Follicular lymphoma (FL) is a cancer of B-cells, representing the second most common type of non-Hodgkin lymphoma and typically diagnosed at advanced stage in older adults. In contrast to the wide ...range of available molecular genetic data, limited data relating the metabolomic features of follicular lymphoma are known. Metabolomics is a promising analytical approach employing metabolites (molecules < 1 kDa in size) as potential biomarkers in cancer research. In this pilot study, we performed proton nuclear magnetic resonance spectroscopy (
H-NMR) on 29 cases of FL and 11 control patient specimens. The resulting spectra were assessed by both unsupervised and supervised statistical methods. We report significantly discriminant metabolomic models of common metabolites distinguishing FL from control tissues. Within our FL case series, we also report discriminant metabolomic signatures predictive of progression-free survival.
Approximately 15% to 20% of colorectal cancers are developed through the serrated pathway of tumorigenesis, which is associated with BRAF mutation, CpG island methylation phenotype, and MLH1 ...methylation. However, the detailed process of progression from sessile serrated adenoma (SSA) to dysplasia and carcinoma has not been elucidated. To further characterize mechanisms involved in the dysplastic progression of SSA, we investigated differential expressions of mRNAs between areas with and without dysplasia within the same SSA polyps. Significantly dysregulated genes in paired samples were applied for functional annotation and biological significance. The same lysates from a subset of matched samples were subjected for miRNA expression profiling. Differentially expressed miRNAs were determined, and their targeted mRNAs were compared in parallel to the list of differentially expressed mRNAs from an RNA sequencing study. Fourteen common mRNA targets were identified, which include AXIN2, a known indicator of WNT/β-catenin pathway activation. Together, in this study, different genes, pathways, and biological processes involved in the initiation and progression of dysplasia in the serrated pathway are documented. One of the most significant findings is the involvement of the WNT/β-catenin pathway in the dysplastic progression of SSAs with different genes being targeted in early versus advanced dysplasia.
B-cell non-Hodgkin lymphoma (B-NHL) encompasses multiple clinically and phenotypically distinct subtypes of malignancy with unique molecular etiologies. Common subtypes of B-NHL, such as diffuse ...large B-cell lymphoma, have been comprehensively interrogated at the genomic level, but rarer subtypes, such as mantle cell lymphoma, remain less extensively characterized. Furthermore, multiple B-NHL subtypes have thus far not been comprehensively compared using the same methodology to identify conserved or subtype-specific patterns of genomic alterations. Here, we employed a large targeted hybrid-capture sequencing approach encompassing 380 genes to interrogate the genomic landscapes of 685 B-NHL tumors at high depth, including diffuse large B-cell lymphoma, mantle cell lymphoma, follicular lymphoma, and Burkitt lymphoma. We identified conserved hallmarks of B-NHL that were deregulated in the majority of tumors from each subtype, including frequent genetic deregulation of the ubiquitin proteasome system. In addition, we identified subtype-specific patterns of genetic alterations, including clusters of co-occurring mutations and DNA copy number alterations. The cumulative burden of mutations within a single cluster were more discriminatory of B-NHL subtypes than individual mutations, implicating likely patterns of genetic cooperation that contribute to disease etiology. We therefore provide the first cross-sectional analysis of mutations and DNA copy number alterations across major B-NHL subtypes and a framework of co-occurring genetic alterations that deregulate genetic hallmarks and likely cooperate in lymphomagenesis.
Intestinal T-cell and natural killer (NK)–cell lymphomas are clinically aggressive and can be challenging to diagnose in small endoscopic biopsies. We describe 8 patients in whom atypical NK-cell ...lymphoproliferative lesions mimicked NK- or T-cell lymphoma. The patients (2 men; 6 women; ages 27-68 years) presented with vague gastrointestinal symptoms with lesions involving stomach, duodenum, small intestine, and colon. At endoscopy, the lesions exhibited superficial ulceration, edema, and hemorrhage. Biopsies revealed a mucosal infiltrate of atypical cells with an NK-cell phenotype (CD56+/TIA-1+/Granzyme B+/cCD3+), which displaced but did not invade the glandular epithelium. Epstein-Barr virus–encoded RNA in situ hybridization was negative, and T-cell receptor-γ gene rearrangement showed no evidence of a clonal process. Based on an original diagnosis of lymphoma, 3 patients received aggressive chemotherapy followed by autologous bone marrow transplantation in 2. Five patients were followed without treatment. However, no patient developed progressive disease or died of lymphoma (median follow-up, 30 months). Repeat endoscopies in 6 of 8 patients showed persistence or recurrence of superficial gastrointestinal lesions. This unique entity mimics intestinal and NK-/T-cell lymphomas on endoscopic biopsies and can result in erroneous diagnosis, leading to aggressive chemotherapy. We propose the term “NK-cell enteropathy” for this syndrome of as yet unknown etiology.
