Highlights d Integrated analysis provides insight into the molecular classification in NKTCL d EBV lytic genes play an important role on NKTCL pathogenesis d Genomic alteration-based molecular subtypes associate with clinical outcomes d MYC, histone acetylation, and PD-L1/2 are potential therapeutic targets of NKTCL

Graphical AbstractHighlights d A comprehensive scRNA-seq roadmap of early mouse development before gastrulation d Three cellular states of the epiblast cells transit the pluripotency continuum d X-reactivation in the epiblast initiates before completion of imprinted X-inactivation d Faster X-inactivation in visceral endoderm than in the extraembryonic ectoderm SUMMARY Following implantation, the epiblast (EPI) cells transit from the naive to primed pluripotency, accompanied by dynamic changes in X chromosome activity in females. To investigate the molecular attributes of this process, we performed single-cell RNA-seq analysis of 1,724 cells of E5.25, E5.5, E6.25, and E6.5 mouse embryos. We identified three cellular states in the EPI cells that capture the transition along the pluripotency continuum and the acquisition of primitive streak propensity. The transition of three EPI states was driven by inductive signaling activity emanating from the visceral endoderm (VE). In the EPI of female embryos, X chromosome reactivation (XCR) was initiated prior to the completion of imprinted X chromosome inactivation (XCI), and the ensuing random XCI was highly asynchronous. Moreover, imprinted paternal XCI proceeded faster in the VE than the extraembryonic ectoderm. Our study has provided a detailed molecular roadmap of the emergent lineage commitment before gastrulation and characterized X chromosome dynamics during early mouse development.

Epigenetic alterations play an important role in tumor progression of diffuse large B-cell lymphoma (DLBCL). However, the biological relevance of epigenetic gene mutations on tumor microenvironment remains to be determined. The core set of genes relating to histone methylation (KMT2D, KMT2C, EZH2), histone acetylation (CREBBP, EP300), DNA methylation (TET2), and chromatin remodeling (ARID1A) were detected in the training cohort of 316 patients by whole-genome/exome sequencing (WGS/WES) and in the validation cohort of 303 patients with newly diagnosed DLBCL by targeted sequencing. Their correlation with peripheral blood immune cells and clinical outcomes were assessed. Underlying mechanisms on tumor microenvironment were investigated both in vitro and in vivo. Among all 619 DLBCL patients, somatic mutations in KMT2D (19.5%) were most frequently observed, followed by mutations in ARID1A (8.7%), CREBBP (8.4%), KMT2C (8.2%), TET2 (7.8%), EP300 (6.8%), and EZH2 (2.9%). Among them, CREBBP/EP300 mutations were significantly associated with decreased peripheral blood absolute lymphocyte-to-monocyte ratios, as well as inferior progression-free and overall survival. In B-lymphoma cells, the mutation or knockdown of CREBBP or EP300 inhibited H3K27 acetylation, downregulated FBXW7 expression, activated the NOTCH pathway, and downstream CCL2/CSF1 expression, resulting in tumor-associated macrophage polarization to M2 phenotype and tumor cell proliferation. In B-lymphoma murine models, xenografted tumors bearing CREBBP/EP300 mutation presented lower H3K27 acetylation, higher M2 macrophage recruitment, and more rapid tumor growth than those with CREBBP/EP300 wild-type control via FBXW7-NOTCH-CCL2/CSF1 axis. Our work thus contributed to the understanding of aberrant histone acetylation regulation on tumor microenvironment as an alternative mechanism of tumor progression in DLBCL.

Due to heterogeneous morphological and immunophenotypic features, approximately 50% of peripheral T-cell lymphomas are unclassifiable and categorized as peripheral T-cell lymphomas, not otherwise specified. These conditions have an aggressive course and poor clinical outcome. Identification of actionable biomarkers is urgently needed to develop better therapeutic strategies. Epigenetic alterations play a crucial role in tumor progression. Histone modifications, particularly methylation and acetylation, are generally involved in chromatin state regulation. Here we screened the core set of genes related to histone methylation (KMT2D, SETD2, KMT2A, KDM6A) and acetylation (EP300, CREBBP) and identified 59 somatic mutations in 45 of 125 (36.0%) patients with peripheral T-cell lymphomas, not otherwise specified. Histone modifier gene mutations were associated with inferior progression-free survival time of the patients, irrespective of chemotherapy regimens, but an increased response to the histone deacetylase inhibitor chidamide. In vitro, chidamide significantly inhibited the growth of EP300-mutated T-lymphoma cells and KMT2D-mutated T-lymphoma cells when combined with the hypomethylating agent decitabine. Mechanistically, decitabine acted synergistically with chidamide to enhance the interaction of KMT2D with transcription factor PU.1, regulated H3K4me-associated signaling pathways, and sensitized T-lymphoma cells to chidamide. In a xenograft KMT2D-mutated T-lymphoma model, dual treatment with chidamide and decitabine significantly retarded tumor growth and induced cell apoptosis through modulation of the KMT2D/H3K4me axis. Our work thus contributes to the understanding of aberrant histone modification in peripheral T-cell lymphomas, not otherwise specified and the stratification of a biological subset that can benefit from epigenetic treatment.

