Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0684249 (lung carcinoma)
 23,830 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Because of the bias toward successful cloning of human tumor cells from more advanced malignancies, alternative approaches to clinical correlations of drug resistance are needed to determine the validity of the human tumor clonogenic assay (HTCA) as a clinically useful test. Capitalizing on the prevalence of clinical drug resistance among these advanced malignancies, we have taken an independent approach to testing the validity of HTCAs based upon pharmacologic principles rather than tumor response. A database of results from drug sensitivity/resistance testing in 1,777 HTCAs has been examined retrospectively for specimens exhibiting either the MDR1 or Topo-II pleiotropic drug resistance phenotype. Twenty specimens were identified as MDR1 based upon test results showing resistance to adriamycin, vinca alkaloid, and etoposide. Test results with mitomycin-c confirmed the MDR1 phenotype in eight out of nine of these specimens. Seven out of eight of the confirmed MDR1 samples were resistant to either cis-platinum or alkylating agents or to both. There was no significant difference in the 5-fluorouracil resistance of these MDR1 specimens and the database as a whole, demonstrating the specific nature of this drug resistance phenotype in vitro. One specimen, a squamous carcinoma of the lung, was mitomycin-c sensitive, even though it exhibited all the other drug resistances characteristic of the MDR1 phenotype. Six specimens with the Topo-II phenotype were identified based upon resistance to adriamycin and etoposide with sensitivity to vinca alkaloids. Surprisingly, the Topo-II phenotype showed a strong association with increased cis-platinum resistance and a weaker one with decreased 5-fluorouracil resistance. Thus, 26/30 (87%) of analyzable specimens showed some form of clinically characterized multidrug resistance, illustrating how easily one can obtain 90% accuracy in predicting clinical drug resistance with HTCAs that are heavily biased by a disproportionate number of successful cloning assays with advanced malignancies. The data analysis also shows that prediction of adriamycin resistance based on lack of Topoisomerase II expression will not be very accurate, in contrast to a previous claim. Until cell culture technology can facilitate frequent successes in the cloning of early detected, drug-sensitive lesions, this bias will remain in HTCA databases, and studies comparing HTCA results with clinical response will continue to be uninformative. However, the in vitro identification of pleiotropic drug resistance phenotypes exactly analogous to those previously observed in patients provides pharmacologic validation at least for the prediction of drug resistance as measured by current HTCAs using suprapharmacologic drug concentrations.
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PMID:Pharmacologic validation of human tumor clonogenic assays based on pleiotropic drug resistance: implications for individualized chemotherapy and new drug screening programs. 133 13

A non-P-glycoprotein-mediated mechanism of multidrug resistance (non-Pgp MDR) has been identified in doxorubicin-selected sublines of the human non-small cell lung carcinoma cell line SW-1573. These sublines are cross-resistant to daunorubicin, VP16-213, Vinca alkaloids, colchicine, gramicidin D, and 4'-(9-acridinylamino)methanesulfon-m-anisidide (m-AMSA). They accumulate less drug than the parental cells and their resistance is not due to the MDR1-encoded P-glycoprotein, as the resistant cell lines have lost the low amount of MDR1 mRNA detectable in parental cells. Here we show that the resistant cell lines also contain less topoisomerase II mRNA and enzyme activity than the parental cells. This might contribute to the resistance of these lines to drugs interacting with topoisomerase II, such as doxorubicin, daunorubicin, and VP16-213, but cannot account for the resistance to the other drugs. We have tested whether all properties of the non-Pgp MDR cell lines cosegregate in somatic cell fusions between lethally gamma-irradiated, resistant donor cells and drug-sensitive acceptor cells. Whereas a MDR phenotype with reduced drug accumulation and the loss of MDR1 P-glycoprotein mRNA were cotransferred to the acceptor cells, the decrease in topoisomerase II gene expression was not. We conclude that the MDR phenotype, the reduced drug accumulation, and the loss of MDR1 P-glycoprotein mRNA are genetically linked. They might be due to a single dominant mutation, which does not cause the alteration in topoisomerase II.
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PMID:Genetic transfer of non-P-glycoprotein-mediated multidrug resistance (MDR) in somatic cell fusion: dissection of a compound MDR phenotype. 134 62

