Mechanism of action of dexniguldipine-HCl (B8509-035), a new potent modulator of multidrug resistance

Hofmann, Johann; Gekeler, Volker; Ise, W; Noller, A.; Mitterdorfer, Jörg; Hofer, Susanne; Utz, Irene; Gotwald, Markus; Boer, Rainer; Glossmann, Hartmut; Grunicke, H.

doi:10.1016/0006-2952(94)00479-6

Cited by 37 publications

(22 citation statements)

References 19 publications

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“…The purpose of this study was to design and synthesize multidrug resistance inhibitors through systematic modifications of the lead compound, dexniguldipine, which was reported to modulate multidrug resistance by direct interaction with P-glycoprotein (Hofmann et al, 1995). The initial design of the target compounds was therefore focused on the modifications of certain key structural features, including the following two groups of 4-aryl-1,4-dihydropyridines and corresponding analogs as shown in Table 1.…”

Section: Discussionmentioning

confidence: 99%

New 4-Aryl-1,4-Dihydropyridines and 4-Arylpyridines as P-Glycoprotein Inhibitors

Zhou

Zhang²,

Tseng³

et al. 2004

Drug Metab Dispos

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ABSTRACT:Efflux of cytotoxic agents mediated by P-glycoprotein is believed to be an important mechanism of multidrug resistance, which remains a serious limitation to successful chemotherapy in cancers such as metastatic breast cancer. A series of 4-aryl-1,4-dihydropyridines and corresponding aromatized 4-arylpyridines have been synthesized based on structure modifications of niguldipine to enhance multidrug resistance reversal activity, while minimizing calcium channel binding. Thirty new compounds were characterized.

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Section: Discussionmentioning

confidence: 99%

New 4-Aryl-1,4-Dihydropyridines and 4-Arylpyridines as P-Glycoprotein Inhibitors

Zhou

Zhang²,

Tseng³

et al. 2004

Drug Metab Dispos

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“…The selection of the multidrug-resistant CCRF-ADR5000 subcell line has been reported previously (Kimming et al, 1990). The cell lines were maintained as described previously (Borchers et al, 1995;Hofmann et al, 1995). The monoclonal antibody C219 was purchased from Centocor (Malvern, PA).…”

Section: Experimental Procedures Materialsmentioning

confidence: 99%

Characterization of the Dexniguldipine Binding Site in the Multidrug Resistance-Related Transport Protein P-Glycoprotein by Photoaffinity Labeling and Mass Spectrometry

et al. 2002

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Human P-glycoprotein (P-gp), an integral membrane transport protein, is responsible for the efflux of various drugs, including cytostatics from cancer cells leading to multidrug resistance. P-gp is composed of two homologous half domains, each carrying one nucleotide binding site. The drug extrusion is ATP-dependent and can be inhibited by chemosensitizers, such as the dihydropyridine derivative dexniguldipine-HCl, through direct interaction with P-gp. To evaluate the mechanism(s) of chemosensitization and identify the binding sites of dexniguldipine-HCl, a tritium-labeled azido analog of dexniguldipine, [3 H]B9209-005, was used as a photoaffinity probe. Using the multidrug resistant T-lymphoblastoid cell line CCRF-ADR5000, two proteins were specifically labeled in membranes by [3 H]B9209-005. These proteins were identified by immunoprecipitation such as P-gp and its N-terminal fragment. The membranes were solubilized and the labeled P-gp proteins first isolated by lectin-chromatography and then digested with trypsin. SDS-polyacrylamide gel electrophoresisanalysis of the digest revealed a major radioactive 7-kDa fragment. The tryptic fragments were separated by high-performance liquid chromatography and analyzed by matrix-assisted laser desorption/ ionization mass spectrometry (MALDI-MS). The MS results, corroborated by MALDI-MS of peptides after one step of Edman analysis, identified the radioactive 7-kDa band as the dexniguldipine-bound, tryptic P-gp peptide, 468 -527. This sequence region is flanked by the Walker motifs A and B of the N-terminal ATP-binding cassette suggesting direct interaction of the chemosensitizer with the nucleotide binding site is involved in the mechanism of chemosensitization.Tumor cells in vitro and in vivo can develop simultaneous resistance to the lethal effects of a variety of cytotoxic drugs (Endicott and Ling, 1989). This so-called multidrug resistance (MDR) is a major limiting factor for the efficacy of cancer chemotherapy. Currently, a variety of mechanisms are known that can lead to drug resistance, including reduced cellular drug accumulation, increased detoxification, intracellular vesicularization of drugs, altered enzymatic activities, up-or down-regulation of targets, and enhanced DNA repair (Hayes and Wolf, 1990). One important resistance mechanism is the transport out of cancer cells of chemically-unrelated cytotoxic drugs (such as anthracylines, Vinca alkaloids, colchicine, and taxanes) by the integral membrane phosphoglycoprotein P-glycoprotein (P-gp) under ATP hydrolysis, resulting in low and ineffective intracellular drug concentrations (Gottesman and Pastan, 1993). Although considerable progress has been made during the last few years, the mechanism of recognition and transport of such a broad spectrum of compounds is still poorly understood.Reversal of multidrug resistance is of major clinical interest, and MDR-reversing agents called chemosensitizers have been intensively investigated (Raderer and Scheithauer, 1993;Sikic, 1993). The capability of reversi...

