Burkitt lymphoma- a rare but challenging lymphoma

Ciwujianoside E inhibits Burkitt lymphoma cell proliferation and invasion by blocking ENO1-plasminogen interaction and TGF-β1 activation

Burkitt's lymphoma (BL) is a rare and highly aggressive B-cell non-Hodgkin lymphoma. Although the outcomes of patients with BL have greatly improved, options for patients with relapsed and refractory BL are limited. Therefore, there is an urgent need to improve BL therapeutics and to develop novel drugs with reduced toxicity. In this study, we demonstrated that enolase 1 (ENO1) is a potential novel drug target for BL treatment. We determined that ENO1 was aberrantly upregulated in BL, which was closely related to its invasiveness and poor clinical outcomes. Furthermore, using RNA interference, we demonstrated that ENO1 depletion significantly inhibited cell proliferation and invasion both in vitro and in vivo. Mechanistically, we established that ENO1 knockdown suppressed the PI3K-AKT and epithelial-mesenchymal transition (EMT) signaling pathways by reducing plasminogen (PLG) recruitment, plasmin (PL) generation, and TGF-β1 activation. Addition of activated TGF-β1 protein to the culture medium of shENO1 cells reversed the inhibitory effects on cell proliferation and invasion, as well as those on the PI3K-AKT and EMT signaling pathways. Notably, our research led to the discovery of a novel ENO1-PLG interaction inhibitor, Ciwujianoside E (L-06). L-06 effectively disrupts the interaction between ENO1 and PLG, consequently reducing PL generation and suppressing TGF-β1 activation. In both in vitro and in vivo experiments, L-06 exerted impressive antitumor effects. In summary, our study elucidated the critical role of ENO1 in BL cell proliferation and invasion and introduced a novel ENO1 inhibitor, which holds promise for improving the treatment of patients with BL in the future.

Primary manifestation of HIV-related Burkitt lymphoma in the oral and maxillofacial regions

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.

From the archives of MD Anderson Cancer Center: Sporadic Burkitt lymphoma with a complex karyotype and SOX11 expression

Burkitt lymphoma (BL) is a mature B-cell neoplasm arising from germinal center B-cells. There are three epidemiological variants of which the sporadic variant is most prevalent in developed countries representing 1-2 % of all lymphomas in adults. Patients usually present with bulky abdominal masses and ~ 30 % have bone marrow involvement. BL is characterized by a germinal center B-cell immunophenotype and usually has a simple karyotype. Here we report an unusual case of sporadic BL in a 44-year-old man and we use this case to review sporadic BL in adults. The patient presented with a cecal mass and bone marrow involvement. Biopsy of the cecal mass and bone marrow evaluation showed infiltration by intermediate-size lymphoma cells positive for monotypic kappa, CD10, CD19, CD20, CD22, CD38 bright, CD43, CD45, Bcl6 and ROR1, and negative for CD11c, CD23, CD30, CD44, CD200 and Bcl2. As expected, the lymphoma cells were strongly positive for MYC and Ki-67 showed a proliferation rate of nearly 100 %, but the cells were also positive for SOX11 and cytoplasmic LEF1. Conventional chromosomal analysis revealed t(8;14) as part of a complex karyotype. Based on our literature review, and is shown in this case, sporadic BL in adults shows some differences with the classic description of BL in children. We also discuss the differential diagnosis of BL.

Activity of tafasitamab in combination with rituximab in subtypes of aggressive lymphoma

Background

Despite recent advances in the treatment of aggressive lymphomas, a significant fraction of patients still succumbs to their disease. Thus, novel therapies are urgently needed. As the anti-CD20 antibody rituximab and the CD19-targeting antibody tafasitamab share distinct modes of actions, we investigated if dual-targeting of aggressive lymphoma B-cells by combining rituximab and tafasitamab might increase cytotoxic effects.

Methods

Antibody single and combination efficacy was determined investigating different modes of action including direct cytotoxicity, antibody-dependent cell-mediated cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) in in vitro and in vivo models of aggressive B-cell lymphoma comprising diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma (BL).

Results

Three different sensitivity profiles to antibody monotherapy or combination treatment were observed in in vitro models: while 1/11 cell lines was primarily sensitive to tafasitamab and 2/11 to rituximab, the combination resulted in enhanced cell death in 8/11 cell lines in at least one mode of action. Treatment with either antibody or the combination resulted in decreased expression of the oncogenic transcription factor MYC and inhibition of AKT signaling, which mirrored the cell line-specific sensitivities to direct cytotoxicity. At last, the combination resulted in a synergistic survival benefit in a PBMC-humanized Ramos NOD/SCID mouse model.

