Funded by the Apple Gold Group
Neuroblastoma is the third most common childhood cancer. Unfortunately, despite intensive treatment, two-thirds of children with advanced neuroblastoma succumb to their disease. New treatment options must be developed to improve outcomes in this devastating disease. This requires a better understanding of how neuroblastoma cells survive in the face of these intensive therapies. N-Myc is a member of a family of proto-oncogenes (genes capable of leading to cancer development) implicated as a cause of several cancers. N-Myc plays a central role in the aggressiveness of neuroblastoma tumors. Children whose neuroblastoma tumors have extra copies of the N-Myc gene (N-Myc amplification) fare worse than children whose tumors have the normal number of N-Myc genes. However, it is unknown why extra N-Myc leads to poor outcomes. Mxi1 is a protein related to the Myc family, however, it counteracts the ability of N-Myc to cause cell growth. Mxi0 is a similar protein, but it does not inhibit N-Myc like Mxi1. In this proposal, we will test the hypothesis that the balance of Mxi1 and Mxi0 expression is important for maintaining normal growth, and that N-Myc alters this balance, leading to treatment resistance. To accomplish this, we developed a new kind of mouse which has its Mxi1 or Mxi0 genes removed. In this project, we will examine the impact of decreasing Mxi1 or Mxi0 expression on neuroblastoma tumor formation and response to treatment, with the overall goal of finding a mechanism to bypass the effects of N-Myc and improve the outcomes of children with neuroblastoma.