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3.
J Virol ; 98(7): e0054824, 2024 Jul 23.
Article in English | MEDLINE | ID: mdl-38864622

ABSTRACT

Most mature B-cell malignancies originate from the malignant transformation of germinal center (GC) B cells. The GC reaction appears to have a role in malignant transformation, in which a major player of the GC reaction is BCL6, a key regulator of this process. We now demonstrate that BCL6 protein levels were dramatically decreased in Epstein-Barr virus (EBV)-positive lymphoblastoid cell lines and Burkitt's lymphoma cell lines. Notably, BCL6 degradation was significantly enhanced in the presence of both EBNA3C and FBXO11. Furthermore, the amino-terminal domain of EBNA3C, which contains residues 50-100, interacts directly with FBXO11. The expression of EBNA3C and FBXO11 resulted in a significant induction of cell proliferation. Furthermore, BCL6 protein expression levels were regulated by EBNA3C via the Skp Cullin Fbox (SCF)FBXO11 complex, which mediated its ubiquitylation, and knockdown of FBXO11 suppressed the transformation of lymphoblastoid cell lines. These data provide new insights into the function of EBNA3C in B-cell transformation during GC reaction and raise the possibility of developing new targeted therapies against EBV-associated cancers. IMPORTANCE: The novel revelation in our study involves the suppression of BCL6 expression by the essential Epstein-Barr virus (EBV) antigen EBNA3C, shedding new light on our current comprehension of how EBV contributes to lymphomagenesis by impeding the germinal center reaction. It is crucial to note that while several EBV latent proteins are expressed in infected cells, the collaborative mechanisms among these proteins in regulating B-cell development or inducing B-cell lymphoma require additional investigation. Nonetheless, our findings carry significance for the development of emerging strategies aimed at addressing EBV-associated cancers.


Subject(s)
Epstein-Barr Virus Nuclear Antigens , F-Box Proteins , Herpesvirus 4, Human , Proto-Oncogene Proteins c-bcl-6 , Humans , Epstein-Barr Virus Nuclear Antigens/metabolism , Epstein-Barr Virus Nuclear Antigens/genetics , Proto-Oncogene Proteins c-bcl-6/metabolism , Proto-Oncogene Proteins c-bcl-6/genetics , F-Box Proteins/metabolism , F-Box Proteins/genetics , Herpesvirus 4, Human/metabolism , Herpesvirus 4, Human/genetics , Cell Line, Tumor , B-Lymphocytes/metabolism , B-Lymphocytes/virology , Epstein-Barr Virus Infections/metabolism , Epstein-Barr Virus Infections/virology , Proteolysis , Cell Proliferation , Ubiquitination , Burkitt Lymphoma/virology , Burkitt Lymphoma/metabolism , Burkitt Lymphoma/genetics , Burkitt Lymphoma/pathology , Antigens, Viral/metabolism , Antigens, Viral/genetics , Germinal Center/metabolism , Germinal Center/virology , Protein-Arginine N-Methyltransferases
4.
PLoS One ; 19(5): e0302701, 2024.
Article in English | MEDLINE | ID: mdl-38728286

ABSTRACT

Although the toxicity of arsenic depends on its chemical forms, few studies have taken into account the ambiguous phenomenon that sodium arsenite (NaAsO2) acts as a potent carcinogen while arsenic trioxide (ATO, As2O3) serves as an effective therapeutic agent in lymphoma, suggesting that NaAsO2 and As2O3 may act via paradoxical ways to either promote or inhibit cancer pathogenesis. Here, we compared the cellular response of the two arsenical compounds, NaAsO2 and As2O3, on the Burkitt lymphoma cell model, the Epstein Barr Virus (EBV)-positive P3HR1 cells. Using flow cytometry and biochemistry analyses, we showed that a NaAsO2 treatment induces P3HR1 cell death, combined with drastic drops in ΔΨm, NAD(P)H and ATP levels. In contrast, As2O3-treated cells resist to cell death, with a moderate reduction of ΔΨm, NAD(P)H and ATP. While both compounds block cells in G2/M and affect their protein carbonylation and lipid peroxidation, As2O3 induces a milder increase in superoxide anions and H2O2 than NaAsO2, associated to a milder inhibition of antioxidant defenses. By electron microscopy, RT-qPCR and image cytometry analyses, we showed that As2O3-treated cells display an overall autophagic response, combined with mitophagy and an unfolded protein response, characteristics that were not observed following a NaAsO2 treatment. As previous works showed that As2O3 reactivates EBV in P3HR1 cells, we treated the EBV- Ramos-1 cells and showed that autophagy was not induced in these EBV- cells upon As2O3 treatment suggesting that the boost of autophagy observed in As2O3-treated P3HR1 cells could be due to the presence of EBV in these cells. Overall, our results suggest that As2O3 is an autophagic inducer which action is enhanced when EBV is present in the cells, in contrast to NaAsO2, which induces cell death. That's why As2O3 is combined with other chemicals, as all-trans retinoic acid, to better target cancer cells in therapeutic treatments.