Conclusion

This study demonstrates that the combination of tafasitamab and rituximab improves efficacy compared to single-agent treatments in models of aggressive B-cell lymphoma in vitro and in vivo.

Action Mechanism of Metformin and Its Application in Hematological Malignancy Treatments: A Review

Hematologic malignancies (HMs) mainly include acute and chronic leukemia, lymphoma, myeloma and other heterogeneous tumors that seriously threaten human life and health. The common effective treatments are radiotherapy, chemotherapy and hematopoietic stem cell transplantation (HSCT), which have limited options and are prone to tumor recurrence and (or) drug resistance. Metformin is the first-line drug for the treatment of type 2 diabetes (T2DM). Recently, studies identified the potential anti-cancer ability of metformin in both T2DM patients and patients that are non-diabetic. The latest epidemiological and preclinical studies suggested a potential benefit of metformin in the prevention and treatment of patients with HM. The mechanism may involve the activation of the adenosine monophosphate-activated protein kinase (AMPK) signaling pathway by metformin as well as other AMPK-independent pathways to exert anti-cancer properties. In addition, combining current conventional anti-cancer drugs with metformin may improve the efficacy and reduce adverse drug reactions. Therefore, metformin can also be used as an adjuvant therapeutic agent for HM. This paper highlights the anti-hyperglycemic effects and potential anti-cancer effects of metformin, and also compiles the in vitro and clinical trials of metformin as an anti-cancer and chemosensitizing agent for the treatment of HM. The need for future research on the use of metformin in the treatment of HM is indicated.

DEVELOPMENT AND VALIDATION OF A NOVEL DUPLEX PROBE-HYBRIDIZATION QUANTITATIVE PCR FOR LYMPHOMA-ASSOCIATED MIROUNGINE GAMMAHERPESVIRUS 3 IN NORTHERN ELEPHANT SEALS (MIROUNGA ANGUSTIROSTRIS)

Recently, a novel gammaherpesvirus, miroungine gammaherpesvirus 3 (MirGHV3), was described in two juvenile elephant seals (Mirounga angustirostris) with diffuse large B-cell lymphoma. We developed and validated a quantitative (q)PCR for rapid detection of MirGHV3 and investigated its potential association with lymphoma. We developed a duplex probe-hybridization qPCR with MirGHV3 DNA polymerase (pol) as the target gene. Each primer-probe combination was cross-validated against the others. Interference was not seen when they were run in the same well as a duplex assay. Twenty-three samples from seven northern elephant seals were tested using the duplex assay. Viral DNA was detected by the assay in 9 of 9 (100%) tissues affected by lymphoma and in 6 of 14 (43%) samples from tissues unaffected by lymphoma. There was a strong correlation between viral copies detected with each of the assays (P=0.0002). Viral load was significantly higher in tissues affected by lymphoma than in those unaffected (P<0.0001). Excluding the virus-negative samples, viral load was still significantly higher in tissues affected by lymphoma than in those unaffected (P=0.0004). This is consistent with a potential role of MirGHV3 in oncogenesis in northern elephant seals, although more studies are needed to determine this definitively. The qPCR developed has utility for further investigations of MirGHV3.

The role of LncRNA MCM3AP-AS1 in human cancer

Long noncoding RNAs (lncRNA) play pivotal roles in every level of gene and genome regulation. MCM3AP-AS1 is a lncRNA that has an oncogenic role in several kinds of cancers. Aberrant expression of MCM3AP-AS1 has been reported to be involved in the progression of diverse malignancies, including colorectal, cervical, prostate, lymphoma, lung, ovary, liver, bone, and breast cancers. It is generally believed that MCM3AP-AS1 expression is associated with cancer cell growth, proliferation, angiogenesis, and metastasis. MCM3AP-AS1 by targeting various signaling pathways and microRNAs (miRNAs) presents an important role in cancer pathogenesis. MCM3AP-AS1 as a competitive endogenous RNA has the ability to sponge miRNA, inhibit their expressions, and bind to different target mRNAs related to cancer development. Therefore, MCM3AP-AS1 by targeting several signaling pathways, including the FOX family, Wnt, EGF, and VEGF can be a potent target for cancer prediction and diagnosis. In this review, we will summarize the role of MCM3AP-AS1 in various human cancers.

l-Asparaginase synergizes with etoposide via the PI3K/Akt/mTOR pathway in Epstein-Barr virus-positive Burkitt lymphoma

