One concept of improving anticancer effects of conventional platinum-based antitumor drugs consists of conjugating these compounds with other biologically (antitumor) active agents, acting by a different mechanism. Here, we present synthesis, physicochemical characterization, biological effects, and mechanisms of action of four new analogs of conventional cisplatin, namely, cis-Pt(II) complexes containing either methyl or ethyl pyrazole N-donor ligands and chlorido or iodido ligands. It is noteworthy that while chlorido complexes display activity in a variety of cancer cell lines comparable to cisplatin, iodido complexes are considerably more potent due to their enhanced hydrophobicity and consequently enhanced cellular accumulation. Moreover, all of the studied Pt(II) alkylpyrazole complexes display a higher selectivity for tumor cells and effectively overcome the acquired resistance to cisplatin. Further results focused on the mechanism of action of the studied complexes and showed that in contrast to cisplatin and several platinum-based antitumor drugs, DNA damage by the investigated Pt(II)-alkylpyrazole complexes does not play a major role in their mechanism of action. Our findings demonstrate that inhibition of the tubulin kinesin Eg5, which is essential for forming a functional mitotic spindle, plays an important role in their mechanism of antiproliferative action.

• Publikační typ
• časopisecké články MeSH

The kinetics of the hydration reaction on trans-[Pt(NH3)2(pyrX)Cl]+ (pyr = pyridine) complexes (X = OH-, Cl-, F-, Br-, NO2 -, NH2, SH-, CH3, C≡CH, and DMA) was studied by density functional theory calculations in the gas phase and in water solution described by the implicit polarizable continuum model method. All possible positions ortho, meta, and para of the substituent X in the pyridine ring were considered. The substitution of the pyr ligand by electron-donating X's led to the strengthening of the Pt-N1(pyrX) (Pt-NpyrX) bond and the weakening of the trans Pt-Cl or Pt-Ow bonds. The electron-withdrawing X's have exactly the opposite effect. The strengths of these bonds can be predicted from the basicity of sigma electrons on the NpyrX atom determined on the isolated pyrX ligand. As the pyrX ring was oriented perpendicularly with respect to the plane of the complex, the nature of the X···Cl electrostatic interaction was the decisive factor for the transition-state (TS) stabilization which resulted in the highest selectivity of ortho-substituted systems with respect to the reaction rate. Because of a smaller size of X's, the steric effects influenced less importantly the values of activation Gibbs energies ΔG ⧧ but caused geometry changes such as the elongation of the Pt-NpyrX bonds. Substitution in the meta position led to the highest ΔG ⧧ values for most of the X's. The changes of ΔG ⧧ because of electronic effects were the same in the gas phase and the water solvent. However, as the water solvent dampened electrostatic interactions, 2200 and 150 times differences in the reaction rate were observed between the most and the least reactive mono-substituted complexes in the gas phase and the water solvent, respectively. An additional NO2 substitution of the pyrNO2 ligand further decelerated the rate of the hydration reaction, but on the other hand, the poly-NH2 complexes were no more reactive than the fastest o-NH2 system. In the gas phase, the poly-X complexes showed the additivity of the substituent effects with respect to the Pt-ligand bond strengths and the ligand charges.

• Publikační typ
• časopisecké články MeSH

The trithiolato bridged diruthenium complex DiRu-1 [(p-MeC6H4iPr)2Ru2(SC6H4-p-But)3]+ is highly cytotoxic against various cancer cell lines, but its exact mode of action remains unknown. The present 1H HR-MAS NMR-based metabolomic study was performed on ovarian cancer cell line A2780, on its cis-Pt resistant variant A2780cisR, and on the cell line HEK-293 treated with 0.03 µM and 0.015 µM of DiRu-1 corresponding to full and half IC50 doses, respectively, to investigate the mode of action of this ruthenium complex. The resulting changes in the metabolic profile of the cell lines were studied using HR-MAS NMR of cell lysates and a subsequent statistical analysis. We show that DiRu-1 in a 0.03 µM dose has significant impact on the levels of a number of metabolites, such as glutamine, glutamate, glutathione, cysteine, lipid, creatine, lactate, and acetate, especially pronounced in the A2780cisR cell line. The IC50/2 dose shows some significant changes, but full IC50 appears to be necessary to observe the full effect. Overall, the metabolic changes observed suggest that redox homeostasis, the Warburg effect, and the lipid metabolism are affected by DiRu-1.

