- Publikační typ
- abstrakt z konference MeSH
- Publikační typ
- abstrakt z konference MeSH
Small molecule inhibitors of cyclin-dependent kinases (CDK) have been developed as anticancer drugs with cytostatic and cytotoxic properties, but some of them have also been shown to limit angiogenesis. Here, we report that the 3,5-diaminopyrazole CAN508 inhibits endothelial cell migration and tube formation. In addition, it reduces phosphorylation of the C-terminus of RNA polymerase II and inhibits mRNA synthesis in endothelial cells, in accordance with previous observations that it has high selectivity towards the positive transcriptional regulator P-TEFb. Moreover, CAN508 reduces expression of vascular endothelial growth factor by several human cancer cell lines. The findings suggest that P-TEFb may be an attractive target for anti-angiogenic therapy.
- MeSH
- azosloučeniny farmakologie MeSH
- fosforylace MeSH
- genetická transkripce účinky léků MeSH
- inhibitory proteinkinas farmakologie MeSH
- kultivované buňky MeSH
- lidé MeSH
- messenger RNA genetika MeSH
- patologická angiogeneze prevence a kontrola MeSH
- pyrazoly farmakologie MeSH
- RNA-polymerasa II metabolismus MeSH
- transkripční faktor B aktivující elongaci antagonisté a inhibitory MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
We describe here a new reversed-phase high-performance liquid chromatography with mass spectrometry detection method for quantifying intact cytokinin nucleotides in human K-562 leukemia cells. Tandem mass spectrometry was used to identify the intracellular metabolites (cytokinin monophosphorylated, diphosphorylated, and triphosphorylated nucleotides) in riboside-treated cells. For the protein precipitation and sample preparation, a trichloroacetic acid extraction method is used. Samples are then back-extracted with diethyl ether, lyophilized, reconstituted, and injected into the LC system. Analytes were quantified in negative selected ion monitoring mode using a single quadrupole mass spectrometer. The method was validated in terms of retention time stabilities, limits of detection, linearity, recovery, and analytical accuracy. The developed method was linear in the range of 1-1,000 pmol for all studied compounds. The limits of detection for the analytes vary from 0.2 to 0.6 pmol.
- MeSH
- chromatografie kapalinová MeSH
- cytokininy analýza chemie MeSH
- hmotnostní spektrometrie MeSH
- lidé MeSH
- molekulární struktura MeSH
- nádorové buněčné linie MeSH
- nukleotidy analýza chemie MeSH
- tandemová hmotnostní spektrometrie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Cytokinin ribosides (N(6)-substituted adenosine derivatives) have been shown to have anticancer activity both in vitro and in vivo. This study presents the first systematic analysis of the relationship between the chemical structure of cytokinins and their cytotoxic effects against a panel of human cancer cell lines with diverse histopathological origins. The results confirm the cytotoxic activity of N(6)-isopentenyladenosine, kinetin riboside, and N(6)-benzyladenosine and show that the spectrum of cell lines that are sensitive to these compounds and their tissues of origin are wider than previously reported. The first evidence that the hydroxylated aromatic cytokinins (ortho-, meta-, para-topolin riboside) and the isoprenoid cytokinin cis-zeatin riboside have cytotoxic activities is presented. Most cell lines in the panel showed greatest sensitivity to ortho-topolin riboside (IC(50)=0.5-11.6 microM). Cytokinin nucleotides, some synthesized for the first time in this study, were usually active in a similar concentration range to the corresponding ribosides. However, cytokinin free bases, 2-methylthio derivatives and both O- and N-glucosides showed little or no toxicity. Overall the study shows that structural requirements for cytotoxic activity of cytokinins against human cancer cell lines differ from the requirements for their activity in plant bioassays. The potent anticancer activity of ortho-topolin riboside (GI(50)=0.07-84.60 microM, 1st quartile=0.33 microM, median=0.65 microM, 3rd quartile=1.94 microM) was confirmed using NCI(60), a standard panel of 59 cell lines, originating from nine different tissues. Further, the activity pattern of oTR was distinctly different from those of standard anticancer drugs, suggesting that it has a unique mechanism of activity. In comparison with standard drugs, oTR showed exceptional cytotoxic activity against NCI(60) cell lines with a mutated p53 tumour suppressor gene. oTR also exhibited significant anticancer activity against several tumour models in in vivo hollow fibre assays.