Subject(s)
Arsenic Trioxide , Arsenicals , Arsenites , Autophagy , Mitochondria , Oxidative Stress , Oxides , Sodium Compounds , Arsenic Trioxide/pharmacology , Arsenites/pharmacology , Arsenites/toxicity , Humans , Oxidative Stress/drug effects , Mitochondria/metabolism , Mitochondria/drug effects , Sodium Compounds/pharmacology , Arsenicals/pharmacology , Autophagy/drug effects , Cell Line, Tumor , Oxides/pharmacology , Cell Death/drug effects , Membrane Potential, Mitochondrial/drug effects , Herpesvirus 4, Human/drug effects , Adenosine Triphosphate/metabolism , Hydrogen Peroxide/pharmacology , Lipid Peroxidation/drug effects , Burkitt Lymphoma/virology , Burkitt Lymphoma/metabolism , Burkitt Lymphoma/pathology , Burkitt Lymphoma/drug therapy
5.
Cancer Cell ; 42(5): 833-849.e12, 2024 May 13.
Article in English | MEDLINE | ID: mdl-38701792

ABSTRACT

Glucocorticoids have been used for decades to treat lymphomas without an established mechanism of action. Using functional genomic, proteomic, and chemical screens, we discover that glucocorticoids inhibit oncogenic signaling by the B cell receptor (BCR), a recurrent feature of aggressive B cell malignancies, including diffuse large B cell lymphoma and Burkitt lymphoma. Glucocorticoids induce the glucocorticoid receptor (GR) to directly transactivate genes encoding negative regulators of BCR stability (LAPTM5; KLHL14) and the PI3 kinase pathway (INPP5D; DDIT4). GR directly represses transcription of CSK, a kinase that limits the activity of BCR-proximal Src-family kinases. CSK inhibition attenuates the constitutive BCR signaling of lymphomas by hyperactivating Src-family kinases, triggering their ubiquitination and degradation. With the knowledge that glucocorticoids disable oncogenic BCR signaling, they can now be deployed rationally to treat BCR-dependent aggressive lymphomas and used to construct mechanistically sound combination regimens with inhibitors of BTK, PI3 kinase, BCL2, and CSK.


Subject(s)
Glucocorticoids , Receptors, Antigen, B-Cell , Humans , Glucocorticoids/pharmacology , Receptors, Antigen, B-Cell/metabolism , Animals , Signal Transduction/drug effects , Receptors, Glucocorticoid/metabolism , Mice , Cell Line, Tumor , Lymphoma, Large B-Cell, Diffuse/drug therapy , Lymphoma, Large B-Cell, Diffuse/genetics , Lymphoma, Large B-Cell, Diffuse/metabolism , Burkitt Lymphoma/drug therapy , Burkitt Lymphoma/genetics , Burkitt Lymphoma/metabolism , Burkitt Lymphoma/pathology , Molecular Targeted Therapy/methods , Phosphatidylinositol 3-Kinases/metabolism , src-Family Kinases/metabolism , Gene Expression Regulation, Neoplastic/drug effects
6.
J Investig Med High Impact Case Rep ; 12: 23247096241253341, 2024.
Article in English | MEDLINE | ID: mdl-38767125

ABSTRACT

Primary gastric Burkitt's lymphoma is an aggressive non-Hodgkin's lymphoma that has been rarely reported in the literature. The majority of primary gastric lymphomas are diffuse large B-cell lymphomas and mucosa-associated lymphoid tissue (MALT) lymphomas. Patients with primary gastric Burkitt's lymphoma can present with abdominal pain, hematemesis, melena, perforation, and obstruction. Diagnosis is made with a combination of clinical, radiological, and pathological findings. Treatment data are limited due to the limited cases reported. We present a case of a 47-year-old female who presented with diffuse abdominal pain, melena, and coffee-ground emesis that was diagnosed with primary gastric Burkitt's lymphoma following biopsies taken from a gastric ulcerated mass found on upper endoscopy.