Burkitt lymphoma (BL) is an aggressive Epstein-Barr virus (EBV)-driven B-cell lymphoma characterized by the translocation and rearrangement of the c-Myc proto-oncogene. High-intensity multidrug chemotherapy regimens have a limited effect on the survival of refractory or relapsed BL patients, mainly owing to the high EBV load and drug resistance. l-asparaginase ( l-Asp) and etoposide (VP-16) play a beneficial role in EBV-related lymphoproliferative diseases; however, their roles and mechanisms in BL remain unclear. In this study, we found that VP-16 inhibited BL cell proliferation and arrested the cell cycle at the G₂ /M phase. It also induced autophagy and activated the extrinsic and intrinsic apoptotic signaling pathways in BL cells. Mechanistically, VP-16 inhibited c-Myc expression and regulated the PI3K/Akt/mTOR signaling pathway. Notably, VP-16 also showed a specific synergistic effect with l-Asp to induce apoptosis in EBV-positive BL cells but not in EBV-negative BL cells. VP-16 combined with l-Asp further inhibited c-Myc expression and downregulated the PI3K/Akt/mTOR signaling pathway. Additionally, we found that VP-16 inhibited the expression of latent membrane protein 1 (LMP1), and in combination with l-Asp further decreased LMP1 expression in Raji cells. Our in vivo data also showed that the dual-drug combination significantly inhibited the growth of BL tumors and prolonged the survival of mice compared to VP-16 alone. In conclusion, this study provides new evidence that l-Asp may enhance the antitumor effect of VP-16 by inhibiting the PI3K/Akt/mTOR signaling pathway in EBV-positive BL cells.

Diffuse large B cell lymphoma and a novel gammaherpesvirus in northern elephant seals Mirounga angustirostris

Two emaciated male northern elephant seal (NES) Mirounga angustirostris pups were admitted to The Marine Mammal Center (Sausalito, California, USA) and treated for malnutrition. Complete blood counts showed a progressive moderate to marked leukocytosis characterized by a predominance of large monomorphic mononuclear cells of probable lymphoid origin, frequently with flower-shaped nuclei. Both seals were euthanized due to suspected lymphoid neoplasia. At necropsy, most lymph nodes in both pups were markedly enlarged, some with distinct white nodules, the spleens were diffusely enlarged, and the intestinal mucosae were thickened. Histopathologic features consistent with disseminated large cell lymphoma were identified to varying degrees of severity in lymph nodes, bone marrow, liver, tonsils, spleen, liver, intestines, kidneys, lower urinary tract, and several other organs. Immunohistochemical staining of neoplastic cells was most consistent with B lymphocyte origin, with most cells staining positively for Pax 5 and CD20 with admixed small CD3-positive T lymphocytes and CD204-positive macrophages. PCR and sequencing identified a novel gammaherpesvirus, herein called miroungine gammaherpesvirus 3, from affected tissues. This virus is in a clade outside of named genera that utilize hosts in the suborder Caniformia. The present study is the first description of diffuse large B cell lymphoma with leukemic manifestation and concomitant detection of a novel gammaherpesvirus in free-living NESs. Further research regarding the prevalence of this new gammaherpesvirus and its associated pathogenesis in this species is indicated.

Chimeric Antigen Receptor-Modified T Cell Immunotherapy for Relapsed and Refractory Adult Burkitt Lymphoma

Patients with Burkitt lymphoma who are refractory to initial therapy or who relapse after undergoing intensive chemotherapy and autologous stem cell transplantation (ASCT) usually have a poor prognosis. While there has been considerable progress in the use of chimeric antigen receptor-modified (CAR) T cell immunotherapy for the treatment of relapsed and refractory (r/r) malignancies, explicit data on adult patients with r/r Burkitt lymphoma are limited. We conducted two single-arm clinical trials to evaluate the clinical efficacy and toxicity of CD19/CD22 CAR T cell immunotherapy both alone (trial A) and in combination with ASCT (trial B) in adult patients with r/r Burkitt lymphoma. In total, 28 adult patients with r/r Burkitt lymphoma were enrolled [trial A (n = 15) and trial B (n = 13)]. The median doses of CD22 and CD19 CAR T cell infusions were 4.1 × 10⁶/kg and 4.0 × 10⁶/kg, respectively. Subsequently, after CAR T cell infusion, overall and complete responses were observed in 19 (67.9%) and 16 (57.1%) patients, respectively. The cumulative incidence rates of grade 2–4 cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome were 39.3% (11/28) and 10.7% (3/28), respectively. After a median follow-up duration of 12.5 months, 16 patients (5 in trial A and 11 in trial B) survived. Both the estimated 1-year progression-free and overall survival rates were 55.6%. Our preliminary results indicated that salvage therapy with CD19/CD22 CAR T cell infusion alone and that in combination with ASCT are effective in treating some adult patients with r/r Burkitt lymphoma.

