidence indicates that malignant transformation may occur at an earlier stage of T cell maturation. In this study, we determined clonal architectures in a broad range of T cell lymphomas. Our multidimensional profiling indicates that a large part of these lymphomas in fact emerge from an immature lymphoid T cell precursor at a maturation stage prior to V(D)J rearrangement that undergoes branching evolution. Consequently, at single cell resolution we observed considerable clonal tiding under selective therapeutic pressure. T cell receptor next-generation sequencing suggested a highly biased usage of TRBV20-1 gene segments as part of multiple antigen receptor rearrangements per patient. The predominance of TRBV20-1 was found across all major T cell lymphoma subtypes analyzed. This suggested that this particular V gene - independently of complementarity-determining region 3 (CDR3) configuration - may represent a driver of malignant transformation. Together, our data indicate that T cell lymphomas derive from immature lymphoid precursors and display considerable intratumoral heterogeneity that may provide the basis for relapse and resistance in these hard-to-treat cancers.

SAM-Competitive EZH2-Inhibitors Induce Platinum Resistance by EZH2-Independent Induction of ABC-Transporters.

T-cell lymphomas are heterogeneous and rare lymphatic malignancies with unfavorable prognosis. Consequently, new therapeutic strategies are needed. The enhancer of zeste homologue 2 (EZH2) is the catalytic subunit of the polycomb repressive complex 2 and responsible for lysine 27 trimethylation of histone 3. EZH2 is overexpressed in several tumor entities including T-cell neoplasms leading to epigenetic and consecutive oncogenic dysregulation. Thus, pharmacological EZH2 inhibition is a promising target and its clinical evaluation in T-cell lymphomas shows favorable results. We have investigated EZH2 expression in two cohorts of T-cell lymphomas by mRNA-profiling and immunohistochemistry, both revealing overexpression to have a negative impact on patients' prognosis. Furthermore, we have evaluated EZH2 inhibition in a panel of leukemia and lymphoma cell lines with a focus on T-cell lymphomas characterized for canonical EZH2 signaling components. The cell lines were treated with the inhibitors GSK126 or EPZ6438 that inhibit EZH2 specifically by competitive binding at the S-adenosylmethionine (SAM) binding site in combination with the common second-line chemotherapeutic oxaliplatin. The change in cytotoxic effects under pharmacological EZH2 inhibition was evaluated revealing a drastic increase in oxaliplatin resistance after 72 h and longer periods of combinational incubation. This outcome was independent of cell type but associated to reduced intracellular platinum. Pharmacological EZH2 inhibition revealed increased expression in SRE binding proteins, SREBP1/2 and ATP binding cassette subfamily G transporters ABCG1/2. The latter are associated with chemotherapy resistance due to increased platinum efflux. Knockdown experiments revealed that this was independent of the EZH2 functional state. The EZH2 inhibition effect on oxaliplatin resistance and efflux was reduced by additional inhibition of the regulated target proteins. In conclusion, pharmacological EZH2 inhibition is not suitable in combination with the common chemotherapeutic oxaliplatin in T-cell lymphomas revealing an EZH2-independent off-target effect.

Online Learning for Wearable EEG-Based Emotion Classification.

Giving emotional intelligence to machines can facilitate the early detection and prediction of mental diseases and symptoms. Electroencephalography (EEG)-based emotion recognition is widely applied because it measures electrical correlates directly from the brain rather than indirect measurement of other physiological responses initiated by the brain. Therefore, we used non-invasive and portable EEG sensors to develop a real-time emotion classification pipeline. The pipeline trains different binary classifiers for Valence and Arousal dimensions from an incoming EEG data stream achieving a 23.9% (Arousal) and 25.8% (Valence) higher F1-Score on the state-of-art AMIGOS dataset than previous work. Afterward, the pipeline was applied to the curated dataset from 15 participants using two consumer-grade EEG devices while watching 16 short emotional videos in a controlled environment. Mean F1-Scores of 87% (Arousal) and 82% (Valence) were achieved for an immediate label setting. Additionally, the pipeline proved to be fast enough to achieve predictions in real-time in a live scenario with delayed labels while continuously being updated. The significant discrepancy from the readily available labels on the classification scores leads to future work to include more data. Thereafter, the pipeline is ready to be used for real-time applications of emotion classification.

