Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0079731 (B-cell lymphoma)
 16,671 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Viruses implicated in the development of human cancers include hepatitis B (and C) viruses in hepatocellular carcinoma; human papillomaviruses in anogenital cancers; Epstein-Barr virus in nasopharyngeal carcinoma and Burkitt's lymphoma; human T-cell leukaemia/lymphoma viruses in adult T-cell leukaemia/lymphoma; and indirectly, human immunodeficiency viruses in Kaposi's sarcoma and B-cell lymphoma. Together, they contribute significantly to the cancer statistics in the Southeast Asian region. Neoplastic proliferation may be instigated by the presence and expression of viral oncogenes which may be integrated into the host genome and/or exist in episomal molecules. Critical viral genes may also interfere with host genes, resulting in the activation of cellular proto-oncogenes and/or the inactivation of anti-oncogenes and their products. The molecular pathogenesis of virally-induced cancers has led to major breakthroughs in the understanding of carcinogenesis at a molecular level. The occurrence of some of these viruses in a significant proportion of normal individuals suggests long latency periods necessitating multi-step co-operating events arising from multi-factorial agents such as host genetic susceptibility, immunological and hormonal status, as well as chemical and physical cocarcinogens in the environment. Successful intervention achieved with effective vaccines such as the hepatitis B vaccine and measures to severe the chain of viral transmission culminating in reduced incidence of the corresponding cancer will provide conclusive evidence for the virus-cancer relationship.
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PMID:Cancer and viruses. 810 16

The successful clinical experience with antibody LL2 (an IgG2a, anti-B-cell lymphoma antibody) in radioimmunodetection and radioimmunotherapy suggests that this antibody may have potential as a carrier of cytotoxic agents. The internalization, cellular trafficking, and catabolism of this antibody in target human Burkitt lymphoma cells (Raji) were investigated. Internalization of intact antibody as well as of the F(ab')2 and Fab' fragments was detected by an FITC-labeled anti-mouse second antibody probe, and evaluated by fluorescence microscopy. Internalization of intact IgG (or the fragments) was observed as early as 5 min after incubation at 37 degrees C. Initially, the internalized antibodies were present as micro-particles inside the cell membrane, and were translocated to the lysosomal compartment within 2 hr. The anatomic location of the internalized antibody, before translocation to the lysosomal compartment, was deduced by comparing the fluorescence images obtained with the antibody to those obtained with fluorescent probes with known cellular distribution in a co-internalization study. A Golgi-like compartment was found to be involved in the translocation of the antibody. Cellular catabolism of the bound antibody was studied by using 125I-labeled antibody on the target cells. At 21 h, 40% of the radioactivity was released into the supernatant as degraded fragments. The observation suggested that the antibody was degraded mainly in the lysosomes, since the degradation was significantly inhibited in the presence of lysosomal inhibitors such as ammonium chloride or leupeptin. Subcellular fractionation of Raji cells after the binding of 125I-labeled LL2 indicated that the antibody was translocated to lysosomes as evidenced by SDS-PAGE. The rate of internalization (Ke) of LL2, and the re-expression of the antigen were determined. The rapid internalization of LL2 and the re-expression of the antigen suggest that this antibody may have potential as a therapeutic immunoconjugate, since it could deliver a higher accumulation of cytotoxic agents into lymphoma cells.
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PMID:Internalization and intracellular processing of an anti-B-cell lymphoma monoclonal antibody, LL2. 811 89

All cases of gastrointestinal (GI) non-Hodgkin's lymphoma diagnosed in Finland between 1972 and 1977 were histologically reexamined and immunostained in order to study the value of histological classification. One hundred and eleven cases were found. The crude annual incidence was 0.51/10(5) and the age-adjusted (world standard population) incidence 0.23/10(5). The male-to-female ratio of age-adjusted incidence rates was 2.7. The most common histological type was large B-cell lymphoma comprising 61% of all classifiable cases. Low-grade mucosa-associated lymphoid tissue (MALT) lymphoma comprised 12%, centrocytic lymphoma 9%, peripheral T-cell lymphoma 9%, Burkitt's lymphoma 7% and large-cell anaplastic lymphoma 3% of the total. In the jejunum, almost one half of the cases were T-cell lymphomas and there were no lymphomas with definite MALT features. Gastric lymphomas had higher survival rates than intestinal lymphomas, B-cell lymphomas slightly higher survival rates than T-cell lymphomas, and low-grade MALT lymphomas higher survival rates than other B-cell lymphomas. The other types of lymphomas differed only slightly from each other in prognosis. The histological grade according to the Working Formulation correlated with survival rates, but a great majority of cases were classified as intermediate grade. Classification of GI lymphomas into the types mentioned above appears to correlate with several clinical and pathological parameters.
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PMID:Gastrointestinal non-Hodgkin's lymphoma. A population-based clinicopathological study of 111 adult cases with a follow-up of 10-15 years. 821 15

