Investigation of the role of SLIT2 protein in mesenchymal stromal cells and its influence on the bone marrow microenvironment in acute myeloid leukemia

Abstract

Among myeloid neoplasms, acute myeloid leukemia (AML) is a heterogeneous group of clonal bone marrow diseases that affect hematopoietic progenitors making them unable to differentiate terminally and to respond to natural regulators of cell death and proliferation. The bone marrow microenvironment acts as an important factor in the development, progression, maintenance and evolution of AML. Mesenchymal stem cells (MSC) are part of this microenvironment and express high levels of hematopoietic stem cells support genes, being their interaction mediated mainly by cytokines. In this context, the Slit/Robo pathway is a promising therapeutic target in the treatment of different types of cancer, due to its involvement in several pathways such as proliferation, cell motility, and angiogenesis. Its abnormal expression is also related to the development and progression of various neoplasms. Among the components of the Slit/Robo pathway, SLIT2 protein plays an important role in different types of cancer, acting as an inhibitor of invasion, migration, cell motility and colony formation, in which the latter is a promising feature in hematological malignancies. Within this context, our research group reported reduced expression of SLIT2 in MSC of AML patients when compared to MSC isolated from hematologically healthy subjects. Therefore, this study aims to determine whether the expression of SLIT2 in MSC can influence the development and progression of AML in in vitro and in vivo models. To determine this influence, it will be used primary cells (from patients with AML and from hematologically healthy donors) and cell lines of MSC and AML. The SLIT2 gene will be overexpressed in MSC and the influence of SLIT2 protein secreted by these cells on different AML lineages will be analyzed using a co-culture system, evaluating its effect on cell proliferation, ROS production and colony formation. Moreover, the gene and protein expression of targets involved in cell cycle regulation and apoptosis, along with downstream targets of the Slit/Robo pathway will be assessed by quantitative PCR and Western Blotting, respectively, as well as the assessment of its influence on in vivo xenotransplantation models. (AU)