Subject(s)
Burkitt Lymphoma , Stomach Neoplasms , Humans , Female , Burkitt Lymphoma/diagnosis , Burkitt Lymphoma/pathology , Middle Aged , Stomach Neoplasms/pathology , Stomach Neoplasms/diagnosis , Abdominal Pain/etiology , Biopsy , Melena/etiology , Tomography, X-Ray Computed , Lymphoma, Non-Hodgkin
7.
PLoS Pathog ; 20(4): e1012132, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38620028

ABSTRACT

Epstein-Barr virus (EBV) is an important cause of human lymphomas, including Burkitt lymphoma (BL). EBV+ BLs are driven by Myc translocation and have stringent forms of viral latency that do not express either of the two major EBV oncoproteins, EBNA2 (which mimics Notch signaling) and LMP1 (which activates NF-κB signaling). Suppression of Myc-induced apoptosis, often through mutation of the TP53 (p53) gene or inhibition of pro-apoptotic BCL2L11 (BIM) gene expression, is required for development of Myc-driven BLs. EBV+ BLs contain fewer cellular mutations in apoptotic pathways compared to EBV-negative BLs, suggesting that latent EBV infection inhibits Myc-induced apoptosis. Here we use an EBNA2-deleted EBV virus (ΔEBNA2 EBV) to create the first in vivo model for EBV+ BL-like lymphomas derived from primary human B cells. We show that cord blood B cells infected with both ΔEBNA2 EBV and a Myc-expressing vector proliferate indefinitely on a CD40L/IL21 expressing feeder layer in vitro and cause rapid onset EBV+ BL-like tumors in NSG mice. These LMP1/EBNA2-negative Myc-driven lymphomas have wild type p53 and very low BIM, and express numerous germinal center B cell proteins (including TCF3, BACH2, Myb, CD10, CCDN3, and GCSAM) in the absence of BCL6 expression. Myc-induced activation of Myb mediates expression of many of these BL-associated proteins. We demonstrate that Myc blocks LMP1 expression both by inhibiting expression of cellular factors (STAT3 and Src) that activate LMP1 transcription and by increasing expression of proteins (DNMT3B and UHRF1) known to enhance DNA methylation of the LMP1 promoters in human BLs. These results show that latent EBV infection collaborates with Myc over-expression to induce BL-like human B-cell lymphomas in mice. As NF-κB signaling retards the growth of EBV-negative BLs, Myc-mediated repression of LMP1 may be essential for latent EBV infection and Myc translocation to collaboratively induce human BLs.


Subject(s)
B-Lymphocytes , Burkitt Lymphoma , Epstein-Barr Virus Infections , Herpesvirus 4, Human , Proto-Oncogene Proteins c-myc , Virus Latency , Animals , Burkitt Lymphoma/virology , Burkitt Lymphoma/metabolism , Burkitt Lymphoma/pathology , Burkitt Lymphoma/genetics , Humans , Mice , Epstein-Barr Virus Infections/virology , Epstein-Barr Virus Infections/metabolism , Epstein-Barr Virus Infections/complications , Epstein-Barr Virus Infections/genetics , Herpesvirus 4, Human/genetics , Proto-Oncogene Proteins c-myc/metabolism , Proto-Oncogene Proteins c-myc/genetics , B-Lymphocytes/virology , B-Lymphocytes/metabolism , Epstein-Barr Virus Nuclear Antigens/metabolism , Epstein-Barr Virus Nuclear Antigens/genetics , Apoptosis , Viral Proteins/metabolism , Viral Proteins/genetics
8.
J Hematop ; 17(2): 51-61, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38561469