Mutations of p53 gene have been recognized to be the most common genetic changes in human cancers. Recently, p53 gene mutations have been found in some patients with common subtypes of B-cell lymphoma (9/48:18.8%), Burkitt lymphoma (9/27:33.3%) and chronic lymphocytic leukemia (6/40:15%). Evidences to suggest that p53 gene mutations are associated with the disease progression in B-cell lymphoma have emerged. Functions of wild-type p53 and its mutant's probable role in B-cell lymphomagenesis are described in this review.
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PMID:Mutations of the p53 gene in B-cell lymphoma. 822 Jan 52

Screening by Northern blot for lck expression in 51 patients with diverse hematologic diseases has shown, for four of them, a 3 to 15-fold increase in the level of lck mRNA when compared with expression in healthy donors. These patients suffered from diverse malignancies: one Burkitt lymphoma, one T-cell lymphoma and two non-Hodgkin B-cell lymphoma. Specific analysis of the different lck transcripts in these patients by polymerase chain reaction and their relative quantitation demonstrate a significant increase of only the type IB and the type IC lck transcripts arising from the proximal promotor. Our study shows: (a) a high lck expression may occur in diverse hematologic diseases, (b) whatever the type of malignancy, this high expression results in a specific increase of the spliced transcripts arising only from the proximal promotor, and (c) in these four patients without any rearrangement or amplification, the high lck expression probably results from the specific activation of the proximal promotor.
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PMID:Selective increase of alternatively spliced Lck transcripts from the proximal promotor in hematopoietic malignancies. 842 78

We have produced immunotoxins using LL2, a monoclonal antibody which binds to human B-cell lymphomas and which, in a radioiodinated form, induced responses in lymphoma patients (D.M. Goldberg et al., J. Clin. Oncol., 9: 548-564, 1991). We have coupled LL2 to Lys-PE38KDEL, a derivative of Pseudomonas exotoxin (PE) which does not bind to the PE receptor. LL2-PE38KDEL was cytotoxic toward several Burkitt's lymphoma lines, with 50% inhibitory concentration values ranging from 2 to 6 ng/ml (10-30 pM). Another immunotoxin, LL2-Fab'-PE38KDEL, was produced by chemically coupling the Fab' fragment of LL2 to Lys-PE38KDEL. LL2-Fab'-PE38KDEL also was cytotoxic toward the Burkitt's cells, with a 50% inhibitory concentration of 1-2 ng/ml (13-24 PM). The antibody LL2 alone had no cytotoxicity toward the malignant cells, and excess LL2 prevented the cytotoxicity of LL2-PE38KDEL and LL2-Fab'-PE38KDEL. Control immunotoxins UPC-10-PE38KDEL and Mu-9-Fab'-PE38KDEL were not cytotoxic. LL2-PE38KDEL and LL2-Fab'-PE38KDEL bound to cells with 50% and 17% of the affinity of LL2, respectively. Both immunotoxins, but not UPC-10-PE38KDEL, prevented the development of CA-46 tumors in nude mice. LL2-PE38KDEL and LL2-Fab'-PE38KDEL, but not the control immunotoxins, led to complete regressions of measurable s.c. CA-46 tumors in nude mice, when given at 50% and 35% of the 50% lethal dose, respectively. LL2 alone significantly retarded the growth of CA-46 tumors but did not cause complete tumor regressions. Immunotoxins containing derivatives of Pseudomonas exotoxin can be targeted to human B-cell lymphoma and merit further study as potential therapeutic agents.
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PMID:Pseudomonas exotoxin-based immunotoxins containing the antibody LL2 or LL2-Fab' induce regression of subcutaneous human B-cell lymphoma in mice. 842 63

