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

Typical multidrug resistance in human and animal cell lines is caused by overactivity of an unidirectional transmembrane drug efflux pump, encoded by the MDR genes, called mdr genes in mice and humans and pgp genes in hamsters. In humans, two mdr genes, mdr1 and mdr3, with approximately 80% nucleotide homology, have been identified. There is increasing evidence that overexpression of the mdr1 gene plays a role in resistance to anticancer agents in specific tumor types. However, currently no data are available on a possible role for mdr3 in drug resistance. Here we report high levels of expression of mdr3 gene sequences in leukemic cells from 6 out of 6 patients with prolymphocytic leukemia (PLL). No mdr1 expression was detected in 5 out of 6 of these samples, whereas a low level of mdr1 expression was found in a sample from one PLL patient in the course of transformation to non-Hodgkin's lymphoma. Except for this patient, all other PLL cases studied had not received prior chemotherapy. In vitro drug uptake studies showed that daunorubicin accumulation in PLL cells was increased by cyclosporin A. Since cyclosporin A is an inhibitor of the mdr1-encoded P-glycoprotein drug pump, these data suggest that in PLL cells mdr3 also codes for a drug efflux pump. Our findings could partly explain the primary refractoriness of PLL to chemotherapy.
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PMID:Expression of the mdr3 gene in prolymphocytic leukemia: association with cyclosporin-A-induced increase in drug accumulation. 232 39

A 75-year-old man was admitted to our hospital on June 1st, 1993, because of nasal obstruction, epistaxis, fever, night sweats and weight loss. Examination disclosed a 2-cm white necrotic mass in the nasal septum, and a biopsy disclosed non-Hodgkin's lymphoma, diffuse, mixed-type. Imprint smears showed cytoplasmic azurophilic granules in the tumor cells. Dense granules were demonstrated by electron microscopy. The tumor cells were CD1-2+3-4-7+8-16+56+57-, and T cell receptor genes were in germline configuration. NK activity against K562 was strongly positive. Based on morphologic, phenotypic, immunogenotypic, and cytotoxic findings, the tumor cells seemed to be derived from activated NK cells. Because the tumor cells were positive for the EB virus and CD21 antigen, EB virus seemed to have infected CD21-positive NK cells and transformed them. MDR P-glycoprotein was also positive. This finding may explain why nasal lymphomas are resistant to chemotherapy and have a poor prognosis.
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PMID:[Nasal NK-cell lymphoma]. 807 94

Peripheral T-cell lymphomas (PTCL) are usually characterized by aggressive clinical behaviour and poor clinical outcome, but their biological background has not been extensively investigated to date, due to their low incidence, about 10% of all non-Hodgkin's lymphoma cases in Western countries, and also to the paucity of specific molecular-genetic abnormalities. Neverthless, there is increasing biological and clinical evidence that primary nodal PTCL should be considered separately from extra-nodal cases, but little is known about biological factors of possible clinical and prognostic impact. This immunohistochemical study has analysed the expression of p53, Mdm2, p21(WAF1), BCL-2 and p-glycoprotein (MDR-1 gene product) in a series of 45 cases of nodal peripheral T-cell lymphomas (PTCL) with 'high-grade' histology. The immunohistochemical findings were then correlated with proliferative activity and clinical outcome. p53 was over-expressed in 13 cases (28.9%). p53 positive cases showed significantly higher proliferative activity (p<0.01), more frequent expression of Bcl-2 (p<0.01) and less frequent expression of p21(WAF1) than p53 negative cases. Mdm2 and p-glycoprotein were expressed in 4/13 (30.8%) and 8/13 (61.5%) p53 positive cases respectively, and in none (0%) of the p53 negative cases (p<0.01). Analysis of the survival curves showed that p53 positive cases were associated with a significantly poorer clinical outcome than p53 negative cases, in terms of both overall survival (p=0.0032) and event-free survival (p=0.0004). Furthermore, multivariate analysis showed that p53 expression was the most important independent prognostic variable. These findings indicate that p53 over-expression identifies a subset of nodal PTCL cases with a distinctive biological profile (higher proliferative activity, less frequent expression of p21(WAF1) and more frequent expression of Bcl-2, Mdm2 and p-glycoprotein than p53 negative cases) and poor clinical outcome. The immunohistochemical analysis of p53 expression is a simple, rapid and low-cost method which may provide information of potential clinical and prognostic value in nodal peripheral T-cell lymphomas.
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PMID:p53 over-expression identifies a subset of nodal peripheral T-cell lymphomas with a distinctive biological profile and poor clinical outcome. 1167 35

