Asunto(s)
Linfoma de Burkitt , Herpesvirus Humano 4 , Factores de Transcripción SOXC , Adulto , Femenino , Humanos , Masculino , Linfoma de Burkitt/patología , Linfoma de Burkitt/genética , Linfoma de Burkitt/virología , Linfoma de Burkitt/diagnóstico , Infecciones por Virus de Epstein-Barr/complicaciones , Infecciones por Virus de Epstein-Barr/virología , Infecciones por Virus de Epstein-Barr/patología , Herpesvirus Humano 4/aislamiento & purificación , Factores de Transcripción SOXC/genética , Factores de Transcripción SOXC/metabolismoAsunto(s)
Mutación , Humanos , Linfoma de Burkitt/genética , Linfoma de Burkitt/patología , Masculino , Infecciones por Virus de Epstein-Barr/genética , Proteínas Tirosina Quinasas/genética , Linfadenopatía/genética , Linfadenopatía/patología , Síndromes de Inmunodeficiencia/genética , Síndrome Linfoproliferativo Autoinmune/genética , Síndrome Linfoproliferativo Autoinmune/diagnóstico , Femenino , Trastornos Linfoproliferativos/genética , Trastornos Linfoproliferativos/patología , Enfermedades de Inmunodeficiencia Primaria/genéticaRESUMEN
Obesity is associated with increased cancer risk, yet the underlying mechanisms remain elusive. Obesity-associated cancers involve disruptions in metabolic and cellular pathways, which can lead to genomic instability. Repetitive DNA sequences capable of adopting alternative DNA structures (e.g., H-DNA) stimulate mutations and are enriched at mutation hotspots in human cancer genomes. However, it is not known if obesity impacts DNA repeat-mediated endogenous mutation hotspots. We address this gap by measuring mutation frequencies in obese and normal-weight transgenic reporter mice carrying either a control human B-DNA- or an H-DNA-forming sequence (from a translocation hotspot in c-MYC in Burkitt lymphoma). Here, we discover that H-DNA-induced DNA damage and mutations are elevated in a tissue-specific manner, and DNA repair efficiency is reduced in obese mice compared to those on the control diet. These findings elucidate the impact of obesity on cancer-associated endogenous mutation hotspots, providing mechanistic insight into the link between obesity and cancer.
Asunto(s)
Daño del ADN , Reparación del ADN , Inestabilidad Genómica , Ratones Transgénicos , Mutación , Obesidad , Animales , Obesidad/genética , Humanos , Ratones , Reparación del ADN/genética , Daño del ADN/genética , Secuencias Repetitivas de Ácidos Nucleicos/genética , Masculino , Ratones Endogámicos C57BL , Femenino , Linfoma de Burkitt/genética , ADN/genética , ADN/metabolismoRESUMEN
Epstein-Barr virus (EBV) is a ubiquitous human tumor virus that establishes lifelong, persistent infections in B cells. The presence of EBV in cancer cells presents an opportunity to target these cells by reactivating the virus from latency. In this study, we developed a novel approach for EBV reactivation termed clustered regularly interspaced short palindromic repeats (CRISPR)/dCas9-mediated EBV reactivation (CMER) strategy. Using modified CRISPR-associated protein 9 (dCas9) fused with VP64, we designed 10 single guide RNAs (sgRNAs) to target and activate the EBV immediate-early gene promoter. In Akata Burkitt lymphoma cells, 9 out of 10 CMER sgRNAs effectively reactivated EBV. Among these, CMER sgRNA-5 triggered robust reactivation across various cell types, including lymphoma, gastric cancer, and nasopharyngeal carcinoma cells. Importantly, the combination of CMER and ganciclovir selectively eliminated EBV-positive cells, regardless of their cell origin. These findings indicate that targeted virus reactivation by CMER, combined with nucleoside analog therapy, holds promise for EBV-associated cancer treatment. IMPORTANCE: This study explores a novel strategy called clustered regularly interspaced short palindromic repeats (CRISPR)/dCas9-mediated Epstein-Barr virus (EBV) reactivation (CMER) to reactivate the Epstein-Barr virus in cancer cells. EBV is associated with various cancers, and reactivating EBV from latency offers a potential therapeutic strategy. We utilized an enzymatically inactive CRISPR-associated protein 9 (dCas9) fused with VP64 and designed 10 single guide RNAs to target the EBV immediate-early gene promoter. Nine of these sgRNAs effectively reactivated EBV in Burkitt lymphoma cells, with CMER sgRNA-5 demonstrating strong reactivation across different cancer cell types. Combining CMER with ganciclovir selectively eliminated EBV-positive cells, showing promise for EBV-associated cancer treatment.
