Naoko Kunami1, Hiroo Katsuya1, Rumiko Nogami1, Kenji Ishitsuka2, Kazuo Tamura1. 1. Department of Internal Medicine, Division of Medical Oncology, Hematology and Infectious Diseases, Fukuoka University, Jonan, Fukuoka, Japan. 2. Department of Internal Medicine, Division of Medical Oncology, Hematology and Infectious Diseases, Fukuoka University, Jonan, Fukuoka, Japan kenjiishitsuka@fukuoka-u.ac.jp.
Abstract
BACKGROUND: Adult T-cell leukemia/lymphoma (ATL) is an aggressive malignancy of peripheral T-lymphocytes and its prognosis still remains very poor. MATERIALS AND METHODS: The potential of combining the Bcl-2 homology 3 mimetic ABT-737, which blocks Bcl-2, Bcl-XL, and Bcl-w, with either the proteasome inhibitor bortezomib or histone deacetylase (HDAC) inhibitor suberoylanilide hydroxamic acid (SAHA) to inhibit the growth of human T-lymphotropic virus type-I (HTLV-1) infected T-cell lines and its mechanism was further evaluated. RESULTS: ABT-737 synergistically induced apoptosis when combined with either bortezomib or SAHA in HTLV-1 infected T-cell lines and fresh ATL cells. Bortezomib increased the expression of Noxa, which subsequently enhanced the formation of Mcl-1-Noxa complexes, resulting in the functional neutralization of Mcl-1, an inducer of resistance to ABT-737. On the other hand, SAHA reduced the expression of survivin, an anti-apoptotic molecule that confers drug resistance on ATL cells. CONCLUSION: The combination of ABT-737 with bortezomib or SAHA is promising for the treatment of ATL. Copyright
BACKGROUND:Adult T-cell leukemia/lymphoma (ATL) is an aggressive malignancy of peripheral T-lymphocytes and its prognosis still remains very poor. MATERIALS AND METHODS: The potential of combining the Bcl-2 homology 3 mimetic ABT-737, which blocks Bcl-2, Bcl-XL, and Bcl-w, with either the proteasome inhibitor bortezomib or histone deacetylase (HDAC) inhibitor suberoylanilide hydroxamic acid (SAHA) to inhibit the growth of human T-lymphotropic virus type-I (HTLV-1) infected T-cell lines and its mechanism was further evaluated. RESULTS:ABT-737 synergistically induced apoptosis when combined with either bortezomib or SAHA in HTLV-1 infected T-cell lines and fresh ATL cells. Bortezomib increased the expression of Noxa, which subsequently enhanced the formation of Mcl-1-Noxa complexes, resulting in the functional neutralization of Mcl-1, an inducer of resistance to ABT-737. On the other hand, SAHA reduced the expression of survivin, an anti-apoptotic molecule that confers drug resistance on ATL cells. CONCLUSION: The combination of ABT-737 with bortezomib or SAHA is promising for the treatment of ATL. Copyright
Authors: Ercan Cacan; Alexander M Spring; Anita Kumari; Susanna F Greer; Charlie Garnett-Benson Journal: Int J Mol Sci Date: 2015-12-21 Impact factor: 5.923