Most cited article - PubMed ID 12102553
DNA modifications by antitumor platinum and ruthenium compounds: their recognition and repair
We present the anticancer properties of cis, cis, trans-[Pt(IV)(NH3)2Cl2(OA)2] [Pt(IV)diOA] (OA = octanoato), Pt(IV) derivative of cisplatin containing two OA units appended to the axial positions of a six-coordinate Pt(IV) center. Our results demonstrate that Pt(IV)diOA is a potent cytotoxic agent against many cancer cell lines (the IC50 values are approximately two orders of magnitude lower than those of clinically used cisplatin or Pt(IV) derivatives with biologically inactive axial ligands). Importantly, Pt(IV)diOA overcomes resistance to cisplatin, is significantly more potent than its branched Pt(IV) valproato isomer and exhibits promising in vivo antitumor activity. The potency of Pt(IV)diOA is a consequence of several factors including enhanced cellular accumulation correlating with enhanced DNA platination and cytotoxicity. Pt(IV)diOA induces DNA hypermethylation and reduces mitochondrial membrane potential in cancer cells at levels markedly lower than the IC50 value of free OA suggesting the synergistic action of platinum and OA moieties. Collectively, the remarkable antitumor effects of Pt(IV)diOA are a consequence of the enhanced cellular uptake which makes it possible to simultaneously accumulate high levels of both cisplatin and OA in cells. The simultaneous dual action of cisplatin and OA by different mechanisms in tumor cells may result in a markedly enhanced and unique antitumor effects of Pt(IV) prodrugs.
- MeSH
- Cisplatin * analogs & derivatives pharmacokinetics pharmacology MeSH
- DNA, Neoplasm metabolism MeSH
- Epigenesis, Genetic drug effects MeSH
- Humans MeSH
- DNA Methylation drug effects MeSH
- Cell Line, Tumor MeSH
- Ovarian Neoplasms * drug therapy metabolism pathology MeSH
- Antineoplastic Agents * pharmacokinetics pharmacology MeSH
- Gene Expression Regulation, Neoplastic drug effects MeSH
- Check Tag
- Humans MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Cisplatin * MeSH
- DNA, Neoplasm MeSH
- Antineoplastic Agents * MeSH
Nuclear DNA is the target responsible for anticancer activity of platinum anticancer drugs. Their activity is mediated by altered signals related to programmed cell death and the activation of various signaling pathways. An example is activation of nuclear factor kappaB (NF-κB). Binding of NF-κB proteins to their consensus sequences in DNA (κB sites) is the key biochemical activity responsible for the biological functions of NF-κB. Using gel-mobility-shift assays and surface plasmon resonance spectroscopy we examined the interactions of NF-κB proteins with oligodeoxyribonucleotide duplexes containing κB site damaged by DNA adducts of three platinum complexes. These complexes markedly differed in their toxic effects in tumor cells and comprised highly cytotoxic trinuclear platinum(II) complex BBR3464, less cytotoxic conventional cisplatin and ineffective transplatin. The results indicate that structurally different DNA adducts of these platinum complexes exhibit a different efficiency to affect the affinity of the platinated DNA (κB sites) to NF-κB proteins. Our results support the hypothesis that structural perturbations induced in DNA by platinum(II) complexes correlate with their higher efficiency to inhibit binding of NF-κB proteins to their κB sites and cytotoxicity as well. However, the full generalization of this hypothesis will require to evaluate a larger series of platinum(II) complexes.