Asunto(s)
Sistemas CRISPR-Cas , Infecciones por Virus de Epstein-Barr , Ganciclovir , Herpesvirus Humano 4 , Activación Viral , Humanos , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/efectos de los fármacos , Herpesvirus Humano 4/fisiología , Activación Viral/efectos de los fármacos , Activación Viral/genética , Infecciones por Virus de Epstein-Barr/virología , Infecciones por Virus de Epstein-Barr/genética , Línea Celular Tumoral , Ganciclovir/farmacología , Latencia del Virus/genética , Latencia del Virus/efectos de los fármacos , Antivirales/farmacología , Linfoma de Burkitt/genética , Linfoma de Burkitt/virología , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Proteína 9 Asociada a CRISPR/genéticaRESUMEN
Reactivation from latency plays a significant role in maintaining persistent lifelong Epstein-Barr virus (EBV) infection. Mechanisms governing successful activation and progression of the EBV lytic phase are not fully understood. EBV expresses multiple viral microRNAs (miRNAs) and manipulates several cellular miRNAs to support viral infection. To gain insight into the host miRNAs regulating transitions from EBV latency into the lytic stage, we conducted a CRISPR/Cas9-based screen in EBV+ Burkitt lymphoma (BL) cells using anti-Ig antibodies to crosslink the B cell receptor (BCR) and induce reactivation. Using a gRNA library against >1500 annotated human miRNAs, we identified miR-142 as a key regulator of EBV reactivation. Genetic ablation of miR-142 enhanced levels of immediate early and early lytic gene products in infected BL cells. Ago2-PAR-CLIP experiments with reactivated cells revealed miR-142 targets related to Erk/MAPK signaling, including components directly downstream of the B cell receptor (BCR). Consistent with these findings, disruption of miR-142 enhanced SOS1 levels and Mek phosphorylation in response to surface Ig cross-linking. Effects could be rescued by inhibitors of Mek (cobimetinib) or Raf (dabrafenib). Taken together, these results show that miR-142 functionally regulates SOS1/Ras/Raf/Mek/Erk signaling initiated through the BCR and consequently, restricts EBV entry into the lytic cycle.
Asunto(s)
Sistemas CRISPR-Cas , Infecciones por Virus de Epstein-Barr , Herpesvirus Humano 4 , MicroARNs , Activación Viral , Latencia del Virus , Humanos , Herpesvirus Humano 4/genética , MicroARNs/genética , MicroARNs/metabolismo , Infecciones por Virus de Epstein-Barr/virología , Infecciones por Virus de Epstein-Barr/genética , Infecciones por Virus de Epstein-Barr/metabolismo , Linfoma de Burkitt/virología , Linfoma de Burkitt/genética , Linfoma de Burkitt/metabolismo , Línea Celular TumoralRESUMEN
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.
