The Fanconi anaemia gene FANCF encodes a novel protein with homology to ROM.
Explore the source record for details and available documents.
Amino Acid Sequence↗
Biomedical subjects
R J Scheper
Publications and source records attributed to R J Scheper.
P-glycoprotein and multidrug resistance-associated protein, but not lung resistance protein, lower the intracellular daunorubicin accumulation in acute myeloid leukaemic cells.
The in vitro intracellular daunorubicin accumulation (IDA) of blast cells from 69 patients with newly diagnosed acute myeloid leukaemia (AML) was correlated with the expression and functional activity of the multidrug resistance (MDR) proteins, P-glycoprotein (Pgp), multidrug resistance-associated protein (MRP) and lung-resistance protein (LRP). An inverse and significant association was found between IDA and Pgp-related efflux activity (r = -0.31, P = 0.01) and also MRP (r = -0.25, P = 0.04) but not with LRP (r = -0.13, P = 0.28). Coexpression of the MDR proteins had an additive effect in further lowering of IDA levels, suggesting that the clinical MDR phenotype is dependent on the sum of multiple MDR factors available to the leukaemic cell. Thus, the median IDA of leukaemic cells without any MDR proteins was significantly higher than that of blasts carrying two MDR proteins (0.466 vs. 0.296, P = 0.046). Seven patients with no expression of Pgp, MRP and LRP still had low IDA levels, suggesting the presence of efflux MDR mechanisms other than those studied. The relation of IDA to clinical parameters known to be associated with poor prognosis, such as age, secondary AML, karyotype, peripheral blood blast and CD34 counts, was also studied, but no significance was found on multifactorial analysis. There was a non-significant trend for earlier relapse in patients with low IDA levels (leukaemia-free survival of 16.3 months compared with 21.1 months in patients with high IDA levels). Our data suggest that, while the IDA assay is a quick and relatively easy test for the combined efflux MDR phenotype, it is unable to detect other MDR mechanisms, such as LRP, which may be important to the clinical outcome of patients with AML.
ATP Binding Cassette Transporter, Subfamily B, Mem↗
Lung resistance-related protein/major vault protein and vaults in multidrug-resistant cancer.
Tumor cells that are insensitive to anticancer drugs frequently have a multidrug-resistant (MDR) phenotype. Proteins that can be involved in this phenomenon are transport-associated proteins such as P-glycoprotein, multidrug-resistance protein 1, breast cancer resistance protein, and lung resistance-related protein (LRP). LRP was identified as the major vault protein (MVP), the main component of multimeric vault particles. With the recent identification of the two minor vault proteins as telomerase-associated protein (TEP1) and vault-poly (ADP-ribose) polymerase (VPARP), and with high-resolution three-dimensional imaging, the composition of vaults is almost unraveled. Although the first direct evidence for a causal relationship between LRP/MVP expression and drug resistance has been obtained, many functional aspects of vaults in normal physiology and in MDR still need to be clarified. The current clinical data on LRP/MVP detection indicate that LRP/MVP expression can be of high clinical value to predict the response to chemotherapy of several tumor types.
Animals↗
Transport of topoisomerase I inhibitors by the breast cancer resistance protein. Potential clinical implications.
The multidrug resistance protein BCRP (breast cancer resistance protein) is a member of the ATP-binding cassette family of drug transporters. Overexpression of BCRP caused by exposure of cells to mitoxantrone (MX) or doxorubicin/verapamil resulted in a resistance pattern that is different from what is generally seen in the case of P-glycoprotein and MRP1 overexpression. Recently, the BCRP gene has been described in ovarian, breast, colon, and gastric cancer and fibrosarcoma cell lines. Our human tumor cells T8 and MX3, derived from the ovarian cancer cell line IGROV1 by stepwise increased exposure to topotecan and MX, are resistant to topotecan, CPT11, SN38, and 9-aminocamptothecin as well as MX. Increased energy-dependent efflux of affected drugs was noted. BCRP is a very efficient transporter of topotecan. Our recent studies, using the monoclonal antibody (mAb) BXP34, revealed that BCRP is located in the plasma membrane of the T8 and MX3 cell lines. Preliminary results of staining of human tumor cells showed low or absent levels of BCRP in a panel of solid tumors and acute myeloid leukemia cells.
