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

Rituximab has been established as an effective and safe therapy for cutaneous B-cell lymphoma (CBCL). Different survival pathways, that is the Raf/MEK/Erk- or the p38MAPK cascade, have been suggested as downstream mediators of rituximab and may be involved in treatment failure. Biopsies from four patients, suffering from different subtypes of CBCL, which were obtained at various time points of relapse during or after therapy with 375 mg rituximab per m2 of body surface area, were analysed for the expression of CD20, CD3, Ki-67, Raf-kinase inhibitory protein (RKIP) and bcl-2 by immunohistochemistry. No CD20-loss variants, that is the suggested main tumour escape mechanism to rituximab therapy, were observed in any specimen of relapsing CBCL. Notably, the expression of proapoptotic RKIP remained increased in these tumour samples. This was concomitated by a constant to slightly reduced proliferation status as demonstrated by Ki-67 staining. However, relapsing CBCL exhibited a strong upregulation of the antiapoptotic molecule bcl-2 in comparison to pretherapeutic levels. The immunohistochemical analyses of this case series of rituximab refractory CBCL suggest that upregulation of bcl-2 may play a major role in therapy resistance.
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PMID:Bcl-2 expression in rituximab refractory cutaneous B-cell lymphoma. 1747 27

A 43-year-old man presented with erythematous, indurated plaques on the scalp in the setting of a 16-year history of recurrent cutaneous tumors of the head and trunk. Clinical and histopathologic findings were consistent with a diagnosis of primary cutaneous B-cell lymphoma. Laboratory data and computed tomography imaging of the chest, abdomen, and pelvis failed to show an associated systemic lymphoma. Primary cutaneous B-cell lymphomas are a heterogenous group of lymphomas that primarily involve the skin but have variable clinical, histopathologic, and immunologic phenotypes. Successful treatment for most localized subtypes consists of surgical excision and radiation therapy. Rituximab, a chimeric monoclonal antibody that binds the B-cell-specific antigen CD20, has shown promise in treating a number of primary cutaneous B-cell lymphomas.
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PMID:Primary cutaneous B-cell lymphoma (low-grade, non large cell). 1751 41

Rituximab is the first monoclonal antibody to have been registered for the treatment of B-cell lymphomas. Randomized studies have demonstrated its activity in follicular lymphoma (FL), mantle cell lymphoma and diffuse large B-cell lymphoma (DLBCL) in untreated or relapsing patients. Non-comparative studies have shown an activity in all other lymphomas. Because of its high activity and low toxicity ratio, rituximab has transformed the outcome of patients with B-cell lymphoma. A combination of rituximab plus chemotherapy, rituximab+cyclophosphamide+doxorubicin+vincristine+prednisolone (R-CHOP), has the highest efficacy ever described with any chemotherapy in DLBCL and FL. Some patients are refractory to rituximab but the precise mechanisms of this refractoriness are not understood.
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PMID:Rituximab therapy in malignant lymphoma. 1753 14

Rituximab is a chimeric monoclonal antibody to the surface antigen CD20 and has provided better outcomes against CD20+ B-cell lymphomas than chemotherapy with conventional antitumor drugs alone. Treatment with rituximab poses a considerable problem, however, because of CD20- tumor transformation and subsequent disease progression. We have established a CD20- lymphoma cell line, RRBL1, from a diffuse large B-cell lymphoma with CD20- transformation from CD20+ follicular lymphoma after treatment with rituximab. RRBL1 was CD10+, CD19+, and CD20- by flow cytometry. CD20 expression was not detected by immunohistochemistry. Immunoblotting with whole RRBL1 cell lysate showed a very faint CD20 band only with longer exposures. The level of CD20 messenger RNA (mRNA) expression detected by quantitative reverse transcriptase-polymerase chain reaction analysis was almost 100 times lower than that in CD20+ lymphoma cells. When we treated RRBL1 cells with trichostatin A, an epigenetic drug that modulates histone-acetylation status, we detected dramatically increased CD20 mRNA and protein expression, suggesting that epigenetic mechanisms may explain the CD20- phenotype in RRBL1 cells. Thus, RRBL1 may be useful not only for analyses of mechanisms for the absence of CD20 expression in vitro but also for exploration of therapies against CD20- B-cell malignancies in vivo.
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PMID:Epigenetic regulation of CD20 protein expression in a novel B-cell lymphoma cell line, RRBL1, established from a patient treated repeatedly with rituximab-containing chemotherapy. 1767 67

