Research in the Crispino laboratory is investigating the regulatory mechanisms governing normal and malignant blood cell development, with an emphasis on understanding the growth of erythroid cells (red blood cells) and megakaryocytes (platelet-producing cells). In addition, the group has a major interest in learning how changes in normal essential regulatory molecules lead to human blood diseases, including acute leukemias and myeloproliferative neoplasms (MPNs). The lab seeks to make seminal basic science discoveries while simultaneously translating these discoveries in ways that will benefit patients with hematologic malignancies.
Following our discoveries that the transcription factor GATA1 is mutated in Acute Megakaryoblastic Leukemia (AMKL) in children with Down syndrome (DS) and that GATA1 mutations are also present in a pre-leukemia named Transient Myeloproliferative Disorder (TMD), we are characterizing the role of GATA1 in normal megakaryocyte development and investigating how GATA1 mutations contribute to leukemia. We are also studying the mechanisms by which trisomy 21 promotes the development of leukemia with a long-term goal of unraveling the mystery of why children with DS are predisposed to leukemia. Our current efforts are focused on characterizing the contributions of two chromosome 21 genes: DYRK1A, a kinase, and ERG, a transcription factor. These studies are performed in collaboration with Nobuko Hijiya, MD and other colleagues at Lurie Children’s.
Megakaryocytes, the precursors to platelets, are one of the few cells types to undergo polyploidization (an accumulation of DNA) in the normal course of maturation. We are using high throughput methods to identify genes that control the switch between the proliferation and polyploidization. We are also examining the contribution of key transcription factors, such as GATA1, GATA2 and ETS proteins in the regulation of megakaryocyte gene expression, terminal differentiation, and lineage commitment. In addition to these studies, we are characterizing megakaryocyte maturation in patients with myeloproliferative neoplasms. These studies have provided new insights into the mechanisms by which MPN associated mutations lead to the production of atypical immature megakaryocytes and suggest new avenues for therapeutic intervention.
In collaboration with the Broad Institute, we identified several small molecules that induce proliferation arrest, polyploidization and terminal maturation of malignant megakaryocytes. By a three-pronged target identification approach, we discovered that a key target of these small molecules is Aurora A Kinase. We are currently investigating the utility of AURKA inhibitors as potential new, targeted therapies for acute megakaryocytic leukemia. In addition, we have completed extensive pre-clinical studies to support the testing of AURKA inhibitors in a related blood disease named primary myelofibrosis, a subtype of the MPNs.
We are currently studying two aspects of red blood cell development. First, based on our previous discovery that the coalescence of cytoplasmic vesicles is required for enucleation of erythroblasts, we are probing the requirements for specific motor proteins in enucleation and identifying small molecules that enhance enucleation in culture. This research will aid in the development of new strategies to generate red blood cells for transfusion in vitro from stem cells. Second, in line with our expertise and significant interest in GATA1 biology, we are studying the effects of GATA1 mutations on erythropoiesis. We are using state-of-the-art approaches to identify essential, direct GATA1 target genes whose expression depends on the presence of the full-length wild-type protein. This research is relevant to rare red blood cell disorders such as Diamond Blackfan Anemia.
John Crispino, PhD: Professor of Medicine; Robert I. Lurie, MD, and Lora S. Lurie Professor, Northwestern University Feinberg School of Medicine; Associate Director of Education, Robert H. Lurie Comprehensive Cancer Center