ATP Binding Cassette Transporter, Subfamily G, Mem↗
Multidrug resistance protein 1 protects the choroid plexus epithelium and contributes to the blood-cerebrospinal fluid barrier.
Multidrug resistance protein 1 (MRP1) is a transporter protein that helps to protect normal cells and tumor cells against the influx of certain xenobiotics. We previously showed that Mrp1 protects against cytotoxic drugs at the testis-blood barrier, the oral epithelium, and the kidney urinary collecting duct tubules. Here, we generated Mrp1/Mdr1a/Mdr1b triple-knockout (TKO) mice, and used them together with Mdr1a/Mdr1b double-knockout (DKO) mice to study the contribution of Mrp1 to the tissue distribution and pharmacokinetics of etoposide. We observed increased toxicity in the TKO mice, which accumulated etoposide in brown adipose tissue, colon, salivary gland, heart, and the female urogenital system. Immunohistochemical staining revealed the presence of Mrp1 in the oviduct, uterus, salivary gland, and choroid plexus (CP) epithelium. To explore the transport function of Mrp1 in the CP epithelium, we used TKO and DKO mice cannulated for cerebrospinal fluid (CSF). We show here that the lack of Mrp1 protein causes etoposide levels to increase about 10-fold in the CSF after intravenous administration of the drug. Our results indicate that Mrp1 helps to limit tissue distribution of certain drugs and contributes to the blood-CSF drug-permeability barrier.
ATP Binding Cassette Transporter, Subfamily B, Mem↗
Aberrant Fanconi anaemia protein profiles in acute myeloid leukaemia cells.
Fanconi anaemia (FA) is an autosomal recessive disease strongly predisposing to bone marrow failure and acute myeloid leukaemia (AML). Four FA genes, corresponding to complementation groups A, C, F and G, have been cloned, but the molecular functions of the corresponding proteins are unknown. The high risk of AML in FA patients suggests that the 'FA pathway' helps to prevent AML in non-FA individuals. We examined 10 AML cell lines, as well as primary cells from 15 AML patients representing the French-American-British subclasses M1-M5a, for possible deficiencies in the 'FA pathway'. Cellular lysates were analysed for the presence of the FA proteins FANCA, FANCC, FANCF and FANCG, as well as the complexes reported to be formed between these proteins, using immunoprecipitation and Western blot analysis. Aberrant protein profiles were observed in five of the 10 cell lines and in 11 of the 15 primary AML samples. Aberrations, that included absence or reduced presence of FA proteins and/or their complexes, were noted in the subclasses M1-M4, but not in M5a (n = 3). Our results suggest that a significant proportion of general AML is characterized by a disturbance of the 'FA pathway' that may represent an early event in the development of this type of leukaemia.
Acute Disease↗
Lung resistance-related protein: determining its role in multidrug resistance.
Explore the source record for details and available documents.
ATP Binding Cassette Transporter, Subfamily B, Mem↗
A physical complex of the Fanconi anemia proteins FANCG/XRCC9 and FANCA.
Fanconi anemia (FA) is a recessively inherited disease characterized at the cellular level by spontaneous chromosomal instability and specific hypersensitivity to cross-linking agents. FA is genetically heterogeneous, comprising at least eight complementation groups (A-H). We report that the protein encoded by the gene mutated in complementation group G (FANCG) localizes to the cytoplasm and nucleus of the cell and assembles in a molecular complex with the FANCA protein, both in vivo and in vitro. Endogenous FANCA/FANCG complex was detected in both non-FA cells and in FA cells from groups D and E. By contrast, no complex was detected in specific cell lines belonging to groups A and G, whereas reduced levels were found in cells from groups B, C, F, and H. Wild-type levels of FANCA/FANCG complex were restored upon correction of the cellular phenotype by transfection or cell fusion experiments, suggesting that this complex is of functional significance in the FA pathway. These results indicate that the cellular FA phenotype can be connected to three biochemical subtypes based on the levels of FANCA/FANCG complex. Disruption of the complex may provide an experimental strategy for chemosensitization of neoplastic cells.
Cell Fusion↗
Genomic organization, sequence and transcriptional regulation of the human CXCL 11(1) gene.