Asunto(s)
Antígenos Nucleares del Virus de Epstein-Barr , Proteínas F-Box , Herpesvirus Humano 4 , Proteínas Proto-Oncogénicas c-bcl-6 , Humanos , Antígenos Nucleares del Virus de Epstein-Barr/metabolismo , Antígenos Nucleares del Virus de Epstein-Barr/genética , Proteínas Proto-Oncogénicas c-bcl-6/metabolismo , Proteínas Proto-Oncogénicas c-bcl-6/genética , Proteínas F-Box/metabolismo , Proteínas F-Box/genética , Herpesvirus Humano 4/metabolismo , Herpesvirus Humano 4/genética , Línea Celular Tumoral , Linfocitos B/metabolismo , Linfocitos B/virología , Infecciones por Virus de Epstein-Barr/metabolismo , Infecciones por Virus de Epstein-Barr/virología , Proteolisis , Proliferación Celular , Ubiquitinación , Linfoma de Burkitt/virología , Linfoma de Burkitt/metabolismo , Linfoma de Burkitt/genética , Linfoma de Burkitt/patología , Antígenos Virales/metabolismo , Antígenos Virales/genética , Centro Germinal/metabolismo , Centro Germinal/virología , Proteína-Arginina N-MetiltransferasasRESUMEN
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.
Asunto(s)
Glucocorticoides , Receptores de Antígenos de Linfocitos B , Humanos , Glucocorticoides/farmacología , Receptores de Antígenos de Linfocitos B/metabolismo , Animales , Transducción de Señal/efectos de los fármacos , Receptores de Glucocorticoides/metabolismo , Ratones , Línea Celular Tumoral , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Linfoma de Células B Grandes Difuso/genética , Linfoma de Células B Grandes Difuso/metabolismo , Linfoma de Burkitt/tratamiento farmacológico , Linfoma de Burkitt/genética , Linfoma de Burkitt/metabolismo , Linfoma de Burkitt/patología , Terapia Molecular Dirigida/métodos , Fosfatidilinositol 3-Quinasas/metabolismo , Familia-src Quinasas/metabolismo , Regulación Neoplásica de la Expresión Génica/efectos de los fármacosRESUMEN
Herpesviruses have two distinct life cycle stages, latency and lytic replication. Epstein-Barr virus (EBV), a gamma-herpesvirus, establishes latency in vivo and in cultured cells. Cell lines harboring latent EBV can be induced into the lytic cycle by treatment with chemical inducing agents. In the Burkitt lymphoma cell line HH514-16 the viral lytic cycle is triggered by butyrate, a histone deacetylase (HDAC) inhibitor. Butyrate also alters expression of thousands of cellular genes. However, valproic acid (VPA), another HDAC inhibitor with global effects on cellular gene expression blocks EBV lytic gene expression in Burkitt lymphoma cell lines. Valpromide (VPM), an amide derivative of VPA, is not an HDAC inhibitor, but like VPA blocks induction of the EBV lytic cycle. VPA and VPM are the first examples of inhibitors of initial stages of lytic reactivation. We compared the effects of VPA and VPM, alone and in combination with butyrate, on host cellular gene expression using whole transcriptome analysis (RNA-seq). Gene expression was analyzed 6 h after addition of the compounds, a time before the first EBV lytic transcripts are detected. The results address two alternative, yet possibly complementary, mechanisms for regulation of EBV lytic reactivation. First, cellular genes that were up- or down-regulated by butyrate, but no longer altered in the presence of VPA or VPM, represent genes that correlated with EBV lytic reactivation. Second, genes regulated similarly by VPA and VPM in the absence and presence of butyrate are candidates for suppressors of EBV reactivation. Two genes upregulated by the lytic cycle inhibitors, CHAC1 and SLC7A11, are related to redox status and the iron-dependent cell death pathway ferroptosis. This study generates new hypotheses for control of the latency to lytic cycle switch of EBV and provides the first description of effects of the anti-convulsant drug VPM on global human cellular gene expression.
Asunto(s)
Linfoma de Burkitt , Infecciones por Virus de Epstein-Barr , Ácido Valproico/análogos & derivados , Humanos , Linfoma de Burkitt/tratamiento farmacológico , Linfoma de Burkitt/genética , Herpesvirus Humano 4/fisiología , Inhibidores de Histona Desacetilasas/farmacología , Inhibidores de Histona Desacetilasas/metabolismo , Infecciones por Virus de Epstein-Barr/tratamiento farmacológico , Activación Viral , Perfilación de la Expresión Génica , Butiratos/farmacologíaRESUMEN
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.
