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Modulation of human telomerase activity by nucleoside and nucleotide analogues
Hájek, Miroslav ; Votruba, Ivan (advisor) ; Fajkus, Jiří (referee) ; Hejnar, Jiří (referee)
CONCLUSIONS Considering human telomerase as a promising target of anti-cancer therapy, the thesis deals with the study of inhibitory potency of selected ANP diphosphates towards telomerase, and the capability of nucleoside-type DNA methylation inhibitors to inhibit hTERT expression, knowing that hTERT expression closely correlates with telomerase activity in vitro and in vivo. The results can be summarized as follows: All the purine ANP diphosphates except for (S)-PMPApp and 6-Me2PMEDAPpp show dose- dependent inhibition of human telomerase in cell-free assay, the adenine derivatives are less effective inhibitors than the guanine derivatives. The only two pyrimidine ANP diphosphates tested (PMECpp and PMETpp) do not show any significant inhibitory potency towards telomerase. Activity of tested ANPs on telomerase is limited to their diphosphates (ANPpp) only. (R)-enantiomers are more inhibitory compared to (S)-enantiomers. This indicates that absolute configuration plays an important role in the telomerase inhibition and that the enzyme distinguishes between the (R)- and (S)-enantiomers. PMEGpp is the most potent human telomerase inhibitor among all ANPs studied with the IC50 value of 12.7 ± 0.5 mol.l-1 at 125 M dNTPs. Its inhibitory potency towards telomerase is comparable to that of ddGTP (IC50...
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Modulation of human telomerase activity by nucleoside and nucleotide analogues
Hájek, Miroslav ; Votruba, Ivan (advisor) ; Fajkus, Jiří (referee) ; Hejnar, Jiří (referee)
CONCLUSIONS Considering human telomerase as a promising target of anti-cancer therapy, the thesis deals with the study of inhibitory potency of selected ANP diphosphates towards telomerase, and the capability of nucleoside-type DNA methylation inhibitors to inhibit hTERT expression, knowing that hTERT expression closely correlates with telomerase activity in vitro and in vivo. The results can be summarized as follows: All the purine ANP diphosphates except for (S)-PMPApp and 6-Me2PMEDAPpp show dose- dependent inhibition of human telomerase in cell-free assay, the adenine derivatives are less effective inhibitors than the guanine derivatives. The only two pyrimidine ANP diphosphates tested (PMECpp and PMETpp) do not show any significant inhibitory potency towards telomerase. Activity of tested ANPs on telomerase is limited to their diphosphates (ANPpp) only. (R)-enantiomers are more inhibitory compared to (S)-enantiomers. This indicates that absolute configuration plays an important role in the telomerase inhibition and that the enzyme distinguishes between the (R)- and (S)-enantiomers. PMEGpp is the most potent human telomerase inhibitor among all ANPs studied with the IC50 value of 12.7 ± 0.5 mol.l-1 at 125 M dNTPs. Its inhibitory potency towards telomerase is comparable to that of ddGTP (IC50...
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Study of interaction of antimicrobial peptides with cells in culture
Kroupová, Hilda ; Stiborová, Marie (advisor) ; Votruba, Ivan (referee)
In English The thesis deals with research of novel antimicrobial peptides (AMP) Halictines (HAL-1, GMWSKILGHLIR-NH2 a HAL-2, GKWMSLLKHILK-NH2) and their structural analogs isolated from the venom of the wild bee Halictus sexcinctus. The structure and antimicrobial activity of these peptides had been described earlier [1]. The goal of this diploma thesis is to find peptide which is strongly toxic only for cancer cells and nontoxic for normal cells. Using of the fluorescent marked peptides we aimed to acquire the information about mechanism of action of the studied peptides on the cells. Using the MTT test (determination of valuation IC50), the toxicity of HAL-1 and HAL-2 and their analogs against 2 normal cell lines (Human umbilical vein endothelial cells, HUVEC, and normal rat intestinal cells, IEC) and against 2 cancer cell lines (cancer cells of suppository uterine, HeLa-S3 and cancer cells of human colorectal carcinoma, CRC SW 480) was determined. First we tested antimicrobial peptides with antimicrobial activity and low hemolytic activity. For verification the toxicity of less active analogs was also determined. We found out that the HeLa-S3 cells are the most sensitive to these peptides. The most toxic peptides (HAL-1/9, HAL-1/18, HAL-2/2) kill 50% of cells in the concentration 2,5 - 10 µM. To obtain...
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Efficient one-pot synthesis of polysubstituted 6-[(1H-1,2,3-triazol-1-yl)methyl]uracils through the "click" protocol
Jansa, Petr ; Špaček, Petr ; Holý, Antonín ; Votruba, Ivan ; Janeba, Zlatko
Synthesis of triazoloacyclic nucleosides and nucleoside phosphonates was developed as the one-pot Cu(I)-catalyzed azide alkyne Huisgen "click" cycloaddition. A novel Cu(I)-catalyzed decarboxylation reaction of 1-substituted 1H-1,2,3-triazole-4-carboxylates at room temperature was observed and used for the preparation of 1-substituted 1H-1,2,3-triazoles.
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Nukleosidy a nukleotidy obsahující 8-aza-7,9-dideazaxanthin
Mařák, David ; Otmar, Miroslav ; Dračínský, Martin ; Votruba, Ivan ; Holý, Antonín
The described preparation of 8-aza-7,9-dideazaxanthine from 1,3-dibenzyluracil and TosMIC was improved by using AlCl3 for final debenzylation. Treatment of 6-dibromomethyl- 5-formyluracil with benzyl-, 4-methoxybenzyl-, and 1-adamantylamine gave the corresponding 8-alkyl-8-aza-7,9-dideazaxanthines. N1- and N8-(8-phosphonooctyl)-8-aza-7,9-dideazaxanthines were prepared and found as inhibitors of thymidine phosphorylase (V79 cells, human placenta, Escherichia coli). IC50 values ranged at 3–27 .mu.M.
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