Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.6.3.44 (P-glycoprotein)
 13,344 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Major advances in cellular biology, genetics, pharmacology and immunology in the past decade are beginning to be translated into progress in cancer treatment. This progress is manifested by new cytotoxic drugs which have recently entered clinical practice (taxanes, topoisomerase I inhibitors, gemcitabine, vinorelbine, new purines), as well as the efficacy of monoclonal antibody therapies against the CD-20 antigen of B-cell lymphomas and the Her2/neu oncogene in breast cancer. Several new drugs in development are targeted at reversal or prevention of the multidrug resistance mechanism caused by expression of the MDR1 gene (P-glycoprotein). Tumour angiogenesis as a target is being studied in several early clinical trials. As with many other biological therapies, the evaluation of these compounds and their integration with standard therapies presents a major challenge to clinical investigators. The emerging field of genomics and gene expression micro-arrays will provide enormous information about the biology of cancers. This technology offers great opportunities for the discovery of new therapeutic targets, which should provide a basis for the design and evaluation of many new agents in the coming decade.
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PMID:New approaches in cancer treatment. 1067 67

Some follicular lymphomas histologically transform into diffuse aggressive lymphomas, the prognosis of which is poor. There are, however, no reliable histological criteria for predicting which cases will later undergo such transformation. In low-grade B-cell lymphomas, follicular dendritic cells form dense mesh-like networks that contain accumulating neoplastic B-cells. These are rare in high-grade lymphomas. We immunohistochemically analyzed CD21-positive follicular dendritic cells in 32 follicular lymphomas, including 3 transformed lymphomas, in addition to immunohistological study using P-glycoprotein, p53, and Ki-67. We found that the mesh-like networks in follicles are more clearly defined in low-grade lymphomas than in high-grade lymphomas (p = 0.015). Neoplastic follicles in 2 transformed lymphomas lost the networks of follicular dendritic cells before transformation despite the existence of morphologically clear follicles. This differed from the non-transformed cases of the same cytological grades. Prognosis was statistically better for patients with low-grade tumor than for those with high-grade tumor (p = 0.026), and there was a trend toward poorer survival among CD21-negative cases (p = 0.186). P-glycoprotein, p53, and Ki-67 expressions did not provide sufficient information to predict the transformation of follicular lymphoma. The presence of CD21-positive follicular dendritic cells in neoplastic follicles might help predict the potential of follicular lymphoma to transform to diffuse large B-cell lymphoma.
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PMID:Disappearance of CD21-positive follicular dendritic cells preceding the transformation of follicular lymphoma: immunohistological study of the transformation using CD21, p53, Ki-67, and P-glycoprotein. 1290 19

Mature T-cell and natural killer (NK)-cell lymphomas are rare neoplasms, differing geographically in frequencies. T-cell lymphomas are more common in Asia than in western countries, and NK-cell lymphomas occur almost exclusively in Asia and South America. The rarity of these lymphomas means that treatment algorithms of T-cell and NK-cell lymphomas have not been well established. Angioimmunoblastic T-cell lymphoma, anaplastic large cell lymphoma and peripheral T-cell lymphoma, not otherwise specified, are the more commonly encountered T-cell lymphomas. Treatment with anthracycline-based regimens designed for aggressive B-cell lymphomas gives unsatisfactory results. Cutaneous T-cell lymphomas may remain indolent, but outcome is poor for advanced diseases. Novel therapies, including monoclonal antibodies, nucleoside analogs, histone deacetylase inhibitors and small molecules targeting cellular signaling pathways, are being explored alone or in combination with chemotherapy. High-dose chemotherapy with hematopoietic stem cell transplantation (HSCT) is recommended for high-risk cases. NK-cell lymphomas exhibit the multidrug resistance phenotype due to P-glycoprotein expression, so that anthracycline-based regimens are ineffective. Non-multidrug resistance-dependent regimens and L-asparaginase-based protocols have been shown to be highly active. Autologous HSCT is not routinely performed. The role of allogeneic HSCT is being examined.
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PMID:Treatment algorithms for mature T-cell and natural killer-cell neoplasms. 2191 97

Treatment outcomes of malignant lymphoma have improved due to the discovery of novel chemotherapeutic and molecular targeted agents as well as advances in their combination uses. However, the prognosis of T-cell lymphoma remains poorer than that of B-cell lymphomas, and progress is slow. The reasons include their chemotherapeutic resistant nature and the absence of effective antibody agents for T-cell lymphomas. The number of T-cell lymphoma subtypes increased from 21 in the WHO classification 2008 to 29 in the WHO classification 2016. This means that T-cell lymphomas are heterogeneous. T-cell lymphomas can be divided to ALK-positive anaplastic lymphoma (ALCL) with a good prognosis and others with poorer prognoses. ALK-positive ALCL can be successfully treated with CHOP, but the others cannot. P-glycoprotein resistant anthracyclines, etoposide, or hematopoietic stem cell transplantations are increasingly applied to improve outcomes, but no standard treatment approach has yet been established. Regarding relapsed/refractory T-cell lymphoma, many novel agents are currently under development. The treatment outcomes of T-cell lymphoma need to be improved by applying innovative strategies including further novel agents.
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PMID:Progress in the treatment of mature T-cell lymphoma. 2779 7

Introduction: Natural killer (NK)/T-cell lymphomas are aggressive malignancies that present predominantly in nasal and adjacent sites (nasal subtype), occasionally in skin, gastrointestinal tract and other tissues (non-nasal), and rarely as disseminated disease with a leukemic phase (aggressive NK-cell leukemia, or leukemia/lymphoma, subtype).Areas covered: The diagnosis and treatment of NK/T-cell lymphoma are discussed, based on a PubMed literature search. The diagnostic criteria for NK/T-cell lymphoma are highlighted, followed by an update of the diagnostic and prognostic importance (on presentation, at interim and end-of-treatment) of plasma EBV DNA as a surrogate biomarker of lymphoma load. Prognostic models based on clinicopathologic features and EBV DNA load are discussed. For stage I/II NK/T-cell lymphomas, combined chemotherapy, and radiotherapy gives the best results, with their concomitant or sequential administration equally efficacious. For stage III/IV NK/T-cell lymphoma, chemotherapy is the mainstay of treatment. Conventional anthracycline-based regimens for B-cell lymphomas are ineffective. Recommended regimens combine L-asparaginase with other drugs not affected by P-glycoprotein. For relapsed/refractory patients, immune checkpoint blockade with antibodies against programmed cell death protein 1 has shown much promise.Expert opinion: Current strategies result in durable remissions in a significant proportion of NK/T-cell lymphomas. Immune checkpoint inhibition and other novel approaches are promising for relapsed/refractory cases.
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PMID:Recent advances in the diagnosis and treatment of natural killer/T-cell lymphomas. 3148 2