Elucidating the Role of N-Myc in a High-risk Pediatric T Cell Leukemia
Acute lymphoblastic leukemia (ALL) is the most frequent tumor diagnosed in children. Although many efficient therapies are available to treat ALL, there are specific subtypes of the disease that either do not respond to the drugs or tend to relapse after an initial response. Among these difficult subtypes is the Early T-cell Progenitor Acute Lymphoblastic Leukemia (ETP-ALL), an ALL caused by an alteration of the T-lymphocyte progenitor cells. The mechanism that makes ETP-ALL, among all acute leukemias, so difficult to treat is still unknown. While analyzing the blood samples of children with acute leukemia, we observed that those affected by the ETP-ALL subtype had an abnormally high expression of the Mycn gene. This gene encodes for a protein (N-myc) that regulates cell growth and is critical for brain development. An excessive N-myc expression has been observed in brain tumors, therefore we considered that a similar mechanism might drive ETP-ALL as well.
To test this hypothesis, we will study mice affected by a leukemia comparable to human ETP-ALL and investigate if the ablation of N-myc will make their leukemia regress. At the same time, we will transplant patient-derived ETP-ALL cells into recipient mice and treat them with drugs targeting N-myc. This set of experiments will allow us to see if the inhibition of N-myc is a promising therapy for ETP-ALL patients. In parallel, we will accurately analyze the molecular changes induced by N-myc aberrant expression to better understand what drives this disease and what makes it so difficult to treat.