Primary epidural sporadic Burkitt lymphoma in a 3-year-old: Case report and literature review

Background:

Burkitt lymphoma (BL) is a common tumor of childhood that usually arises in the abdomen or pelvis in its sporadic form. In a minority of cases, BL can present with CNS involvement, usually as a secondary site. Rarely, BL can arise primarily in the epidural space and present with back pain, or less commonly, acute myelopathy. This presentation is a surgical emergency and requires vigilant management.

Case Description:

We describe a case of pediatric BL arising primarily within the epidural space and presenting with progressive difficulty walking in a 3-year-old boy. Progression to complete inability to walk, absent lower extremity deep tendon reflexes, and new urinary incontinence prompted MRI of the spine, which showed a lesion extending from T5 to T10 and wrapping around the anterior and posterior portions of the spine with evidence of spinal cord compression. The patient underwent decompressive laminectomies from T5 to T10 and partial debulking of the posterior portions of the tumor. Microscopic examination showed a prominent “starry sky” pattern with abundant mitotic figures. Immunohistochemistry confirmed the diagnosis of BL. The patient is 10 months post-op and continues to undergo chemotherapy with partial neurologic improvement. He was free of recurrence 10 months post-operative.

Conclusion:

This appears to be the youngest described patient presenting with acute myelopathy in primary paraspinal BL. Management should include surgical decompression of the spinal cord followed by one of the various described chemotherapeutic regimens. Preoperative staging and neurologic function correlate with prognosis.

Histone Modifications and Their Targeting in Lymphoid Malignancies

In a wide range of lymphoid neoplasms, the process of malignant transformation is associated with somatic mutations in B cells that affect the epigenetic machinery. Consequential alterations in histone modifications contribute to disease-specific changes in the transcriptional program. Affected genes commonly play important roles in cell cycle regulation, apoptosis-inducing signal transduction, and DNA damage response, thus facilitating the emergence of malignant traits that impair immune surveillance and favor the emergence of different B-cell lymphoma subtypes. In the last two decades, the field has made a major effort to develop therapies that target these epigenetic alterations. In this review, we discuss which epigenetic alterations occur in B-cell non-Hodgkin lymphoma. Furthermore, we aim to present in a close to comprehensive manner the current state-of-the-art in the preclinical and clinical development of epigenetic drugs. We focus on therapeutic strategies interfering with histone methylation and acetylation as these are most advanced in being deployed from the bench-to-bedside and have the greatest potential to improve the prognosis of lymphoma patients.

Clinical and Therapeutic Implications of Epstein-Barr Virus in HIV-Related Lymphomas

The incidence of lymphomas is increased in people living with HIV (PLWH). Aggressive B-cell non-Hodgkin lymphomas (NHLs) are the most common and are considered an AIDS-defining cancer (ADC). Although Hodgkin lymphoma (HL) is not considered an ADC, its incidence is also increased in PLWH. Among all HIV-related lymphomas (HRL), the prevalence of Epstein-Barr virus (EBV) is high. It has been shown that EBV is involved in different lymphomagenic mechanisms mediated by some of its proteins, contributing to the development of different lymphoma subtypes. Additionally, cooperation between both HIV and EBV can lead to the proliferation of aberrant B-cells, thereby being an additional lymphomagenic mechanism in EBV-associated HRL. Despite the close relationship between EBV and HRL, the impact of EBV on clinical aspects has not been extensively studied. These lymphomas are treated with the same therapeutic regimens as the general population in combination with cART. Nevertheless, new therapeutic strategies targeting EBV are promising for these lymphomas. In this article, the different types of HRL are extensively reviewed, focusing on the influence of EBV on the epidemiology, pathogenesis, clinical presentation, and pathological characteristics of each lymphoma subtype. Moreover, novel therapies targeting EBV and future strategies to treat HRL harboring EBV are discussed.

Tomentosin a Sesquiterpene Lactone Induces Antiproliferative and Proapoptotic Effects in Human Burkitt Lymphoma by Deregulation of Anti- and Pro-Apoptotic Genes

(1) Tomentosin is the most representative sesquiterpene lactone extracted by I. viscosa. Recently, it has gained particular attention in therapeutic oncologic fields due to its anti-tumor properties. (2) In this study, the potential anticancer features of tomentosin were evaluated on human Burkitt’s lymphoma (BL) cell line, treated with increasing tomentosin concentration for cytotoxicity screening. (3) Our data showed that both cell cycle arrest and cell apoptosis induction are responsible of the antiproliferative effects of tomentosin and may end in the inhibition of BL cell viability. Moreover, a microarray gene expression profile was performed to assess differentially expressed genes contributing to tomentosin activity. Seventy-five genes deregulated by tomentosin have been identified. Downregulated genes are enriched in immune-system pathways, and PI3K/AKT and JAK/STAT pathways which favor proliferation and growth processes. Importantly, different deregulated genes identified in tomentosin-treated BL cells are prevalent in molecular pathways known to lead to cellular death, specifically by apoptosis. Tomentosin-treatment in BL cells induces the downregulation of antiapoptotic genes such as BCL2A1 and CDKN1A and upregulation of the proapoptotic PMAIP1 gene. (4) Overall, our results suggest that tomentosin could be taken into consideration as a potential natural product with limited toxicity and relevant anti-tumoral activity in the therapeutic options available to BL patients.