Asunto(s)
Linfocitos B , Linfoma de Burkitt , Infecciones por Virus de Epstein-Barr , Herpesvirus Humano 4 , Proteínas Proto-Oncogénicas c-myc , Latencia del Virus , Animales , Linfoma de Burkitt/virología , Linfoma de Burkitt/metabolismo , Linfoma de Burkitt/patología , Linfoma de Burkitt/genética , Humanos , Ratones , Infecciones por Virus de Epstein-Barr/virología , Infecciones por Virus de Epstein-Barr/metabolismo , Infecciones por Virus de Epstein-Barr/complicaciones , Infecciones por Virus de Epstein-Barr/genética , Herpesvirus Humano 4/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , Linfocitos B/virología , Linfocitos B/metabolismo , Antígenos Nucleares del Virus de Epstein-Barr/metabolismo , Antígenos Nucleares del Virus de Epstein-Barr/genética , Apoptosis , Proteínas Virales/metabolismo , Proteínas Virales/genéticaRESUMEN
Cellular therapies for the treatment of human diseases, such as chimeric antigen receptor (CAR) T and natural killer (NK) cells have shown remarkable clinical efficacy in treating hematological malignancies; however, current methods mainly utilize viral vectors that are limited by their cargo size capacities, high cost, and long timelines for production of clinical reagent. Delivery of genetic cargo via DNA transposon engineering is a more timely and cost-effective approach, yet has been held back by less efficient integration rates. Here, we report the development of a novel hyperactive TcBuster (TcB-M) transposase engineered through structure-guided and in vitro evolution approaches that achieves high-efficiency integration of large, multicistronic CAR-expression cassettes in primary human cells. Our proof-of-principle TcB-M engineering of CAR-NK and CAR-T cells shows low integrated vector copy number, a safe insertion site profile, robust in vitro function, and improves survival in a Burkitt lymphoma xenograft model in vivo. Overall, TcB-M is a versatile, safe, efficient and open-source option for the rapid manufacture and preclinical testing of primary human immune cell therapies through delivery of multicistronic large cargo via transposition.
Asunto(s)
Linfoma de Burkitt , Vectores Genéticos , Inmunoterapia Adoptiva , Receptores Quiméricos de Antígenos , Transposasas , Humanos , Transposasas/genética , Transposasas/metabolismo , Animales , Receptores Quiméricos de Antígenos/genética , Receptores Quiméricos de Antígenos/metabolismo , Inmunoterapia Adoptiva/métodos , Ratones , Vectores Genéticos/genética , Vectores Genéticos/administración & dosificación , Linfoma de Burkitt/terapia , Linfoma de Burkitt/genética , Ensayos Antitumor por Modelo de Xenoinjerto , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/metabolismo , Línea Celular Tumoral , Elementos Transponibles de ADN , Linfocitos T/inmunología , Linfocitos T/metabolismo , TransgenesRESUMEN
Multiagent chemoimmunotherapy remains the standard of care treatment for Burkitt lymphoma leading to a cure in the majority of cases. However, frontline treatment regimens are associated with a significant risk of treatment related toxicity especially in elderly and immunocompromised patients. Additionally, prognosis remains dismal in refractory/relapsed Burkitt lymphoma. Thus, novel therapies are required to not only improve outcomes in relapsed/refractory Burkitt lymphoma but also minimize frontline treatment related toxicities. Recurrent genomic changes and signalling pathway alterations that have been implicated in the Burkitt lymphomagenesis include cell cycle dysregulation, cell proliferation, inhibition of apoptosis, epigenetic dysregulation and tonic B-cell receptor-phosphatidylinositol 3-kinase (BCR-PI3K) signalling. Here, we will discuss novel targeted therapy approaches using small molecule inhibitors that could pave the way to the future treatment landscape based on the understanding of recurrent genomic changes and signalling pathway alterations in the lymphomagenesis of adult Burkitt lymphoma.
