RESUMEN
By combining the ability of short G-rich oligodeoxyribonucleotides (ODNs) containing the sequence 5'CGGA3' to form higher order G-quadruplex (G4) complexes with the tetra-end-linked (TEL) concept to produce aptamers targeting the HIV envelope glycoprotein 120 (gp120), three new TEL-ODNs (1-3) having the sequence 5'CGGAGG3' were synthesized with the aim of studying the effect of G4 dimerization on their anti-HIV activity. Furthermore, in order to investigate the effect of the groups at the 5' position, the 5' ends of 1-3 were left uncapped (1) or capped with either the lipophilic dimethoxytrityl (DMT) (2) or the hydrophilic glucosyl-4-phosphate (3) moieties. The here reported results demonstrate that only the DMT-substituted TEL-ODN 2 is effective in protecting human MT-4 cell cultures from HIV infection (76% max protection), notwithstanding all the three new aptamers proved to be capable of forming stable higher order dimeric G4s when annealed in K+-containing buffer, thus suggesting that the recognition of a hydrophobic pocket on the target glycoprotein by the aptamers represents a main structural feature for triggering their anti-HIV activity.
Asunto(s)
Fármacos Anti-VIH/farmacología , Aptámeros de Nucleótidos/farmacología , Oligodesoxirribonucleótidos/farmacología , Fármacos Anti-VIH/síntesis química , Fármacos Anti-VIH/metabolismo , Aptámeros de Nucleótidos/síntesis química , Aptámeros de Nucleótidos/genética , Aptámeros de Nucleótidos/metabolismo , Línea Celular , G-Cuádruplex , Proteína gp120 de Envoltorio del VIH/metabolismo , Infecciones por VIH/prevención & control , Humanos , Oligodesoxirribonucleótidos/síntesis química , Oligodesoxirribonucleótidos/genética , Oligodesoxirribonucleótidos/metabolismo , Unión ProteicaRESUMEN
Cytostatic agents often do not discriminate in their cytostatic potential between different tumor cell types in vitro. In this study, several 2-aminothiophene-3-carboxylic acid ester derivatives were discovered that show an unusual cytostatic selectivity for several T-cell (but not B-cell) lymphoma, prostate cancer, kidney carcinoma and hepatoma cell lines. Their 50 % cytostatic concentrations were generally in the higher nanomolar range and were approximately 20- to 50-fold lower for these tumor cell types than for any other tumor cell line or non-tumorigenic cells. The tumor-selective compounds caused a more preferential suppression of protein synthesis than DNA or RNA synthesis and the prototype compound 3 resulted in an accumulation of prostate cancer cells in the G1 phase of their cell cycle. Compound 3 was also shown to induce apoptosis in prostate cancer cells. The 2-aminothiophene-3-carboxylic acid ester derivatives represent novel candidate cytostatic agents to be further explored for their tumor-selective potential.