- MeSH
- DNA Adducts chemistry metabolism MeSH
- Cisplatin chemistry metabolism pharmacology MeSH
- HEK293 Cells MeSH
- Kinetics MeSH
- Coordination Complexes chemistry metabolism pharmacology MeSH
- Consensus Sequence MeSH
- Humans MeSH
- NF-kappa B chemistry genetics metabolism MeSH
- Oligodeoxyribonucleotides chemistry metabolism MeSH
- Organoplatinum Compounds chemistry toxicity MeSH
- Platinum chemistry metabolism MeSH
- Surface Plasmon Resonance MeSH
- Antineoplastic Agents chemistry metabolism pharmacology MeSH
- Recombinant Proteins biosynthesis chemistry isolation & purification MeSH
- Electrophoretic Mobility Shift Assay MeSH
- Thermodynamics MeSH
- Protein Binding MeSH
- Binding Sites MeSH
- Cell Survival drug effects MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Extramural MeSH
- Names of Substances
- DNA Adducts MeSH
- BBR 3464 MeSH Browser
- Cisplatin MeSH
- Coordination Complexes MeSH
- NF-kappa B MeSH
- Oligodeoxyribonucleotides MeSH
- Organoplatinum Compounds MeSH
- Platinum MeSH
- Antineoplastic Agents MeSH
- Recombinant Proteins MeSH
The moderate-to-high in vitro cytotoxicity against ovarian A2780 (IC50 = 4.7-14.4 μM), prostate LNCaP (IC50 = 18.7-30.8 μM) and prostate PC-3 (IC50 = 17.6-42.3 μM) human cancer cell lines of the platinum(II) cyclobutane-1,1'-dicarboxylato complexes [Pt(cbdc)(naza)2] (1-6; cbdc = cyclobutane-1,1'-dicarboxylate(2-); naza = halogeno-substituted 7-azaindoles), derived from the anticancer metallodrug carboplatin, are reported. The complexes containing the chloro- and bromo-substituted 7-azaindoles (1, 2, and 4-6) showed a significantly higher (p < 0.05) cytotoxicity against A2780 cell line as compared to cisplatin used as a reference drug. Addition of the non-toxic concentration (5.0 μM) of L-buthionine sulfoximine (L-BSO, an effective inhibitor of γ-glutamylcysteine synthase) markedly increases the in vitro cytotoxicity of the selected complex 3 against A2780 cancer cell line by a factor of about 4.4. The cytotoxicity against A2780 and LNCaP cells, as well as the DNA platination, were effectively enhanced by UVA light irradiation (λmax = 365 nm) of the complexes, with the highest phototoxicity determined for compound 3, resulting in a 4-fold decline in the A2780 cells viability from 25.1% to 6.1%. The 1H NMR and ESI-MS experiments suggested that the complexes did not interact with glutathione as well as their ability to interact with guanosine monophosphate. The studies also confirmed UVA light induced the formation of the cis [Pt(H2O)2(cbdc`)(naza)] intermediate, where cbdc` represents monodentate-coordinated cbdc ligand, which is thought to be responsible for the enhanced cytotoxicity. This is further supported by the results of transcription mapping experiments showing that the studied complexes preferentially form the bifunctional adducts with DNA under UVA irradiation, in contrast to the formation of the less effective monofunctional adducts in dark.
- MeSH
- DNA Adducts chemistry genetics MeSH
- Buthionine Sulfoximine pharmacology MeSH
- DNA Breaks, Double-Stranded drug effects radiation effects MeSH
- Spectrometry, Mass, Electrospray Ionization MeSH
- Indoles chemistry pharmacology MeSH
- Carboplatin chemistry pharmacology MeSH
- Nucleic Acid Conformation MeSH
- Humans MeSH
- Molecular Structure MeSH
- Cell Line, Tumor MeSH
- Neoplasms genetics pathology MeSH
- Antineoplastic Agents chemistry pharmacology MeSH
- Proton Magnetic Resonance Spectroscopy MeSH
- Drug Synergism MeSH
- Ultraviolet Rays * MeSH
- Cell Survival drug effects genetics radiation effects MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- 7-azaindole dimer MeSH Browser
- DNA Adducts MeSH
- Buthionine Sulfoximine MeSH
- Indoles MeSH
- Carboplatin MeSH
- Antineoplastic Agents MeSH
Carboplatin, an analogue of "classical" cis-diamminedichloridoplatinum(II) (cisplatin), is a widely used second-generation platinum anticancer drug. Cytotoxicity of cisplatin and carboplatin is mediated by platinum-DNA adducts. Markedly higher concentrations of carboplatin are required, and the rate of adduct formation is considerably slower. The reduced toxic effects in tumor cells and a more acceptable side-effect profile are attributable to the lower reactivity of carboplatin with nucleophiles, since the cyclobutanedicarboxylate ligand is a poorer leaving group than the chlorides in cisplatin. Recently, platinum complexes were shown to be particularly attractive as potential photochemotherapeutic anticancer agents. Selective photoactivation of platinum complexes by irradiation of cancer cells may avoid enhancement of toxic side-effects, but may increase toxicity selectively in cancer cells and extend the application of photoactivatable platinum complexes to resistant cells and to a wider range of cancer types. Therefore, it was of interest to examine whether carboplatin can be affected by irradiation with light to the extent that its DNA binding and cytotoxic properties are altered. We have found that carboplatin is converted to species capable of enhanced DNA binding by UVA irradiation and consequently its toxicity in cancer cells is markedly enhanced. Recent advances in laser and fiber-optic technologies make it possible to irradiate also internal organs with light of highly defined intensity and wavelength. Thus, carboplatin is a candidate for use in photoactivated cancer chemotherapy.
