Burkitt Lymphoma: A form of undifferentiated malignant LYMPHOMA usually found in central Africa, but also reported in other parts of the world. It is commonly manifested as a large osteolytic lesion in the jaw or as an abdominal mass. B-cell antigens are expressed on the immature cells that make up the tumor in virtually all cases of Burkitt lymphoma. The Epstein-Barr virus (HERPESVIRUS 4, HUMAN) has been isolated from Burkitt lymphoma cases in Africa and it is implicated as the causative agent in these cases; however, most non-African cases are EBV-negative.Lymphoma: A general term for various neoplastic diseases of the lymphoid tissue.Lymphoma, B-Cell: A group of heterogeneous lymphoid tumors generally expressing one or more B-cell antigens or representing malignant transformations of B-lymphocytes.Lymphoma, Non-Hodgkin: Any of a group of malignant tumors of lymphoid tissue that differ from HODGKIN DISEASE, being more heterogeneous with respect to malignant cell lineage, clinical course, prognosis, and therapy. The only common feature among these tumors is the absence of giant REED-STERNBERG CELLS, a characteristic of Hodgkin's disease.Lymphoma, Large B-Cell, Diffuse: Malignant lymphoma composed of large B lymphoid cells whose nuclear size can exceed normal macrophage nuclei, or more than twice the size of a normal lymphocyte. The pattern is predominantly diffuse. Most of these lymphomas represent the malignant counterpart of B-lymphocytes at midstage in the process of differentiation.Lymphoma, T-Cell: A group of heterogeneous lymphoid tumors representing malignant transformations of T-lymphocytes.Herpesvirus 4, Human: The type species of LYMPHOCRYPTOVIRUS, subfamily GAMMAHERPESVIRINAE, infecting B-cells in humans. It is thought to be the causative agent of INFECTIOUS MONONUCLEOSIS and is strongly associated with oral hairy leukoplakia (LEUKOPLAKIA, HAIRY;), BURKITT LYMPHOMA; and other malignancies.Lymphoma, Follicular: Malignant lymphoma in which the lymphomatous cells are clustered into identifiable nodules within the LYMPH NODES. The nodules resemble to some extent the GERMINAL CENTER of lymph node follicles and most likely represent neoplastic proliferation of lymph node-derived follicular center B-LYMPHOCYTES.Lymphoma, AIDS-Related: B-cell lymphoid tumors that occur in association with AIDS. Patients often present with an advanced stage of disease and highly malignant subtypes including BURKITT LYMPHOMA; IMMUNOBLASTIC LARGE-CELL LYMPHOMA; PRIMARY EFFUSION LYMPHOMA; and DIFFUSE, LARGE B-CELL, LYMPHOMA. The tumors are often disseminated in unusual extranodal sites and chromosomal abnormalities are frequently present. It is likely that polyclonal B-cell lymphoproliferation in AIDS is a complex result of EBV infection, HIV antigenic stimulation, and T-cell-dependent HIV activation.Translocation, Genetic: A type of chromosome aberration characterized by CHROMOSOME BREAKAGE and transfer of the broken-off portion to another location, often to a different chromosome.Chromosomes, Human, 6-12 and X: The medium-sized, submetacentric human chromosomes, called group C in the human chromosome classification. This group consists of chromosome pairs 6, 7, 8, 9, 10, 11, and 12 and the X chromosome.Lymphoma, B-Cell, Marginal Zone: Extranodal lymphoma of lymphoid tissue associated with mucosa that is in contact with exogenous antigens. Many of the sites of these lymphomas, such as the stomach, salivary gland, and thyroid, are normally devoid of lymphoid tissue. They acquire mucosa-associated lymphoid tissue (MALT) type as a result of an immunologically mediated disorder.Epstein-Barr Virus Nuclear Antigens: Nuclear antigens encoded by VIRAL GENES found in HUMAN HERPESVIRUS 4. At least six nuclear antigens have been identified.Chromosomes, Human, 13-15: The medium-sized, acrocentric human chromosomes, called group D in the human chromosome classification. This group consists of chromosome pairs 13, 14, and 15.Glutamate Formimidoyltransferase: A PYRIDOXAL PHOSPHATE-containing enzyme that catalyzes the transfer of a formyl group from L-GLUTAMATE to N-formimidoyl-L-glutamate and TETRAHYDROFOLATE. This enzyme may also catalyze formyl transfer from 5-formyltetrahydrofolate to L-GLUTAMATE. This enzyme was formerly categorized as EC 2.1.2.6.Genes, myc: Family of retrovirus-associated DNA sequences (myc) originally isolated from an avian myelocytomatosis virus. The proto-oncogene myc (c-myc) codes for a nuclear protein which is involved in nucleic acid metabolism and in mediating the cellular response to growth factors. Truncation of the first exon, which appears to regulate c-myc expression, is crucial for tumorigenicity. The human c-myc gene is located at 8q24 on the long arm of chromosome 8.Proto-Oncogene Proteins c-myc: Cellular DNA-binding proteins encoded by the c-myc genes. They are normally involved in nucleic acid metabolism and in mediating the cellular response to growth factors. Elevated and deregulated (constitutive) expression of c-myc proteins can cause tumorigenesis.B-Lymphocytes: Lymphoid cells concerned with humoral immunity. They are short-lived cells resembling bursa-derived lymphocytes of birds in their production of immunoglobulin upon appropriate stimulation.Epstein-Barr Virus Infections: Infection with human herpesvirus 4 (HERPESVIRUS 4, HUMAN); which may facilitate the development of various lymphoproliferative disorders. These include BURKITT LYMPHOMA (African type), INFECTIOUS MONONUCLEOSIS, and oral hairy leukoplakia (LEUKOPLAKIA, HAIRY).Lymphoma, Mantle-Cell: A form of non-Hodgkin lymphoma having a usually diffuse pattern with both small and medium lymphocytes and small cleaved cells. It accounts for about 5% of adult non-Hodgkin lymphomas in the United States and Europe. The majority of mantle-cell lymphomas are associated with a t(11;14) translocation resulting in overexpression of the CYCLIN D1 gene (GENES, BCL-1).Lymphoma, T-Cell, Cutaneous: A group of lymphomas exhibiting clonal expansion of malignant T-lymphocytes arrested at varying stages of differentiation as well as malignant infiltration of the skin. MYCOSIS FUNGOIDES; SEZARY SYNDROME; LYMPHOMATOID PAPULOSIS; and PRIMARY CUTANEOUS ANAPLASTIC LARGE CELL LYMPHOMA are the best characterized of these disorders.Hodgkin Disease: A malignant disease characterized by progressive enlargement of the lymph nodes, spleen, and general lymphoid tissue. In the classical variant, giant usually multinucleate Hodgkin's and REED-STERNBERG CELLS are present; in the nodular lymphocyte predominant variant, lymphocytic and histiocytic cells are seen.Lymphoma, T-Cell, Peripheral: A group of malignant lymphomas thought to derive from peripheral T-lymphocytes in lymph nodes and other nonlymphoid sites. They include a broad spectrum of lymphocyte morphology, but in all instances express T-cell markers admixed with epithelioid histiocytes, plasma cells, and eosinophils. Although markedly similar to large-cell immunoblastic lymphoma (LYMPHOMA, LARGE-CELL, IMMUNOBLASTIC), this group's unique features warrant separate treatment.Lymphoma, Large-Cell, Anaplastic: A systemic, large-cell, non-Hodgkin, malignant lymphoma characterized by cells with pleomorphic appearance and expressing the CD30 ANTIGEN. These so-called "hallmark" cells have lobulated and indented nuclei. This lymphoma is often mistaken for metastatic carcinoma and MALIGNANT HISTIOCYTOSIS.Chromosomes, Human, Pair 14: A specific pair of GROUP D CHROMOSOMES of the human chromosome classification.Vincristine: An antitumor alkaloid isolated from VINCA ROSEA. (Merck, 11th ed.)Tumor Cells, Cultured: Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.Germinal Center: The activated center of a lymphoid follicle in secondary lymphoid tissue where B-LYMPHOCYTES are stimulated by antigens and helper T cells (T-LYMPHOCYTES, HELPER-INDUCER) are