• Klíčová slova
• A2780, HR-MAS NMR, NMR metabolomics, cis-Pt resistant, cytotoxicity, metal-based drugs, ovarian cancer, ruthenium complex,
• Publikační typ
• časopisecké články MeSH

Due to their high kinetic inertness and consequently reduced side reactions with biomolecules, PtIV complexes are considered to define the future of anticancer platinum drugs. The aqueous stability of a series of biscarboxylato PtIV complexes was studied under physiologically relevant conditions. Unexpectedly and in contrast to the current chemical understanding, especially oxaliplatin and satraplatin complexes underwent fast hydrolysis in equatorial position (even in cell culture medium and serum). Notably, the resulting hydrolysis products strongly differ in their reduction kinetics, a crucial parameter for the activation of PtIV drugs, which also changes the anticancer potential of the compounds in cell culture. The discovery that intact PtIV complexes can hydrolyze at equatorial position contradicts the dogma on the general kinetic inertness of PtIV compounds and needs to be considered in the screening and design for novel platinum-based anticancer drugs.

• Klíčová slova
• antitumor agents, hydrolysis, platinum(IV) complexes, prodrugs, reduction,
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Structural properties of plasmid DNA and model lipid membrane treated with newly synthesized platinum(II) complex cis-[PtCl2{P(CH2CH2COOH)3}2] (cis-DTCEP for short) were studied and compared with effects of anticancer drug cisplatin, cis-[Pt(NH3)2Cl2] (cis-DDP for short). Time Correlated Single Photon Counting Fluorescence Correlation Spectroscopy (TCSPC-FCS) was employed to study interactions between those platinum complexes and DNA. The TCSPC-FCS results suggest that bonding of cis-DTCEP derivative to DNA leads to plasmid strain realignment towards much more compact structure than in the case of cis-DDP. Application of both differential scanning calorimetry and infrared spectroscopy to platinum complexes/DPPC showed that cis-DTCEP slightly increases the phospholipid's main phase transition temperature resulting in decreased fluidity of the model membrane. The newly investigated compound-similarly to cis-DDP-interacts mainly with the DPPC head group however not only by the means of electrostatic forces: this compound probably enters into hydrophilic region of the lipid bilayer and forms hydrogen bonds with COO groups of glycerol and PO2- group of DPPC.

• Klíčová slova
• DNA, DPPC bilayer, DSC, IR spectroscopy, Platinum(II) complex, TCSPC-FCS,
• MeSH
• chemické modely * MeSH
• DNA chemie   MeSH
• fluidita membrány MeSH
• fluorescenční spektrometrie MeSH
• fosfiny chemie   MeSH
• komplexní sloučeniny chemie   MeSH
• lipidové dvojvrstvy chemie   MeSH
• platina chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• DNA MeSH
• fosfiny MeSH
• komplexní sloučeniny MeSH
• lipidové dvojvrstvy MeSH
• platina MeSH

A series of platinum(II) diiodido complexes containing 7-azaindole derivatives, having the general formula cis-[PtI2(naza)2] (1-8), has been prepared and thoroughly characterized, including X-ray structure analysis of cis-[PtI2(2Me4Claza)2]∙DMF (8∙DMF; 2Me4Claza = 2-methyl-4-chloro-7-azaindole). Complexes showed high in vitro cytotoxicity against nine human cancer cell lines (IC50 ranging from 0.4 to 12.8 μM), including the cisplatin-resistant ovarian cancer cell line (A2780R; IC50 = 1.0-3.5 μM). The results of in vivo testing, using the L1210 lymphocytic leukaemia model, at the equimolar doses of Pt with cisplatin (2 mg/kg) confirmed the activity of complex 8 comparable to cisplatin. From the mechanistic point of view, evaluated ex vivo by Western blot analyses on the samples of isolated tumour tissues, the treatment of the animals with complex 8, contrary to cisplatin, decreased the levels of tumour suppressor p53 and increased significantly the amount of intracellular anti-apoptotic protein MCL-1L (37 kDa). Additionally, the active form of caspase 3 was significantly elevated in the sample of tumour tissues treated with complex 8, indicating that the activation of p53-independent cell-death pathway was initiated. The light and electron microscopy observations of the cancerous tissues revealed necrosis as a dominant mechanism of cell death, followed by scarce signs of apoptosis. The additional results (e.g. in vitro interaction experiments with selected biomolecules, cell cycle perturbations, gel electrophoretic studies on pUC19 plasmid DNA) supported the hypothesis that the complexes might be involved in the mechanism of action quite different from cisplatin.