S 9788 is a novel triazinoaminopiperidine derivative which does not belong to any of the classes of compounds known to reverse multidrug resistance (MDR). S 9788 was far more potent than verapamil (VRP) in reversing resistance to adriamycin (ADR) in the ADR-selected murine leukaemia cell lines P388/ADR-1 and P388/ADR-10, and the human chronic myelogenous leukaemia K562/R. Fold reversion with S 9788 (5 microM) was, respectively, 3.5, 5.4 and 11.3 times greater than that with VRP (5 microM). S 9788 was also a more potent reversant of ADR resistance in the intrinsically resistant human colon adenocarcinoma COLO 320DM (2.3 fold), and of vincristine (VCR) resistance in the human MDR1 gene-transfected squamous lung carcinoma line S1/tMDR1 (5.6 fold). The activity of S 9788 depended on both the MDR cell line and the cytotoxic agent. S 9788 (50-100 mg/kg/d) administered IP once a day on days 1-4 resulted in a dose-dependent increase in the chemotherapeutic effect of VCR (0.25 mg/kg/d) in P388/VCR - bearing mice and ADR (4 mg/kg/d) in P388/ADR - bearing mice. Increases in antitumor activity were (% T/C) of +20-34% in the P388/ADR model and + 50-78% in the P388/VCR model with respect to cytotoxic agent treatment alone. S 9788 appeared to be devoid of toxicity at its effective doses. The mechanism of action of S 9788 is unknown but S 9788 (0.5-10 microM) induced a dose-dependent increase in ADR accumulation in KB-Al cells and compared to verapamil its effect was twice as active and approximately seven times more potent. We conclude that S 9788 is a novel agent capable of reversing MDR in vitro and in vivo, and whose pharmacological profile warrants its selection as a candidate drug for eventual assessment in the clinic.
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PMID:In vitro and in vivo circumvention of multidrug resistance by Servier 9788, a novel triazinoaminopiperidine derivative. 142 23

Many cancers have been cured by chemotherapeutic agents. However, other cancers are intrinsically drug resistant, and some acquire resistance following chemotherapy. Cloning of the cDNA for the human MDR1 gene (also known as PGY1), which encodes the multidrug efflux protein P-glycoprotein, has made it possible to measure levels of MDR1 RNA in human cancers. We report the levels of MDR1 RNA in greater than 400 human cancers. MDR1 RNA levels were usually elevated in untreated, intrinsically drug-resistant tumors, including those derived from the colon, kidney, adrenal gland, liver, and pancreas, as well as in carcinoid tumors, chronic myelogenous leukemia in blast crisis, and cell lines of non-small cell carcinoma of the lung (NSCLC) with neuroendocrine properties. MDR1 RNA levels were occasionally elevated in other untreated cancers, including neuroblastoma, acute lymphocytic leukemia (ALL) in adults, acute nonlymphocytic leukemia (ANLL) in adults, and indolent non-Hodgkin's lymphoma. MDR1 RNA levels were also increased in some cancers at relapse after chemotherapy, including ALL, ANLL, breast cancer, neuroblastoma, pheochromocytoma, and nodular, poorly differentiated lymphoma. Many types of drug-sensitive and drug-resistant tumors, including NSCLC and melanoma, contained undetectable or low levels of MDR1 RNA. The consistent association of MDR1 expression with several intrinsically resistant cancers and the increased expression of the MDR1 gene in certain cancers with acquired drug resistance indicate that the MDR1 gene contributes to multidrug resistance in many human cancers. Thus, evaluation of MDR1 gene expression may prove to be a valuable tool in the identification of individuals whose cancers are resistant to specific agents. The information may be useful in designing or altering chemotherapeutic protocols in these patients.
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PMID:Expression of a multidrug resistance gene in human cancers. 256 56

Multidrug-resistance-associated protein (MRP) is a plasma membrane glycoprotein that can confer multidrug resistance (MDR) by lowering intracellular drug concentration. Here we demonstrate that depletion of intracellular glutathione by DL-buthionine (S,R)-sulfoximine results in a complete reversal of resistance to doxorubicin, daunorubicin, vincristine, and VP-16 in lung carcinoma cells transfected with a MRP cDNA expression vector. Glutathione depletion had less effect on MDR in cells transfected with MDR1 cDNA encoding P-glycoprotein and did not increase the passive uptake of daunorubicin by cells, indicating that the decrease of MRP-mediated MDR was not due to nonspecific membrane damage. Glutathione depletion resulted in a decreased efflux of daunorubicin from MRP-transfected cells, but not from MDR1-transfected cells, suggesting that glutathione is specifically required for the export of drugs from cells by MRP. We also show that MRP increases the export of glutathione from the cell and this increased export is further elevated in the presence of arsenite. Our results support the hypothesis that MRP functions as a glutathione S-conjugate carrier.
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PMID:Role of glutathione in the export of compounds from cells by the multidrug-resistance-associated protein. 764 78

