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| Author(s): |
Nathália Moreno Cury
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia |
| Defense date: | 2019-08-22 |
| Examining board members: |
José Andrés Yunes;
Flávia Cristina Rodrigues Lisoni;
Fabiana Regina Nonato;
Ana Lucia Tasca Gois Ruiz;
Patricia Yoshioka Jotta
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| Advisor: | José Andrés Yunes |
| Abstract | |
Medical chemistry is a growing area in Brazil that depends on a multidisciplinary team. Many groups have been working on the synthesis of new drugs with potential use in oncology. However, the majority of these studies describes only the in vitro cytotoxic activity of these compounds against cancer culture cells, but not the elucidation of their mechanism of action. In this context, the present research aimed to discover the mechanism of action of three new classes of drugs followed by preclinical studies using the most effective drug of each class. Standard cytotoxicity tests allowed us to choose the best compounds of each class, which are called, compound 12, indole 20 and epoxy. The effects of these compounds on cellular viability and apoptosis as well as the transcriptional profile of leukemia cells treated with them were characterized. Gene expression data analysis in GSEA platform allowed us to investigate cellular processes and / or metabolic and signaling pathways affected by the drugs, while analyzes on CMap platform indicated analogous drugs whose mechanisms of action are already known. Both compounds 12 and indole 20 were characterized as tubulin destabilizing agents whose antimitotic effects are due to the tubulin dynamics interference leading to cell cycle arrest in G2 / M and consequent induction of apoptosis. Biochemical studies and subsequent crystallography of the tubulin-compound 12 complex evidenced their interaction in the colchicine binding site of ?-tubulin. Compound 12 binds to tubulin through hydrophobic interactions and a single hydrogen bond, unlike other microtubule inhibitors that bind to the same pocket through two or more hydrogen bonds. In preclinical studies, compound 12 demonstrated anti-leukemia activity at doses lower than 1 mg / kg, with no acute toxicity when given intraperitoneally in repeated doses of 10 mg / kg. In addition, we showed the efficacy of compound 12 against leukemia cells expressing the multi-drug resistance phenotype both in vitro and in vivo. Indole 20 compound also showed its own efficacy against leukemia cells, however, it was lower in the leukemia animal model when compared to compound 12’ efficacy. One particularity found for indole 20 was its ability to induce differentiation of acute promyelocytic leukemia cells, HL60. The epoxy compound induced electrophilic stress in leukemia cells with consequent cellular glutathione depletion and positive regulation of genes involved in the NRF2-mediated oxidative stress response. In addition, epoxy caused DNA adducts formation leading to chromosomal breaks, as described for alkylating agents. In conclusion, the methodology adopted in the present thesis proved to be valid for the characterization of the mechanism of action of three new compounds aiming the development of new drugs for the treatment of acute leukemias (AU) | |
| FAPESP's process: | 14/08247-8 - Preclinical studies of novel inhibitors of DNA methyltransferase in acute leukemia |
| Grantee: | Nathalia Moreno Cury |
| Support Opportunities: | Scholarships in Brazil - Doctorate |