Divergent Effects of EZH1 and EZH2 Protein Expression on the Prognosis of Patients with T-Cell Lymphomas.

T-cell lymphomas are highly heterogeneous and their prognosis is poor under the currently available therapies. Enhancers of zeste homologue 1 and 2 (EZH1/2) are histone H3 lysine-27 trimethyltransferases (H3K27me3). Despite the rapid development of new drugs inhibiting EZH2 and/or EZH1, the molecular interplay of these proteins and the impact on disease progression and prognosis of patients with T-cell lymphomas remains insufficiently understood. In this study, EZH1/2 mutation status was evaluated in 33 monomorphic epitheliotropic intestinal T-cell lymphomas by next generation sequencing and EZH1/2 and H3K27me3 protein expression levels were detected by immunohistochemistry in 46 T-cell lymphomas. Correlations with clinicopathologic features were analyzed and survival curves generated. No EZH1 mutations and one (3%) EZH2 missense mutation were identified. In univariable analysis, high EZH1 expression was associated with an improved overall survival (OS) and progression-free survival (PFS) whereas high EZH2 and H3K27me3 expression were associated with poorer OS and PFS. Multivariable analysis revealed EZH1 (hazard ratio (HR) = 0.183; 95% confidence interval (CI): 0.044-0.767; p = 0.020;) and EZH2 (HR = 8.245; 95% CI: 1.898-35.826; p = 0.005) to be independent, divergent prognostic markers for OS. In conclusion, EZH1/2 protein expression had opposing effects on the prognosis of T-cell lymphoma patients.

RBMX Protein Expression in T-Cell Lymphomas Predicts Chemotherapy Response and Prognosis.

T-cell non-Hodgkin's lymphomas (T-NHL) are a heterogeneous group of lymphomas with a mature T-cell phenotype. While in some hematological diseases the prognosis improved over the last decades, T-NHL cases often relapse early or present with an initially refractory course. Recently, it has been shown that RNA binding proteins have a crucial role for malignant tumor initiation, progression and treatment response while contributing to chemotherapy resistance. Therefore, we investigated the protein expression of the RNA binding protein X (RBMX), which has been shown to be of great relevance in disease initiation and progression in hematological diseases in 53 T-NHL cases using conventional immunohistochemistry. Low RBMX expression was associated with better response to anthracycline-containing first-line treatment. Furthermore, low RBMX expression predicted an improved overall survival and progression-free survival in univariate analysis. Multivariable Cox regression revealed RBMX as an independent prognostic marker for overall survival (p = 0.007; hazard ratio (HR) = 0.204; 95% confidence interval (CI): 0.064-0.646) and progression-free survival (p = 0.006; HR = 0.235; 95% CI: 0.083-0.666). The study identifies low RBMX expression to predict better chemotherapy response, overall survival and progression-free survival in patients with T-cell non-Hodgkin's lymphomas. These results suggest that RBMX protein expression levels might be a contributing factor towards chemotherapy resistance and thus affect prognosis. Hence, RBMX may be a potential therapeutic target and prognostic marker in T-cell lymphomas.

SigsPack, a package for cancer mutational signatures.

BACKGROUND: Mutational signatures are specific patterns of somatic mutations introduced into the genome by oncogenic processes. Several mutational signatures have been identified and quantified from multiple cancer studies, and some of them have been linked to known oncogenic processes. Identification of the processes contributing to mutations observed in a sample is potentially informative to understand the cancer etiology. RESULTS: We present here SigsPack, a Bioconductor package to estimate a sample's exposure to mutational processes described by a set of mutational signatures. The package also provides functions to estimate stability of these exposures, using bootstrapping. The performance of exposure and exposure stability estimations have been validated using synthetic and real data. Finally, the package provides tools to normalize the mutation frequencies with respect to the tri-nucleotide contents of the regions probed in the experiment. The importance of this effect is illustrated in an example. CONCLUSION: SigsPack provides a complete set of tools for individual sample exposure estimation, and for mutation catalogue & mutational signatures normalization.