ABSTRACT

MYC-rearranged B-cell lymphoma (BCL) in the pediatric/young adult (YA) age group differs substantially in disease composition from adult cohorts. However, data regarding the partner genes, concurrent rearrangements, and ultimate diagnoses in these patients is scarce compared to that in adult cohorts. We aimed to characterize the spectrum of MYC-rearranged (MYC-R) mature, aggressive BCL in the pediatric/YA population. A retrospective study of morphologic, immunophenotypic, and fluorescence in situ hybridization (FISH) results of patients age ≤ 30 years with suspected Burkitt lymphoma (BL), diffuse large B-cell lymphoma (DLBCL) or high-grade B-cell lymphoma (HGBCL), and a MYC-R by FISH between 2013-2022 was performed. Two-hundred fifty-eight cases (129 (50%) pediatric (< 18 years) and 129 (50%) YA (18-30 years)) were included. Most MYC-R BCL in pediatric (89%) and YA (66%) cases were BL. While double-hit (DH) cytogenetics (MYC with BCL2 and/or BCL6-R, HGBCL-DH) was rare in the pediatric population (2/129, 2%), HGBCL-DH increased with age and was identified in 17/129 (13%) of YA cases. Most HGBCL-DH had MYC and BCL6-R, while BCL2-R were rare in both groups (3/258, 1%). MYC-R without an IG partner was more common in the YA group (14/116 (12%) vs 2/128 (2%), p = 0.001). The pediatric to YA transition is characterized by decreasing frequency in BL and increasing genetic heterogeneity of MYC-R BCL, with emergence of DH-BCL with MYC and BCL6-R. FISH to evaluate for BCL2 and BCL6 rearrangements is likely not warranted in the pediatric population but should continue to be applied in YA BCL.


Subject(s)
Gene Rearrangement , Proto-Oncogene Proteins c-myc , Humans , Adolescent , Child , Male , Young Adult , Adult , Female , Proto-Oncogene Proteins c-myc/genetics , Retrospective Studies , Child, Preschool , In Situ Hybridization, Fluorescence , Lymphoma, B-Cell/genetics , Lymphoma, B-Cell/pathology , Burkitt Lymphoma/genetics , Burkitt Lymphoma/pathology
10.
Blood ; 144(2): 187-200, 2024 Jul 11.
Article in English | MEDLINE | ID: mdl-38620074

ABSTRACT

ABSTRACT: SRY-related HMG-box gene 11 (SOX11) is a transcription factor overexpressed in mantle cell lymphoma (MCL), a subset of Burkitt lymphomas (BL) and precursor lymphoid cell neoplasms but is absent in normal B cells and other B-cell lymphomas. SOX11 has an oncogenic role in MCL but its contribution to BL pathogenesis remains uncertain. Here, we observed that the presence of Epstein-Barr virus (EBV) and SOX11 expression were mutually exclusive in BL. SOX11 expression in EBV-negative (EVB-) BL was associated with an IG∷MYC translocation generated by aberrant class switch recombination, whereas in EBV-negative (EBV-)/SOX11-negative (SOX11-) tumors the IG∷MYC translocation was mediated by mistaken somatic hypermutations. Interestingly, EBV- SOX11-expressing BL showed higher frequency of SMARCA4 and ID3 mutations than EBV-/SOX11- cases. By RNA sequencing, we identified a SOX11-associated gene expression profile, with functional annotations showing partial overlap with the SOX11 transcriptional program of MCL. Contrary to MCL, no differences on cell migration or B-cell receptor signaling were found between SOX11- and SOX11-positive (SOX11+) BL cells. However, SOX11+ BL showed higher adhesion to vascular cell adhesion molecule 1 (VCAM-1) than SOX11- BL cell lines. Here, we demonstrate that EBV- BL comprises 2 subsets of cases based on SOX11 expression. The mutual exclusion of SOX11 and EBV, and the association of SOX11 with a specific genetic landscape suggest a role of SOX11 in the early pathogenesis of BL.


Subject(s)
Burkitt Lymphoma , Herpesvirus 4, Human , SOXC Transcription Factors , Humans , Burkitt Lymphoma/genetics , Burkitt Lymphoma/virology , Burkitt Lymphoma/metabolism , Burkitt Lymphoma/pathology , SOXC Transcription Factors/genetics , SOXC Transcription Factors/metabolism , Herpesvirus 4, Human/genetics , Gene Expression Regulation, Neoplastic , Epstein-Barr Virus Infections/genetics , Epstein-Barr Virus Infections/complications , Epstein-Barr Virus Infections/virology , Mutation , DNA Helicases/genetics , DNA Helicases/metabolism , Translocation, Genetic , Transcription Factors/genetics , Transcription Factors/metabolism , Male , Inhibitor of Differentiation Proteins/genetics , Inhibitor of Differentiation Proteins/metabolism , Nuclear Proteins
11.
Sci Rep ; 14(1): 8730, 2024 04 16.
Article in English | MEDLINE | ID: mdl-38627588

