Study of pre-leukemic hematopoiesis caused by RUNX1 mutations
Mentor: Dr. Lucio Castilla
The transcription factor RUNX1 is a master regulator of hematopoietic differentiation. Mutations in the RUNX1 gene is found in a variety of pediatric cancers, including predisposition to leukemia. The role of RUNX1 mutant function in the pre-leukemic stem cell activity, and as a driver of leukemia, however, is poorly understood. Research at the Castilla laboratory focuses on understanding mechanisms directing hematopoietic stem cell dysfunction and transformation. To better understand the role of RUNX1 mutations in pre-leukemia stage, the Castilla laboratory recently utilized CRISPR/Cas9 technology to develop a mouse strain with an allelic R201Q mutation in the RUNX1 gene (RUNX1+/R201Q). This mutation is frequently found in patients with heme-malignancies, and it has been reported to have dominant negative activity. The hypothesis of this application is that RUNX1-R201Q protein impairs normal blood development, and that it reduces the DNA-damage response function in these cells thereby inducing leukemia. The overall goal of this POST summer internship application is divided in two parts: First, the applicant will study how RUNX1-R201Q protein disrupts hematopoietic differentiation, by analyzing the representation of hematopoietic progenitors and differentiated leukocytes, using flow cytometry. Second, the applicant will determine the level of DNA-damage in bone marrow hematopoietic progenitors, utilizing specific markers by microscopy and flow cytometry. Furthermore, these studies will include the use of RUNX-null mice to determine whether the defects observed in progenitor cell with the RUNX1-R201Q mutation have a dominant negative phenotype. These studies will provide critical information on how this mutation promotes leukemia development, and provide the applicant with first-hand training in the field of leukemia.