BAG3 gene silencing sensitizes leukemic cells to Bortezomib-induced apoptosis

Proteasome inhibition has emerged as a powerful option for the treatment of a number of malignancies including leukemias. However, Bortezomib showed limited single-agent activity for patients with leukemia. Here, we report for the first time that Bortezomib up-regulated a novel antiapoptotic protein, BAG3, in human leukemic cells. BAG3 gene knockdown with shRNA greatly potentiated the generation of apoptosis by Bortezomib in leukemia cells. Furthermore, BAG3 silencing enhanced the antitumor activity of Bortezomib dramatically in a nude mouse model. Our results indicate that knocking down BAG3 gene is a promising new approach to enhance the therapeutic potency of Bortezomib in leukemia. (C) 2008 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved.