Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:Q06643 (non-Hodgkin's lymphoma)
 11,307 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The novel human pre-B cell line OZ was established from a patient with an aggressive form of non-Hodgkin's lymphoma. Karyotypic analysis of both the primary tumour and OZ cells revealed several marker chromosomes, including the t(14;18)(q32;q21) translocation, which involves the Bcl-2 gene, and alterations on chromosome 17p. Southern blot analysis found identical rearrangements in the 5' region of Bcl-2 gene in the primary tumour and OZ cells. Homozygous deletions of the p15INK4B and p16INK4A genes, however, were present only in OZ cells. Western blot analysis detected aberrant small molecular-weight p53 proteins in both cell types. In addition, OZ cells no longer expressed the CD20 antigen. These findings suggest that Bcl-2 gene rearrangement and aberrant p53 expression resulted in the original B-cell tumour. A subsequent transforming event involving the p15INK4B and p16INK4A genes may have generated more immature cells with a growth advantage during in vitro culture. The genetic alterations involving p53, p15INK4B, and p16INK4A may be implicated in the aggressive form of t(14;18)(q32;q21)-bearing tumours and their poor prognosis.
 ...
PMID:Establishment of a novel human B-cell line (OZ) with t(14;18)(q32;q21) and aberrant p53 expression was associated with the homozygous deletions of p15INK4B and p16INK4A genes. 960 Jan 10

Rituximab (Rituxan; IDEC Pharmaceuticals, San Diego, CA) is the first monoclonal antibody approved by the US Food and Drug Administration for the treatment of cancer. It is a genetically engineered chimeric (murine-human) monoclonal antibody (mAb) directed against the CD20 antigen found on the surface of normal and malignant B cells. Multicenter studies have demonstrated its efficacy against relapsed low-grade and follicular non-Hodgkin's lymphoma (NHL). The mAb demonstrated tolerable side effects, primarily limited to fevers and chills associated with the first infusion. The currently recommended dosage is 375 mg/m2/infusion, given weekly for 4 weeks. Because of its human component, rituximab has low immunogenicity and should not significantly hinder future retreatment. Future studies will evaluate the antitumor activity of rituximab combined with various other chemotherapeutic or biologic agents in the treatment of B-cell lymphoma and other CD20-positive lymphoid neoplasms.
 ...
PMID:Use of rituximab, the new FDA-approved antibody. 981 34

Significant advances have been made in the application of monoclonal antibody-based therapies to the treatment of patients with lymphoma. The most promising areas appear to be the use of unconjugated monoclonal antibodies and the use of radiolabeled monoclonal antibodies. The recent approval by the US Food and Drug Administration (FDA) of rituximab (Rituxan), an unconjugated chimeric antibody against the CD20 antigen for the treatment of relapsed low-grade or follicular B-cell non-Hodgkin's lymphoma marked a milestone in the development of these antibody-based treatments. Other new drug applications to the FDA are pending using both unconjugated and radiolabeled monoclonal antibodies, and it is anticipated that further new treatment options based on monoclonal antibody technology will soon be available for the treatment of patients with non-Hodgkin's lymphoma. Forthcoming clinical trial results combining these new agents with current therapies are needed to determine if the addition of these new biologic agents to our armamentarium against lymphoma will alter the natural history of this disease for our patients. The most promising of these treatments and the comparison of these strategies are reviewed here.
 ...
PMID:Newer treatments for non-Hodgkin's lymphoma: monoclonal antibodies. 983 Jun 35

Rituximab is a chimeric antibody with human gamma-1 and kappa constant regions and murine variable regions. It recognizes the CD20 antigen, a pan B-cell marker. Therapeutic trials in patients with B-cell non-Hodgkin's lymphoma (NHL) have shown significant efficacy with a primary response rate of 50%, and a secondary response rate of 44% after repeat treatments in prior responders. The selection for proliferating tumor cells that no longer express CD20 may compromise repeated treatment. We have identified a patient who developed a transformed NHL that lost CD20 protein expression after two courses of therapy with rituximab. In a pretreatment lymph node biopsy, 83% of B cells (as defined by CD19 and surface immunoglobulin) expressed surface CD20. A biopsy from the recurrent tumor after two courses of rituximab revealed a diffuse large cell NHL where 0% of B cells expressed CD20 with no evidence of bound rituximab. Cytoplasmic staining showed no CD20 protein. Sequencing of immunoglobulin heavy chain cDNA identified identical variable sequences in the initial and recurrent lymphomas, confirming the association between the two tumors. Literature and database review suggests that approximately 98% of diffuse large cell lymphomas express CD20, which suggests that these tumors rarely survive without CD20. This is the first identified case of loss of CD20 expression in a lymphoma that has relapsed after rituximab therapy, although several other cases have since been identified. Considering the significant number of patients treated with anti-CD20 antibodies, this may occur only rarely and is unlikely to preclude recurrent therapy with anti-CD20 antibodies in the majority of patients. However, because many patients have relapsed after anti-CD20 antibody therapy and have not been biopsied to identify clones with down-regulated CD20 antigen, we do not currently know the true frequency of this phenomenon. When possible, patients should undergo evaluation for CD20 expression before repeated courses of anti-CD20 therapy.
 ...
PMID:Therapy of B-cell lymphoma with anti-CD20 antibodies can result in the loss of CD20 antigen expression. 1065 64