Chromosomal instability is a defining feature of clonal myeloma plasma cells that results in the perpetual accumulation of genomic aberrations. In addition to its role in protein homeostasis, the ...ubiquitin-proteasome system is also involved in the regulation of DNA damage-repair proteins. In the present study, we show that proteasome inhibition induces a “BRCAness” state in myeloma cells (MM), with depletion of their nuclear pool of ubiquitin and abrogation of H2AX polyubiquitylation, an essential step for the recruitment of BRCA1 and RAD51 to the sites of DNA double-stranded breaks (DSBs) and the initiation of homologous recombination (HR)–mediated DNA repair. Inhibition of poly-ADP-ribose-polymerase 1 and 2 (PARP1/2) with ABT-888 induced transient DNA DSBs that were rapidly resolved and thus had no effect on viability of the MM cells. In contrast, cotreatment of MM cell lines and primary CD138+ cells with bortezomib and ABT-888 resulted in the sustained accumulation of unrepaired DNA DSBs with persistence of unubiquitylated γH2AX foci, lack of recruitment of BRCA1 and RAD51, and ensuing MM-cell death. The heightened cytotoxicity of ABT-888 in combination with bortezomib compared with either drug alone was also confirmed in MM xenografts in SCID mice. Our studies indicate that bortezomib impairs HR in MM and results in a contextual synthetic lethality when combined with PARP inhibitors.
MS4A4A is a member of the membrane‐spanning, four domain family, subfamily A (MS4A) that includes CD20 (MS4A1), FcRβ (MS4A2) and Htm4 (MS4A3). Like the first three members of this family, ...transcription of MS4A4A appears to be limited to hematopoietic cells. To evaluate expression of the MS4A4A protein in hematopoietic cell lineages and subsets we generated monoclonal antibodies against extracellular epitopes for use in flow cytometry. In human peripheral blood we found that MS4A4A is expressed at the plasma membrane in monocytes but not in granulocytes or lymphocytes. In vitro differentiation of monocytes demonstrated that MS4A4A is expressed in immature but not activated dendritic cells, and in macrophages generated in the presence of interleukin‐4 (‘alternatively activated’ or M2 macrophages) but not by interferon‐γ and lipopolysaccharide (‘classically’ activated or M1 macrophages). MS4A4A was expressed in the U937 monocytic cell line only after differentiation. In normal bone marrow, MS4A4A was expressed in mature monocytes but was undetected, or detected at only a low level, in myeloid/monocytic precursors, as well as their malignant counterparts in patients with various subtypes of myeloid leukemia. Although MS4A4A was not expressed in healthy B lymphocytes, it was highly expressed in normal plasma cells, CD138+ cells from multiple myeloma patients, and bone marrow B cells from a patient with mantle cell lymphoma. These findings suggest immunotherapeutic potential for MS4A4A antibodies in targeting alternatively activated macrophages such as tumor‐associated macrophages, and in the treatment of multiple myeloma and mantle cell lymphoma.
Integrin-β7 (ITGB7) mRNA is detected in multiple myeloma (MM) cells and its presence is correlated with MAF gene activation. Although the involvement of several integrin family members in MM-stoma ...cell interaction is well documented, the specific biologic functions regulated by integrin-β7 in MM are largely unknown. Clinically, we have correlated integrin-β7 expression in MM with poor survival outcomes post autologous stem cell transplantation and postsalvage therapy with bortezomib. Functionally, we have found that shRNA-mediated silencing of ITGB7 reduces MM-cell adhesion to extra-cellular matrix elements (fibronectin, E-cadherin) and reverses cell-adhesion–mediated drug resistance (CAM-DR) sensitizing them to bortezomib and melphalan. In addition, ITGB7 silencing abrogated MM-cell transwell migration in response to SDF1α gradients, reduced vessel density in xenografted tumors, and altered MM cells in vivo homing into the BM. Mechanistically, ITGB7 knockdown inhibited focal adhesion kinase (FAK) and Src phosphorylation, Rac1 activation, and SUMOylation, reduced VEGF production in MM–BM stem cell cocultures and attenuated p65-NF-κB activity. Our findings support a role for integrin-β7 in MM-cell adhesion, migration, and BM homing, and pave the way for a novel therapeutic approach targeting this molecule.
