Academic Background

Lucio Castilla received his B. S. from the University of Buenos Aires in 1988, and his Ph.D. from the University of Michigan in 1995. He was a postdoctoral fellow in the National Human Genome Research Institute, at the National Institutes of Health, from 1995 to 2000. He joined the University of Massachusetts Medical School, in the Program of Gene Function and Expression, as an Assistant Professor in 2000. He is the recipient of a Special Fellow Award from the Leukemia and Lymphoma Society (1999) and an AACR-Sidney Kimmel Symposium for Cancer Research Scholar Award (2002). Dr. Castilla is a Leukemia and Lymphoma Society Scholar (2007-2012).

Genetics of Leukemia, Mouse Models

The goal of our laboratory is to understand the molecular mechanisms of leukemia development. Leukemia arises from the abnormal expansion of hematopoietic stem cells that have acquired multiple genetic alterations that block differentiation programs and provide proliferation and survival capacity. The dimeric transcription factor “core-binding-factor” (CBF) is a master regulator of gene expression during development and differentiation. Genetic alterations in either CBF subunit, RUNX1 or CBFß, have been associated with human leukemia. For example, acute myeloid leukemia (AML) samples with chromosome 16 inversion express the fusion gene CBFB-MYH11. We and others have shown that Cbfb-MYH11 expression hinders multi-lineage differentiation. We have recently used a conditional Cbfb-MYH11 knock-in mouse model to show that the fusion gene also creates an abnormal myeloid progenitor that progress to AML upon the accumulation of cooperating mutations that provide proliferation and/or survival advantage (see Figure).

One line of our research uses conditional knock-in and knock-out strategies to better understand the role of CBF factors in hematopoietic stem cells and the alterations induced by Cbfb-MYH11 expression in this compartment as well as during multi-lineage differentiation. Second, we are characterizing the contribution of other de-regulated genes that collaborate with Cbfb-MYH11 in leukemogenesis. We use retroviral insertional mutagenesis in mice expressing Cbfb-MYH11 to identify candidate cooperating genes. We are particularly interested on one of these factors, the pleomorphic adenoma like-2 gene (PlagL2), and are studying its role in normal and malignant hematopoiesis. Third, the leukemic cells are a heterogeneous group of cells at different stages of differentiation. Few of these cells, called leukemia-initiating cells, hold the capacity to expand indefinitely and recreate the disease. We focus part of our efforts on characterizing the CBF leukemia-initiating cells, with the goal of identifying small molecules that inhibit Cbfb-MYH11 function and may be used in the design of improved therapy.