Synergistic disruption of BTK and BCL-2 causes apoptosis while inducing ferroptosis in double-hit lymphoma

Area of Science:

• Oncology
• Hematology
• Molecular Biology

Background:

• Double-hit lymphoma (DHL) is an aggressive subtype of Diffuse Large B-cell Lymphoma (DLBCL) with limited treatment options and poor prognosis.
• Bruton's tyrosine kinase (BTK) inhibitor monotherapy shows limited efficacy in aggressive lymphomas, necessitating combination therapies.

Purpose of the Study:

• To investigate the synergistic effect of zanubrutinib (a second-generation BTK inhibitor) and navitoclax (a BCL-2 inhibitor) in suppressing DHL.
• To elucidate the underlying mechanisms, including apoptosis and ferroptosis induction.

Main Methods:

• Utilized a comprehensive in silico approach, including single-cell and bulk-level profiling.
• Performed in vitro validation using DHL cell lines and in vivo studies in mouse models.
• Assessed apoptosis, ferroptosis markers (ROS, lipid peroxidation, glutathione), and key regulatory proteins (NRF2, HMOX1, GPX4).

Main Results:

• Zanubrutinib and navitoclax demonstrated synergistic activity against DHL cells, with a higher synergy score in the DHL subset.
• The combination induced both apoptosis and ferroptosis, characterized by ROS accumulation and lipid peroxidation.
• BTK inhibition enhanced sensitivity to navitoclax and sensitized DHL cells to ferroptosis by downregulating NRF2, HMOX1, and GPX4.
• The combination therapy effectively suppressed tumor growth in vivo.

Conclusions:

• Zanubrutinib and navitoclax exhibit potent synergistic anti-lymphoma activity in DHL by co-inducing apoptosis and ferroptosis.
• This combination represents a promising therapeutic strategy for patients with double-hit lymphoma.
• Targeting BTK and BCL-2 pathways concurrently offers a novel approach to overcome treatment resistance in aggressive lymphomas.