Burkitt lymphoma/leukemia: improving prognosis

Acute lymphoblastic leukaemia

Acute lymphoblastic leukaemia (ALL) is a haematological malignancy characterized by the uncontrolled proliferation of immature lymphoid cells. Over past decades, significant progress has been made in understanding the biology of ALL, resulting in remarkable improvements in its diagnosis, treatment and monitoring. Since the advent of chemotherapy, ALL has been the platform to test for innovative approaches applicable to cancer in general. For example, the advent of omics medicine has led to a deeper understanding of the molecular and genetic features that underpin ALL. Innovations in genomic profiling techniques have identified specific genetic alterations and mutations that drive ALL, inspiring new therapies. Targeted agents, such as tyrosine kinase inhibitors and immunotherapies, have shown promising results in subgroups of patients while minimizing adverse effects. Furthermore, the development of chimeric antigen receptor T cell therapy represents a breakthrough in ALL treatment, resulting in remarkable responses and potential long-term remissions. Advances are not limited to treatment modalities alone. Measurable residual disease monitoring and ex vivo drug response profiling screening have provided earlier detection of disease relapse and identification of exceptional responders, enabling clinicians to adjust treatment strategies for individual patients. Decades of supportive and prophylactic care have improved the management of treatment-related complications, enhancing the quality of life for patients with ALL.

BURKITT LYMPHOMA IN GASTROINTESTINAL TRACT: A REPORT OF TWO CASES

Burkitt lymphoma, a type of non-Hodgkin B-cell lymphoma, is the fastest growing human cancer, presenting pathologically with a ‘starry sky’ pattern. It is most often found in the abdomen and the jaw, however, localization in the abdomen other than the ileocecal area is very rare and described only in a handful of cases. Standard treatment consists of initial tumor cytoreduction followed by intense chemotherapy. Most of the relapses occur within one year of the diagnosis, while the 5-year survival is around 80%. We present two cases which are specific for unusual location of Burkitt lymphoma in the colon and stomach, in immunocompetent patients with negative Epstein-Barr virus tests. Also, one of the patients presented is one of the oldest ever reported with abdominal Burkitt lymphoma, while the other patient is an example of diagnostic difficulties in distinguishing Burkitt lymphoma from similar lymphomas. Due to the rapidly growing tumors and urgent need for cytoreductive surgery, it is crucial to consider the diagnosis of Burkitt lymphoma even in atypical localizations or absence of the common risk factors associated with Burkitt lymphoma.

Growth-inhibition of cell lines derived from B cell lymphomas through antagonism of serotonin receptor signaling

A majority of lymphomas are derived from B cells and novel treatments are required to treat refractory disease. Neurotransmitters such as serotonin and dopamine influence activation of B cells and the effects of a selective serotonin 1A receptor (5HT1A) antagonist on growth of a number of B cell-derived lymphoma cell lines were investigated. We confirmed the expression of 5HT1A in human lymphoma tissue and in several well-defined experimental cell lines. We discovered that the pharmacological inhibition of 5HT1A led to the reduced proliferation of B cell-derived lymphoma cell lines together with DNA damage, ROS-independent caspase activation and apoptosis in a large fraction of cells. Residual live cells were found ‘locked’ in a non-proliferative state in which a selective transcriptional and translational shutdown of genes important for cell proliferation and metabolism occurred (e.g., AKT, GSK-3β, cMYC and p53). Strikingly, inhibition of 5HT1A regulated mitochondrial activity through a rapid reduction of mitochondrial membrane potential and reducing dehydrogenase activity. Collectively, our data suggest 5HT1A antagonism as a novel adjuvant to established cancer treatment regimens to further inhibit lymphoma growth.

Bortezomib inhibits Burkitt's lymphoma cell proliferation by downregulating sumoylated hnRNP K and c-Myc expression

Bortezomib (Velcal) was the first proteasome inhibitor to be approved by the US Food and Drug Administration to treat patients with relapsed/refractory multiple myelomas. Previous studies have demonstrated that bortezomib inhibits tumor cell proliferation and induces apoptosis by blocking the nuclear factor (NF)-κB pathway. However, the exact mechanism by which bortezomib induces cancer cell apoptosis is still not well understood. In this study, we found that bortezomib significantly inhibited cell proliferation in both human Burkitt's lymphoma CA46 and Daudi cells. Through proteomic analysis, we found that bortezomib treatment changed the expression of various proteins in distinct functional categories including unfolding protein response (UPS), RNA processing, protein targeting and biosynthesis, apoptosis, and signal transduction. Among the proteins with altered expression, hnRNP K, hnRNP H, Hsp90α, Grp78, and Hsp7C were common to both Daudi and CA46 cells. Interestingly, bortezomib treatment downregulated the expression of high-molecular-weight (HMw) hnRNP K and c-Myc but upregulated the expression of low-molecular-weight (LMw) hnRNP K. Moreover, cell proliferation was significantly correlated with high expression of HMw hnRNP K and c-Myc. HMw and LMw hnRNP K were identified as sumoylated and desumoylated hnRNP K, respectively. Using transient transfection, we found that sumoylated hnRNP K increased c-Myc expression at the translational level and contributed to cell proliferation, and that Lys422 of hnRNP K is the candidate sumoylated residue. Our results suggest that besides inhibiting the ubiquitin-proteasome pathway, bortezomib may inhibit cell proliferation by downregulating sumoylated hnRNP K and c-Myc expression in Burkitt's lymphoma cells.