Metabolic Switch and Cytotoxic Effect of Metformin on Burkitt Lymphoma

Altered cellular energetic metabolism has recently emerged as important feature of neoplastic cells. Indeed, interfering with cancer cell metabolism might represent a suitable therapeutic strategy. In this study, we aimed to assess glucose metabolism activation in human lymphomas and evaluate how metformin can exert its action on lymphoma cells. We studied a large series of human lymphomas (N = 252) and an in vitro model of Burkitt lymphoma (BL) cells. We combined molecular biology techniques, including global gene expression profiling (GEP) analysis, quantitative PCR (qPCR) and Western blotting, and biochemical assays, aimed to assess pentose phosphate pathway, tricarboxylic acid (TCA) cycle, and aerobic glycolysis rates. We found that glucose metabolism is overall enhanced in most lymphoma subtypes, based on gene expression profiling (GEP), with general shift to aerobic glycolysis. By contrast, normal B cells only showed an overall increase in glucose usage during germinal center transition. Interestingly, not only highly proliferating aggressive lymphomas but also indolent ones, like marginal zone lymphomas, showed the phenomenon. Consistently, genes involved in glycolysis were confirmed to be overexpressed in BL cells by qPCR. Biochemical assays showed that while aerobic glycolysis is increased, TCA cycle is reduced. Finally, we showed that metformin can induce cell death in BL cells by stressing cellular metabolism through the induction of GLUT1, PKM2, and LDHA. In conclusion, we unveiled glucose metabolism abnormalities in human lymphomas and characterized the mechanism of action of metformin in Burkitt lymphoma model.

The Role of Non-Coding RNAs in the Regulation of the Proto-Oncogene MYC in Different Types of Cancer

Alterations in the expression level of the MYC gene are often found in the cells of various malignant tumors. Overexpressed MYC has been shown to stimulate the main processes of oncogenesis: uncontrolled growth, unlimited cell divisions, avoidance of apoptosis and immune response, changes in cellular metabolism, genomic instability, metastasis, and angiogenesis. Thus, controlling the expression of MYC is considered as an approach for targeted cancer treatment. Since c-Myc is also a crucial regulator of many cellular processes in healthy cells, it is necessary to find ways for selective regulation of MYC expression in tumor cells. Many recent studies have demonstrated that non-coding RNAs play an important role in the regulation of the transcription and translation of this gene and some RNAs directly interact with the c-Myc protein, affecting its stability. In this review, we summarize current data on the regulation of MYC by various non-coding RNAs that can potentially be targeted in specific tumor types.

Molecular Update and Evolving Classification of Large B-Cell Lymphoma

Simple Summary

The development of high-throughput technologies in recent years has increased our understanding of the molecular complexity of lymphomas, providing new insights into the pathogenesis of large B-cell neoplasms and identifying different molecular biomarkers with prognostic impact, that lead to the revision of the World Health Organization consensus classification of lymphomas. This review addresses the main histopathological and molecular features of large B-cells lymphomas, providing an overview of the main recent novelties introduced by the last update of the consensus classification.

Abstract

Diffuse large B-cell lymphomas (DLBCLs) are aggressive B-cell neoplasms with considerable clinical, biologic, and pathologic diversity. The application of high throughput technologies to the study of lymphomas has yielded abundant molecular data leading to the identification of distinct molecular identities and novel pathogenetic pathways. In light of this new information, newly refined diagnostic criteria have been established in the fourth edition of the World Health Organization (WHO) consensus classification of lymphomas, which was revised in 2016. This article reviews the histopathological and molecular features of the various aggressive B-cell lymphoma subtypes included in the updated classification.

Mandibular sporadic Burkitt lymphoma in an adult patient: A case report and review of the literature

Only a minor percent of lymphomas arise in the oral cavity. Although rare, dentists and clinicians should not neglect them as a possible consideration in the differential diagnosis of oral lesions.

