Bortezomib sensitizes human acute myeloid leukemia cells to all-trans-retinoic acid-induced differentiation by modifying the RARα/STAT1 axis.

Abstract

All-trans-retinoic acid (ATRA) has held great promise for differentiation-based therapy but reportedly downregulates retinoic acid receptor-α (RARα) in a proteasome-dependent manner, which leads to decreased acute myeloid leukemia (AML) cell differentiation efficiency. Therefore, research strategies that seek to further sensitize cells to retinoids and extend the range of retinoid-affected myeloid malignancies beyond acute promyelocytic leukemia (APL) are key investigative avenues. Here, we show that bortezomib, the first proteasome inhibitor approved for newly diagnosed and relapsed multiple myeloma, exhibited strong synergism with ATRA to promote HL60 and NB4 AML cell differentiation. We observed that bortezomib sensitized AML cells to ATRA-induced morphologic, biochemical, and functional changes, indicative of myeloid differentiation without cell death. In addition, treatment of human leukemia HL60 xenografts with bortezomib and ATRA together did not increase bortezomib-induced progressive weight loss but resulted in significant tumor growth inhibition in addition to increased differentiation (P < 0.05). These enhanced differentiation effects were accompanied by RARα stabilization and STAT1 activation. Taken together, our study was the first to evaluate bortezomib and ATRA synergy in AML cell differentiation and to assess new opportunities for bortezomib and ATRA combination as a promising approach for future differentiation therapy.

• Authors: Meidan Ying, Xinglu Zhou, Like Zhong, Nengming Lin, Hui Jing, Peihua Luo, Xiaochun Yang, Hua Song, Bo Yang, Qiaojun He
• Journal: Molecular cancer therapeutics (Mol Cancer Ther) Vol. 12 Issue 2 Pg. 195-206 (Feb 2013) ISSN: 1538-8514 [Electronic] United States
• PMID: 23243061 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: ©2012 AACR.

Chemical References

• Boronic Acids
• Pyrazines
• RARA protein, human
• Rara protein, mouse
• Receptors, Retinoic Acid
• Retinoic Acid Receptor alpha
• STAT1 Transcription Factor
• STAT1 protein, human
• Tretinoin
• Bortezomib

Topics

• Animals
• Antineoplastic Combined Chemotherapy Protocols (pharmacology)
• Apoptosis (drug effects)
• Boronic Acids (administration & dosage, pharmacology)
• Bortezomib
• Cell Differentiation (drug effects)
• Cell Proliferation (drug effects)
• Drug Synergism
• HL-60 Cells
• Humans
• Leukemia, Myeloid, Acute (drug therapy, pathology)
• Mice
• Mice, Nude
• Pyrazines (administration & dosage, pharmacology)
• Random Allocation
• Receptors, Retinoic Acid (metabolism)
• Retinoic Acid Receptor alpha
• STAT1 Transcription Factor (metabolism)
• Tretinoin (administration & dosage, pharmacology)
• Tumor Cells, Cultured
• Xenograft Model Antitumor Assays