CXCL 11, encoded by the cDNA sequences designated beta-R1, H-174, or I-TAC, is a CXC chemokine ligand for CXCR3 and assumed to be involved in inflammatory diseases characterized by the presence of activated T-cells. We here describe the genomic organization (four exons interrupted by three introns of 585, 98 and 230 bp) and sequence including 960 bp from the immediate 5'-upstream region of the human CXCL 11 gene. Within the promoter region, consensus sequences for regulatory elements (ISRE, GAS, NF-kappaB) important for cytokine-induced gene transcription were identified. The effect of (pro)inflammatory cytokines on CXCL 11 mRNA expression in monocytic cell lines (THP-1, U937) and primary cultures of dermal fibroblasts and endothelial cells were examined using Northern blot analysis. For these cell types, IFN-gamma was a potent inducer of CXCL 11 transcription, which was synergistically enhanced by TNF-alpha.
Base Sequence↗
MRP3, an organic anion transporter able to transport anti-cancer drugs.
The human multidrug-resistance protein (MRP) gene family contains at least six members: MRP1, encoding the multidrug-resistance protein; MRP2 or cMOAT, encoding the canalicular multispecific organic anion transporter; and four homologs, called MRP3, MRP4, MRP5, and MRP6. In this report, we characterize MRP3, the closest homolog of MRP1. Cell lines were retrovirally transduced with MRP3 cDNA, and new monoclonal antibodies specific for MRP3 were generated. We show that MRP3 is an organic anion and multidrug transporter, like the GS-X pumps MRP1 and MRP2. In Madin-Darby canine kidney II cells, MRP3 routes to the basolateral membrane and mediates transport of the organic anion S-(2,4-dinitrophenyl-)glutathione toward the basolateral side of the monolayer. In ovarian carcinoma cells (2008), expression of MRP3 results in low-level resistance to the epipodophyllotoxins etoposide and teniposide. In short-term drug exposure experiments, MRP3 also confers high-level resistance to methotrexate. Neither 2008 cells nor Madin-Darby canine kidney II cells overexpressing MRP3 showed an increase in glutathione export or a decrease in the level of intracellular glutathione, in contrast to cells overexpressing MRP1 or MRP2. We discuss the possible function of MRP3 in (hepatic) physiology and its potential contribution to drug resistance of cancer cells.
ATP-Binding Cassette Transporters↗
Maturation of dendritic cells accompanies high-efficiency gene transfer by a CD40-targeted adenoviral vector.
Important therapeutic applications of genetically modified dendritic cells (DC) have been proposed; however, current vector systems have demonstrated only limited gene delivery efficacy to this cell type. By means of bispecific Abs, we have dramatically enhanced gene transfer to monocyte derived DC (MDDC) by retargeting adenoviral (Ad) vectors to a marker expressed on DC, CD40. Adenovirus targeted to CD40 demonstrated dramatic improvements in gene transfer relative to untargeted Ad vectors. Fundamental to the novelty of this system is the capacity of the vector itself to modulate the immunological status of the MDDC. This vector induces DC maturation as demonstrated phenotypically by increased expression of CD83, MHC, and costimulatory molecules, as well as functionally by production of IL-12 and an enhanced allostimulatory capacity in a MLR. In comparing this vector to other Ad-based gene transfer systems, we have illustrated that the features of DC maturation are not a function of the Ad particle, but rather a consequence of targeting to the CD40 marker. This vector approach may thus mediate not only high-efficiency gene delivery but also serve a proactive role in DC activation that could ultimately strengthen the utility of this vector for immunotherapy strategies.
Adenoviruses, Human↗
Antifolate resistance mediated by the multidrug resistance proteins MRP1 and MRP2.
Transfection of multidrug resistance proteins (MRPs) MRP1 and MRP2 in human ovarian carcinoma 2008 cells conferred a marked level of resistance to short-term (1-4 h) exposure to the polyglutamatable antifolates methotrexate (MTX; 21-74-fold), ZD1694 (4-138-fold), and GW1843 (101-156-fold). Evidence for MRP-mediated antifolate efflux relies upon the following findings: (a) a 2-3.3-fold lower accumulation of [3H]MTX and subsequent reduced formation of long-chain polyglutamate forms of MTX; (b) reversal of MTX resistance by probenecid in both transfectants, and (c) ATP-dependent uptake of [3H]MTX in inside-out vesicles of MRP1 and MRP2 transfectants. This report provides a mechanistic basis for resistance to polyglutamatable antifolates through an MRP-mediated drug extrusion.
