The purpose of this research study is to evaluate an investigational drug (DFMO) in combination with bortezomib, for relapsed and refractory neuroblastoma. DFMO is an investigational drug because it has not been approved by the U.S. Food and Drug Administration (FDA). This study will look at the safety and tolerability of DFMO in combination with bortezomib as well as the tumors response to this study drug.