The effect of osmotic stress on Cl- permeability in human squamous lung carcinoma epithelial (S1) cells was investigated using a macroscopic 125I efflux assay. Hypotonic challenge of monolayers led to a significant (P < 0.01) dose-related increase in efflux from pre-loaded cells, returning to pre-activation rates within 10 min. A similar magnitude of response could be produced by challenge with an isotonic low chloride-containing solution. Neither 100 mM dideoxy-forskolin nor 100 mM verapamil inhibited the increase in Cl- secretion after hypotonic challenge, whereas 100 mM DIDS inhibited volume-activated Cl- secretion by 55%. Both Northern and Western blot analysis confirmed the absence of MDR1 mRNA and P-glycoprotein in the S1 cells. We conclude that these cells have a volume-regulated Cl- secretory pathway that is independent of the ABC transporter, P-glycoprotein.
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PMID:Lack of inhibition by dideoxy-forskolin and verapamil of DIDS-sensitive volume-activated Cl- secretion in human squamous lung carcinoma epithelial cells. 780 88

The effect of human wild type and mutant p53 proteins on the human multidrug resistance (MDR1) promoter was studied in a p53-negative human cell line. Transient expression of MDR1 promoter-chloramphenicol acetyltransferase reporter gene constructs (MDRCAT) cotransfected with p53 expression vectors was analyzed in H358 lung carcinoma cells. Cotransfection with a wild type p53 expression vector stimulated MDRCAT activity, while cotransfection with mutant p53 expression vectors altered at amino acid positions 181, 252, 258, or 273 failed to stimulate expression. Wild type p53 stimulation of MDRCAT activity was time dependent with maximal expression occurring 24-30 h following transfection and correlating with high p53 protein levels. MDR1 promoter deletion analysis suggested that the sequences involved in wild type p53 stimulation of MDRCAT activity were contained within the region from -39 to +53 relative to the start of transcription at +1. This region contains no TATA or p53 consensus binding sequence but does contain an initiator sequence. Wild type p53 stimulation of MDRCAT expression also occurred in parental and doxorubicin-resistant SW620 colon and parental 2780 ovarian cancer cell lines, indicating that wild type p53-mediated simulation of the MDR1 promoter is not restricted to a single cell line.
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PMID:Wild type p53 stimulates expression from the human multidrug resistance promoter in a p53-negative cell line. 782 27

Five small-cell lung carcinoma (SCLC) cell lines were established from xenografted tumor lines. These tumor lines were established after transplantation into nude mice of primary tumors or metastatic foci obtained surgically, from untreated (IRSC-2M, IRSC6M, IRSC-10M and IRSC-61M) or treated patients (IRSC-74M). They were then set-up in culture as parallel cell lines. Histologically, these tumor lines were classified as being of the classic (IRSC-2M, IRSC-10M and IRSC-61M) or intermediate type (IRSC-6M and IRSC74M). Four of these 5 SCLC cell lines grew as floating cell aggregates, while one (IRSC6M) grew as an adherent cell monolayer. Growth rates were slow (doubling times ranged between 120 and 194 h) but could be accelerated (67 to 144 h) by cultivating cells in medium mixed (v/v) with self-conditioned medium. Electron microscopical examination revealed that all SCLC cell lines contained dense core granules, characteristic of their neuroendocrine origin. These cell lines formed colonies in agarose with colony forming efficiencies ranging from 0.02-0.36%. The classic-type cell lines retained their tumorigenic capacity when re-injected intracranially into naive nude mice, whereas the intermediatetype cells did not. Cytogenetic analysis confirmed the human origin of SCLC xenografts and cultured cell lines. Various numerical and structural chromosome abnormalities were found, with deletion in the short arm of chromosome 3 being the most common (4 of the 5 cell lines). Deletions in or loss of the chromosome 10 were also observed. Oncogene expression was studied in 3 representative cell lines (IRSC-10M, IRSC-2M and IRSC-74M). L-myc was overexpressed only in IRSC-74M, while the GRP gene was overexpressed in the classic (IRSC-2M and IRSC-10M) but not in the intermediate-type cells (IRSC-74M). The Ki-ras oncogene was overexpressed in the 3 cell lines, while c-myc, N-myc, Ha-ras, N-ras, erb B2 and sis were not detected in any of them. The 3 cell lines weakly expressed the MDR1 gene, while the GST-pi gene was not expressed. These cell lines constitute a multifaceted well-characterized in vitro model for studying the biology of these phenotypically diverse cancer cells.
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PMID:Establishment and characterization of five human small cell lung cancer cell lines from early tumor xenografts. 784 23