ATP Binding Cassette Transporter, Subfamily B↗
Active specific immunotherapy for stage II and stage III human colon cancer: a randomised trial.
BACKGROUND: Colon cancer is curable by surgery, but cure rate depends on the extent of disease. We investigated whether adjuvant active specific immunotherapy (ASI) with an autologous tumour cell-BCG vaccine with surgical resection was more beneficial than resection alone in stage II and III colon cancer. METHODS: In a prospective randomised trial, 254 patients with colon cancer were randomly assigned postoperative ASI or no adjuvant treatment. ASI was three weekly vaccinations starting 4 weeks after surgery, with a booster vaccination at 6 months with 10(7) irradiated autologous tumour cells. The first vaccinations contained 10(7) BCG organisms. We followed up patients for time to recurrence, and recurrence-free and overall survival. Analysis was by intention to treat. FINDINGS: The 5.3 year median follow-up (range 8 months to 8 years 11 months) showed 44% (95% CI 7-66) risk reduction for recurrence in the recurrence-free period in all patients receiving ASI (p=0.023). Overall, there were 40 recurrences in the control group and 25 in the ASI group. Analysis by stage showed no significant benefit of ASI in stage III disease. The major impact of ASI was seen in patients with stage II disease, with a significantly longer recurrence-free period (p=0.011) and 61% (18-81) risk reduction for recurrences. Recurrence-free survival was significantly longer with ASI (42% risk reduction for recurrence or death [0-68], p=0.032) and there was a trend towards improved overall survival. INTERPRETATION: ASI gave significant clinical benefit in surgically resected patients with stage II colon cancer. ASI has minimal adverse reactions and should be considered in the management of stage II colon cancer.
Adjuvants, Immunologic↗
Multidrug resistance related proteins in primary cutaneous lymphomas.
BACKGROUND: In patients with primary cutaneous B-cell lymphomas (CBCL) and primary cutaneous T-cell lymphomas (CTCL), extracutaneous sites may become involved and then polychemotherapy is indicated. Multi-agent chemotherapy may induce long lasting complete remissions in CBCL's. Most CTCL's, especially mycosis fungoides (MF), and CD30 negative primary cutaneous large T-cell lymphoma (PCLTCL) respond poorly or partially to Multi-agent Chemotherapy. PURPOSE: We have studied whether cutaneous lymphomas express the following multidrug resistance (MDR) related proteins: multidrug resistance protein (MRP), lung resistance protein (LRP) and P-glycoprotein (Pgp). METHODS: From the files of the Dutch Cutaneous Lymphoma Working Group we selected pretreatment punch biopsy specimens of the skin from 14 patients with MF, 10 patients with a PCLTCL and 8 patients with a CBCL. In several patients with a clinical relapse of their disease after multi-agent chemotherapy, punch biopsy specimens of cutaneous lesions were available (6 MF, 3 PCLTCL, 1 CBCL). Benign dermatoses with a dense lymphoid infiltrate were included as a control. Immunohistochemistry was done on formalin fixed, paraffin-embedded punch biopsy specimens with monoclonal antibodies MRPrl (anti-MRP); LRP-56 (anti-LRP); C219 (anti-Pgp). Staining was performed by the biotin-streptavidin immunoperoxidase method. RESULTS: MRPrl staining was found in the cytoplasm of > or = 5%-50% of lymphoid cells in 13 out of 14 cases of MF and in 6 out of 10 patients with a PCLTCL. In 2 out of 8 cases of CBCL > or = 5%-50% positive tumorcells were found. Strong staining (> or = 50% of the cells positive) was found in 10 out of the total of 24 CTCL cases. LRP56 staining of lymphoid cells was found in 1 out of 14 cases of MF and in 1 out of 10 cases of PCLTCL and in 1 out of 8 cases of CBCL. C219 expression was found in 4 out of 10 cases of PCLTCL and in 2 out of 8 cases of CBCL. After chemotherapy both a higher staining intensity and a higher number of positive cells were found with MRPrl especially in patients with MF. CONCLUSION: The present study shows that lymphoid cells in both primary cutaneous lymphomas and benign skin disorders may express MDR related proteins and that the expression profile of these proteins is roughly related to the tumor cell phenotype. However, the functional role of these proteins in clinical drug resistance in primary cutaneous lymphomas has to be proven.