Interplay between Epstein-Barr virus infection and environmental xenobiotic exposure in cancer

Epstein-Barr virus (EBV) is a herpesvirus associated with lymphoid and epithelial malignancies. Both B cells and epithelial cells are susceptible and permissive to EBV infection. However, considering that 90% of the human population is persistently EBV-infected, with a minority of them developing cancer, additional factors are necessary for tumor development. Xenobiotics such as tobacco smoke (TS) components, pollutants, pesticides, and food chemicals have been suggested as cofactors involved in EBV-associated cancers. In this review, the suggested mechanisms by which xenobiotics cooperate with EBV for carcinogenesis are discussed. Additionally, a model is proposed in which xenobiotics, which promote oxidative stress (OS) and DNA damage, regulate EBV replication, promoting either the maintenance of viral genomes or lytic activation, ultimately leading to cancer. Interactions between EBV and xenobiotics represent an opportunity to identify mechanisms by which this virus is involved in carcinogenesis and may, in turn, suggest both prevention and control strategies for EBV-associated cancers.

Post-transplant lymphoproliferative disorder after paediatric liver transplantation

OBJECTIVE

The purpose of this study was to analyse the clinical and pathological characteristics, treatments and outcomes of post-transplant lymphoproliferative disorder (PTLD) in paediatric liver transplant recipients.

METHOD

A retrospective analysis of records from nine paediatric liver transplant recipients with PTLD who were treated at our Liver Transplant Center over the period from June 2013 to August 2018.

RESULT

Of these nine patients, seven received liver transplantation in our centre and the remaining two patients at other hospitals. The overall incidence of PTLD in paediatric liver transplant recipients in our centre was 1.4% (7/485). The median onset of PTLD after liver transplantation was 11 months. Three cases were classified as infectious mononucleosis PTLD, one case was plasmacytic hyperplasia PTLD, one case was polymorphic PTLD and two cases were Burkitt lymphoma. One case showed diffuse large B-cell lymphoma and one was classical Hodgkin lymphoma-like PTLD. These patients presented with different clinical manifestations including fever, anaemia, diarrhoea, hypoproteinaemia, enlargement of lymph nodes, hepatosplenomegaly, jaundice, bowel obstruction and even intestinal perforation. Nine patients were positive for EBV-DNA in serum. After diagnosis, immunosuppressants were reduced or discontinued in all cases. Eight patients received anti-CD20 monoclonal antibody (Rituximab) therapy, four cases were treated with a combination of chemotherapy (R-CHOP, ABVD, COPP/ABV) and one case was combined with radiotherapy. Two cases received surgical treatment due to bowel obstruction. Eight of these patients achieved a complete remission and remained healthy when assessed at the time of final follow-up. One patient died as a result of PTLD progression.

CONCLUSION

PTLD is one of the most serious and fatal complications after liver transplantation. The definitive diagnosis requires histopathology. Treatment varies and basically includes immunosuppression reduction, anti-CD20 antibody, surgery, radiotherapy and chemotherapy.

Karonudib has potent anti-tumor effects in preclinical models of B-cell lymphoma

Chemo-immunotherapy has improved survival in B-cell lymphoma patients, but refractory/relapsed diseases still represent a major challenge, urging for development of new therapeutics. Karonudib (TH1579) was developed to inhibit MTH1, an enzyme preventing oxidized dNTP-incorporation in DNA. MTH1 is highly upregulated in tumor biopsies from patients with diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma, hence confirming a rationale for targeting MTH1. Here, we tested the efficacy of karonudib in vitro and in preclinical B-cell lymphoma models. Using a range of B-cell lymphoma cell lines, karonudib strongly reduced viability at concentrations well tolerated by activated normal B cells. In B-cell lymphoma cells, karonudib increased incorporation of 8-oxo-dGTP into DNA, and prominently induced prometaphase arrest and apoptosis due to failure in spindle assembly. MTH1 knockout cell lines were less sensitive to karonudib-induced apoptosis, but were displaying cell cycle arrest phenotype similar to the wild type cells, indicating a dual inhibitory role of the drug. Karonudib was highly potent as single agent in two different lymphoma xenograft models, including an ABC DLBCL patient derived xenograft, leading to prolonged survival and fully controlled tumor growth. Together, our preclinical findings provide a rationale for further clinical testing of karonudib in B-cell lymphoma.