stimulated to generate memory cells.Oncogenes: Genes whose gain-of-function alterations lead to NEOPLASTIC CELL TRANSFORMATION. They include, for example, genes for activators or stimulators of CELL PROLIFERATION such as growth factors, growth factor receptors, protein kinases, signal transducers, nuclear phosphoproteins, and transcription factors. A prefix of "v-" before oncogene symbols indicates oncogenes captured and transmitted by RETROVIRUSES; the prefix "c-" before the gene symbol of an oncogene indicates it is the cellular homolog (PROTO-ONCOGENES) of a v-oncogene.Antibodies, Monoclonal, Murine-Derived: Antibodies obtained from a single clone of cells grown in mice or rats.Cyclophosphamide: Precursor of an alkylating nitrogen mustard antineoplastic and immunosuppressive agent that must be activated in the LIVER to form the active aldophosphamide. It has been used in the treatment of LYMPHOMA and LEUKEMIA. Its side effect, ALOPECIA, has been used for defleecing sheep. Cyclophosphamide may also cause sterility, birth defects, mutations, and cancer.In Situ Hybridization, Fluorescence: A type of IN SITU HYBRIDIZATION in which target sequences are stained with fluorescent dye so their location and size can be determined using fluorescence microscopy. This staining is sufficiently distinct that the hybridization signal can be seen both in metaphase spreads and in interphase nuclei.Antigens, CD20: Unglycosylated phosphoproteins expressed only on B-cells. They are regulators of transmembrane Ca2+ conductance and thought to play a role in B-cell activation and proliferation.Chromosomes, Human, 1-3: The large, metacentric human chromosomes, called group A in the human chromosome classification. This group consists of chromosome pairs 1, 2, and 3.Genes, Immunoglobulin Heavy Chain: Genes and gene segments encoding the IMMUNOGLOBULIN HEAVY CHAINS. Gene segments of the heavy chain genes are symbolized V (variable), D (diversity), J (joining), and C (constant).Cell Line, Tumor: A cell line derived from cultured tumor cells.Immunophenotyping: Process of classifying cells of the immune system based on structural and functional differences. The process is commonly used to analyze and sort T-lymphocytes into subsets based on CD antigens by the technique of flow cytometry.Immunoglobulin Heavy Chains: The largest of polypeptide chains comprising immunoglobulins. They contain 450 to 600 amino acid residues per chain, and have molecular weights of 51-72 kDa.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Sesquiterpenes, Guaiane: SESQUITERPENES cyclized into two adjoining rings, one being 7-carbons and the other is 5-carbons.Leukemia, B-Cell: A malignant disease of the B-LYMPHOCYTES in the bone marrow and/or blood.Doxorubicin: Antineoplastic antibiotic obtained from Streptomyces peucetius. It is a hydroxy derivative of DAUNORUBICIN.Gene Rearrangement: The ordered rearrangement of gene regions by DNA recombination such as that which occurs normally during development.Sesquiterpenes, Eudesmane: SESQUITERPENES cyclized into two adjoining cyclohexane rings but with a different configuration from the ARTEMISININS.Chromosomes, Human, Pair 8: A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.Neprilysin: Enzyme that is a major constituent of kidney brush-border membranes and is also present to a lesser degree in the brain and other tissues. It preferentially catalyzes cleavage at the amino group of hydrophobic residues of the B-chain of insulin as well as opioid peptides and other biologically active peptides. The enzyme is inhibited primarily by EDTA, phosphoramidon, and thiorphan and is reactivated by zinc. Neprilysin is identical to common acute lymphoblastic leukemia antigen (CALLA Antigen), an important marker in the diagnosis of human acute lymphocytic leukemia. There is no relationship with CALLA PLANT.Cytogenetics: A subdiscipline of genetics which deals with the cytological and molecular analysis of the CHROMOSOMES, and location of the GENES on chromosomes, and the movements of chromosomes during the CELL CYCLE.Antineoplastic Combined Chemotherapy Protocols: The use of two or more chemicals simultaneously or sequentially in the drug therapy of neoplasms. The drugs need not be in the same dosage form.Lymphoma, Large-Cell, Immunoblastic: Malignant lymphoma characterized by the presence of immunoblasts with uniformly round-to-oval nuclei, one or more prominent nucleoli, and abundant cytoplasm. This class may be subdivided into plasmacytoid and clear-cell types based on cytoplasmic characteristics. A third category, pleomorphous, may be analogous to some of the peripheral T-cell lymphomas (LYMPHOMA, T-CELL, PERIPHERAL) recorded in both the United States and Japan.Viral Matrix Proteins: Proteins associated with the inner surface of the lipid bilayer of the viral envelope. These proteins have been implicated in control of viral transcription and may possibly serve as the "glue" that binds the nucleocapsid to the appropriate membrane site during viral budding from the host cell.HLA-A11 Antigen: A specific HLA-A surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-A*11 allele family.Genes, myb: Retrovirus-associated DNA sequences (v-myb) originally isolated from the avian myeloblastosis and E26 leukemia viruses. The proto-oncogene c-myb codes for a nuclear protein involved in transcriptional regulation and appears to be essential for hematopoietic cell proliferation. The human myb gene is located at 6q22-23 on the short arm of chromosome 6. This is the point of break in translocations involved in T-cell acute lymphatic leukemia and in some ovarian cancers and melanomas. (From Ibelgaufts, Dictionary of Cytokines, 1995).Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Gene Expression Regulation, Neoplastic: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in neoplastic tissue.Proto-Oncogene Proteins c-bcl-2: Membrane proteins encoded by the BCL-2 GENES and serving as potent inhibitors of cell death by APOPTOSIS. The proteins are found on mitochondrial, microsomal, and NUCLEAR MEMBRANE sites within many cell types. Overexpression of bcl-2 proteins, due to a translocation of the gene, is associated with follicular lymphoma.Genes, bcl-2: The B-cell leukemia/lymphoma-2 genes, responsible for blocking apoptosis in normal cells, and associated with follicular lymphoma when overexpressed. Overexpression results from the t(14;18) translocation. The human c-bcl-2 gene is located at 18q24 on the long arm of chromosome 18.Plasmacytoma: Any discrete, presumably solitary, mass of neoplastic PLASMA CELLS either in BONE MARROW or various extramedullary sites.Cytarabine: A pyrimidine nucleoside analog that is used mainly in the treatment of leukemia, especially acute non-lymphoblastic leukemia. Cytarabine is an antimetabolite antineoplastic agent that inhibits the synthesis of DNA. Its actions are specific for the S phase of the cell cycle. It also has antiviral and immunosuppressant properties. (From Martindale, The Extra Pharmacopoeia, 30th ed, p472)Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Apoptosis: One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.Antibodies, Monoclonal: Antibodies produced by a single clone of cells.Tanacetum parthenium: An aromatic perennial plant species that has been used to treat migraines, arthritis, and as a febrifuge. It contains TANNINS, volatile oils (OILS, ESSENTIAL), and sesquiterpene lactones, especially parthenolide.Flow Cytometry: Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.Virus Latency: The ability of a pathogenic virus to lie dormant within a cell (latent infection). In eukaryotes, subsequent activation and viral replication is thought to be caused by extracellular stimulation of cellular transcription factors. Latency in bacteriophage is maintained by the expression of virally encoded