Asunto(s)
Linfoma de Burkitt , Terapia Molecular Dirigida , Linfoma de Burkitt/tratamiento farmacológico , Linfoma de Burkitt/genética , Humanos , Terapia Molecular Dirigida/métodos , Transducción de Señal/efectos de los fármacos , Antineoplásicos/uso terapéutico , Antineoplásicos/farmacologíaRESUMEN
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.
Asunto(s)
Reordenamiento Génico , Proteínas Proto-Oncogénicas c-myc , Humanos , Adolescente , Niño , Masculino , Adulto Joven , Adulto , Femenino , Proteínas Proto-Oncogénicas c-myc/genética , Estudios Retrospectivos , Preescolar , Hibridación Fluorescente in Situ , Linfoma de Células B/genética , Linfoma de Células B/patología , Linfoma de Burkitt/genética , Linfoma de Burkitt/patologíaRESUMEN
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 IGâ·MYC translocation generated by aberrant class switch recombination, whereas in EBV-negative (EBV-)/SOX11-negative (SOX11-) tumors the IGâ·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.
Asunto(s)
Linfoma de Burkitt , Herpesvirus Humano 4 , Factores de Transcripción SOXC , Humanos , Linfoma de Burkitt/genética , Linfoma de Burkitt/virología , Linfoma de Burkitt/metabolismo , Linfoma de Burkitt/patología , Factores de Transcripción SOXC/genética , Factores de Transcripción SOXC/metabolismo , Herpesvirus Humano 4/genética , Regulación Neoplásica de la Expresión Génica , Infecciones por Virus de Epstein-Barr/genética , Infecciones por Virus de Epstein-Barr/complicaciones , Infecciones por Virus de Epstein-Barr/virología , Mutación , ADN Helicasas/genética , ADN Helicasas/metabolismo , Translocación Genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Masculino , Proteínas Inhibidoras de la Diferenciación/genética , Proteínas Inhibidoras de la Diferenciación/metabolismo , Proteínas NuclearesAsunto(s)
Linfoma de Burkitt , Homocigoto , Endonucleasa PMS2 de Reparación del Emparejamiento Incorrecto , Leucemia-Linfoma Linfoblástico de Células Precursoras , Humanos , Linfoma de Burkitt/genética , Linfoma de Burkitt/tratamiento farmacológico , Linfoma de Burkitt/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Endonucleasa PMS2 de Reparación del Emparejamiento Incorrecto/genética , Masculino , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , FemeninoRESUMEN
Plk1-interacting checkpoint helicase (PICH) is a DNA translocase involved in resolving ultrafine anaphase DNA bridges and, therefore, is important to safeguard chromosome segregation and stability. PICH is overexpressed in various human cancers, particularly in lymphomas such as Burkitt lymphoma, which is caused by MYC translocations. To investigate the relevance of PICH in cancer development and progression, we have combined novel PICH-deficient mouse models with the Eµ-Myc transgenic mouse model, which recapitulates B-cell lymphoma development. We have observed that PICH deficiency delays the onset of MYC-induced lymphomas in Pich heterozygous females. Moreover, using a Pich conditional knockout mouse model, we have found that Pich deletion in adult mice improves the survival of Eµ-Myc transgenic mice. Notably, we show that Pich deletion in healthy adult mice is well tolerated, supporting PICH as a suitable target for anticancer therapies. Finally, we have corroborated these findings in two human Burkitt lymphoma cell lines and we have found that the death of cancer cells was accompanied by chromosomal instability. Based on these findings, we propose PICH as a potential therapeutic target for Burkitt lymphoma and for other cancers where PICH is overexpressed.