• MeSH
• apoptóza účinky léků   MeSH
• buněčný cyklus účinky léků   MeSH
• chemorezistence účinky léků   MeSH
• cisplatina aplikace a dávkování   MeSH
• indoly aplikace a dávkování   chemie   MeSH
• kaspasa 3 genetika   MeSH
• lidé MeSH
• molekulární struktura MeSH
• nádorové buněčné linie MeSH
• nádorový supresorový protein p53 genetika   MeSH
• nádory vaječníků farmakoterapie   genetika   patologie   MeSH
• organoplatinové sloučeniny aplikace a dávkování   chemie   MeSH
• plazmidy účinky léků   MeSH
• proliferace buněk účinky léků   MeSH
• viabilita buněk účinky léků   MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 7-azaindole dimer MeSH Prohlížeč
• cisplatina MeSH
• indoly MeSH
• kaspasa 3 MeSH
• nádorový supresorový protein p53 MeSH
• organoplatinové sloučeniny MeSH

Our study demonstrates that Pt(iv) derivative of cisplatin, with two axial PhB ligands, ctc-[Pt(NH3)2(PhB)2Cl2], is a very potent cytotoxic agent against many different human cancer cell lines and is up to 100 fold more potent than cisplatin, and significantly more potent than the Pt(iv) derivatives of cisplatin with either two hydroxido, two acetato or two valproato ligands. The high potency of this compound (and some others) is due to several factors including enhanced internalization, probably driven by "synergistic accumulation" of both the Pt moiety and the phenylbutyrate, that correlates with enhanced DNA binding and cytotoxicity. ctc-[Pt(NH3)2(PhB)2Cl2] inhibits 60-70% HDAC activity in cancer cells, at levels below the IC50 values of PhB, suggesting synergism between Pt and PhB. Mechanistically, ctc-[Pt(NH3)2(PhB)2Cl2] induces activation of caspases (3 and 9) triggering apoptotic signaling via the mitochondrial pathway. Data also suggest that the antiproliferative effect of ctc-[Pt(NH3)2(PhB)2Cl2] may not depend of p53. Pt(iv) derivatives of cisplatin with either two axial PhB or valproate ligands are more potent than their oxaliplatin analogs. ctc-[Pt(NH3)2(PhB)2Cl2] is significantly more potent than its valproate analog ctc-[Pt(NH3)2(VPA)2Cl2]. These compounds combine multiple effects such as efficient uptake of both Pt and PhB with DNA binding, HDAC inhibition and activation of caspases to effectively kill cancer cells.

• Publikační typ
• časopisecké články MeSH

The cis-[PtCl2(naza)2] complexes (1-3) containing monosubstituted 7-azaindole halogeno-derivatives (naza), showed significantly higher activity than cisplatin towards ovarian carcinoma A2780, its cisplatin-resistant variant A2780R, osteosarcoma HOS, breast carcinoma MCF7 and cervix carcinoma HeLa cell lines, with the IC50 values of 3.8, 3.5, 4.5, 2.7, and 9.2 μM, respectively, obtained for the most active complex 3. As for 4 and 5 having disubstituted 7-azaindoles in their molecule, the significant cytotoxicity was detected only for 4 against A2780 (IC50 = 4.8 μM), A2780R (IC50 = 3.8 μM) and HOS (IC50 = 4.3 μM), while 5 was evaluated as having only moderate antiproliferative effect against the mentioned cancer cell lines with IC50 = 33.4, 24.7 and 46.7 μM, respectively. All the studied complexes 1-5 effectively avoided the acquired resistance of ovarian carcinoma cell line. On the other hand, the complexes did not reveal any inhibition activity on the purified 20S proteasome from the A2780 cells. The representative complexes 3 and 5 showed low ability to be hydrolysed, but their stability was markedly lowered in the presence of physiological sulphur-containing biomolecule glutathione (GSH), as proved by the 1H NMR spectroscopy and mass spectrometry studies. A rate of interaction of the studied complexes with GSH was affected by an addition of another mechanistically relevant biomolecule guanosine monophosphate. The differences in interactions of 3 and 5 with GSH correlate well with their different cytotoxicity profiles.

• MeSH
• chemorezistence MeSH
• cisplatina chemie   farmakologie   MeSH
• glutathion chemie   MeSH
• HeLa buňky MeSH
• hmotnostní spektrometrie MeSH
• indoly chemie   farmakologie   MeSH
• lidé MeSH
• MFC-7 buňky MeSH
• molekulární struktura MeSH
• nukleární magnetická rezonance biomolekulární MeSH
• organoplatinové sloučeniny chemie   farmakologie   MeSH
• protinádorové látky chemie   farmakologie   MeSH
• viabilita buněk účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 7-azaindole dimer MeSH Prohlížeč
• cisplatina MeSH
• glutathion MeSH
• indoly MeSH
• organoplatinové sloučeniny MeSH
• protinádorové látky MeSH