ABSTRACT

We previously showed that MYC promoted Burkitt lymphoma (BL) growth by inhibiting the tumor suppressor miR-150, resulting in release of miR-150 targets MYB and ZDHHC11. The ZDHHC11 gene encodes three different transcripts including a mRNA (pcZDHHC11), a linear long non-coding RNA (lncZDHHC11) and a circular RNA (circZDHHC11). All transcripts contain the same region with 18 miR-150 binding sites. Here we studied the relevance of circZDHHC11, including this miR-150 binding site region, for growth of BL cells. CircZDHHC11 was mainly present in the cytoplasmic fraction in BL cells and its localization was not altered upon miR-150 overexpression. Knockdown of circZDHHC11 caused a strong inhibition of BL growth without affecting the expression levels of MYC, MYB, miR-150 and other genes. Overexpression of circZDHHC11 neither affected cell growth, nor rescued the phenotype induced by miR-150 overexpression. Genomic deletion of the miR-150 binding site region did not affect growth, nor did it change the effect of circZDHHC11 knockdown. This indicated that the miR-150 binding site region is dispensable for the growth promoting role of circZDHHC11. To conclude, our results show that circZDHHC11 is a crucial factor supporting BL cell growth independent of its ability to sponge miR-150.


Subject(s)
Burkitt Lymphoma , MicroRNAs , Humans , Burkitt Lymphoma/pathology , Cell Line, Tumor , Cell Proliferation/genetics , Gene Expression Regulation, Neoplastic , MicroRNAs/genetics , RNA, Messenger/genetics , RNA, Circular
12.
Front Immunol ; 15: 1342455, 2024.
Article in English | MEDLINE | ID: mdl-38464537

ABSTRACT

Epstein-Barr virus (EBV) contributes to the development of a significant subset of human lymphomas. As a herpes virus, EBV can transition between a lytic state which is required to establish infection and a latent state where a limited number of viral antigens are expressed which allows infected cells to escape immune surveillance. Three broad latency programs have been described which are defined by the expression of viral proteins RNA, with latency I being the most restrictive expressing only EBV nuclear antigen 1 (EBNA1) and EBV-encoded small RNAs (EBERs) and latency III expressing the full panel of latent viral genes including the latent membrane proteins 1 and 2 (LMP1/2), and EBNA 2, 3, and leader protein (LP) which induce a robust T-cell response. The therapeutic use of EBV-specific T-cells has advanced the treatment of EBV-associated lymphoma, however this approach is only effective against EBV-associated lymphomas that express the latency II or III program. Latency I tumors such as Burkitt lymphoma (BL) and a subset of diffuse large B-cell lymphomas (DLBCL) evade the host immune response to EBV and are resistant to EBV-specific T-cell therapies. Thus, strategies for inducing a switch from the latency I to the latency II or III program in EBV+ tumors are being investigated as mechanisms to sensitize tumors to T-cell mediated killing. Here, we review what is known about the establishment and regulation of latency in EBV infected B-cells, the role of EBV-specific T-cells in lymphoma, and strategies to convert latency I tumors to latency II/III.


Subject(s)
Burkitt Lymphoma , Epstein-Barr Virus Infections , Latent Infection , Lymphoma, Large B-Cell, Diffuse , Humans , Herpesvirus 4, Human , Epstein-Barr Virus Infections/complications , Virus Latency , Burkitt Lymphoma/pathology , Viral Proteins/genetics , Lymphoma, Large B-Cell, Diffuse/pathology
13.
PLoS One ; 19(3): e0299777, 2024.
Article in English | MEDLINE | ID: mdl-38466670

ABSTRACT

INTRODUCTION: The role of age and sex in the presentation and outcome of endemic Burkitt lymphoma (BL) has not been studied recently. This study analysed these factors in 934 patients with BL who had received cyclophosphamide and intrathecal methotrexate as treatment. METHODS: Records of 934 children diagnosed with BL from 2004 to 2015 were obtained from our Paediatric Oncology Networked Database (POND) cancer registry. Age at diagnosis, sex, disease stage, time to diagnosis, delay in diagnosis, completion of treatment, rate of abandonment, and one-year survival rates were recorded and statistically analysed. RESULTS: The male to female ratio of 1.41 for the study population of 934. The median delay from onset of symptoms to diagnosis was 31 days. The St Jude stage distribution was I = 6.4%, II = 5.9%, III = 71.5% and IV = 16.2%. Significantly more patients presented with stage III disease in age groups 5-9 and 10-14 years than 0-4 years. The overall 1-year survival rate was 53.45%, respectively 77.1% for stage I, 67.9% for stage II, 55.1% for stage III and 32.4% for stage IV disease (p<0.001). There was no significant difference in survival by sex and age group. CONCLUSION: Patients aged under 5 years presented with less-advanced disease, but survival was not affected by age. Sex did not influence delay to diagnosis and overall survival. The long delay between the onset of symptoms and diagnosis emphasises the need for interventions to achieve an earlier diagnosis and a better survival rate.


