Antimyeloma effects of arsenic trioxide are enhanced by melphalan, bortezomib and ascorbic acid

Area of Science:

• Hematology
• Oncology
• Pharmacology

Background:

• Multiple myeloma (MM) is a plasma cell malignancy characterized by chemoresistance.
• Nuclear factor kappa-B (NF-κB) plays a crucial role in MM chemoresistance.
• Arsenic trioxide (ATO) induces apoptosis in malignant plasma cells, potentially overcoming chemoresistance.

Purpose of the Study:

• To evaluate the in vitro and in vivo antimyeloma effects of ATO alone and in combination with bortezomib, melphalan, and ascorbic acid (AA).
• To assess the potential synergistic activity of ATO with other antimyeloma agents in treating MM.

Main Methods:

• In vitro studies using human MM LAGlambda-1 cells treated with ATO and other agents.
• In vivo studies utilizing a severe combined immunodeficient (SCID)-hu murine myeloma model engrafted with human MM LAGlambda-1 cells.
• Assessment of tumor growth and serum paraprotein levels in treated SCID mice.

Main Results:

• ATO demonstrated marked synergistic antimyeloma effects when combined with bortezomib, melphalan, or AA in vitro.
• Combination therapy with ATO significantly suppressed tumor growth in SCID mice compared to single-agent treatments.
• ATO-containing combinations led to significantly reduced serum paraprotein levels, indicating reduced tumor burden.

Conclusions:

• ATO exhibits synergistic activity with bortezomib, melphalan, and AA against multiple myeloma.
• Combining ATO with existing antimyeloma drugs holds promise for improving treatment outcomes in relapsed or refractory MM.
• These findings support the potential clinical utility of ATO-based combination therapies for MM patients.