Hematologic malignancies of the gastrointestinal luminal tract

Hematologic malignancies include several lymphoproliferative and myeloproliferative disorders, many of which are frequently encountered in current health care settings. These malignancies frequently affect the gastrointestinal (GI) tract, either by secondary extranodal or extramedullary extension to the GI tract, or as a primary process arising in the GI tract. In fact, the GI tract may represent the most common extranodal site of involvement in many of them, such as lymphoma. Furthermore, in the current era of improved cancer treatment and advanced transplant procedures with increased survival, it has been quite common to encounter GI involvement by these malignancies through the disease course. Post-transplant lymphoproliferative disorder following kidney transplantation, for example, very commonly involves the GI tract. Other conditions that can involve the GI tract include multiple myeloma, plasmacytoma, myeloid sarcoma, mastocytosis, and Castleman disease. Imaging diagnosis of these malignancies can be challenging, since they are much less common than primary GI cancers and both share many common imaging features as well. However, certain imaging features, particularly in combination with a matching clinical scenario, play a pivotal role in diagnosing these conditions and directing further evaluation. In this article, we review common and rare hematologic malignancies of the GI tract and discuss their pathophysiologic, clinical, and imaging features.

Mandibular non-Hodgkin's lymphoma: two observations of a challenging disease

Lymphomas are a heterogeneous group of malignant tumours of the haematopoietic system characterized by an aberrant proliferation of mature lymphoid cells or their precursors and mainly represented by non-Hodgkin´s lymphomas (NHL). The aim of this paper was to report two cases of NHLs with mandibular locations by detailing their different clinical, radiological, and histopathological aspects, as well as the approach followed to diagnose these diseases and to provide patients with the appropriate therapeutic management. The first case is about a 72-year-old female patient who was diagnosed with a large B-cell lymphoma while the second one concerns a 16-year-old male patient who was diagnosed with a Burkitt’s lymphoma. These observations represent the two highly aggressive known NHLs according to the WHO classification. The mandibular locations of these diseases are rare and represent only 0.6% of all the reported cases. It is important to note that only a deep and good quality tumour biopsy can provide a diagnosis of certainty. The reference treatment is medical consisting in the introduction of chemo-immunotherapy. As oral surgeons, we have an important role in the early diagnosis of these malignancies and in the patient’s referral to specialized care in order to get the appropriate treatment.

Recurrent small bowel obstruction caused by Burkitt lymphoma in an elderly man: a case report and review of the literature

BACKGROUND

Acute small bowel obstruction is a common surgical emergency usually caused by abdominal adhesions, followed by intraluminal tumors from metastatic disease. Although lymphomas have been known to cause bowel obstruction, Burkitt lymphoma is seldom reported to induce an obstruction in the adult population.

CASE PRESENTATION

A 78-year-old Hispanic man with a history of abdominal interventions presented to our hospital with abdominal pain. Computed tomography revealed a partial small bowel obstruction attributed to local inflammation or adhesions. Medical management with bowel rest and nasogastric decompression resulted in resolution of symptoms and quick discharge. He returned 2 days later with worsening abdominal pain. Repeat imaging showed progression of the partial small bowel obstruction, but with an additional 1.6-cm nodular density abutting the anterior aspect of the gastric antrum and lobulated anterior gastric antral wall thickening. He was taken to the operating room, where several masses were found. Intraoperative frozen sections were consistent with lymphoma, and pathology later revealed Burkitt lymphoma. Disease was found on both sides of the diaphragm by positron emission tomography. After the initial resection and adjuvant chemotherapy, the patient is alive and well about 14 months after resection.

CONCLUSIONS

Small bowel obstruction is uncommonly due to Burkitt lymphoma in the geriatric population and is more frequently seen in the pediatric and young adult populations. Burkitt lymphoma is very aggressive with rapid cell turnover leading to significant morbidity. The rapid recurrence of an acute abdominal process should prompt an investigation for a more sinister cause such as malignancy.

Lymphotropic Viruses EBV, KSHV and HTLV in Latin America: Epidemiology and Associated Malignancies. A Literature-Based Study by the RIAL-CYTED

The Epstein-Barr virus (EBV), Kaposi sarcoma herpesvirus (KSHV) and human T-lymphotropic virus (HTLV-1) are lymphomagenic viruses with region-specific induced morbidity. The RIAL-CYTED aims to increase the knowledge of lymphoma in Latin America (LA), and, as such, we systematically analyzed the literature to better understand our risk for virus-induced lymphoma. We observed that high endemicity regions for certain lymphomas, e.g., Mexico and Peru, have a high incidence of EBV-positive lymphomas of T/NK cell origin. Peru also carries the highest frequency of EBV-positive classical Hodgkin lymphoma (HL) and EBV-positive diffuse large B cell lymphoma, not otherwise specified (NOS), than any other LA country. Adult T cell lymphoma is endemic to the North of Brazil and Chile. While only few cases of KSHV-positive lymphomas were found, in spite of the close correlation of Kaposi sarcoma and the prevalence of pathogenic types of KSHV. Both EBV-associated HL and Burkitt lymphoma mainly affect young children, unlike in developed countries, in which adolescents and young adults are the most affected, correlating with an early EBV seroconversion for LA population despite of lack of infectious mononucleosis symptoms. High endemicity of KSHV and HTLV infection was observed among Amerindian populations, with differences between Amazonian and Andean populations.