- MeSH
- DNA chemistry drug effects MeSH
- Photochemical Processes radiation effects MeSH
- Carboplatin chemistry pharmacology radiation effects toxicity MeSH
- Kinetics MeSH
- Humans MeSH
- Tumor Cells, Cultured MeSH
- Plasmids MeSH
- DNA Damage drug effects MeSH
- Cell Proliferation drug effects MeSH
- Antineoplastic Agents chemistry pharmacology radiation effects toxicity MeSH
- Drug Screening Assays, Antitumor MeSH
- Cattle MeSH
- Ultraviolet Rays MeSH
- Binding Sites drug effects MeSH
- Cell Survival drug effects MeSH
- Dose-Response Relationship, Drug MeSH
- Structure-Activity Relationship MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Cattle MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- DNA MeSH
- Carboplatin MeSH
- Antineoplastic Agents MeSH
The effects of major DNA intrastrand cross-links of antitumor dinuclear Pt(II) complexes [{trans-PtCl(NH(3))(2)}(2)-μ-{trans-(H(2)N(CH(2))(6)NH(2)(CH(2))(2)NH(2)(CH(2))(6)NH(2))}](4+) (1) and [{PtCl(DACH)}(2)-μ-{H(2)N(CH(2))(6)NH(2)(CH(2))(2)NH(2)(CH(2))(6)NH(2))}](4+) (2) (DACH is 1,2-diaminocyclohexane) on DNA stability were studied with emphasis on thermodynamic origins of that stability. Oligodeoxyribonucleotide duplexes containing the single 1,2, 1,3, or 1,5 intrastrand cross-links at guanine residues in the central TGGT, TGTGT, or TGTTTGT sequences, respectively, were prepared and analyzed by differential scanning calorimetry. The unfolding of the platinated duplexes was accompanied by unfavorable free energy terms. The efficiency of the cross-links to thermodynamically destabilize the duplex depended on the number of base pairs separating the platinated bases. The trend was 1,5→1,2→1,3 cross-link of 1 and 1,5→1,3→1,2 cross-link of 2. Interestingly, the results showed that the capability of the cross-links to reduce the thermodynamic stability of DNA (ΔG(298)(0)) correlated with the extent of conformational distortions induced in DNA by various types of intrastrand cross-links of 1 or 2 determined by chemical probes of DNA conformation. We also examined the efficiency of the mammalian nucleotide excision repair systems to remove from DNA the intrastrand cross-links of 1 or 2. The efficiency of the excinucleases to remove the cross-links from DNA depended on the length of the cross-link; the trend was identical to that observed for the efficiency of the intrastrand cross-links to thermodynamically destabilize the duplex. Thus, the results are consistent with the thesis that an important factor that determines the susceptibility of the intrastrand cross-links of dinuclear platinum complexes 1 and 2 to be removed from DNA by nucleotide excision repair is the efficiency of these lesions to thermodynamically destabilize DNA.