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“…The preparations of the various protein fractions and the transfer onto Immobilon-P membranes (Millipore, Eschborn, Germany) were performed as described (Kimmig et al, 1990;Neumann et al, 1992;Hofmann et al, 1995 Figure 10). While staurosporine, as expected, inhibited cell growth in the nanomolar concentration range, the bisindolylmaleimide GF 109203X did not produce any anti-proliferative activity up to 2 jgM, or even 10 gM, depending on the cell line.…”

Section: Western Immunoblottingmentioning

confidence: 99%

“…Thus, the effects of the bisindolylmaleimide PKC inhibitor GF 109203X were compared with the activities of the enantiomeric pure dihydropyridine dexniguldipine-HCl (DNIG, B8509-035) and the phenylalkylamine dexverapamil-HCl (DVER; for structures see Figure 2b and c). The last two compounds modulate a P-gp-associated MDR accordingly by direct interaction with P-gp (Yusa and Tsuruo, 1989;Hofmann et al, 1995;Borchers et al, 1995). DNIG also exhibits PKC-inhibitory qualities (Uberall et al, 1991), however only at about 100-fold higher concentrations compared with the bisindolylmaleimide GF 109203X.…”

mentioning

confidence: 99%

Effects of the selective bisindolylmaleimide protein kinase C inhibitor GF 109203X on P-glycoprotein-mediated multidrug resistance

Gekeler

Boer²,

Überall³

et al. 1996

Br J Cancer

113

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Summary Inhibition of protein kinase C (PKC) is discussed as a new approach for overcoming multidrug resistance (MDR) in cancer chemotherapy. For evaluation of this concept we applied the bisindolylmaleimide GF 109203X, which shows a highly selective inhibition of PKC isozymes a, /31, ,B2, y, 6 and e in vitro. The efficacy of this compound in modulation of MDR was examined using several P-glycoprotein (P-gp)-overexpressing cell lines including a MDRI-transfected HeLa clone, and was compared with the activities of dexniguldipine-HCl (DNIG) and dexverapamil-HCl (DVER), both of which essentially act via binding to P-gp. As PKCa has been suggested to play a major role in P-gp-mediated MDR, cell lines exhibiting different expression levels of this PKC isozyme were chosen. On crude PKC preparations or in a cellular assay using a cfos(-71 I)CAT-transfected NIH 3T3 clone, the inhibitory qualities of the bisindolylmaleimide at submicromolar concentrations were demonstrated. At up to 1 gm final concentrations of the PKC inhibitor GF 109203X, a concentration at which many PKC isozymes should be blocked substantially, no cytotoxic or MDR-reversing effects whatsoever were seen, as monitored by 72 h tetrazolium-based colorimetric MTT assays or a 90 min rhodamine 123 accumulation assay. Moreover, depletion of PKCa by phorbol ester in HeLa-MDR1 transfectants had no influence on rhodamine 123 accumulation after 24 or 48 h. MDR reversal activity of GF 109203X was seen at higher final drug concentrations, however. Remarkably, [3H]vinblastine-sulphate binding competition experiments using P-gp-containing crude membrane preparations demonstrated similar dose dependencies as found for MDR reversion by the three modulators, i.e. decreasing efficacy in the series dexniguldipine-HCl>dexverapamil-HCl>GF 109203X. Similar interaction with the P-gp in the micromolar concentration range was revealed by competition of GF 109203X with photoincorporation of [3H]azidopine into P-gp-containing crude membrane preparations. No significant effect of the PKC inhibitor on MDR1 expression was seen, which was examined by cDNA-PCR. Thus, the bisindolylmaleimide GF 109203X probably influences MDR mostly via direct binding to P-gp. Our work identifies the bisindolylmaleimide GF 109203X as a new type of drug interacting with P-gp directly, but does not support the concept of a major contribution of PKC to a P-gp-associated MDR, at least using the particular cellular model systems and the selective, albeit general, PKC inhibitor GF 109203X.

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Mechanism of action of dexniguldipine-HCl (B8509-035), a new potent modulator of multidrug resistance

Cited by 37 publications

References 19 publications

New 4-Aryl-1,4-Dihydropyridines and 4-Arylpyridines as P-Glycoprotein Inhibitors

New 4-Aryl-1,4-Dihydropyridines and 4-Arylpyridines as P-Glycoprotein Inhibitors

Characterization of the Dexniguldipine Binding Site in the Multidrug Resistance-Related Transport Protein P-Glycoprotein by Photoaffinity Labeling and Mass Spectrometry

Effects of the selective bisindolylmaleimide protein kinase C inhibitor GF 109203X on P-glycoprotein-mediated multidrug resistance

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