repressors.Antigens, Viral: Substances elaborated by viruses that have antigenic activity.Prednisone: A synthetic anti-inflammatory glucocorticoid derived from CORTISONE. It is biologically inert and converted to PREDNISOLONE in the liver.Inhibitor of Differentiation Proteins: Inhibitor of differentiation proteins are negative regulators of BASIC HELIX-LOOP-HELIX TRANSCRIPTION FACTORS. They inhibit CELL DIFFERENTIATION and induce CELL PROLIFERATION by modulating different CELL CYCLE regulators.Lymphoproliferative Disorders: Disorders characterized by proliferation of lymphoid tissue, general or unspecified.DNA, Neoplasm: DNA present in neoplastic tissue.Genes, Immunoglobulin: Genes encoding the different subunits of the IMMUNOGLOBULINS, for example the IMMUNOGLOBULIN LIGHT CHAIN GENES and the IMMUNOGLOBULIN HEAVY CHAIN GENES. The heavy and light immunoglobulin genes are present as gene segments in the germline cells. The completed genes are created when the segments are shuffled and assembled (B-LYMPHOCYTE GENE REARRANGEMENT) during B-LYMPHOCYTE maturation. The gene segments of the human light and heavy chain germline genes are symbolized V (variable), J (joining) and C (constant). The heavy chain germline genes have an additional segment D (diversity).Chromosome Banding: Staining of bands, or chromosome segments, allowing the precise identification of individual chromosomes or parts of chromosomes. Applications include the determination of chromosome rearrangements in malformation syndromes and cancer, the chemistry of chromosome segments, chromosome changes during evolution, and, in conjunction with cell hybridization studies, chromosome mapping.Karyotyping: Mapping of the KARYOTYPE of a cell.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Methotrexate: An antineoplastic antimetabolite with immunosuppressant properties. It is an inhibitor of TETRAHYDROFOLATE DEHYDROGENASE and prevents the formation of tetrahydrofolate, necessary for synthesis of thymidylate, an essential component of DNA.Receptors, Antigen, B-Cell: IMMUNOGLOBULINS on the surface of B-LYMPHOCYTES. Their MESSENGER RNA contains an EXON with a membrane spanning sequence, producing immunoglobulins in the form of type I transmembrane proteins as opposed to secreted immunoglobulins (ANTIBODIES) which do not contain the membrane spanning segment.Cell Transformation, Viral: An inheritable change in cells manifested by changes in cell division and growth and alterations in cell surface properties. It is induced by infection with a transforming virus.Neoplasm Proteins: Proteins whose abnormal expression (gain or loss) are associated with the development, growth, or progression of NEOPLASMS. Some neoplasm proteins are tumor antigens (ANTIGENS, NEOPLASM), i.e. they induce an immune reaction to their tumor. Many neoplasm proteins have been characterized and are used as tumor markers (BIOMARKERS, TUMOR) when they are detectable in cells and body fluids as monitors for the presence or growth of tumors. Abnormal expression of ONCOGENE PROTEINS is involved in neoplastic transformation, whereas the loss of expression of TUMOR SUPPRESSOR PROTEINS is involved with the loss of growth control and progression of the neoplasm.Antineoplastic Agents: Substances that inhibit or prevent the proliferation of NEOPLASMS.Etoposide: A semisynthetic derivative of PODOPHYLLOTOXIN that exhibits antitumor activity. Etoposide inhibits DNA synthesis by forming a complex with topoisomerase II and DNA. This complex induces breaks in double stranded DNA and prevents repair by topoisomerase II binding. Accumulated breaks in DNA prevent entry into the mitotic phase of cell division, and lead to cell death. Etoposide acts primarily in the G2 and S phases of the cell cycle.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Proto-Oncogenes: Normal cellular genes homologous to viral oncogenes. The products of proto-oncogenes are important regulators of biological processes and appear to be involved in the events that serve to maintain the ordered procession through the cell cycle. Proto-oncogenes have names of the form c-onc.Leukemia, Lymphoid: Leukemia associated with HYPERPLASIA of the lymphoid tissues and increased numbers of circulating malignant LYMPHOCYTES and lymphoblasts.Prognosis: A prediction of the probable outcome of a disease based on a individual's condition and the usual course of the disease as seen in similar situations.Lymphocytes: White blood cells formed in the body's lymphoid tissue. The nucleus is round or ovoid with coarse, irregularly clumped chromatin while the cytoplasm is typically pale blue with azurophilic (if any) granules. Most lymphocytes can be classified as either T or B (with subpopulations of each), or NATURAL KILLER CELLS.Remission Induction: Therapeutic act or process that initiates a response to a complete or partial remission level.Lymphoma, Extranodal NK-T-Cell: An extranodal neoplasm, usually possessing an NK-cell phenotype and associated with EPSTEIN-BARR VIRUS. These lymphomas exhibit a broad morphologic spectrum, frequent necrosis, angioinvasion, and most commonly present in the midfacial region, but also in other extranodal sites.Cell Transformation, Neoplastic: Cell changes manifested by escape from control mechanisms, increased growth potential, alterations in the cell surface, karyotypic abnormalities, morphological and biochemical deviations from the norm, and other attributes conferring the ability to invade, metastasize, and kill.Tumor Markers, Biological: Molecular products metabolized and secreted by neoplastic tissue and characterized biochemically in cells or body fluids. They are indicators of tumor stage and grade as well as useful for monitoring responses to treatment and predicting recurrence. Many chemical groups are represented including hormones, antigens, amino and nucleic acids, enzymes, polyamines, and specific cell membrane proteins and lipids.Transcription, Genetic: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.Cell Line, Transformed: Eukaryotic cell line obtained in a quiescent or stationary phase which undergoes conversion to a state of unregulated growth in culture, resembling an in vitro tumor. It occurs spontaneously or through interaction with viruses, oncogenes, radiation, or drugs/chemicals.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.Gene Expression Regulation, Viral: Any of the processes by which cytoplasmic factors influence the differential control of gene action in viruses.DNA, Viral: Deoxyribonucleic acid that makes up the genetic material of viruses.Chaperonin Containing TCP-1: A group II chaperonin found in eukaryotic CYTOSOL. It is comprised of eight subunits with each subunit encoded by a separate gene. This chaperonin is named after one of its subunits which is a T-COMPLEX REGION-encoded polypeptide.Biopsy: Removal and pathologic examination of specimens in the form of small pieces of tissue from the living body.Hybrid Cells: Any cell, other than a ZYGOTE, that contains elements (such as NUCLEI and CYTOPLASM) from two or more different cells, usually produced by artificial CELL FUSION.Virus Activation: The mechanism by which latent viruses, such as genetically transmitted tumor viruses (PROVIRUSES) or PROPHAGES of lysogenic bacteria, are induced to replicate and then released as infectious viruses. It may be effected by various endogenous and exogenous stimuli, including B-cell LIPOPOLYSACCHARIDES, glucocorticoid hormones, halogenated pyrimidines, IONIZING RADIATION, ultraviolet light, and superinfecting viruses.National Cancer Institute (U.S.): Component of the NATIONAL INSTITUTES OF HEALTH. Through basic and clinical biomedical research and training, it conducts and supports research with the objective of cancer prevention, early stage identification and elimination. This Institute was established in 1937.