Subject(s)
Burkitt Lymphoma , Child , Humans , Male , Female , Aged , Burkitt Lymphoma/diagnosis , Burkitt Lymphoma/drug therapy , Burkitt Lymphoma/pathology , Cameroon , Cyclophosphamide/therapeutic use , Methotrexate/therapeutic use , Disease-Free Survival , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Treatment Outcome
14.
Chemistry ; 30(25): e202400559, 2024 May 02.
Article in English | MEDLINE | ID: mdl-38411573

ABSTRACT

Dimeric naphthopyranones are known to be biologically active, however, for the corresponding monomeric naphthopyranones this information is still elusive. Here the first enantioselective total synthesis of semi-viriditoxic acid as well as the synthesis of semi-viriditoxin and derivatives is reported. The key intermediate in the synthesis of naphthopyranones is an α,ß-unsaturated δ-lactone, which we synthesized in two different ways (Ghosez-cyclization and Grubbs ring-closing metathesis), while the domino-Michael-Dieckmann reaction of the α,ß-unsaturated δ-lactone with an orsellinic acid derivative is the key reaction. A structure-activity relationship study was performed measuring the cytotoxicity in Burkitt B lymphoma cells (Ramos). The dimeric structure was found to be crucial for biological activity: Only the dimeric naphthopyranones showed cytotoxic and apoptotic activity, whereas the monomers did not display any activity at all.


Subject(s)
Antineoplastic Agents , Burkitt Lymphoma , Structure-Activity Relationship , Cell Line, Tumor , Humans , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Burkitt Lymphoma/drug therapy , Burkitt Lymphoma/pathology , Stereoisomerism , Apoptosis/drug effects , Lactones/chemistry , Lactones/pharmacology , Lactones/chemical synthesis , Cyclization
15.
J Am Dent Assoc ; 155(4): 344-348, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38244019

ABSTRACT

BACKGROUND: Burkitt lymphoma (BL) is a subtype of non-Hodgkin lymphoma. It is strongly associated with HIV infection and has a highly aggressive clinical course. The involvement of the maxillofacial region in BL has rarely been reported. CASE DESCRIPTION: A 36-year-old woman with HIV-positive status had painless bilateral swelling of the oral mucosa and middle and lower thirds of the face. Microscopic analysis of the oral lesion revealed an atypical lymphoid infiltrate with a starry sky pattern. The lymphoid cells expressed cluster of differentiation 20, cluster of differentiation 10, B-cell lymphoma 6, and c-Myc; the Ki-67 proliferative index was high. The tumor cells were positive for Epstein-Barr virus. These results led to the diagnosis of HIV-related BL. PRACTICAL IMPLICATIONS: BL and other immunodeficiency-related lymphoproliferative malignancies may affect the oral and maxillofacial regions and should be included in the differential diagnosis of rapidly expanding swelling in young patients.


Subject(s)
Burkitt Lymphoma , Epstein-Barr Virus Infections , HIV Infections , Female , Humans , Adult , Burkitt Lymphoma/complications , Burkitt Lymphoma/diagnosis , Burkitt Lymphoma/pathology , Epstein-Barr Virus Infections/diagnosis , Epstein-Barr Virus Infections/pathology , Herpesvirus 4, Human , HIV Infections/complications , HIV Infections/diagnosis
16.
Cytometry B Clin Cytom ; 106(2): 92-98, 2024 03.
Article in English | MEDLINE | ID: mdl-38243626