- MeSH
- adenosin analogy a deriváty chemie farmakologie MeSH
- antitumorózní látky chemie farmakologie MeSH
- cytokininy analýza chemie metabolismus MeSH
- geny p53 účinky léků genetika MeSH
- inhibiční koncentrace 50 MeSH
- isopentenyladenosin analogy a deriváty chemie farmakologie MeSH
- kinetin chemie farmakologie MeSH
- léky antitumorózní - screeningové testy MeSH
- lidé MeSH
- molekulární struktura MeSH
- National Cancer Institute (U.S.) MeSH
- regulátory růstu rostlin farmakologie MeSH
- stereoizomerie MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Spojené státy americké MeSH
In an attempt to improve specific biological functions of cytokinins routinely used in plant micropropagation, 33 6-benzylamino-9-tetrahydropyran-2-ylpurine (THPP) and 9-tetrahydrofuran-2-ylpurine (THFP) derivatives, with variously positioned hydroxy and methoxy functional groups on the benzyl ring, were prepared. The new derivatives were prepared by condensation of 6-chloropurine with 3,4-dihydro-2H-pyran or 2,3-dihydrofuran and then by the condensation of these intermediates with the corresponding benzylamines. The prepared compounds were characterized by elemental analyses, TLC, HPLC, melting point determinations, CI+ MS and (1)H NMR spectroscopy. The cytokinin activity of all the prepared derivatives was assessed in three classical cytokinin bioassays (tobacco callus, wheat leaf senescence and Amaranthus bioassay). The derivatives 6-(3-hydroxybenzylamino)-9-tetrahydropyran-2-ylpurine (3) and 6-(3-hydroxybenzylamino)-9-tetrahydrofuran-2-ylpurine (23) were selected, because of the high affinity of their parent compound meta-topolin (mT, 6-(3-hydroxybenzylamino)purine) to cytokinin receptors, as model compounds for studying their perception by the receptors CRE1/AHK4 and AHK3 in a bacterial assay. Both receptors perceived these two derivatives less well than they perceived the parent compound. Subsequently, the susceptibility of several new derivatives to enzyme degradation by cytokinin oxidase/dehydrogenase was studied. Substitution of tetrahydropyran-2-yl (THP) at the N(9) position decreased the turnover rates of all new derivatives to some extent. To provide a practical perspective, the cytotoxicity of the prepared compounds against human diploid fibroblasts (BJ) and the human cancer cell lines K-562 and MCF-7 was also assayed in vitro. The prepared compounds showed none or marginal cytotoxicity compared to the corresponding N(9)-ribosides. Finally, the pH stability of the two model compounds was assessed in acidic and neutral water solutions (pH 3-7) by high-performance liquid chromatography (HPLC).
- MeSH
- cytokininy chemie metabolismus MeSH
- fibroblasty účinky léků MeSH
- financování organizované MeSH
- furany chemická syntéza chemie toxicita MeSH
- kinetika MeSH
- koncentrace vodíkových iontů MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- puriny chemická syntéza chemie toxicita MeSH
- pyrany chemická syntéza chemie toxicita MeSH
- stabilita léku MeSH
- Check Tag
- lidé MeSH
Cytokinin activity of forty-eight 6-benzyladenosine derivatives at both the receptor and cellular levels as well as their anticancer properties were compared in various in vitro assays. The compounds were prepared by the condensation of 6-chloropurine riboside with corresponding substituted benzylamines and characterized by standard collection of physico-chemical methods. The majority of synthesized derivatives exhibited high activity in all three of the cytokinin bioassays used (tobacco callus, wheat leaf senescence and Amaranthus bioassay). The highest activities were observed in the senescence bioassay. For several of the compounds tested, significant differences in activity were found between the bioassays used, indicating that diverse recognition systems may operate. This suggests that it may be possible to modulate particular cytokinin-dependent processes with specific compounds. In contrast to their high activity in bioassays, the tested compounds were recognized with only very low sensitivity in both Arabidopsis thaliana AHK3 and AHK4 receptor assays. The prepared derivatives were also investigated for their antiproliferative properties on cancer and normal cell lines. Several of them showed very strong cytotoxic activity against various cancer cell lines. On the other hand, they were not cytotoxic for normal murine fibroblast (NIH/3T3) cell line. This anticancer activity of cytokinin ribosides may be important, given that several of them occur as endogenous compounds in different organisms.
- MeSH
- adenosin analogy a deriváty farmakologie chemie MeSH
- antitumorózní látky farmakologie chemická syntéza chemie MeSH
- biotest MeSH
- buňky NIH 3T3 MeSH
- cytokininy farmakologie chemická syntéza chemie MeSH
- fibroblasty účinky léků MeSH
- financování organizované MeSH
- kultivované buňky MeSH
- myši MeSH
- proteinkinasy MeSH
- proteiny huseníčku MeSH
- receptory buněčného povrchu MeSH
- rostliny cytologie účinky léků MeSH
- Check Tag
- myši MeSH