Epstein-barr virus regulates c-MYC, apoptosis, and tumorigenicity in Burkitt lymphoma. (1/1897)

Loss of the Epstein-Barr virus (EBV) genome from Akata Burkitt lymphoma (BL) cells is coincident with a loss of malignant phenotype, despite the fact that Akata and other EBV-positive BL cells express a restricted set of EBV gene products (type I latency) that are not known to overtly affect cell growth. Here we demonstrate that reestablishment of type I latency in EBV-negative Akata cells restores tumorigenicity and that tumorigenic potential correlates with an increased resistance to apoptosis under growth-limiting conditions. The antiapoptotic effect of EBV was associated with a higher level of Bcl-2 expression and an EBV-dependent decrease in steady-state levels of c-MYC protein. Although the EBV EBNA-1 protein is expressed in all EBV-associated tumors and is reported to have oncogenic potential, enforced expression of EBNA-1 alone in EBV-negative Akata cells failed to restore tumorigenicity or EBV-dependent down-regulation of c-MYC. These data provide direct evidence that EBV contributes to the tumorigenic potential of Burkitt lymphoma and suggest a novel model whereby a restricted latency program of EBV promotes B-cell survival, and thus virus persistence within an immune host, by selectively targeting the expression of c-MYC.  (+info)

Differential expression and phosphorylation of CTCF, a c-myc transcriptional regulator, during differentiation of human myeloid cells. (2/1897)

