AMG-۲۳۲, a New Inhibitor of MDM-۲,Enhance Doxorubicin Efficiency in Pre-B Acute Lymphoblastic Leukemia Cells

Background: Doxorubicin (DOX)-induced cardiotoxicity appears to be a growing concern for extensive use in acute lymphoblastic leukemia (ALL). The new combination treatment strategies, therefore might be an effective way of decreasing its side effects as well as improving efficacy. AMG۲۳۲ (KRT-۲۳۲) is a potential MDM-۲ inhibitor, increasing available p۵۳ through disturbing p۵۳-MDM-۲ interaction. In this study, we examined the effects of AMG۲۳۲ on DOX-induced apoptosis of NALM-۶ cells. Methods: The anti-leukemic effects of Doxorubicin on NALM-۶ cells, either alone or in combination with AMG۲۳۲, were confirmed by MTT assay, Annexin/PI apoptosis assay, and cell cycle analysis. Expression of apoptosis and autophagy-related genes were further evaluated by Real time-PCR method. To investigate the effect of AMG۲۳۲ on NALM-۶ cells, the activation of p۵۳, p۲۱, MDM-۲, cleaved Caspase-۳ proteins was evaluated using western blot analysis. Results: The results showed that AMG۲۳۲ inhibition of MDM-۲ enhances Doxorubicin-induced apoptosis in NALM-۶ cells through caspase-۳ activation in a time and dose-dependent manner. Furthermore, cotreatment of AMG۲۳۲ with Doxorubicin hampered the transition of NALM-۶ cells from G۱ phase through increasing p۲۱ protein. In addition, this combination treatment led to enhanced expression of apoptosis and autophagy-related genes in ALL cell lines. Conclusions: The results declared that AMG۲۳۲ as an MDM-۲ inhibitor could be an effective approach to enhance antitumor effects of Doxorubicin on NALM-۶ cells as well as an effective future treatment for ALL patients.

Keywords:

Acute Lymphoblastic Leukemia , AMG ۲۳۲ , Autophagy , Doxorubicin , p۵۳.