The effect of GSK3b and BRD4 inhibition on acute myeloid leukemia cells

• Grant number: 23/05550-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2024
• End date: April 30, 2025
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Mariane Tami Amano
• Grantee: Bárbara Schroeder Micchelucci
• Host Institution: Hospital Sírio-Libanês. Sociedade Beneficente de Senhoras (SBSHSL). São Paulo , SP, Brazil

Abstract

Acute myeloid leukemia (AML) is the most prevalent type of myeloid leukemia, which is characterized by abnormal growth and differentiation of hematopoietic progenitor cells. The most common treatment strategy for AML is induced therapy and post-remission therapy, relying on the use of cytarabine. In addition, an increasing number of AML varieties are being identified and yet their therapeutic varieties are still very limited and the need to improve the clinical follow-up of these patients still represents a challenge. BET family proteins have Bromodomains and Extraterminal domains, and participate in gene transcription and epigenetic memory, recognizing post-translational changes. BRD4 is the main component of the BET family, which in 2011 through an RNA inhibitor screening technique for epigenetic regulators, was identified as a potent option for AML treatment. GSK3, or glycogen synthase 3, is an enzyme with participation in signaling pathways and that is being discussed about the possibility of becoming a potential therapeutic target in the treatment of many types of cancer from the discovery that it can act intensifying cell proliferation in different types of cancer. Thus, from clinical studies it was observed that GSK3b inhibitors induce apoptosis in neoplastic AML cells. Our group previously observed a synergistic anti-leukemic effect of using BET inhibitors (iBET) with inhibitors of the PI3K/AKT/mTOR pathway and knowing that the enzyme GSK3 has interactions with these signaling pathways, our goal is to verify if the combination of BRD4 inhibitor and GSK3b inhibitor will have a similar result in AML cells. To this end, we will use AML cell lines and inhibitors of BRD4 and GSK3b. We will identify the best working concentration through IC50 by cell count. We will verify through gene expression (qPCR) and protein phosphorylation (Western Blot) if the BRD4 inhibitor acts on the GSK3b pathway and if the GSK3b inhibitor alters the expression of BRD4 target genes, which could indicate mechanisms of action of these inhibitors still little explored, and eventually explain a possible synergistic effect. Developing this project will provide a better understanding of the individual effect of these inhibitors in the treatment of AML neoplastic cells, as well as their effect together, which may enable treatment alternatives among the so scarce options currently offered for AML.