Pediatric Aggressive Mature B-Cell Lymphomas, Version 2.2020, NCCN Clinical Practice Guidelines in Oncology

Pediatric aggressive mature B-cell lymphomas are the most common types of non-Hodgkin lymphoma in children, and they include Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL). These diseases are highly aggressive but curable, the treatment is complex, and patients may have many complicated supportive care issues. The NCCN Guidelines for Pediatric Aggressive Mature B-Cell Lymphomas provide guidance regarding pathology and diagnosis, staging, initial treatment, disease reassessment, surveillance, therapy for relapsed/refractory disease, and supportive care for clinicians who treat sporadic pediatric BL and DLBCL.

Bilateral serous retinal detachments associated with burkitt lymphoma

Purpose

To report a case of bilateral serous retinal detachments in a patient found to have burkitt lymphoma.

Observations

A patient who presented with bilateral serous retinal detachments and “B” symptoms underwent extensive workup and was found to have burkitt lymphoma. Multiagent chemotherapy was initiated with resolution of the serous retinal detachments and visual recovery occurring in parallel to disease remission.

Conclusions and Importance

Burkitt lymphoma can present with serous retinal detachments and should be included in the differential for a patient with bilateral serous retinal detachments along with Vogt-Koyanagi-Harada syndrome.

Burkitt and Burkitt-Like Lymphomas: a Systematic Review

PURPOSE OF REVIEW

Burkitt's lymphoma and its leukemic form (Burkitt cell acute lymphoblastic leukemia) are a highly aggressive disease. We review the classification, clinical presentation, histology, cytogenetics, and the treatment of the disease.

RECENT FINDINGS

Burkitt's lymphoma might be associated with tumor lysis syndrome which is a potentially fatal complication that occurs spontaneously or upon initiation of chemotherapy. Major improvements were made in the treatment of pediatric and adults population using short-course dose-intensive chemotherapy regimens, usually 1 week after a prephase induction. Addition of Rituximab to chemotherapy has become a standard of care. Relapsed/refractory disease has a very poor prognosis and the benefit from autologous/allogeneic hematopoietic stem cell transplant remains uncertain. Rituximab-based short-course dose-intensive chemotherapy is the standard of care of Burkitt's lymphoma even in the immunodeficiency-related form.

Virus-associated human cancers in Moroccan population: From epidemiology to prospective research

Eight human viruses have been classified by the International Agency for Research on Cancer as carcinogenic or probably carcinogenic for humans. Infection with high risk human papillomaviruses, hepatitis B and C viruses, Epstein-Barr virus (EBV), human T-Cell Lymphotropic Virus Type 1 (HTLV-1), Human herpesvirus 8 (HHV-8), Merkel cell polyomavirus and human immunodeficiency virus-1 (HIV1) alone or in combination with other agents are the main etiologic factors of many cancers. This review highlights some aspects of virus-associated human cancers, potentially responsible for >14,000 malignancies per year in Morocco. Given that not all individuals infected with these viruses develop cancer, somatic alterations, genetic predisposition, and lifestyle or environmental factors obviously play potentializing roles modulating viral activity. These viral, host genetic signatures and lifestyle interactions may represent a reservoir of biomarkers for early detection, prevention of cancer and rationale-based therapy.

Oligonucleotide Binding to Non-B-DNA in MYC

MYC, originally named c-myc, is an oncogene deregulated in many different forms of cancer. Translocation of the MYC gene to an immunoglobulin gene leads to an overexpression and the development of Burkitt's lymphoma (BL). Sporadic BL constitutes one subgroup where one of the translocation sites is located at the 5'-vicinity of the two major MYC promoters P₁ and P₂. A non-B-DNA forming sequence within this region has been reported with the ability to form an intramolecular triplex (H-DNA) or a G-quadruplex. We have examined triplex formation at this site first by using a 17 bp triplex-forming oligonucleotide (TFO) and a double strand DNA (dsDNA) target corresponding to the MYC sequence. An antiparallel purine-motif triplex was detected using electrophoretic mobility shift assay. Furthermore, we probed for H-DNA formation using the BQQ-OP based triplex-specific cleavage assay, which indicated the formation of the structure in the supercoiled plasmid containing the corresponding region of the MYC promoter. Targeting non-B-DNA structures has therapeutic potential; therefore, we investigated their influence on strand-invasion of anti-gene oligonucleotides (ON)s. We show that in vitro, non-B-DNA formation at the vicinity of the ON target site facilitates dsDNA strand-invasion of the anti-gene ONs.