ABSTRACT

CD19 is frequently targeted for immunotherapy in B cell malignancies, which may result in loss of CD19 expression in leukemic cells as an escape mechanism. Stage 0 hematogones (Hgs) are normal CD19-negative very early B cell precursors that can be potentially mistaken for CD19 negative residual leukemic cells by flow cytometry (FCM) in B cell acute lymphoblastic leukemia (BCP-ALL) cases treated with anti CD19 therapy. Our main objective was to characterize and study the incidence of stage 0 hematogones in follow-up bone marrow samples of pediatric BCP-ALL cases. We analyzed the flow cytometry standard files of 61 pediatric BCP-ALL cases treated with conventional chemotherapy and targeted anti-CD19 therapy, for identifying the residual disease and normal B cell precursors including stage 0 Hgs. A non-CD19 alternate gating strategy was used to isolate the B cells for detecting the residual disease and stage 0 Hgs. The stage 0 Hgs were seen in 95% of marrow samples containing CD19+ Hgs. When compared with controls and posttransplant marrow samples, the fraction of stage 0 Hgs was higher in patients receiving anti CD19 therapy (p = 0.0048), but it was not significant when compared with patients receiving chemotherapy (p = 0.1788). Isolated stage 0 Hgs are found in samples treated with anti-CD19 therapy simulating CD19 negative residual illness. Our findings aid in understanding the stage 0 Hgs and its association with CD19+ Hgs in anti CD19 therapy and conventional chemotherapy. This is crucial as it can be potentially mistaken for residual disease in patients treated with anti CD19 therapy.


Subject(s)
Burkitt Lymphoma , Precursor B-Cell Lymphoblastic Leukemia-Lymphoma , Precursor Cell Lymphoblastic Leukemia-Lymphoma , Child , Humans , Bone Marrow/pathology , Flow Cytometry , Follow-Up Studies , Immunophenotyping , Antigens, CD19 , Precursor Cell Lymphoblastic Leukemia-Lymphoma/diagnosis , Precursor B-Cell Lymphoblastic Leukemia-Lymphoma/pathology , Burkitt Lymphoma/pathology , Neoplasm, Residual/diagnosis
17.
Nature ; 626(7998): 401-410, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38297129

ABSTRACT

Ferroptosis is a form of cell death that has received considerable attention not only as a means to eradicate defined tumour entities but also because it provides unforeseen insights into the metabolic adaptation that tumours exploit to counteract phospholipid oxidation1,2. Here, we identify proferroptotic activity of 7-dehydrocholesterol reductase (DHCR7) and an unexpected prosurvival function of its substrate, 7-dehydrocholesterol (7-DHC). Although previous studies suggested that high concentrations of 7-DHC are cytotoxic to developing neurons by favouring lipid peroxidation3, we now show that 7-DHC accumulation confers a robust prosurvival function in cancer cells. Because of its far superior reactivity towards peroxyl radicals, 7-DHC effectively shields (phospho)lipids from autoxidation and subsequent fragmentation. We provide validation in neuroblastoma and Burkitt's lymphoma xenografts where we demonstrate that the accumulation of 7-DHC is capable of inducing a shift towards a ferroptosis-resistant state in these tumours ultimately resulting in a more aggressive phenotype. Conclusively, our findings provide compelling evidence of a yet-unrecognized antiferroptotic activity of 7-DHC as a cell-intrinsic mechanism that could be exploited by cancer cells to escape ferroptosis.


Subject(s)
Burkitt Lymphoma , Dehydrocholesterols , Ferroptosis , Neuroblastoma , Animals , Humans , Burkitt Lymphoma/metabolism , Burkitt Lymphoma/pathology , Cell Survival , Dehydrocholesterols/metabolism , Lipid Peroxidation , Neoplasm Transplantation , Neuroblastoma/metabolism , Neuroblastoma/pathology , Oxidation-Reduction , Phenotype , Reproducibility of Results
19.
Haematologica ; 109(2): 543-552, 2024 Feb 01.
Article in English | MEDLINE | ID: mdl-37560813

ABSTRACT

High dose-intensive or infusional intermediate-dose immunochemotherapy is highly effective treatment for Burkitt lymphoma irrespective of human immunodeficiency virus (HIV) infection. However, toxicities of these regimens are relevant, especially in older adults and elderly patients. The prospective multicenter BURKIMAB14 trial included four to six blocks of immunochemotherapy according to stage (localized: 1 and 2 non-bulky; advanced: 2 bulky, 3, 4) and age, with dose reduction in patients >55 years old. Dose-intensity of chemotherapy was reduced in patients ≤55 years old after achieving complete metabolic response (CMR). Their outcomes were compared with those of similar patients included in the former BURKIMAB08 trial, in which there was no dose reduction. CMR was attained in 86 of 107 (80%) patients (17/19 in localized stages and 69/88 in advanced stages). Patients from the BURKIMAB14 trial ≤55 years old showed similar overall survival (OS), fewer infections and cytopenias than patients from the BURKIMAB08 trial. Patients >55 years old had a significantly higher treatment- related mortality despite dose reduction of chemotherapy. With a median follow-up of 3.61 years the 4-year OS probability was 73% (range, 63-81%). Age (≤55 vs. >55 years) and stage (localized vs. advanced) had prognostic significance. No significant differences in OS were observed in HIV-positive versus HIV-negative patients. The results of BURKIMAB14 are similar to those of other dose-intensive immunochemotherapy trials. Age >55 years and advanced stage, but not HIV infection, were associated with poor survival. Dose reduction of chemotherapy in young adults in CMR is safe and does not impact outcomes (clinicaltrials gov. Identifier: NCT05049473).


