The effect of the combined treatment of BET inhibitors and signaling pathways on the induction of DNA damage in leukemic cells

• Grant number: 18/20815-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2018
• End date: April 30, 2021
• Field of knowledge: Biological Sciences - Immunology - Cellular Immunology
• Principal Investigator: Mariane Tami Amano
• Grantee: Elayne Bragança Jardim
• Host Institution: Hospital Sírio-Libanês. Sociedade Beneficente de Senhoras (SBSHSL). São Paulo , SP, Brazil
• Associated scholarship(s): 19/26194-2 - Influence of the genetic background on PLSCR1 tyrosine phosphorylation in IgE receptor-activated mast cells, BE.EP.IC

Abstract

Acute myeloid leukemia (AML) is an aggressive disease and corresponds to the lower survival rate among leukemias types. Only 40% of the patients under 60 y.o. survive more than 5 years and, in patients over 60 y.o., the chemotherapy does not provide the cure and cause death in less than a year. Thus, revealing the urgent seek for new treatments. The BRD4 (Bromodomain-containing protein 4), belongs to the family of proteins with Bromodomain and Extraterminal domain (BET) and it is a component of the transcription complexes, was identified as the main target for the AML treatment. Our group previously observed the anti-leukemic synergistic effect of the use of BET inhibitors (iBET) with signaling pathway PI3K/AKT/mTOR inhibitors. Since the DNA damage and/or repair failure can foment cell death, and there are a few words that show the effect of iBET on DNA damage, our objective is to check if the combination of iBET with the inhibitors of the signaling pathways interferes in the induction of DNA damage and/or repair. First, we will standardize inhibitors concentrations by cell viability using different cell lines (HL-60, HEL, U937, THP-1, MOLM-13 and K562). Then, we will analyze the DNA damage promoted by the combining of iBET with the inhibitors of the signaling pathways using ³H2AX labeling by flow cytometry (FACS). Finally, we will evaluate the gene expression of factors associated with DNA damage and repair in this combined treatment by qPCR. In this way, we intend to verify whether the synergistic effect of the combined treatment involves the mechanism of DNA damage and/or repair, besides verifying if the inhibition of other signaling pathways also has the same effect increasing cell death. Therefore, a better understanding of the role of iBET in the antitumor process, as well as the possibility of a better response with the combination of other drugs, will allow an alternative treatment in the context of scarce options for AML.