No abstract

BackgroundA phase II study of methotrexate, etoposide, dexamethasone, and pegaspargase (MESA) sandwiched with radiotherapy for newly diagnosed, stage IE-IIE extranodal natural-killer/T-cell lymphoma, nasal-type (ENKTL) was conducted to explore its clinical efficacy and safety, as well as novel serum biomarkers upon anti-metabolic treatment.MethodsFour cycles of MESA sandwiched with radiotherapy were administered. The primary end point was the overall response rate (ORR). Serum metabolomic profiles were assessed by liquid chromatography-mass spectrometry, with specific metabolites quantified by targeted metabolic analysis.FindingsForty patients were enrolled and the ORR was 92.1% (95%CI, 83.1%–100.0%). The 2-year progression-free survival (PFS) rate was 89.1% and overall survival (OS) rate was 92.0%. Grade 3/4 non-hematologic and hematologic toxicities were observed in 17 (42.5%) and 26 patients (65·0%) during chemotherapy, and in 9 (22.5%) and 0 (0.0%) patients during radiotherapy, respectively. Fifty-six significantly decreased and 59 increased metabolites were identified in ENKTL, as compared to healthy volunteers. A predictive principal components analysis model of asparaginase-associated metabolites, asparaginase-associated metabolic score (AspM), was established, including alanine, aspartate, glutamate, and succinic acid. Patients with high AspM score displayed superior survival and prognostic significance of AspM was validated in a historical cohort of early and advanced-stage ENKTL treated with asparaginase-based regimens. Multivariate analysis confirmed AspM as a prognostic score independent of PINK and PINK combined with Epstein-Barr virus DNA.InterpretationMESA sandwiched with radiotherapy is an effective and safe regimen for early-stage ENKTL. AspM score may be a promising prognostic index of serum metabolites in addition to clinical prognostic index in ENKTL.

Purpose: Anti-CD19 chimeric antigen receptor (CAR) T cells represent a novel immunotherapy and are highly effective in treating relapsed/refractory B-cell non-Hodgkin's lymphoma (B-NHL). How tumor microenvironment influences clinical response to CAR T therapy remains of great interest.Patients and Methods: A phase I, first-in-human, doseescalation study of anti-CD19 JWCAR029 was conducted in refractory B-NHL (NCT03355859) and 10 patients received CAR T cells at an escalating dose of 2.5 Â 10 7 (n ¼ 3), 5 Â 10 7 (n ¼ 4), and 1 Â 10 8 (n ¼ 3) cells. Core needle biopsy was performed on tumor samples collected from diffuse large B-cell lymphoma patients on Day À6 (1 day before lymphodepletion) and on Day 11 after CAR T-cell infusion when adequate CAR T-cell expansion was detected.Results: The overall response rate was 100%, with 6 of 9 (66.7%) evaluable patients achieving complete remission. The most common adverse events of grade 3 or higher were neutropenia (10/10, 100%), anemia (3/10, 30%), thrombocytopenia (3/10, 30%), and hypofibrinogenemia (2/10, 20%). Grade 1 cytokine release syndrome occurred in all patients and grade 3 neurotoxicity in 1 patient. The average peak levels of peripheral blood CAR T cells and cytokines were similar in 3 different dose levels, but CAR T cells were significantly higher in patients achieved complete remission on Day 29. Meanwhile, RNA sequencing identified gene expression signatures differentially enriched in complete and partial remission patients. Increased tumor-associated macrophage infiltration was negatively associated with remission status.Conclusions: JWCAR029 was effective and safe in treating refractory B-NHL. The composition of the tumor microenvironment has a potential impact in CAR T therapy response.

1. DLBCL patients with multiple extranodal involvement presented advanced disease stage and poor prognosis. 2. Oncogenic mutations were associated with multiple extranodal involvement. 3. Increased Treg-recruiting activity and decreased extracellular matrix expression of the tumor microenvironment correlated with multiple extranodal involvement.