Group I Burkitt lymphoma (BL) cell lines, which retain the original biopsy phenotype, have been shown to enter apoptosis in response to a number of external stimuli including serum deprivation, thermal shock, addition of calcium ionophore, and ligation of surface immunoglobulin (Ig) by antibody. Transforming growth factor-beta 1 (TGF beta 1) is known to cause growth arrest in BL lines. Here we show that while it is by itself capable of promoting some degree of apoptosis in group IBL cells, TGF beta 1 cooperates with anti-immunoglobulin to this end. Trimeric soluble recombinant human CD40 ligand (sCD40L) was able to inhibit apoptosis induced by the combination of agonists to some degree, but such rescue proved to be short-lived. Both TGF beta 1 and anti-Ig individually caused BL cells to undergo growth arrest at the G1 phase of cell cycle before their entry into apoptosis: the consequence of sCD40L addition was to maintain the cells in cycle for longer. No induction of the apoptosis-protecting gene, bcl-2, occurred in the presence of sCD40L. These findings are discussed, particularly highlighting the relationship existing between survival and the cell cycle. The strong cooperative effects observed between anti-Ig and TGF beta 1 in promoting apoptosis and the inability of CD40 to signal for long-term rescue raise the potential for a novel therapeutic attack on B-cell lymphoma.
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PMID:Transforming growth factor-beta 1 cooperates with anti-immunoglobulin for the induction of apoptosis in group I (biopsy-like) Burkitt lymphoma cell lines. 856 41

A conditional mutant of Epstein-Barr virus nuclear antigen 2 (EBNA2) regulated by estrogen was employed to study the effect of EBNA2 on the cellular phenotype. Activation of EBNA2 in lymphoblastoid cell lines (LCLs) and in B cell lymphoma lines resulted in down-regulation of cell surface IgM and Ig-mu steady-state RNA expression. In LCLs, activation of EBNA2 is required for maintaining proliferation, whereas in Burkitt's lymphoma (BL) cell lines with t(8;14) translocations, activation of EBNA2 induces growth arrest. In these cells, Northern and nuclear run-on analyses revealed rapid simultaneous repression of Ig-mu and c-myc transcription as early as 30 min after activation of EBNA2. Since c-myc expression is under the control of the Ig heavy chain locus in BL cell lines with a t(8;14) translocation, we propose that Ig-mu and c-myc are down-regulated by EBNA2 through a common mechanism.
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PMID:Epstein-Barr virus nuclear antigen 2 is a transcriptional suppressor of the immunoglobulin mu gene: implications for the expression of the translocated c-myc gene in Burkitt's lymphoma cells. 861 12

The Epstein-Barr virus (EBV) nuclear antigen-1 (EBNA-1) is a pleiotropic protein which has been characterized extensively both biochemically and functionally. It is the only one of the identified latent protein-encoding genes to be consistently expressed in viral-associated endemic Burkitt's lymphoma cells. As such, it is the only candidate viral protein to possibly perform a maintenance function in the tumour pathology. Despite this, no oncogenic activity has been attributed to the protein in tissue culture assays. The experiments described here were initiated to explore the activity of the protein in B cells in vivo. EBNA-1 transgenic mice were generated with transgene expression directed to the B cell compartment using the mouse Ig heavy chain intron enhancer. Transgene expression was demonstrated in the lymphoid tissues of mice of two independent lines. Transgenic positive mice of both lines succumb to B cell lymphoma. The B cell tumours are monoclonal, frequently of follicular centre cell origin and remarkably similar to those induced by transgenic c-myc expression. These results demonstrate that EBNA-1 is oncogenic in vivo and suggest that the gene product may play a direct role in the pathogenesis of Burkitt's lymphoma and possibly other EBV-associated malignancies.
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PMID:Expression of Epstein-Barr virus nuclear antigen-1 induces B cell neoplasia in transgenic mice. 867 Aug 12

A total of 179 cases of lymphoma, both nodal and extranodal, recorded in the Papua New Guinea Tumor Registry were reviewed and classified by the updated Kiel classification. Fifteen (8.4%) were Hodgkin's disease, 39 (21.8%) probable Burkitt's lymphoma (poorly preserved), 46 (25.7%) Burkitt's lymphoma, 33 (18.4%) Burkitt's-like lymphoma, 36 (20.1%) other B-cell subtypes and 10 (5.6%) T-cell lymphoma. No case of follicular B-cell lymphoma was encountered.
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PMID:Malignant lymphomas in Papua New Guinea: an immunohistological study of 125 cases. 871 68


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