Small-cell lung carcinomas (SCLC) are highly responsive to various chemotherapies. However only a minority of patients benefit from long survival. SCLC patients treated at the Institut Gustave Roussy received a combined chemotherapy (CCAV) including cisplatin, cyclophosphamide (Cpa), Adriamycin (doxorubicin; Adm) and vepeside (VP16). We report here the intrinsic sensitivity of a small-cell lung carcinoma, designated SCLC-6, grafted in nude mice. This xenografted tumour was derived from an untreated patient. The CCAV regimen given to the patient donor of the tumour sample resulted in a complete response followed by recurrence and death, 8 months after the initial cure. The expression of P-glycoprotein encoded by the MDR1 gene was detected with the C219 antibody on the membrane of SCLC-6 tumour cells. When given to SCLC-6-tumour-bearing nude mice, CCAV induced a strong inhibition of tumour growth (84% of growth inhibition, 20 days after start of the treatment), but no cure. Intensification of CCAV doses did not improve the response. The efficacy of individual agents of the CCAV, given at maximal tolerated doses was analysed. Only cisplatin (10 mg/kg) and Cpa (3 x 50 mg/kg) inhibited SCLC-6 growth (79% and 100% inhibition respectively), VP16 (3 x 24 mg/kg) was poorly efficient (42%) and Adm (10 mg/kg) not at all. Two-drug combinations such as cisplatin plus VP16 or cisplatin plus Cpa inhibited tumour growth (81% and 70%, respectively). Curiously, the efficacy of Cpa, given in combination with cisplatin was less than that of Cpa alone. Repeated treatments with CCAV administered to mice at each in vivo passage of the tumour induced a loss of chemosensitivity, which was observed until the ninth passage. An improvement of the therapeutic response was obtained by adding a headline reverser of multi-drug resistance, verapamil (25 mg/kg), to CCAV (81% versus 63% inhibition). MDR1-related resistance appeared to play a role in the failure of SCLC-6 chemotherapy; frequent recurrences after treatment with cisplatin and Cpa, two drugs that are not recognized by the P-glycoprotein, indicated that other modes of resistance were simultaneously active.
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PMID:Response of a multidrug-resistant human small-cell lung cancer xenograft to chemotherapy. 790 68

In this paper, we review recent work on multidrug resistance (MDR) in Amsterdam. We have generated mice homozygous for a disruption of one of their P-glycoprotein (Pgp) genes. The mutations do not interfere with viability or fertility, showing that these Pgps have no indispensable role in early development or metabolism. Mice homozygous for a disruption of their mdr2 gene, however, develop liver disease and this appears to be due to their complete inability to secrete phospholipids into bile. This suggests that the mdr2 Pgp (and, by inference, its human MDR3 homologue) is essential for translocating phospholipids through the hepatocyte canalicular membrane in which this Pgp is located. These and other results show the importance of the genetic approach for studying drug metabolism. MDR is not only caused by increased activity of Pgps. When the human non-small cell lung carcinoma cell line SW-1573 is selected in vitro for low level doxorubicin resistance, the resistant variants are nearly always multidrug resistant, but this is not due to increased Pgp activity. Only when resistance is pushed to higher levels does activation of the MDR1 Pgp gene occur. This suggests that clinically relevant levels of drug resistance in some cells may be caused predominantly by non-Pgp-mediated drug resistance mechanisms. The protein responsible for MDR in the SW-1573 cells has not yet been identified and experiments are in progress to find the gene encoding it.
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PMID:Classical and novel forms of multidrug resistance and the physiological functions of P-glycoproteins in mammals. 791 35


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