Single-cell profiling-guided combination therapy of c-Fos and histone deacetylase inhibitors in diffuse large B-cell lymphoma.
Clinical and translational medicine
BACKGROUND:Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma. Histone deacetylase inhibitors (HDACis) have been widely applied in multiple tumours, but the expected efficacy was not observed in DLBCL. Therefore, this study is aimed to explore superior HDACis and optimise a relative combinational therapeutic strategy. METHODS:The antitumour effects of the drug were evaluated by Cell Counting Kit-8 (CCK-8) assay and apoptosis analysis. Single-cell RNA sequencing (scRNA-Seq) was used to analyse the intratumoural heterogeneity of DLBCL cells. Whole-exome sequencing and RNA sequencing were performed to analyse the genetic and transcriptional features. Western blotting, qRT-PCR, protein array, immunohistochemistry, and chromatin immunoprecipitation assays were applied to explore the involved pathways. The antitumour effects of the compounds were assessed using subcutaneous xenograft tumour models. RESULTS:LAQ824 was screened and confirmed to kill DLBCL cells effectively. Using scRNA-Seq, we characterised the heterogeneity of DLBCL cells under different drug pressures, and c-Fos was identified as a critical factor in the survival of residual tumour cells. Moreover, we demonstrated that combinatorial treatment with LAQ824 and a c-Fos inhibitor more potently inhibited tumour cells both in vitro and in vivo. CONCLUSION:Altogether, we found an HDACi, LAQ824, with high efficacy in DLBCL and provided a promising HDACi-based combination therapy strategy.
10.1002/ctm2.798
CircEAF2 counteracts Epstein-Barr virus-positive diffuse large B-cell lymphoma progression via miR-BART19-3p/APC/β-catenin axis.
Zhao Chen-Xing,Yan Zi-Xun,Wen Jing-Jing,Fu Di,Xu Peng-Peng,Wang Li,Cheng Shu,Hu Jian-da,Zhao Wei-Li
Molecular cancer
BACKGROUND:Epstein-Barr virus (EBV) represents an important pathogenic factor of lymphoma and is significantly associated with poor clinical outcome of diffuse large B-cell lymphoma (DLBCL). Circular RNAs (circRNAs) play an essential role in lymphoma progression. However, the underlying mechanism of circRNA on DLBCL progression related to EBV remains largely unknown. METHODS:CircRNA was screened by high-throughput sequencing in tumor samples of 12 patients with DLBCL according to EBV infection status. Expression of circEAF2, as well as the relationship with clinical characteristics and prognosis, were further analyzed in tumor samples of 100 DLBCL patients using quantitative real-time PCR. Gain- and loss-of-function experiments were conducted to investigate the biological functions of circEAF2 both in vitro and in vivo. The underlying mechanism of circRNA on DLBCL progression were further determined by RNA sequencing, RNA pull down assay, dual-luciferase reporter assay, rescue experiments and western blotting. RESULTS:We identified a novel circRNA circEAF2, which was downregulated in EBV + DLBCL and negatively correlated with EBV infection and DLBCL progression. In EBV-positive B lymphoma cells, circEAF2 overexpression induced lymphoma cell apoptosis and sensitized lymphoma cells to epirubicin. As mechanism of action, circEAF2 specifically targeted EBV-encoded miR-BART19-3p, upregulated APC, and suppressed downstream β-catenin expression, resulting in inactivation of Wnt signaling pathway and inhibition of EBV + DLBCL cell proliferation. In EBV-positive B-lymphoma murine models, xenografted tumors with circEAF2 overexpression presented decreased Ki-67 positivity, increased cell apoptosis and retarded tumor growth. CONCLUSIONS:CircEAF2 counteracted EBV + DLBCL progression via miR-BART19-3p/APC/β-catenin axis, referring circEAF2 as a potential prognostic biomarker. Therapeutic targeting EBV-encoded miRNA may be a promising strategy in treating EBV-associated lymphoid malignancies.
10.1186/s12943-021-01458-9
Tracking the evolution of untreated high-intermediate/high-risk diffuse large B-cell lymphoma by circulating tumour DNA.
Zhang Sicong,Zhang Tingting,Liu Hengqi,Zhao Jing,Zhou Haifei,Su Xiaoxing,Liu Xianming,Li Lanfang,Qiu Lihua,Qian Zhengzi,Zhou Shiyong,Gong Wenchen,Meng Bin,Ren Xiubao,He Jin,Wang Xianhuo,Zhang Huilai
British journal of haematology
Diffuse large B-cell lymphoma (DLBCL) is a highly heterogenous malignancy, early identification of patients for relapse remains challenging. The potential to non-invasively monitor tumour evolutionary dynamics of DLBCL needs to be further established. In the present study, 17 tumour biopsy and 38 plasma samples from 38 patients with high-intermediate/high-risk DLBCL were evaluated at baseline. Longitudinal blood samples were also collected during therapy. Circulating tumour DNA (ctDNA) was analysed using targeted sequencing based on a gene panel via a recently developed methodology, circulating single-molecule amplification and re-sequencing technology (cSMART). We found that the most frequently mutated genes were tumour protein p53 (TP53; 42·1%), histone-lysine N-methyltransferase 2D (KMT2D; 28·9%), caspase recruitment domain family member 11 (CARD11; 21·1%), cAMP response element-binding protein binding protein (CREBBP; 15·8%), β -microglobulin (B2M; 15·8%), and tumour necrosis factor alpha-induced protein 3 (TNFAIP3; 15·8%). The mutation profiles between ctDNA and matched tumour tissue showed good concordance; however, more mutation sites were detected in ctDNA samples. Either TP53 or B2M mutations before treatment predicted poor prognosis. Analysis of dynamic blood samples confirmed the utility of ctDNA for the real-time assessment of treatment response and revealed that the increases in ctDNA levels and changes in KMT2D mutation status could be useful predictors of disease progression. Our present results suggest that ctDNA is a promising method for the detection of mutation spectrum and serves as a biomarker for disease monitoring and predicting clinical recurrence.
10.1111/bjh.17894
Single-cell analysis of germinal-center B cells informs on lymphoma cell of origin and outcome.
Holmes Antony B,Corinaldesi Clarissa,Shen Qiong,Kumar Rahul,Compagno Nicolo,Wang Zhong,Nitzan Mor,Grunstein Eli,Pasqualucci Laura,Dalla-Favera Riccardo,Basso Katia
The Journal of experimental medicine
In response to T cell-dependent antigens, mature B cells are stimulated to form germinal centers (GCs), the sites of B cell affinity maturation and the cell of origin (COO) of most B cell lymphomas. To explore the dynamics of GC B cell development beyond the known dark zone and light zone compartments, we performed single-cell (sc) transcriptomic analysis on human GC B cells and identified multiple functionally linked subpopulations, including the distinct precursors of memory B cells and plasma cells. The gene expression signatures associated with these GC subpopulations were effective in providing a sc-COO for ∼80% of diffuse large B cell lymphomas (DLBCLs) and identified novel prognostic subgroups of DLBCL.
10.1084/jem.20200483