Pediatric non-Hodgkin lymphoma: a retrospective 14-year experience with Berlin-Frankfurt-Münster (BFM) protocols from a tertiary care hospital in Serbia

Use of current intensive chemotherapy protocols in pediatric non-Hodgkin lymphoma (NHL) in high-income countries resulted in event-free survival (EFS) rates ranging from 80 to 90%. The results are inferior in less privileged countries with limited resources for medical care. There are no reports about comprehensive data analysis in pediatric NHL in Serbia. A retrospective study was carried out at University Children's Hospital, Belgrade, in children aged less than 18 years diagnosed with non-Hodgkin lymphoma from 1997 to 2011. Fifty-seven children were eligible for analysis. Fourteen were diagnosed with lymphoblastic lymphoma, 38 with mature B-cell NHL (B-NHL), and 5 with anaplastic large-cell lymphoma. Mean age at diagnosis was 9.2 years, with male to female ratio 2.35:1. Children were treated according to Berlin-Frankfurt-Münster (BFM) protocols. With median follow-up of 59.3 months, 5-year probability of EFS was 84.1% for all patients, whereas overall survival was 93%. These results with BFM protocol administration, although inferior to leading international groups, reflect good treatment outcome in our patients. To the best of the authors' knowledge, this article presents the first results regarding treatment and survival of childhood NHL in Serbia.

Expression of JL1 in Burkitt lymphoma is associated with improved overall survival

JL1 is a novel molecule expressed in the surface of hematopoietic precursor cells, but not on any other mature human tissue. Accordingly, JL1 is expressed in acute lymphoblastic leukemia (ALL) cells and can be used both for specific diagnosis and as a target for treatment. However, expression of JL1 by lymphomas has not been thoroughly assessed. Burkitt lymphoma is a potentially curable aggressive lymphoma, but prognostic markers that stratify risk have not been established. We therefore assayed JL1 expression in Burkitt lymphoma patients to assess its value as a prognostic marker for this disease. Tissue microarray blocks of formalin-fixed paraffin-embedded tissue samples from patients with Burkitt lymphoma and other B-cell lymphomas, at the Asan Medical Center and Seoul National University Hospital from January 1998 to December 2008 were immunohistochemically assayed using a mouse monoclonal antibody against JL1. We found that 30.2% of Burkitt lymphoma samples, but no other lymphoma samples, were positive for JL1. JL-1 expression was significantly correlated with patient survival (P = 0.022), but not with other clinical manifestations of the disease, with 91.6% of JL1-positive patients achieving complete remission in response to chemotherapy and 6.25% experiencing disease recurrence. JL1 positivity was significantly correlated with prolonged overall survival by both Kaplan-Meier survival (P = 0.035) and Cox proportional hazard model (P = 0.043) analysis. JL1 expression in Burkitt lymphoma was positively correlated with overall survival and better response to chemotherapy, suggesting that JL1 may be a prognostic marker for risk stratification in these patients.

HLA antigen and NK cell activating ligand expression in malignant cells: a story of loss or acquisition

Malignant transformation of cells is often associated with changes in classical and non-classical HLA class I antigen, HLA class II antigen as well as NK cell activating ligand (NKCAL) expression. These changes are believed to play a role in the clinical course of the disease since these molecules are critical to the interactions between tumor cells and components of both innate and adaptive immune system. For some time, it has been assumed that alterations in the expression profile of HLA antigens and NKCAL on malignant cells represented loss of classical HLA class I antigen and induction of HLA class II antigen, non-classical HLA class I antigen and/or NKCAL expression. In contrast to these assumptions, experimental evidence suggests that in some cases dysplastic and malignant cells can acquire classical HLA class I antigen expression and/or lose the ability to express HLA class II antigens. In light of the latter findings as well as of the revival of the cancer immune surveillance theory, a reevaluation of the interpretation of changes in HLA antigen and NKCAL expression in malignant lesions is warranted. In this article, we first briefly describe the conventional types of changes in HLA antigen and NKCAL expression that have been identified in malignant cells to date. Second, we discuss the evidence indicating that, in at least some cell types, classical HLA class I antigen expression can be acquired and/or the ability to express HLA class II antigens is lost. Third, we review the available evidence for the role of immune selective pressure in the generation of malignant lesions with changes in HLA antigen expression. This information contributes to our understanding of the role of the immune system in the control of tumor development and to the optimization of the design of immunotherapeutic strategies for the treatment of cancer.

Burkitt lymphoma and atypical Burkitt or Burkitt-like lymphoma: should these be treated as different diseases?

Burkitt lymphoma (BL) is a mature B-cell non-Hodgkin lymphoma with an aggressive clinical course. Since the advent of short, intensive, multiagent chemoimmunotherapy regimens, it has carried a favorable prognosis. BL has been rather well characterized, whereas the other lymphomas morphologically resembling it are more heterogeneous. The cases classified as atypical BL/Burkitt-like lymphoma by the 2001 World Health Organization (WHO) Classification of Tumors of Hematopoietic and Lymphoid Tissue were thought to represent a continuum between BL and diffuse large B-cell lymphoma (DLBCL). The optimal therapeutic strategy for this provisional entity was not definitively established. However, recent incorporation of molecular genetic data into the 2008 WHO Classification has allowed further refinements with significant therapeutic implications, including the designation of a new provisional entity, "B-cell lymphoma, unclassifiable, with features intermediate between BL and DLBCL." This review presents a comprehensive overview of the previously designated provisional entity of atypical BL/BLL in conjunction with a detailed comparison with BL and DLBCL.

Burkitt's lymphoma mimicking EBV disease as first sign of vertical HIV infection in an adolescent

Burkitt's Lymphoma (BL) rarely represents the first clinical manifestation of vertical HIV infection in adolescent in Western Europe. We report the case of a 17 year-old boy with two week history of fever and enlarged cervical lymph nodes firstly misdiagnosed as EBV infection, subsequently diagnosed as Burkitt's Lymphoma and vertical HIV infection.