- MeSH
- Calorimetry, Differential Scanning MeSH
- DNA chemistry MeSH
- Intercalating Agents chemistry pharmacology MeSH
- Nucleic Acid Conformation drug effects MeSH
- DNA Repair drug effects MeSH
- Organoplatinum Compounds chemistry pharmacology MeSH
- Antineoplastic Agents chemistry pharmacology MeSH
- Base Sequence MeSH
- Thermodynamics MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- DNA MeSH
- Intercalating Agents MeSH
- Organoplatinum Compounds MeSH
- Antineoplastic Agents MeSH
A combination of biophysical, biochemical, and computational techniques was used to delineate mechanistic differences between the platinum-acridine hybrid agent [PtCl(en)(L)](NO(3))(2) (complex 1, en = ethane-1,2-diamine, L = 1-[2-(acridin-9-ylamino)ethyl]-1,3-dimethylthiourea) and a considerably more potent second-generation analogue containing L' = N-[2-(acridin-9-ylamino)ethyl]-N-methylpropionamidine (complex 2). Calculations at the density functional theory level provide a rationale for the binding preference of both complexes for guanine-N7 and the relatively high level of adenine adducts observed for compound 1. A significant rate enhancement is observed for binding of the amidine-based complex 2 with DNA compared with the thiourea-based prototype 1. Studies conducted with chemical probes and on the bending and unwinding of model duplex DNA suggest that adducts of complex 2 perturb B-form DNA more severely than complex 1, however, without denaturing the double strand and significantly less than cisplatin. Circular and linear dichroism spectroscopies and viscosity measurements suggest that subtle differences exist between the intercalation modes and adduct geometries of the two complexes. The adducts formed by complex 2 most efficiently inhibit transcription of the damaged DNA by RNA polymerase II. Not only do complexes 1 and 2 cause less distortion to DNA than cisplatin, they also do not compromise the thermodynamic stability of the modified duplex. This leads to a decreased or negligible affinity of HMG domain proteins for the adducts formed by either Pt-acridine complex. In a DNA repair synthesis assay the lesions formed by complex 2 were repaired less efficiently than those formed by complex 1. These significant differences in DNA adduct formation, structure, and recognition between the two acridine complexes and cisplatin help to elucidate why compound 2 is highly active in cisplatin-resistant, repair proficient cancer cell lines.
- MeSH
- DNA Adducts chemistry MeSH
- Acridines chemistry metabolism pharmacology MeSH
- Amidines chemistry metabolism pharmacology MeSH
- DNA, B-Form chemistry metabolism MeSH
- Cisplatin analogs & derivatives chemistry metabolism pharmacology MeSH
- DNA chemistry metabolism MeSH
- Transcription, Genetic drug effects MeSH
- HeLa Cells MeSH
- Intercalating Agents chemistry metabolism pharmacology MeSH
- Kinetics MeSH
- Nucleic Acid Conformation drug effects MeSH
- Humans MeSH
- DNA Repair drug effects MeSH
- Organoplatinum Compounds chemistry metabolism pharmacology MeSH
- Protein Isoforms metabolism MeSH
- HMGB1 Protein metabolism MeSH
- Antineoplastic Agents chemistry metabolism pharmacology MeSH
- Drug Design MeSH
- Thiourea chemistry metabolism pharmacology MeSH
- Structure-Activity Relationship MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Extramural MeSH
- Comparative Study MeSH
- Names of Substances
- DNA Adducts MeSH
- Acridines MeSH
- Amidines MeSH
- DNA, B-Form MeSH
- Cisplatin MeSH
- DNA MeSH
- Intercalating Agents MeSH
- Organoplatinum Compounds MeSH
- Protein Isoforms MeSH
- HMGB1 Protein MeSH
- Antineoplastic Agents MeSH
- Thiourea MeSH
In this study, we characterized the effects of LA-12 on tumor cell lines possessing wild type p53 and on p53-deficient/mutant cell lines and the results were compared to those obtained using cisplatin. We have determined changes of p53 levels, of its transcriptional activity, of its posttranscriptional modifications and the effect of the treatment on the cell cycle, on the induction of apoptosis and on gene expression. LA-12 induces weak accumulation of both transcriptionally active p53 tumor suppressor and of p21(WAF1/CIP1) protein. LA-12 and cisplatin also significantly differ in their effects on apoptosis and cell cycle and on gene expression spectra in studied cell lines. LA-12 induces higher apoptosis levels in comparison with those induced by cisplatin, especially in p53-deficient H1299 cells and in MCF-7DD cells with transcriptionally inactive p53. We suggest that LA-12-mediated apoptosis is not fully dependent on p53. This confirms the therapeutic potential of LA-12 as a more potent cytostatic agent for both tumor cells expressing wild type p53 and for p53-deficient or mutant cells.