P-glycoprotein is a product of the multidrug resistance (MDR-1) gene. In non-Hodgkin's lymphoma, less than 20% of untreated de novo lymphomas express MDR-1 compared with approximately 50% after failure of chemotherapy. We wished to study the expression of MDR-1 in AIDS-related non-Hodgkin's lymphoma (AIDS-NHL). Tissue biopsies from 50 patients with newly diagnosed AIDS-NHL were studied by immunohistochemical analysis using C494, a monoclonal antibody specific for the MDR-1 isoform of P-gp. MDR-1 expression was correlated with patient demographics, lymphoma characteristics, response to chemotherapy, and survival. Forty-six males and four females with a median age of 38 years (range 26-63) were studied. A prior AIDS-defining opportunistic infection was reported in 35 patients (70%). The median CD4+ lymphocyte count was 69/mm(3) (range 0-920). Thirty-two patients (63%) had received prior anti-HIV therapy, including a protease inhibitor in five (10%). Pathologic types consisted of diffuse large cell in 13 (26%), immunoblastic in 13 (26%), small non-cleaved in 22 (44%), and high grade not otherwise specified in two (4%). The majority of patients (76%) had stage III/IV disease. Pre-treatment lymphoma tissues from 33 patients (66%) stained positively for MDR-1. MDR-1 positive patients had a significantly lower complete remission rate compared to MDR-1 negative patients (33 versus 65%, P=0.042). Duration of complete response was significantly longer in MDR-1 negative patients compared with MDR-1 positive patients (not reached versus 9.9 months, P=0.003). Strategies to overcome MDR-1 expression may be important for initial treatment in patients with AIDS-NHL.
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PMID:Multidrug resistance (MDR-1) expression in AIDS-related lymphomas. 1175 62

We examined the outcome of patients who developed breast cancer after curative chemotherapy (CHOP) for aggressive non-Hodgkin's lymphoma (NHL) in comparison to the outcome of a retrospectively selected matched-pair group of patients with de novo breast cancer, and evaluated the role of drug resistance-related protein (MDR, MRP, LRP) expression in breast cancer tissue. Twenty-two patients presented with breast cancer (BC) in complete remission after CHOP for NHL. The median age was 62 (49-70) years, each had high/intermediate grade B-cell NHL treated with 6 courses of CHOP, and were in complete remission. These patients were compared to a matched-pair group of de novo BC patients selected from our database over the same time period. Breast cancer tissue was stained by immunohistochemistry for drug resistance proteins LRP, MRP, and MDR. Breast cancer developed after a median of 26 (9-49) months of NHL diagnosis; breast tumor grades 1-2 were seen in 12, and grade 3 in 10 patients; 15 were negative and 7 weakly positive for estrogen and progesterone receptors. Twelve patients were stage IIIA/B, and 10 stage IV and were treated with conventional chemotherapy regimens. All progressed early in liver (n=13), brain (n=9), lung (n=6), bone (n=8), lymph nodes (n=7) and soft tissue (n=5), and received second-line chemotherapy with mitomycin-C + vinblastine or taxanes. The overall survival was 11.8 (6-26) months (p<0.01). Time from NHL to breast cancer development was 19 (14-27) months in patients with positive drug resistance proteins (group A), and 37 (26-56) months in patients with 1 or 2 positive resistance proteins (group B) (p<0.001). In patients with stage IIIA/B disease, there was no difference between the examined and control matched-pair group in median TTP, but there was in overall survival (OS) (23 vs 36 months, p=0.029). In advanced disease, there were more responders in the control vs the examined group (p=0.07). Patients in the control matched-pair group had more prolonged OS when compared to group A patients who developed BC in <24 months from NHL to BC (p=0.017). We conclude that breast cancer developing shortly after a complete response in NHL, is an aggressive disease variant with minimal potential for response to conventional chemotherapy. Analysis of drug resistance mechanisms concerning MDR, MRP and LRP indicates that most of these patients have BC that overexpress these proteins leading to the suggestion that these mechanisms might be a part of the aggressive disease phenotype and partially explain the poor outcome.
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PMID:Breast cancer after curative chemotherapy in non-Hodgkin's lymphoma: examination of the role of drug resistance and retrospective comparison to the outcome of de novo breast cancer. 1501 Aug 92

Anthracyclines, including doxorubicin, are widely used in the treatment of B-cell non-Hodgkin's lymphoma (NHL). However, their clinical potential is limited by their cardiotoxic adverse effects, which include cardiomyopathy and congestive heart failure. Anthracycline-induced cardiotoxicity is cumulative and irreversible. Liposomal doxorubicin has been developed with the aim of improving the therapeutic index of doxorubicin by reducing the drug's cardiotoxicity. Nevertheless, liposomal conjugation of doxorubicin results in preferential distribution of the drug in the tumor compared with normal tissue, maintaining its anti-tumor efficacy. Nonpegylated liposomal doxorubicin produced a promising response rate when substituted for conventional doxorubicin in the cyclophosphamide, doxorubicin, vincristine and prednisolone regimen in the treatment of patients with NHL either at diagnosis or at relapse. The ability of nonpegylated liposomal doxorubicin to overcome excessive drug efflux due to P-glycoprotein (MDR-1) overexpression in NHL might confer on this drug a curative potential for patients with a bad prognosis (e.g., MDR-1 overexpressing, the elderly or frail).
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PMID:Nonpegylated liposomal doxorubicin in the treatment of B-cell non-Hodgkin's lymphoma: where we stand. 1927 12