In vitro prednisolone resistance signature in MLL-rearranged infant ALL

Acute Lymphoblastic Leukemia (ALL) in infants (<1 year of age) is characterized by a high incidence of MLL translocations which is associated with a poor prognosis. Contributing to this poor prognosis is cellular drug resistance, especially to glucocorticoids like prednisolone. Although in vitro prednisolone resistance mechanisms have been proposed in pediatric ALL, it has never been studied in MLL-rearranged infant ALL, which are highly resistant to glucocorticoids in vitro and in vivo. We analyzed primary MLL-rearranged infant ALL expression profiles, which were either in vitro prednisolone-resistant or prednisolone-sensitive, in order to study in vitro prednisolone resistance.