Splenic marginal zone lymphoma with or without villous lymphocytes (SLVL/SMZL) is a low grade B-cell lymphoma that affects patients in the sixth decade and has a median survival greater than 10 years. A substantial proportion of patients die from causes unrelated to the disease. Close to a third of the patients do not require intervention and a policy of watch and see is reasonable and recommended. There are several therapeutic options that have proved effective in these patients. Due to the natural history of the lymphoma, the main goal of all these treatments is to achieve control of the disease rather than its eradication. Retrospective designs of all documented studies, the lack of uniform response criteria and the heterogeneity in the patient's features makes interpretation of the data difficult. Splenectomy remains one of the first line options in patients fit for surgery. Amongst chemotherapy, purine analogues, in particular fludarabine in combination or not with Rituximab and Rituximab alone have a greater efficacy than alkylating agents in terms of achieving better quality of response and longer progression free survival; therefore these agents are recommended particularly in patients who are not candidates for surgery or relapse after splenectomy. In the small proportion of patients with concomitant hepatitis C virus (HCV) infection, Interferon-alpha, ribavirin or a combination of both has demonstrated a significant activity with responses correlating with clearance of HCV RNA in the blood; therefore, these agents should be considered in the therapeutic scenario as a first line in these small cohort of patients. Patients that transform to high-grade lymphoma and the minority that have TP53 abnormalities should be treated with other schedules. Prospective randomized trials would be desirable to ascertain the independent prognostic factors and the biological features that predict disease progression and drug resistance to device the optimal management and treatment for SLVL/SMZL.
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PMID:Splenic marginal zone lymphoma with and without villous lymphocytes. 1768 Feb 18

In industrialized nations people infected with HIV remain at increased risk for malignancies despite highly active antiretroviral therapy. In these countries, lymphoma is the most common HIV-associated malignancy. This review summarizes progress from January 2005 to February 2007. The majority of investigation has been in diffuse large B cell lymphoma, with infusional therapy remaining promising but cumbersome. Rituximab likely improves complete response rates, and, possibly overall survival, but is likely associated with increased infections in a subset of patients with very low CD4 counts. Biologic insights have been attained in the spectrum of HIV-associated non-Hodgkin's lymphoma, Hodgkin's lymphoma, and virologic coinfections. Overall, the outcome for non-Hodgkin's lymphoma and Hodgkin's lymphoma in the setting of HIV continues to improve as insights into the pathophysiology and treatment advance.
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PMID:Update on HIV lymphoma. 1770 67

Several studies have shown that adding rituximab to CHOP (cyclophosphamide, doxorubicin, vincristine, prednisolone) or reducing the interval between chemotherapy cycles from 3 weeks to 2 weeks improves survival in patients with diffuse large B-cell lymphoma (DLBCL). These studies prompted our group (GOTEL) to evaluate prospectively in a pilot study the feasibility and efficacy of R-CHOP-14 in patients with DLBCL. Patients (<70 years) with stage II bulky or stage III or IV DLBCL and no significant comorbidities were included in the study. Rituximab was administered on day 1 before chemotherapy. R-CHOP was given every 14 days. All patients received filgrastim (5 microg/kg) from days 4 to 10. From May 2002 to August 2004, 80 patients were recruited. Median age was 53 years and 58 patients were <60 years. According to the age-adjusted international prognostic index (aaIPI), 13 patients (16%) had low-risk disease, 31 (39%) low-to-intermediate risk, 27 (34%) high-to-intermediate risk and 9 (11%) high-risk disease. Grade 3-4 neutropenia was observed in 15 patients (17.5%) and grade 3-4 infections in 13 patients (16%). After therapy, 58 patients (73%) achieved CR-CRu (95% CI: 55-90%). With a median follow-up of 26 months, progression-free survival (PFS) and overall survival (OS) at 30 months were 72% and 86%, respectively. Administration of R-CHOP-14 is feasible and effective in patients <70 years.
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PMID:R-CHOP-14 in patients with diffuse large B-cell lymphoma younger than 70 years: a multicentre, prospective study. 1786 90

Several monoclonal antibodies that target cell surface receptors have gained approval by the U.S. Food and Drug Administration and are widely used in the treatment of some cancers. These include but are not limited to the anti-CD20 antibody Rituximab, used in lymphoma treatment, as well as anti-HER-2 antibody for breast cancer therapy. The efficacy of this cancer immunotherapy modality is, however, limited by the large size of the antibody (160 kd) and its relatively nonspecific binding to the reticuloendothelial system. This latter property is particularly problematic if the antibody is used as a vehicle to deliver radionuclides, cytotoxic drugs, or toxins to the tumor site. Peptides, peptidomimetic, or small molecules are thus attractive as alternative cell surface targeting agents for cancer imaging and therapy. Cancer cell surface targeting peptides can be derived from known native peptide hormones such as somatostatin and bombesin, or they can be identified through screening combinatorial peptide libraries against unknown cell surface receptor targets. Phage-display peptide library and one-bead one-compound (OBOC) combinatorial library methods have been successfully used to discover peptides that target cancer cells or tumor blood vessel endothelial cells. The phage-display peptide library method, because of its biological nature, can only display l-amino acid peptides. In contrast, the OBOC combinatorial library method allows for bead-surface display of peptides that contain l-amino acids, d-amino acids, unnatural amino acids, or other organic moieties. We have successfully used the OBOC method to discover and optimize ligands against unique cell surface receptors of prostate cancer, T- and B-cell lymphoma, as well as ovarian and lung cancers, and we have used some of these peptides to image xenografts in nude mice with high specificity. Here, we (i) review the literature on the use of phage-display and OBOC combinatorial library methods to discover cancer and tumor blood vessel targeting ligands, and (ii) report on the use of an ovarian cancer targeting ligand, OA02, as an in vivo PET imaging probe in a xenograft model in nude mice.
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PMID:From combinatorial chemistry to cancer-targeting peptides. 1788 Jan 66