Asunto(s)
Linfoma de Burkitt , Adulto , Femenino , Animales , Humanos , Ratones , Linfoma de Burkitt/genética , Línea Celular , Inestabilidad Cromosómica , Modelos Animales de Enfermedad , Ratones Noqueados , Ratones Transgénicos , ADNRESUMEN
Burkitt lymphoma (BL) is responsible for many childhood cancers in sub-Saharan Africa, where it is linked to recurrent or chronic infection by Epstein-Barr virus or Plasmodium falciparum. However, whether human leukocyte antigen (HLA) polymorphisms, which regulate immune response, are associated with BL has not been well investigated, which limits our understanding of BL etiology. Here we investigate this association among 4,645 children aged 0-15 years, 800 with BL, enrolled in Uganda, Tanzania, Kenya, and Malawi. HLA alleles are imputed with accuracy >90% for HLA class I and 85-89% for class II alleles. BL risk is elevated with HLA-DQA1*04:01 (adjusted odds ratio [OR] = 1.61, 95% confidence interval [CI] = 1.32-1.97, P = 3.71 × 10-6), with rs2040406(G) in HLA-DQA1 region (OR = 1.43, 95% CI = 1.26-1.63, P = 4.62 × 10-8), and with amino acid Gln at position 53 versus other variants in HLA-DQA1 (OR = 1.36, P = 2.06 × 10-6). The associations with HLA-DQA1*04:01 (OR = 1.29, P = 0.03) and rs2040406(G) (OR = 1.68, P = 0.019) persist in mutually adjusted models. The higher risk rs2040406(G) variant for BL is associated with decreased HLA-DQB1 expression in eQTLs in EBV transformed lymphocytes. Our results support the role of HLA variation in the etiology of BL and suggest that a promising area of research might be understanding the link between HLA variation and EBV control.
Asunto(s)
Linfoma de Burkitt , Infecciones por Virus de Epstein-Barr , Niño , Humanos , Linfoma de Burkitt/genética , Infecciones por Virus de Epstein-Barr/complicaciones , Infecciones por Virus de Epstein-Barr/genética , Herpesvirus Humano 4/genética , Cadenas alfa de HLA-DQ/genéticaRESUMEN
Burkitt lymphoma (BL) is a highly aggressive lymphoma that mainly affects children and young adults. Chemotherapy is effective in young BL patients but the outcome in adults is less satisfactory. Therefore, there is a need to enhance the cytotoxic effect of drugs used in BL treatment. Glutathione (GSH) is an important antioxidant involved in processes such as regulation of oxidative stress and drug detoxification. Elevated GSH levels have been observed in many cancers and were associated with chemoresistance. We previously identified GCLC, encoding an enzyme involved in GSH biosynthesis, as an essential gene in BL. We now confirm that knockout of GCLC decreases viability of BL cells and that the GCLC protein is overexpressed in BL tissues. Moreover, we demonstrate that buthionine sulfoximine (BSO), a known inhibitor of GCLC, decreases growth of BL cells but does not affect control B cells. Furthermore, we show for the first time that BSO enhances the cytotoxicity of compounds commonly used in BL treatment, doxorubicin, and cyclophosphamide. Given the fact that BSO itself was not toxic to control cells and well-tolerated in clinical trials, combination of chemotherapy with BSO may allow reduction of the doses of cytotoxic drugs required to obtain effective responses in BL patients.
Asunto(s)
Linfoma de Burkitt , Glutamato-Cisteína Ligasa , Niño , Humanos , Butionina Sulfoximina/farmacología , Butionina Sulfoximina/uso terapéutico , Glutamato-Cisteína Ligasa/genética , Glutamato-Cisteína Ligasa/metabolismo , Linfoma de Burkitt/tratamiento farmacológico , Linfoma de Burkitt/genética , Dominio Catalítico , Ciclofosfamida/farmacología , Doxorrubicina/farmacología , Glutatión/metabolismoRESUMEN
Aggressive B-cell non-Hodgkin lymphomas are a heterogeneous group of diseases and our concepts are evolving as we learn more about their clinical, pathologic, molecular genetic features. Session IV of the 2020 EAHP Workshop covered aggressive, predominantly high-grade B-cell lymphomas, many that were difficult to classify. In this manuscript, we summarize the features of the submitted cases and highlight differential diagnostic difficulties. We specifically review issues related to high-grade B-cell lymphomas (HGBCLs) with MYC and BCL2 and/or BCL6 rearrangements including TdT expression in these cases, HGBCL, not otherwise specified, large B-cell lymphomas with IRF4 rearrangement, high-grade/large B-cell lymphomas with 11q aberration, Burkitt lymphoma, and pleomorphic mantle cell lymphoma. Since the workshop, the 5th edition of the WHO Classification for Haematolymphoid Tumours (WHO-HAEM5) and International Consensus Classification (ICC) 2022 were published. We endeavor to use the updated terminology.
