All-trans-retinoic acid enhances apoptosis induction by tyrosine kinase inhibitors in the eosinophilic leukemia-derived EoL-1 cell line

Imatinib and retinoids induce apoptosis in FIP1L1/PDGFRα-positive EoL-1 leukemia cells. Although imatinib induces complete remission in most FIP1L1/PDGFRα-positive patients, response to imatinib is sometimes suboptimal. In order to enhance the potency of the molecularly targeted therapy of eosinophilic leukemia, we investigated the effect of retinoids combined with tyrosine kinase inhibitors on EoL-1 cells. We demonstrate that retinoids combined with tyrosine kinase inhibitors lead to enhanced apoptosis induction in EoL-1 cells. Our results suggest that tyrosine kinase inhibitors combined with retinoids may constitute a valuable therapeutic approach for sensitive neoplasias that may display enhanced anti-leukemic potency when compared to single drug treatments.