The in vitro antitumour activity studies on a panel of human cancer cell lines (A549, HeLa, G-361, A2780, and A2780R) and the combined in vivo and ex vivo antitumour testing on the L1210 lymphocytic leukaemia model were performed on the cis-[PtCl2(naza)2] complexes (1-3) involving the 7-azaindole derivatives (naza). The platinum(II) complexes showed significantly higher in vitro cytotoxic effects on cell-based models, as compared with cisplatin, and showed the ability to avoid the acquired resistance of the A2780R cell line to cisplatin. The in vivo testing of the complexes (applied at the same dose as cisplatin) revealed their positive effect on the reduction of cancerous tissues volume, even if it is lower than that of cisplatin, however, they also showed less serious adverse effects on the healthy tissues and the health status of the treated mice. The results of ex vivo assays revealed that the complexes 1-3 were able to modulate the levels of active forms of caspases 3 and 8, and the transcription factor p53, and thus activate the intrinsic (mitochondrial) pathway of apoptosis. The pharmacological observations were supported by both the histological and immunohistochemical evaluation of isolated cancerous tissues. The applicability of the prepared complexes and their fate in biological systems, characterized by the hydrolytic stability and the thermodynamic aspects of the interactions with cysteine, reduced glutathione, and human serum albumin were studied by the mass spectrometry and isothermal titration calorimetric experiments.

• MeSH
• cisplatina farmakologie   MeSH
• HeLa buňky MeSH
• hmotnostní spektrometrie s elektrosprejovou ionizací MeSH
• imunohistochemie MeSH
• indoly chemie   MeSH
• Kaplanův-Meierův odhad MeSH
• kaspasa 3 metabolismus   MeSH
• kaspasa 8 metabolismus   MeSH
• lidé MeSH
• lymfoidní leukemie farmakoterapie   patologie   MeSH
• magnetická rezonanční spektroskopie MeSH
• MFC-7 buňky MeSH
• molekulární struktura MeSH
• myši inbrední DBA MeSH
• nádorové buněčné linie MeSH
• nádorový supresorový protein p53 metabolismus   MeSH
• organoplatinové sloučeniny chemie   farmakologie   MeSH
• protinádorové látky chemie   farmakologie   MeSH
• stabilita léku MeSH
• termodynamika MeSH
• viabilita buněk účinky léků   MeSH
• výsledek terapie MeSH
• western blotting MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 7-azaindole dimer MeSH Prohlížeč
• cisplatina MeSH
• indoly MeSH
• kaspasa 3 MeSH
• kaspasa 8 MeSH
• nádorový supresorový protein p53 MeSH
• organoplatinové sloučeniny MeSH
• protinádorové látky MeSH

Hydration reactions of two anticancer Pt(IV) complexes JM149 and JM216 (Satraplatin) were studied computationally together with the hydration of the Pt(II) complex JM118, which is a product of the Satraplatin reduction. Thermodynamic and kinetic parameters of the reactions were determined at the B3LYP/6-311++G(2df.2pd)//B3LYP/6-31 + G(d)) level of theory. The water solution was modeled using the COSMO implicit solvation model, with cavities constructed using Klamt's atomic radii. It was found that hydration of the Pt(IV) complexes is an endergonic/endothermic reaction. It follows the (pseudo)associative mechanism is substantially slower (k ≈ 10(-11) s(-1)) than the corresponding reaction of Pt(II) analogues ((k ≈ 10(-5) s(-1)). Such a low value of the reaction constant signifies that the hydration of JM149 and Satraplatin is with high probability a kinetically forbidden reaction. Similarly to JM149 and Satraplatin, the hydration of JM118 is an endothermic/endoergic reaction. On the other hand, the kinetic parameters are similar to those of cisplatin Zimmermann et al. (J Mol Model 17:2385-2393, 2011), allowing the hydration reaction to occur at physiological conditions. These results suggest that in order to become active Satraplatin has to be first reduced to JM118, which may be subsequently hydrated to yield the active species.

• MeSH
• chemické modely MeSH
• kinetika MeSH
• kvantová teorie MeSH
• ligandy MeSH
• molekulární modely MeSH
• organoplatinové sloučeniny chemie   MeSH
• oxidace-redukce MeSH
• protinádorové látky chemie   MeSH
• termodynamika MeSH
• voda chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• amminedichloro(cyclohexylamine)platinum(II) MeSH Prohlížeč
• JM 335 MeSH Prohlížeč
• ligandy MeSH
• organoplatinové sloučeniny MeSH
• protinádorové látky MeSH
• satraplatin MeSH Prohlížeč
• voda MeSH