Asunto(s)
Linfoma de Burkitt , Linfoma de Células B Grandes Difuso , Linfoma de Células del Manto , Humanos , Adulto , Linfoma de Burkitt/genética , Linfoma de Células B Grandes Difuso/patología , Aberraciones Cromosómicas , Linfoma de Células del Manto/genética , Fenotipo , Proteínas Proto-Oncogénicas c-myc/genética , Reordenamiento Génico , Proteínas Proto-Oncogénicas c-bcl-2/genéticaRESUMEN
Burkitt lymphoma (BL) is an aggressive B-cell lymphoma that significantly contributes to childhood cancer burden in sub-Saharan Africa. Plasmodium falciparum, which causes malaria, is geographically associated with BL, but the evidence remains insufficient for causal inference. Inference could be strengthened by demonstrating that mendelian genes known to protect against malaria-such as the sickle cell trait variant, HBB-rs334(T)-also protect against BL. We investigated this hypothesis among 800 BL cases and 3845 controls in four East African countries using genome-scan data to detect polymorphisms in 22 genes known to affect malaria risk. We fit generalized linear mixed models to estimate odds ratios (OR) and 95% confidence intervals (95% CI), controlling for age, sex, country, and ancestry. The ORs of the loci with BL and P. falciparum infection among controls were correlated (Spearman's ρ = 0.37, p = .039). HBB-rs334(T) was associated with lower P. falciparum infection risk among controls (OR = 0.752, 95% CI 0.628-0.9; p = .00189) and BL risk (OR = 0.687, 95% CI 0.533-0.885; p = .0037). ABO-rs8176703(T) was associated with decreased risk of BL (OR = 0.591, 95% CI 0.379-0.992; p = .00271), but not of P. falciparum infection. Our results increase support for the etiological correlation between P. falciparum and BL risk.
Asunto(s)
Linfoma de Burkitt , Malaria Falciparum , Malaria , Rasgo Drepanocítico , Humanos , África Oriental , Alelos , Linfoma de Burkitt/epidemiología , Linfoma de Burkitt/genética , Malaria Falciparum/epidemiología , Malaria Falciparum/genética , Malaria Falciparum/complicaciones , Rasgo Drepanocítico/epidemiología , Rasgo Drepanocítico/genética , Rasgo Drepanocítico/complicaciones , Nectinas/metabolismoRESUMEN
The Epstein-Barr Virus (EBV) encodes viral microRNAs (miRs) that have been implicated in the pathogenesis of nasopharyngeal and gastric carcinomas, yet their potential roles in lymphomas remain to be fully elucidated. This study evaluated the impact of CRISPR/Cas9-mediated knockdown of EBV miRs BART-7 and BART-9 in EBV-positive Burkitt lymphoma cells Akata. As anticipated, the Akata cells subjected to CRISPR/Cas9-mediated knockdown of either EBV BART-7 or BART-9 exhibited a significant reduction in the expression of these viral miRs compared to cells with wild-type (wt) EBV genomes. This outcome effectively validates the experimental model employed in this study. Knocking down either BART-7 or BART-9 resulted in a notable reduction in cell viability and proliferation rates, alongside an elevation in the expression of EBV lytic genes. Global proteomic analysis revealed that the knockdown of EBV BART-7 significantly decreased the expression of ubiquitin/proteasome proteins while concurrently increasing RNA binding proteins (RBPs). Conversely, BART-9 knockdown reduced proteins associated with oxidoreductase activity, particularly those involved in fatty acid metabolism. Our findings unveil previously undiscovered EBV miRs BARTs 7 and 9 roles in cellular pathways relevant to both viral biology and lymphomagenesis.