- MeSH
- Amantadine analogs & derivatives pharmacology MeSH
- Apoptosis drug effects MeSH
- Cell Cycle drug effects MeSH
- Cisplatin pharmacology MeSH
- Genes, p53 MeSH
- Cyclin-Dependent Kinase Inhibitor p21 metabolism MeSH
- Humans MeSH
- Mutation MeSH
- Cell Line, Tumor MeSH
- Tumor Suppressor Protein p53 genetics metabolism MeSH
- Organoplatinum Compounds pharmacology MeSH
- Apoptosis Regulatory Proteins metabolism MeSH
- Antineoplastic Agents pharmacology MeSH
- Gene Expression Regulation, Neoplastic drug effects MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Amantadine MeSH
- bis(acetato)(1-adamantylamine)amminedichloroplatinum(IV) MeSH Browser
- CDKN1A protein, human MeSH Browser
- Cisplatin MeSH
- Cyclin-Dependent Kinase Inhibitor p21 MeSH
- Tumor Suppressor Protein p53 MeSH
- Organoplatinum Compounds MeSH
- Apoptosis Regulatory Proteins MeSH
- Antineoplastic Agents MeSH
Using electrophoresis and replication mapping, we show that the presence of DNA adducts of bifunctional antitumor cisplatin or monodentate [PtCl(dien)]Cl (dien = diethylenetriamine) in the substrate DNA inhibits eukaryotic topoisomerase 1 (top1) action, the adducts of cisplatin being more effective. The presence of camptothecin in the samples of platinated DNA markedly enhances effects of Pt-DNA adducts on top1 activity. Interestingly, the effects of Pt-DNA adducts on the catalytic activity of top1 in the presence of camptothecin differ depending on the sequence context. A multiple metallation of the short nucleotide sequences on the scissile strand, immediately downstream of the cleavage site impedes the cleavage by top1. On the other hand, DNA cleavage by top1 at some cleavage sites which were not platinated in their close proximity is notably enhanced as a consequence of global platination of DNA. We suggest that this enhancement of DNA cleavage by top1 may consist in its inability to bind to other cleavage sites platinated in their close neighborhood; thus, more molecules of top1 may become available for cleavage at the sites where top1 normally cleaves and where platination does not interfere.
