The activities of non-haematopoietic cells (NHCs), including mesenchymal stromal cells and endothelial cells, in lymphomas are reported to underlie lymphomagenesis. However, our understanding of ...lymphoma NHCs has been hampered by unexplained NHC heterogeneity, even in normal human lymph nodes (LNs). Here we constructed a single-cell transcriptome atlas of more than 100,000 NHCs collected from 27 human samples, including LNs and various nodal lymphomas, and it revealed 30 distinct subclusters, including some that were previously unrecognized. Notably, this atlas was useful for comparative analyses with lymphoma NHCs, which revealed an unanticipated landscape of subcluster-specific changes in gene expression and interaction with malignant cells in follicular lymphoma NHCs. This facilitates our understanding of stromal remodelling in lymphoma and highlights potential clinical biomarkers. Our study largely updates NHC taxonomy in human LNs and analysis of disease status, and provides a rich resource and deeper insights into LN and lymphoma biology to advance lymphoma management and therapy.
Recent progress in next-generation sequencing technologies has shown that tumor cells in many solid cancers undergo dynamic clonal evolution. 1 Notably, diverse clones have been observed in biopsy ...samples acquired from primary or metastatic legions in solid cancers. 2-4 In contrast, intratumor heterogeneity (ITH) in lymphomas is less characterized: samples are taken only for diagnosis and multiregional sample collection is rarely performed in living patients, because chemotherapy rather than surgery is the standard treatment for most lymphoma subtypes. Black dots indicate a tumor mass; organs with red diagonal lines represent intravascular tumor invasions. kid, kidney; ll, left lung; lym, lymph node; rl1, right lung; spl, spleen. ...this analysis shows a clear phylogenic tree of aggressive lymphoma, confirming that dynamic time-dependent and spatial ITH occurs even in systemic disease.
Objective Graft failure (GF) is a life-threatening complication of hematopoietic stem cell transplantation (HSCT). A standardized conditioning regimen and an appropriate graft source of salvage HSCT ...for GF have not yet been established. Some case series have shown good hematopoietic recoveries after salvage HSCT using a short-term reduced-intensity preparative regimen consisting of fludarabine (30-90 mg/m2), cyclophosphamide (2 g/m2), and total-body irradiation (2 Gy). However, the dose of fludarabine has varied in these reports based on the clinical condition of the patients, resulting in very limited experiences with each dose of fludarabine. Methods We retrospectively analyzed 10 patients who developed GF after allogeneic HSCT and underwent salvage cord blood transplantation (CBT) using the above-mentioned conditioning regimen with a fixed dose (90 mg/m2) of fludarabine. Results Eight patients (80.0%) achieved neutrophil engraftment within 30 days from salvage HSCT with a median of 21 (range, 17-23) days. The 1-year overall survival (OS) rate after the salvage HSCT was 50.0%, and the median OS was 281 (range, 23-1,638) days. Cumulative incidences of non-relapse mortality and relapse at 1 year were 50.0% and 10.0%, respectively. Conclusion CBT using this short-term reduced-intensity conditioning regimen may be a promising salvage therapy for GF.
The transcription factor MafB is specifically expressed in macrophages. We have recently demonstrated that MafB is expressed in anti-inflammatory alternatively activated M2 macrophages in vitro. ...Tumor-associated macrophages (TAMs) are a subset of M2 type macrophages that can promote immunosuppressive activity, induce angiogenesis, and promote tumor cell proliferation. To examine whether MafB express in TAMs, we analyzed green fluorescent protein (GFP) expression in Lewis lung carcinoma tumors of MafB-GFP knock-in heterozygous mice. FACS analysis demonstrated GFP fluorescence in cells positive for macrophage-markers (F4/80, CD11b, CD68, and CD204). Moreover, quantitative RT-PCR analysis with F4/80+GFP+ and F4/80+GFP− sorted cells showed that the GFP-positive macrophages express IL-10, Arg-1, and TNF-α, which were known to be expressed in TAMs. These results indicate that MafB is expressed in TAMs. Furthermore, immunostaining analysis using an anti-MAFB antibody revealed that MAFB is expressed in CD204-and CD68-positive macrophages in human lung cancer samples. In conclusion, MafB can be a suitable marker of TAMs in both mouse and human tumor tissues.
•The GFP was expressed in Lewis lung carcinoma tumors in MafB-GFP knock-in hetero mice.•The marker genes of TAMs were highly expressed in F4/80+GFP+ macrophages.•MAFB was expressed in TAMs in human lung cancer samples, and can be used to assess tumor malignancy.
Cell‐free DNA (cfDNA) analysis to detect circulating tumor DNA has been focused on monitoring malignant lymphomas. However, clonal hematopoiesis of indeterminate potential (CHIP)‐associated mutations ...can also be detected by cfDNA analysis. Our aim is to investigate the origin of mutations detected in cfDNA among B‐cell lymphoma patients. MYD88/CD79B, DNMT3A, and TP53 were chosen as genes of interest, representing each of the following categories: lymphoma driver genes, CHIP‐related genes, and genes shared between lymphoma and CHIP. Seventy‐five B‐cell lymphoma patients were included in this retrospective study. Serum cfDNAs at time of complete metabolic response (CMR) were sequenced for TP53 (N = 75) and DNMT3A (N = 49). MYD88 p.L265P and CD79B p.Y196C/H mutations were analyzed in diffuse large B‐cell lymphoma (DLBCL) patients whose tumor samples were available (N = 29). Two and seven mutations in TP53 and DNMT3A, respectively, were detected in cfDNA at CMR. These mutations were detected in either bone marrow mononuclear cells (BMMC) or PBMC. Although four DNMT3A mutations were also detected in tumors, median variant allele frequencies in the tumors (<1.0%) were significantly lower than those in both BMMC (6.1%) and serum (5.2%) obtained before the therapy. Conversely, five MYD88 and three CD79B mutations detected in tumors were confirmed in cfDNA before therapy, but not in BMMC nor in cfDNA at CMR. Thus, all TP53 and DNMT3A mutations detected in cfDNA at remission seemed to originate from CHIP rather than from residual disease. Results of liquid biopsy should be carefully interpreted, especially in genes shared between lymphomas and CHIP.