Approximately 55,400 new cases of non-Hodgkin's lymphoma (NHL) are diagnosed each year, with the overall prevalence of the disease now estimated to be 243,000. Until recently, treatment alternatives for advanced disease included chemotherapy with or without external beam radiation. Based on the results of several clinical trials, the chimeric monoclonal antibody Rituximab has now been approved by the United States Food and Drug Administration as a treatment for patients with relapsed or refractory, low-grade or follicular, B-cell NHL. Several other monoclonal antibodies in conjugated and unconjugated forms have been evaluated in the treatment of NHL. Ibritumomab, the murine counterpart to Rituximab, radiolabeled with 90Y (Zevalin), is presently being evaluated in clinical trials. The success of radioimmunotherapy is dependent upon the appropriate choice of antibody, isotope, and chelator-linker. The Ibritumomab antibody targets the CD20 antigen. The antibody is covalently bound to the chelator-linker tiuxetan (MX-DTPA), which tightly chelates the isotope 90Y. To date, two Phase I/II Zevalin clinical trials have been completed in patients with low-grade, intermediate-grade, and mantle cell NHL. The overall response rate was 64% in the first trial and 67% in the later trial. Phase II and III trials are ongoing.
 ...
PMID:Radioimmunotherapy of relapsed non-Hodgkin's lymphoma with zevalin, a 90Y-labeled anti-CD20 monoclonal antibody. 1054 76

The CD20 antigen is an attractive target for antibody-directed therapy due to its stable, high-level surface expression on normal and malignant B cells. Rituximab (Rituxan; IDEC Pharmaceuticals, San Diego, and Genentech, Inc, San Francisco, CA) is an anti-CD20 chimeric monoclonal antibody that has shown single-agent activity in phase I and II clinical trials in patients with B-cell non-Hodgkin's lymphoma. This antibody has a long serum half-life and low immunogenicity. Infusional symptoms are common with the initial infusion but rare with subsequent treatments. Temporary B-cell depletion occurs but has not been associated with immunodeficiency. The mechanism of action likely includes both immune-mediated effects and direct effects. The generally mild toxicity profile and excellent single-agent activity provide the rationale for use with or following chemotherapy. Additional studies evaluating these and other combinations are under way.
 ...
PMID:Preclinical and phase I and II trials of rituximab. 1056 Oct 21

Anti-CD20 antibody is an established treatment for low-grade non-Hodgkin's lymphoma (NHL). Augmenting the expression of CD20 antigen on the tumor cells may increase the cell kill and therefore increase the effectiveness of the antibody. To study this, we incubated peripheral blood lymphocytes from CLL patients with the following cytokines: EPO, SCF, TNFalpha, TGFbeta, GMCSF, TPO, IL-1, IL-2, IL-3, IL-4, GCSF. CD20 expression was studied by flow cytometry at baseline, 24 and 72 h after exposure to these cytokines. Upregulation of CD20 antigen expression was observed with IL-4, TNFalpha and GMCSF.
 ...
PMID:Effects of cytokines on CD20 antigen expression on tumor cells from patients with chronic lymphocytic leukemia. 1120 84

Rituximab, a chimeric monoclonal antibody targeting the CD20 antigen on B lymphocytes, is now the standard treatment for relapsed, low-grade or follicular non-Hodgkin's lymphoma.
 ...
PMID:Rituximab immunotherapy for non-Hodgkin's lymphoma. 1085 Mar 9

Rituximab is a chimeric monoclonal antibody (MAb) directed against the B-cell CD20 antigen that has been approved for therapy of relapsed and resistant follicular non-Hodgkin's lymphoma (NHL). This study describes the development and validation of a highly sensitive, rapid, accurate, precise enzyme-linked immunosorbent assay (ELISA) to measure Rituximab serum concentrations. This study also describes the application of the ELISA method to a pharmacokinetic study in a homogeneous group of patients with follicular lymphoma who received 4 weekly doses of MAb at the standard dose of 375 mg/m2 as consolidation of chemotherapy. In the patients in this study, the median Rituximab serum concentrations increased during therapy, and showed a slow decline during the posttreatment period. The Rituximab elimination half-life of approximately 20 days accounts for the demonstrated accumulation of MAb in serum samples. Because previous pharmacokinetic studies showed a correlation between Rituximab serum levels and tumor response, the ELISA method used in this study, which allows a precise control of serum concentrations, could be useful for predicting the final response to the MAb and for selecting patients able to benefit from higher dosage or repeated drug administration.
 ...
PMID:Rituximab (IDEC-C2B8): validation of a sensitive enzyme-linked immunoassay applied to a clinical pharmacokinetic study. 1085 Mar 96

Chimeric CD20 monoclonal antibody as alternative therapy in relapsed low-grade non-Hodgkin's lymphoma (NHL) has produced responses in nearly 50% of patients. Augmenting CD20 expression on tumor cells and/or inducing its expression may increase the cell kill and effectiveness of antibody therapy. Peripheral blood lymphocytes from 19 patients with B-cell chronic lymphocytic leukemia (B-CLL) were incubated in vitro in the presence of interferon-alpha (IFN-alpha) (500 U/ml and 1,000 U/ml) for 24 and 72 hours. The effect on CD20 expression was studied by flow cytometry. The differences in the percentage positivity, the mean fluorescence intensity (MFI), and the product of percentage positivity and MFI were used to assess upregulation. There was a significant upregulation of CD20 expression on B cells seen at both concentrations after 24-hour priming (p < 0.01). B-CLL cells cultured for 72 hours in the presence of IFN-alpha also showed upregulation of CD20 expression; however, the degree of upregulation was much lower than that seen at 24 hours. There was no statistically significant increase in CD20 antigen expression on normal lymphocytes following cytokine exposure. These results suggest that IFN-alpha priming may augment the effectiveness of antibody therapy by directly upregulating CD20 antigen expression in addition to its indirect action through effector cells of the host.
 ...
PMID:Effect of interferon-alpha on CD20 antigen expression of B-cell chronic lymphocytic leukemia. 1110 73


1 2 3 4 5 6 7 Next >>