Ribaudo, Giovanni
Synthesis, characterization and biophysical evaluation of novel G-Quadruplex stabilizing agents [Tesi di dottorato]

The so-called quadruplex forming DNA sequences, with their peculiar feature of being particularly rich in guanines, can be found in many portions of both human and non-human genome. Considering the human genetic information, while one of the traditional localization of these sequences, the telomere, still represents an appealing target in anticancer therapy through indirect telomerase inhibition, many novel involvements are emerging in other portions of the genome. It has to be considered, first of all, that more than 376000 guanine rich sequences were identified in the human genome, with a preferential localization in some regions represented by proto-oncogenes. In this context Gquadruplexes could act as switches turning on and off, or regulating, the transcription of some sequences, according to the fact that structured DNA usually is not processed by the involved enzymes. G-quadruplexes have also been described over the years to be involved in many other key cellular processes such as chromosomal alignment, replication, transcription, genome recombination. This year another important piece of information was added to the quest for G-quadruplex stabilizers as antiviral agents. BRACO-19, an already described acridine-based stabilizing agent, was reported to show anti HIV-1 effects. These attractive targets boost the interest for the discovery of novel G-quadruplex stabilizer and for the investigation of their binding properties with different nucleic acids (DNA, RNA or hybrids), expanding their possible application from the anticancer to the antiviral field. The research project is aimed to the synthesis of small molecules acting as potential stabilizers of this peculiar super molecular arrangement reported to be relatively easily formed by guanine-rich sequences, such as the ones in telomeres. The molecules that were synthesized during this project share, in general, the common structural motifs of previously reported G-quadruplex stabilizing agents (athraquinones, anthracenes, naphtalenediimides, acridines) and are inspired to a compound previously synthesized by the research group of Prof. Zagotto that showed a remarkable activity in stabilizing Gquadruplex DNA. Enhanced techniques such as molecular modeling, fluorescence melting, ESI-MS binding studies and ion mobility MS were then employed for the investigation of the capability of the synthesized molecules of interacting with, and stabilizing, G-quadruplex DNA. These complementary techniques enlightened the relevance of some structural aspects of the synthesized compounds, such as conformational properties, in influencing the efficacy of the DNA stabilization. The results allow to describe preliminary structure-activity relationship data and some promising compounds were finally disclosed.

In relazione con http://paduaresearch.cab.unipd.it/7523/
CHIM/08 - Chimica farmaceutica

Tesi di dottorato. | Lingua: | Paese: | BID: TD16054883