Mutations detected by liquid biopsy can derive not only from tumors but also from clonal hematopoiesis in patients with lymphomas. Results of liquid biopsy should be carefully interpreted because its significance is different according to the origin of the mutations.
Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare subtype of myeloid neoplasm. Clonal evolution in the development of BPDCN remains to be elucidated. In the present study, we examined ...clonal evolution in a case of BPDCN by analyzing the distribution of gene mutations in tumor cells and non-tumor blood cells. The p.D1129fs and p.K1005fs
TET2
mutations, p.P95H
SRSF2
mutation, and p.L287fs
NPM1
mutation were identified in a skin tumor at diagnosis and peripheral blood mononuclear cells at relapse. Notably, the p.D1129fs
TET2
and p.L287fs
NPM1
mutations were observed only in tumor cells, while the p.K1005fs
TET2
and p.P95H
SRSF2
mutations were found in both tumor cells and non-tumor blood cells. Recent genetic studies have suggested that some blood cancers may originate from clonal hematopoiesis, harboring somatic mutations. In the present case, the data suggest that BPDCN originated from clonal hematopoiesis with the p.K1005fs
TET2
and p.P95H
SRSF2
mutations via acquisition of the additional p.D1129fs
TET2
and p.L287fs
NPM1
mutations.
MafB is a transcription factor that induces myelomonocytic differentiation. However, the precise role of MafB in the pathogenic function of macrophages has never been clarified. Here we demonstrate ...that MafB promotes hyperlipidemic atherosclerosis by suppressing foam-cell apoptosis. Our data show that MafB is predominantly expressed in foam cells found within atherosclerotic lesions, where MafB mediates the oxidized LDL-activated LXR/RXR-induced expression of apoptosis inhibitor of macrophages (AIM). In the absence of MafB, activated LXR/RXR fails to induce the expression of AIM, a protein that is normally responsible for protecting macrophages from apoptosis; thus, Mafb-deficient macrophages are prone to apoptosis. Haematopoietic reconstitution with Mafb-deficient fetal liver cells in recipient LDL receptor-deficient hyperlipidemic mice revealed accelerated foam-cell apoptosis, which subsequently led to the attenuation of the early atherogenic lesion. These findings represent the first evidence that the macrophage-affiliated MafB transcription factor participates in the acceleration of atherogenesis.
Follicular lymphoma (FL) is an indolent cancer of mature B-cells but with ongoing risk of transformation to more aggressive histology over time. Recurrent mutations associated with transformation ...have been identified; however, prognostic features that can be discerned at diagnosis could be clinically useful. We present here comprehensive profiling of both tumor and immune compartments in 155 diagnostic FL biopsies at single-cell resolution by mass cytometry. This revealed a diversity of phenotypes but included two recurrent patterns, one which closely resembles germinal center B-cells (GCB) and another which appears more related to memory B-cells (MB). GCB-type tumors are enriched for EZH2, TNFRSF14, and MEF2B mutations, while MB-type tumors contain increased follicular helper T-cells. MB-type and intratumoral phenotypic diversity are independently associated with increased risk of transformation, supporting biological relevance of these features. Notably, a reduced 26-marker panel retains sufficient information to allow phenotypic profiling of future cohorts by conventional flow cytometry.
Cytokine release syndrome (CRS), occurring in more than 70% of HLA-haploidentical hematopoietic stem-cell transplantations with post-transplant cyclophosphamide (PT/CY-haplo), can lead to hemodynamic ...instability and worsen clinical outcomes. A calcineurin inhibitor is initiated after cyclophosphamide administration in the commonly used PT/CY regimens. Here, we conducted a phase I/II, prospective, single-center trial of PT/CY-haplo to evaluate the safety and efficacy of cyclophosphamide on days 3 and 5 along with cyclosporin and mycophenolate mofetil started from day − 1. Thirty-five adults with hematologic malignancies were enrolled. Myeloablative and reduced-intensity conditioning were used in 25 and 10 patients, respectively. Graft sources were bone marrow in 11 patients and mobilized peripheral blood stem cells in 24 patients. Disease-free survival on day 100, the primary endpoint, was 86% (95% confidence interval (CI), 69–94), which was over the predefined threshold of 50%. Unexpectedly, only 20% (95% CI, 8.4–37) of patients developed fever of > 38 °C early after graft infusion, all CRS grade 1, and all of which resolved just after cyclophosphamide administration. The cumulative incidences of grades II–IV acute graft-versus-host disease (GVHD), III–IV acute GVHD, and moderate-severe chronic GVHD were 23% (95% CI, 11–38), 6% (95% CI, 1–17), and 11% (95% CI, 4–25), respectively. The 3-year overall survival rate was 49% (95% CI, 31–64). Our results suggest that administration of cyclosporine and mycophenolate mofetil prior to PT/CY can reduce the frequency and severity of CRS without increasing GVHD. UMIN Clinical Trial Registry numbers: 000006631 and 000015694
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