CTCF is a transcriptional repressor of the c-myc gene. Although CTCF has been characterized in some detail, there is very little information about the regulation of CTCF activity. Therefore we investigated CTCF expression and phosphorylation during induced differentiation of human myeloid leukemia cells. We found that: (i) both CTCF mRNA and protein are down-regulated during terminal differentiation in most cell lines tested; (ii) CTCF down-regulation is retarded and less pronounced than that of c-myc; (iii) CTCF protein is differentially phosphorylated and the phosphorylation profiles depend on the differentiation pathway. We concluded that CTCF expression and activity is controlled at transcriptional and post-transcriptional levels.  (+info)

Involvement of wiskott-aldrich syndrome protein in B-cell cytoplasmic tyrosine kinase pathway. (3/1897)

Bruton's tyrosine kinase (Btk) has been shown to play a role in normal B-lymphocyte development. Defective expression of Btk leads to human and murine immunodeficiencies. However, the exact role of Btk in the cytoplasmic signal transduction in B cells is still unclear. This study represents a search for the substrate for Btk in vivo. We identified one of the major phosphoproteins associated with Btk in the preB cell line NALM6 as the Wiskott-Aldrich syndrome protein (WASP), the gene product responsible for Wiskott-Aldrich syndrome, which is another hereditary immunodeficiency with distinct abnormalities in hematopoietic cells. We demonstrated that WASP was transiently tyrosine-phosphorylated after B-cell antigen receptor cross-linking on B cells, suggesting that WASP is located downstream of cytoplasmic tyrosine kinases. An in vivo reconstitution system demonstrated that WASP is physically associated with Btk and can serve as the substrate for Btk. A protein binding assay suggested that the tyrosine-phosphorylation of WASP alters the association between WASP and a cellular protein. Furthermore, identification of the phosphorylation site of WASP in reconstituted cells allowed us to evaluate the catalytic specificity of Btk, the exact nature of which is still unknown.  (+info)

Analysis of the interaction of monoclonal antibodies with surface IgM on neoplastic B-cells. (4/1897)

In vitro studies identified three Burkitts lymphoma cell lines, Ramos, MUTU-I and Daudi, that were growth inhibited by anti-IgM antibody. However, only Ramos and MUTU-I were sensitive to monoclonal antibodies (mAb) recognizing the Fc region of surface IgM (anti-Fc mu). Experiments using anti-Fc mu mAb (single or non-crossblocking pairs), polyclonal anti-mu Ab, and hyper-crosslinking with a secondary layer of Ab, showed that growth inhibition of B-cell lines was highly dependent on the extent of IgM crosslinking. This was confirmed by using Fab', F(ab')2 and F(ab')3 derivatives from anti-Fc mu mAb, where increasing valency caused corresponding increases in growth arrest and apoptosis, presumably as a result of more efficient BCR-crosslinking on the cell surface. The ability of a single mAb to induce growth arrest was highly dependent on epitope specificity, with mAb specific for the Fc region (C mu2-C mu4 domains) being much more effective than those recognizing the Fab region (anti-L chain, anti-Id and anti-Fd mu, or C mu1). Only when hyper-crosslinked with polyclonal anti-mouse IgG did the latter result in appreciable growth inhibition. Binding studies showed that these differences in function were not related to differences in the affinity, but probably related to intrinsic crosslinking capacity of mAb.  (+info)

Differential responses to CD40 ligation among Burkitt lymphoma lines that are uniformly responsive to Epstein-Barr virus latent membrane protein 1. (5/1897)

