Gene expression analysis in embryos injected with IL7R activating mutation.

• Grant number: 24/01772-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2024
• End date: December 31, 2024
• Field of knowledge: Biological Sciences - Morphology - Embryology
• Principal Investigator: Maraysa de Oliveira Melo Stein
• Grantee: Mariana de Filippi Oliveira
• Host Institution: Centro Infantil de Investigações Hematológicas Dr Domingos A Boldrini (CIB). Campinas , SP, Brazil

Abstract

T-cell acute lymphoblastic leukemia (T-ALL) is a malignant neoplasm that accounts for 15% of cases in children and 25% in adults and is characterized by the uncontrolled proliferation of T- cells lymphocytes. From T-ALL cases described in literature, 25% of them are involved with the IL-7R pathway. Gain-of-function mutations in IL-7Ra were first described at the Boldrini Children`s Center in patients with T-ALL. The majority of diagnosed patients presented cysteine insertion in the juxtamembrane domain at the extracellular portion of the receptor, generating a constitutively active homodimer. With the advancement of molecular biology and omics studies, many mutations have been described, however, little is known about the biological function of these changes and, in vivo models, can contribute to this understanding. With this in mind, the objective of this project is to characterize the hematopoietic gene expression in the presence of the human IL7R activating mutation (hIL7Rmut). We will use the zebrafish model (Dario rerio) because it presents important characteristics such as numerous offspring, transparent embryos, rapid development, ease maintenance and highly conserved hematopoiesis and signaling pathways when compared to humans. The embryos will be injected with constructs containing a ubiquitous promoter or a hematopoietic stem cell-specific promoter driving hIL7Rmut (fused to GFP) expression and their respective controls, expressing only the GFP protein. We will analyze by RT-PCR the differential expression of genes related to the hematopoietic system comparing control with the presence of IL7Rmut and we will validate the findings by in situ hybridization. The generation and consolidation of in vivo models will provide support for future research aimed at studying cancer biology and the function of these mutants during embryonic development.