Abstract Background aims Anti-thymocyte globulin (ATG) is being used increasingly to prevent graft-versus-host disease (GvHD); however, its impact on immune reconstitution is relatively unknown. We ...(i) studied immune reconstitution after ATG-conditioned hematopoietic cell transplantation (HCT), (ii) determined the factors influencing the reconstitution, and (iii) compared it with non-ATG-conditioned HCT. Methods Immune cell subset counts were determined at 1–24 months post-transplant in 125 HCT recipients who received ATG during conditioning. Subset counts were also determined in 46 non-ATG-conditioned patients (similarly treated). Results (i) Reconstitution after ATG-conditioned HCT was fast for innate immune cells, intermediate for B cells and CD8 T cells, and very slow for CD4 T cells and invariant natural killer T (iNKT) (iNKT) cells. (ii) Faster reconstitution after ATG-conditioned HCT was associated with a higher number of cells of the same subset transferred with the graft in the case of memory B cells, naive CD4 T cells, naive CD8 T cells, iNKT cells and myeloid dendritic cells; lower recipient age in the case of naive CD4 T cells and naive CD8 T cells; cytomegalovirus recipient seropositivity in the case of memory/effector T cells; an absence of GvHD in the case of naive B cells; lower ATG serum levels in the case of most T-cell subsets, including iNKT cells; and higher ATG levels in the case of NK cells and B cells. (iii) Compared with non-ATG-conditioned HCT, reconstitution after ATG-conditioned HCT was slower for CD4 T cells, and faster for NK cells and B cells. Conclusions ATG worsens the reconstitution of CD4 T cells but improves the reconstitution of NK and B cells.
Despite the recent advances made in the treatment of multiple myeloma, the disease still remains incurable. The oncolytic potential of reovirus has previously been shown and is currently in phase III ...clinical trials for solid tumors. We tested the hypothesis that reovirus can successfully target human multiple myeloma in vitro, ex vivo, and in vivo without affecting human hematopoietic stem cell (HHSC) re-population/differentiation in a murine model that partially recapitulates human multiple myeloma.
Human myeloma cell lines and ex vivo tumor specimens were exposed to reovirus and oncolysis and mechanisms of cell death were assessed. RPMI 8226(GFP+) cells were injected intravenously to non-obese diabetic/severe combined immune deficient (NOD/SCID) mice and treated with live reovirus (LV) or dead virus (DV). Multiple myeloma disease progression was evaluated via whole-body fluorescence and bone marrow infiltration. HHSCs exposed to LV/DV were injected to NOD/SCID mice and re-population/differentiation was monitored.
A total of six of seven myeloma cell lines and five of seven patient tumor specimens exposed to reovirus showed significant in vitro sensitivity. Tumor response of multiple myeloma by LV, but not DV, was confirmed by comparison of total tumor weights (P = 0.05), and bone marrow infiltration (1/6, LV; 5/6, DV). Mice injected with LV- or DV-exposed HHSCs maintained in vivo re-population/lineage differentiation showing a lack of viral effect on the stem cell compartment. Reovirus oncolysis was mediated primarily by activation of the apoptotic pathways.
The unique ability of reovirus to selectively kill multiple myeloma while sparing HHSCs places it as a promising systemic multiple myeloma therapeutic for clinical testing.
Dysregulated Wnt/β-catenin signal transduction is implicated in initiation, propagation, and poor prognosis in AML. Epigenetic inactivation is central to Wnt/β-catenin hyperactivity, and ...Wnt/β-catenin inhibitors are being investigated as targeted therapy. Dysregulated Wnt/β-catenin signaling has also been linked to accelerated aging. Since AML is a disease of old age (>60 yrs), we hypothesized age-related differential activity of Wnt/β-catenin signaling in AML patients. We probed Wnt/β-catenin expression in a series of AML in the elderly (>60 yrs) and compared it to a cohort of pediatric AML (<18 yrs). RNA from diagnostic bone marrow biopsies (n = 101) were evaluated for key Wnt/β-catenin molecule expression utilizing the NanoString platform. Differential expression of significance was defined as >2.5-fold difference (p < 0.01). A total of 36 pediatric AML (<18 yrs) and 36 elderly AML (>60 yrs) were identified in this cohort. Normal bone marrows (n = 10) were employed as controls. Wnt/β-catenin target genes (MYC, MYB, and RUNX1) showed upregulation, while Wnt/β-catenin inhibitors (CXXR, DKK1-4, SFRP1-4, SOST, and WIFI) were suppressed in elderly AML compared to pediatric AML and controls. Our data denote that suppressed inhibitor expression (through mutation or hypermethylation) is an additional contributing factor in Wnt/β-catenin hyperactivity in elderly AML, thus supporting Wnt/β-catenin inhibitors as potential targeted therapy.
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