Ligation of CD40 on the surface of B cells induces multiple phenotypic effects, many of which are mimicked by the EBV latent membrane protein 1 (LMP1) through its interaction with downstream components of the CD40 signaling pathway. Because the effects of LMP1 have been most closely studied in human Burkitt Lymphoma (BL) cell lines retaining a tumor biopsy-like phenotype in vitro, we have examined the response of a panel of such lines to CD40 ligation. Two distinct patterns of response were observed that were unrelated to the surface level of CD40 or to the EBV genome status of the lines. Following exposure to either CD40-specific mAbs or the soluble trimeric ligand (sCD40L), high responder (HR) lines showed rapid aggregation, activation of NF-kappa B, up-regulation of cell surface markers ICAM-1/CD54 and Fas/CD95, and growth inhibition. Aggregation was seen at lower doses than those required to elicit the other effects. By contrast, low responder (LR) lines showed no detectable response to CD40 mAbs, while their responses to sCD40L were limited to activation of NF-kappa B and up-regulation of CD95 only. However, in transfection experiments, LMP1 uniformly induced the full spectrum of phenotypic effects in both HR and LR lines. We conclude that some BL cell lines show a highly restricted response to CD40 ligation but remain fully susceptible to LMP1.  (+info)

Restricted low-level human antibody responses against Epstein-Barr virus (EBV)-encoded latent membrane protein 1 in a subgroup of patients with EBV-associated diseases. (6/1897)

Human antibody responses to latent membrane protein 1 (LMP1) in patients with Epstein-Barr virus (EBV)-related disease syndromes were analyzed in detail. Only by immunoblot analysis with purified recombinant LMP1 and by IFA on recombinant LMP1-expressing insect cells could human antibodies directed against LMP1 be detected. Low serum levels of LMP1-directed antibodies could be detected in 3 of 8 EBV-positive Hodgkin's disease patients, 3 of 40 nasopharyngeal carcinoma patients, 2 of 23 Burkitt's lymphoma patients, and 1 of 27 non-Burkitt's lymphoma patients. No LMP1-directed antibodies could be detected in healthy EBV carriers, infectious mononucleosis patients, or patients with chronic EBV disease. All sera contained significant levels of EBV antibodies directed against the immunodominant EBV proteins and peptides. From this study, it can be concluded that LMP1 is a protein with a very low immunogenicity for the humoral immune response in humans.  (+info)

Induction of lytic Epstein-Barr virus (EBV) infection in EBV-associated malignancies using adenovirus vectors in vitro and in vivo. (7/1897)

The consistent presence of EBV genomes in certain tumor types (in particular, AIDS-related central nervous system lymphomas and nasopharyngeal carcinomas) may allow novel, EBV-based targeting strategies. Tumors contain the latent (transforming) form of EBV infection. However, expression of either of the EBV immediate-early proteins, BZLF1 and BRLF1, is sufficient to induce lytic EBV infection, resulting in death of the host cell. We have constructed replication-deficient adenovirus vectors expressing the BZLF1 or BRLF1 immediate-early genes and examined their utility for killing latently infected lymphoma cells in vitro and in vivo. We show that both the BZLF1 and BRLF1 vectors efficiently induce lytic EBV infection in Jijoye cells (an EBV-positive Burkitt lymphoma cell line). Furthermore, lytic EBV infection converts the antiviral drug, ganciclovir (GCV), into a toxic (phosphorylated) form, which inhibits cellular as well as viral DNA polymerase. When Jijoye cells are infected with the BZLF1 or BRLF1 adenovirus vectors in the presence of GCV, viral reactivation is induced, but virus replication is inhibited (thus preventing the release of infectious EBV particles); yet cells are still efficiently killed. Finally, we demonstrate that the BZLF1 and BRLF1 adenovirus vectors induce lytic EBV infection when they are directly inoculated into Jijoye cell tumors grown in severe combined immunodeficiency mice. These results suggest that induction of lytic EBV infection in tumors, in combination with GCV, may be an effective strategy for treating EBV-associated malignancies.  (+info)

Deregulation of the proto-oncogene c-myc through t(8;22) translocation in Burkitt's lymphoma. (8/1897)

In Burkitt's lymphoma (BL) cells the proto-oncogene c-myc is juxtaposed to one of the immunoglobulin (Ig) loci on chromosomes 2, 14, or 22. The c-myc gene becomes transcriptionally activated as a consequence of the chromosomal translocation and shows preferential usage of promoter P1 over P2, a phenomenon referred to as promoter shift. In order to define the responsible regulatory elements within the Ig lambda locus, we studied the effect of the human Ig lambda enhancer (HuE lambda) on c-myc expression after stable transfection into BL cells. A 12 kb genomic fragment encompassing HuE lambda, but not HuE lambda alone, strongly activated c-myc expression and induced the promoter shift. To identify additional elements involved in c-myc deregulation, we mapped DNaseI hypersensitive sites within the 12 kb lambda fragment on the construct. Besides one hypersensitive site corresponding to HuE lambda, three additional sites were detected. Two of these elements displayed enhancer activity after transient transfection. The third element did not activate c-myc transcription, but was required for full c-myc activation and promoter shift. Deletion analyses of the c-myc promoter identified the immediate promoter region as sufficient for activation by the Ig lambda. locus, but also revealed that induction of the promoter shift requires additional upstream elements.  (+info)