ATP-Binding Cassette Transporters↗
The lung resistance protein (LRP) predicts poor outcome in acute myeloid leukemia.
To determine the clinical significance of the lung resistance protein (LRP) in acute myeloid leukemia (AML), we have studied LRP expression of leukemic blasts and its association with clinical outcome in patients with de novo AML. LRP expression of leukemic blasts was determined by immunocytochemistry by means of monoclonal antibody LRP-56. LRP expression at diagnosis was detected in 31 out of 86 (36%) patients and correlated with white blood cell count (p = 0.01). The complete remission rate of induction chemotherapy was 72% for all treated patients (n = 82). The complete remission rate was 81% for patients without LRP expression but only 55% for patients with LRP expression (p = 0.01). Overall survival and disease-free survival were estimated according to Kaplan-Meier in 82 and 59 patients, respectively. At a median follow-up of 16 months, median overall survival was 17 months for LRP-negative patients but only 8 months for LRP-positive patients (p = 0.006). Disease-free survival was 9 months for LRP-negative patients and 6 months for LRP-positive patients (p = 0.078). Thus LRP predicts for poor outcome indicating that the LRP gene is a clinically relevant drug resistance gene in AML.
Adolescent↗
Differences in cytokine mRNA profiles between premalignant and malignant lesions of the uterine cervix.
The aim of this study was to assess the expression of cytokine transcripts, reflecting the type of ongoing immune responses at the site of human papillomavirus (HPV) infection, in relation to the development of cervical neoplasia. To this end reverse transcription-polymerase chain reaction (RT-PCR) was performed for interferon (IFN) gamma, interleukin (IL)-2, IL-4, IL-5, IL-10, IL-12 (p35 and p40), and transforming growth factor (TGF beta 1) in snap-frozen cervical biopsies, which were tested for the presence of high risk HPV DNA and histologically classified from normal to invasive carcinoma (n = 40). IFN gamma, IL-10 and IL-12 (p35 and p40) transcripts were found to be expressed at significantly lower frequencies in invasive carcinoma as compared with premalignant biopsies (P = 0.006, P = 0.007 and P = 0.002, respectively). IFN gamma IL-10 mRNA were associated with the presence of the IL-12 p35 and p40 transcripts (P = 0.008 and P < 0.00001, respectively). These results are consistent with a locally reduced cellular (type 1) immunity correlating with HPV-induced invasive cervical carcinoma.
Adult↗
Dendritic cells: a novel therapeutic modality.
Explore the source record for details and available documents.
Animals↗
Expression of CD3-zeta on T-cells in primary cervical carcinoma and in metastasis-positive and -negative pelvic lymph nodes.
Lymphocytic infiltrate is often present in cervical cancer lesions, possibly reflecting an ongoing, but ineffective, immune response to the tumour. Recently, evidence has accumulated for systemically impaired T-cell functions in cancer patients, associated with decreased expression of signal-transducing zeta (zeta) chain dimer molecules on circulating T-cells and NK-cells. Here, we report on the intralesional down-regulation of zeta chain expression on T-cells in cervical carcinoma. Paraffin-embedded or snap-frozen sections from 24 different cervical cancer specimens were studied. Paraffin-embedded tumour-positive (n = 7) and tumour-negative (n = 15) pelvic lymph nodes were also included in the study. Immunostaining was performed on consecutive sections with antibodies specific for CD3-epsilon or the CD3-associated zeta chain dimer. Antigen retrieval by sodium citrate/microwave treatment was essential for zeta staining of paraffin sections. The amount of zeta positive cells was quantitated and related to the number of CD3-epsilon+ cells in corresponding tumour areas. Of the 24 cervical cancer specimens studied, zeta chain dimer expression was reduced in seven cases and strongly reduced in the other 17 samples. In tonsil control sections, CD3-epsilon and CD3-zeta were always co-expressed in almost equal numbers. Also, both tumour-negative and -positive lymph nodes showed zeta chain expression which equalled that of CD3-epsilon expression. These data indicate that a decreased expression of signal-transducing zeta molecules on tumour-infiltrating T-cells is frequent in cervical cancer. The apparently unimpaired zeta chain expression within draining lymph nodes suggests that local tumour-derived factors at the primary site are instrumental in zeta chain down-regulation.
Adult↗