Rituximab (Rit) was the first monoclonal antibody approved for therapeutic use in cancer patients. Rit is a chimeric mouse/human monoclonal antibody, consisting of the human IgG1 and k constant Fc region, and a mouse variable Fab region specific against the B-cell antigen CD20. Rit exerts its antilymphoma activity through many different mechanisms. Binding of antibody to CD20 antigen, provokes apoptosis through downstream signals that lead to caspase-3 activation. Complement activation by the Fc portion of the antibody results in complement-dependent cytotoxicity. However, the most effective mechanism of action seems to be antigen-dependent cellular cytotoxicity. Effector cytotoxic cells such as natural killer cells (NK) are activated after binding to the Fc portion of the anti-CD20 molecule. Activated NK cells kill the coated lymphoma cells with the use of granzyme-perforin system. More recently, pre-clinical data support the concept that Rituximab can provoke a vaccination-like effect. Finally in-vitro experiments and clinical trials have shown that co-administration of the antibody with cytotoxics confers a strong synergistic effect. The relative contribution of these mechanisms in vivo and in different lymphoma subtypes is not well known and remains to be further evaluated. Among the different histological groups, follicular lymphoma (FL) has been proven to be the most sensitive to Rit when used as a single agent, with overall response rates of 80% and 50% in untreated and previously treated patients, respectively. Moreover, Rit in combination with chemotherapy is superior to chemotherapy alone in terms of response rate and event-free survival, while early data indicate a significant prolongation in overall survival as well. Similarly, the addition of Rit to standard chemotherapy improves the disease-free and overall survival of patients with diffuse large B-cell lymphoma. There is no doubt that Rit represents one of the greatest achievements of biotechnology engineering. However, we need to understand better the mechanisms of its action as well as the mechanisms of resistance to Rit, in order to design more effective treatment modalities.
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PMID:Monoclonal antibodies in the treatment of lymphoid malignancies. 1793 74

Rituximab, an anti-CD20 monoclonal antibody, is widely used in the treatment of B-cell lymphoma. Some reports have outlined histologic modifications in bone marrow specimens from patients treated with this antibody, notably the presence of CD3(+) lymphoid aggregates morphologically mimicking residual lymphoma. To gain insight into the significance of such infiltrates, serial BM trephines obtained in 39 patients with B-cell follicular lymphoma treated by rituximab and enrolled in the GOELAMS-GELA intergroup FL2000 protocol were reexamined. The 39 patients were 22 women and 17 men with a median age of 50 years (range, 29-75 years). All pretreatment bone marrow biopsies showed CD20(+) lymphomatous cells. A second biopsy was obtained between 30 and 100 days after the last rituximab injection: 19 (48%) were morphologically diagnosed as negative (no lymphoid infiltrates or only minor lymphoid aggregates) and 20 (51%) as positive because of persistent lymphoid nodules. After immunohistochemical analysis, 13 (33%) cases were reinterpreted as false-positive because of the complete absence of CD20(+) cells, with the lymphoid nodules consisting of CD3(+) and CD5(+) T cells. Most of them also expressed CD4(+), whereas only a few CD8(+) cells were present. Among these 13 false-positive cases, 12 were BCL2-IGH polymerase chain reaction-negative in the bone marrow aspirate at the time of biopsy. The 13th case turned out to be negative in the 18th-month bone marrow aspirate. In all of these cases, lymphoid aggregates had disappeared on bone marrow biopsies performed 18 months after treatment. After a mean follow-up of 4.5 years, 9 of 13 patients were in remission as compared with only 2 among the 7 patients with postrituximab persistent CD20(+) lymphomatous cells. There was no statistically significant difference between this false-positive group of patients and that with negative postrituximab bone marrow regarding sex, age, medullar involvement pattern before treatment, delay between rituximab treatment, and molecular status. Interestingly, we noted a more favorable outcome (70% versus 52% remission) for the false-positive cases, suggesting that these T-cell reactions could be the hallmark of specific antitumoral immunity after rituximab treatment and should be properly investigated.
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PMID:T-cell lymphoid aggregates in bone marrow after rituximab therapy for B-cell follicular lymphoma: a marker of therapeutic efficacy? 1794 86


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