- MeSH
- DNA Adducts chemistry pharmacology MeSH
- Cisplatin analogs & derivatives chemistry pharmacology MeSH
- DNA Topoisomerases, Type I metabolism MeSH
- DNA chemistry metabolism MeSH
- Enzyme Inhibitors chemistry pharmacology MeSH
- Topoisomerase I Inhibitors * MeSH
- Antineoplastic Agents chemistry pharmacology MeSH
- DNA Cleavage MeSH
- DNA, Superhelical metabolism MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- DNA Adducts MeSH
- chlorodiethylenetriamine platinum MeSH Browser
- cisplatin-DNA adduct MeSH Browser
- Cisplatin MeSH
- DNA Topoisomerases, Type I MeSH
- DNA MeSH
- Enzyme Inhibitors MeSH
- Topoisomerase I Inhibitors * MeSH
- Antineoplastic Agents MeSH
- DNA, Superhelical MeSH
We studied the effect of antitumor cisplatin and inefficient transplatin on the structure and stability of G quadruplexes formed by the model human telomere sequence 5'-GGG(TTAGGG)(3)-3' using circular dichroism, UV-monitored thermal denaturation, and gel electrophoresis. In addition, to investigate whether there is a connection between the ability of cisplatin or transplatin to affect telomerase activity and stability of G quadruplexes, we also used a modified telomere repeat amplification protocol assay that uses an oligonucleotide substrate for telomerase elongation susceptible to forming a G quadruplex. The results indicate that cisplatin is more efficient than transplatin in disturbing the quadruplex structure, thereby precluding telomeric sequences from forming quadruplexes. On the other hand, the results of this work also demonstrate that in absence of free platinum complex, DNA adducts of antitumor cisplatin inhibit telomerase catalysis, so the mechanism underlying this inhibition does not involve formation of the G quadruplexes which are not elongated by telomerase.
- MeSH
- DNA Adducts drug effects genetics metabolism MeSH
- Biocatalysis MeSH
- Circular Dichroism MeSH
- Cisplatin chemistry pharmacology MeSH
- Nucleic Acid Denaturation MeSH
- Electrophoresis, Polyacrylamide Gel MeSH
- G-Quadruplexes drug effects MeSH
- Humans MeSH
- Antineoplastic Agents chemistry pharmacology MeSH
- Base Sequence MeSH
- Spectrophotometry, Ultraviolet MeSH
- Nucleic Acid Amplification Techniques MeSH
- Telomerase antagonists & inhibitors metabolism MeSH
- Telomere chemistry genetics MeSH
- Transition Temperature MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- DNA Adducts MeSH
- Cisplatin MeSH
- Antineoplastic Agents MeSH
- Telomerase MeSH
- transplatin MeSH Browser
The global modification of mammalian and plasmid DNAs by the novel platinum compounds cis-[PtCl(2)(isopropylamine)(1-methylimidazole)] and trans-[PtCl(2)(isopropylamine)(1-methylimidazole)] and the reactivity of these compounds with reduced glutathione (GSH) were investigated in cell-free media using various biochemical and biophysical methods. Earlier cytotoxicity studies had revealed that the replacement of the NH(3) groups in cisplatin by the azole and isopropylamine ligands lowers the activity of cisplatin in both sensitive and resistant cell lines. The results of the present work show that this replacement does not considerably affect the DNA modifications by this drug, recognition of these modifications by HMGB1 protein, their repair, and reactivity of the platinum complex with GSH. These results were interpreted to mean that the reduced activity of this analog of cisplatin in tumor cell lines is due to factors that do not operate at the level of the target DNA. In contrast, earlier studies had shown that the replacement of the NH(3) groups in the clinically ineffective trans isomer (transplatin) by the azole and isopropylamine ligands results in a radical enhancement of its activity in tumor cell lines. Importantly, this replacement also markedly alters the DNA binding mode of transplatin, which is distinctly different from that of cisplatin, but does not affect reactivity with GSH. Hence, the results of the present work are consistent with the view and support the hypothesis systematically tested by us and others that platinum drugs that bind to DNA in a fundamentally different manner from that of conventional cisplatin may have altered pharmacological properties.
- MeSH
- Cell-Free System MeSH
- Circular Dichroism MeSH
- DNA chemistry drug effects MeSH
- Glutathione chemistry drug effects MeSH
- Culture Media chemistry MeSH
- Humans MeSH
- Organoplatinum Compounds chemistry pharmacology MeSH
- Antineoplastic Agents chemistry pharmacology MeSH
- Spectrophotometry, Ultraviolet MeSH
- Stereoisomerism MeSH
- Binding Sites MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- dichloro(isopropylamine)(1-methylimidazole)diplatinum(II) MeSH Browser
- DNA MeSH
- Glutathione MeSH
- Culture Media MeSH
- Organoplatinum Compounds MeSH
- Antineoplastic Agents MeSH