  • METHODS: Here we report the cytotoxic effects of a synthesized conjugate of DZ with cisplatin (CIS) on B cell lymphoma CA46, Daudi, Namalwa, Raji, and Ramos cell lines in cell culture and in xenograft tumor formation. (kbco.hr)
  • The lectin depleted expression of mRNA coding multidrug resistant protein, MRP1, time- and dose-dependently through binding with Gb3 glycosphingolipid which is highly expressed on human Burkitt's lymphoma Raji cells. (yokohama-cu.ac.jp)
  • We found out 3 weeks ago, my daughter- in-law, who is about 6 months pregnant, has been taking multiple drugs which began with a cancer ( Burkitt s Lymphoma ) cure 3 yrs ago. (healthcaremagic.com)
  • 2019) 'Targeting Burkitt Lymphoma with a Tumor Cell-specific Heptamethine Carbocyanine-cisplatin Conjugate', Cancer , 125(13), pp. 2222-2232. (kbco.hr)
  • A biopsy of the large abdominal mass was performed which confirmed that she had Burkitt lymphoma. (globalgiving.org)
  • Background: The epidemiology of Burkitt Lymphoma (BL) shows that the endemic type is mainly confined to equatorial Africa and has a very close association with the Epstein-Barr virus (EBV), while the sporadic variant shows only a 20% association with EBV and is seen mainly in Europe and North America. (sun.ac.za)
  • Burkitt's lymphoma is also associated with an infection from the Epstein-Barr virus (EBV). (nicklauschildrens.org)
  • Conclusions: The patients seen at Tygerberg Hospital, South Africa presented typically with the sporadic variant of Burkitt Lymphoma. (sun.ac.za)
  • A "SUEL-type lectin domain"(IPR000922) was described by Yasuhiro Ozeki in 1991 as with a unique primary structure for animal lectins with specificity to D-galactosides in the eggs of the sea urchin Anthocidaris crassispina (http://en.wikipedia.org/wiki/Galactose_binding_lectin_domain) . (yokohama-cu.ac.jp)
  • The tumor cells have a similar appearance to the cancer cells of classical endemic Burkitt lymphoma. (wikipedia.org)
  • Since Burkitt lymphoma and other B-cell lymphomas are a clonal proliferative process, all tumor cells from one patient are supposed to possess identical IgH genes. (wikipedia.org)
  • The tumor cells in Burkitt lymphoma generally strongly express markers of B cell differentiation (CD20, CD22, CD19), as well as CD10 and BCL6. (wikipedia.org)
  • The lymphoma is in only one place, either as a single tumor not in lymph nodes, or in lymph nodes in one part of the body (the neck, groin, underarm, etc. (cancer.org)
  • The lymphoma is more than one tumor and/or in more than one set of lymph nodes, all of which are either above or below the diaphragm (the thin breathing muscle that separates the chest and abdomen). (cancer.org)
  • But other factors can also affect a child's outlook, such as the location and size of the tumor(s), and how well the lymphoma responds to treatment . (cancer.org)
  • Burkitt lymphoma (BL) is a highly malignant B-cell tumor associated with Epstein-Barr Virus (EBV) infection. (hindawi.com)
  • The endemic variant of Burkitt lymphoma observed in equatorial Africa - a rapidly progressive jaw or orbital tumor - is the most common presentation, occurring more frequently in young children. (renalandurologynews.com)
  • The following chapter sheds light on epidemiology, tumor biology, treatment options and prognosis of this lymphoma which has evolved from an enigmatic syndrome to a curable disease. (springer.com)
  • A case of a so-called "Burkitt tumor" in a Dutch boy. (springer.com)
  • In the case of Burkitt's lymphomas (BL), most current evidence indicates that the tumor requires the virus minimally to block apoptosis. (pubmedcentralcanada.ca)
  • For both cervical carcinomas carrying human papillomaviruses (HPV) and Burkitt's lymphomas carrying Epstein-Barr virus (EBV), inhibiting viral genes in cell culture induces cell death in the tumor derived cells [ 8 - 10 ]. (pubmedcentralcanada.ca)
  • There are cases with poor outcome caused by toxic effects of the therapy, tumor lysis syndrome or metastatic spread of lymphomas to the central nervous system. (aacrjournals.org)
  • However, as lymphomas are known to form metastases in several sites, the analysis of their metastatic behavior and the suppression of this by imipramine-blue treatment may have implications for other aggressive tumor types as well. (aacrjournals.org)
  • Nevertheless, there are cases of poor clinical outcome caused by the toxicity of the intensive chemotherapy, tumor lysis syndrome, or metastatic spread of lymphoma cells to the central nervous system ( 4-7 ). (aacrjournals.org)
  • Here, we demonstrated for the first time the overexpression of DNMT1 and DNMT3B in Burkitt lymphoma (BL) tumor samples (69% and 86%, respectively). (sigmaaldrich.com)
  • The first broad genetic landscape map of a Burkitt lymphoma tumor has identified 70 mutations, including several not previously associated with cancer and a new one that is unique to the disease. (oncologynurseadvisor.com)
  • Dave explained that this alteration alone may not cause cancer, but when it occurs along with the MYC gene mutations that are common in Burkitt lymphoma and other malignancies, it works like an accelerant to fuel tumor growth. (oncologynurseadvisor.com)
  • Called also African lymphoma and Burkitt's tumor . (thefreedictionary.com)
  • The underlying mechanism of action of CDBPA in Burkitt`s lymphoma was tested in vitro and its effect on tumor size and survival was tested in a NOD-scid mice model. (omicsonline.org)
  • An abstract of the study "Insertion of IGH into MYC in Burkitt Lymphoma identified by sequential FISH on paraffin sections" is presented. (ebscohost.com)
  • Mark J. Roschewski, MD , of the National Cancer Institute, discusses phase II study findings that showed DA-EPOCH-R cures most adult patients with Burkitt lymphoma, irrespective of HIV status (Abstract 188). (ascopost.com)