Subject(s)
Burkitt Lymphoma , HIV Infections , Leukemia , Humans , Young Adult , Aged , Middle Aged , Burkitt Lymphoma/drug therapy , Burkitt Lymphoma/pathology , Drug Tapering , Feasibility Studies , Prospective Studies , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Leukemia/drug therapy , HIV Infections/drug therapy , Cyclophosphamide/therapeutic use , Doxorubicin/therapeutic use , Rituximab/therapeutic use
20.
Ann Hematol ; 103(3): 893-903, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38091052

ABSTRACT

The current chemotherapy treatments have led to an improvement in survival rates for pediatric Burkitt's lymphoma (BL). Survival in children with high-grade, mature B-cell non-Hodgkin's lymphoma (B-NHL) has been prolonged by six rituximab doses combined with chemotherapy, whereas the efficacy of four doses has not been reported. This study aimed to explore optimal therapeutic strategies-the number of doses of rituximab based on different risk groups-and also aim to investigate the clinical characteristics of Chinese pediatric BL. This study consecutively enrolled children with BL in Beijing Children's Hospital who received French-American-British mature B-cell lymphoma 96 (FAB/LMB96). The patients were divided into three groups: R0 group (chemotherapy alone), R6 group (chemotherapy combined with six rituximab doses), and R4 group (chemotherapy combined with four rituximab doses). The clinical characteristics and outcomes were evaluated. Univariate and multivariate analyses and prognostic nomogram were used to assess prognostic factors. A nomogram was developed that predicted overall survival based on the Cox proportional hazards model, and the concordance index (C-index) and a calibration curve were used to determine its predictive and discriminatory capacity. We enrolled 385 boys and 71 girls, with a median age of 6 years (1-14 years). Of these, 296 patients (65%) had initial abdominal symptoms, 182 (40%) had bulky disease, 46 (10%) had B symptoms, 77 (16.9%) had BL-ALL (blasts ≥ 25% in bone marrow (BM)), 96 (21%) had central nervous system (CNS) disease, 406 (89%) were in stages III-IV, 378 (83%) were in group C, 170 (37.2%) had lactate dehydrogenase (LDH) levels ≥ 1000 U/L at initial diagnosis, and 137 (30%) had tumor lysis syndrome. The R0, R6, and R4 groups included 79, 144, and 227 patients, respectively. Six patients were excluded due to treatment withdrawal for various reasons. The 3-year overall survival (OS) and event-free survival (EFS) percentages were 92% ± 1.3% and 91.3% ± 1.3%, respectively, in all cohorts, whereas the 3-year EFS percentage was 83.5% ± 4.2%, 93% ± 2.1%, and 92.9% ± 1.8% in the R0, R6, and R4 groups, respectively (P = 0.025). The nomogram included four important variables based on a multivariate analysis of the primary cohort: course of disease ≤ 20 days, presence of bulky disease at the beginning of diagnosis, central nervous system(CNS) invasion, and dosage of rituximab. The calibration curve showed that the nomogram was able to predict 3-year OS accurately. The C-index of the nomogram for OS prediction was 0.79 for both cohorts. In our hospital, pediatric BL was more commonly observed in school-age boys with an abdominal mass and mostly in advanced stages at initial diagnosis. The FAB/LMB96 regimen combined with rituximab significantly increased survival outcomes. We observed no significant differences between four and six doses of rituximab in terms of treatment outcomes. The proposed nomogram provides an individualized risk estimate of OS in patients with BL and may assist treatment decision-making or rituximab dose design.


Subject(s)
Burkitt Lymphoma , Lymphoma, B-Cell , Male , Child , Female , Humans , Burkitt Lymphoma/drug therapy , Burkitt Lymphoma/pathology , Rituximab , Cyclophosphamide , Disease-Free Survival , Lymphoma, B-Cell/drug therapy , Treatment Outcome , Antineoplastic Combined Chemotherapy Protocols , Retrospective Studies
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