  • High-grade B-cell lymphoma that contains genetic changes that indicate the patient has a high risk of continued cancer growth. (mskcc.org)
  • Patients must have Burkitt lymphoma/leukemia or high-grade B-cell lymphoma that has continued to grow or came back despite prior treatment. (mskcc.org)
  • Apoptosis resistance is the major cause of chemotherapy failure in most kinds of cancers, including Burkitt lymphomas (BL). (hu-berlin.de)
  • The reactivation of p16 and p14 in our model and our ability to inhibit cell proliferation and induce apoptosis through the Rb- and p-53 pathways opens new prospects for the understanding and treatment of Burkitt lymphoma. (oncologynurseadvisor.com)
  • Exposure to Sonic or Indian Hedgehog or cyclopamine (SMO inhibitor) does not modulate GLI1 expression, cell proliferation, or apoptosis in most Burkitt lymphoma cell lines. (luriechildrens.org)
  • Inhibition of GLI1 by GANT61 increases apoptosis and reduces viability of some Burkitt lymphoma cells. (luriechildrens.org)
  • Discovery of an Apoptosis Inducing Ligand for Burkitt Lymphoma" by Carolyn Laymon, Kyla Bradylong et al. (calpoly.edu)
  • We demonstrated that CDBPA significantly reduced cell viability and induced apoptosis via the extrinsic and the intrinsic apoptotic pathways of Burkitts lymphoma cells without causing cell cycle arrest but reduction of the various phases. (omicsonline.org)
  • J. Durig, W. Fiedler, M. de Wit, M. Steffen and D. Hossfeld, "Lactic Acidosis and Hypoglycemia in a Patient with High-Grade Non-Hodgkin's Lymphoma and Elevated Circulating TNF-a," Annals of Hematology, Vol. 72, No. 2, 1996, pp. 97-99. (scirp.org)
  • Rising incidence HIV is expected to augment growth of the Burkitt lymphoma treatment market, as Burkitt lymphoma is an AIDS-defining cancer that is expected to occur more frequently in people suffering from HIV than in the general population. (coherentmarketinsights.com)
  • No unusual local patterns of leukemia, lymphoma, or infectious mononucleosis incidence were found, and no other persons with childhood cancer were identified as having been in contact with the patients or being in their particular neighborhood. (cdc.gov)
  • In this type of Burkitt lymphoma, the peak incidence of infection is between the ages of 4 and 7. (uexpress.com)
  • The most common type of Burkitt lymphoma in the United States is much rarer -- about three cases per million people per year -- and the peak incidence is about 11 years of age, with the majority of cases occurring in people younger than 35. (uexpress.com)
  • In developed countries where sporadic cases are most commonly encountered, Burkitt lymphoma can occur at any age, although the peak incidence is in the first decade of life. (renalandurologynews.com)
  • Meningeal involvement in non-Hodgkin's lymphoma: symptoms, incidence, risk factors and treatment. (springer.com)
  • Burkitt lymphoma is a rare disease with an incidence rate of approximately 0.2, which means that 2 individuals within a population of 1 million are affected by Burkitt lymphoma per year ( 2 ). (aacrjournals.org)
  • Because of the low incidence of the disease, research on novel drugs for Burkitt lymphoma treatment proceeds only slowly. (aacrjournals.org)
  • Tumour lysis syndrome (TLS) is a group of side effects that develops when a large number of lymphoma cells are killed in a short period of time. (cancer.ca)
  • BL belongs to the non-Hodgkin lymphomas group, and is the first human tumour undoubtedly related to a viral origin (Epstein-Barr virus). (biomedsearch.com)
  • Background: Burkitt lymphoma (BL) is the commonest tumour among Nigerian children. (who.int)
  • 1 BL tumour cells usually express IgM, 13 - 15 B-cell markers such as CD19, CD20 and CD22 and markers of germinal centre (GC) centroblasts such as CD10, BCL6 4 and the human germinal centre-associated lymphoma (HGAL) protein. (bmj.com)
  • Letter: childhood lymphoma resembling Burkitt's tumour in the southern Argentine. (bmj.com)
  • What are the symptoms of Burkitt lymphoma? (webmd.com)
  • Rituximab (Rituxan) is the most common targeted therapy used to treat Burkitt lymphoma. (cancer.ca)
  • Intrathecal chemotherapy may be given to prevent the spread of Burkitt lymphoma to the brain and spinal cord (called the central nervous system, or CNS) or to treat Burkitt lymphoma that has spread to the CNS. (cancer.ca)
  • Immunodeficiency-associated Burkitt lymphoma is usually associated with HIV infection or occurs in the setting of post-transplant patients who are taking immunosuppressive drugs. (wikipedia.org)
  • Immunodeficiency-associated Burkitt lymphoma may demonstrate more plasmacytic appearance or more pleomorphism, but these features are not specific. (wikipedia.org)
  • Immunodeficiency-associated Burkitt lymphoma tends to occur in people with weakened immune systems, typically those with HIV infection. (cancer.ca)
  • The number of cases of immunodeficiency-associated Burkitt lymphoma seems to be dropping because antiretroviral therapy is used to treat HIV. (cancer.ca)
  • If Burkitt lymphoma is suspected, all or part of an enlarged lymph node or other suspicious disease site will be biopsied. (webmd.com)
  • Stage I and II lymphomas are usually considered limited-stage disease and are treated the same way. (cancer.org)
  • Stage III and IV lymphomas are usually thought of as advanced-stage disease and are also treated alike. (cancer.org)
  • And the second point is that even though you succeed in treating properly elderly patients, the fraction of long survivors is lower and this is probably due to a different biology of disease when this type of lymphoma arises in a patient who is older than 65. (ecancer.org)