IFNγ Drives Long-Term Bone Marrow Niche Dysfunction Following Doxorubicin-Based Chemotherapy.

Area of Science:

• Oncology
• Immunology
• Regenerative Medicine

Background:

• Chemotherapy (CTX) can lead to long-term skeletal and hematopoietic complications in cancer survivors.
• The underlying mechanisms of chemotherapy-induced bone marrow (BM) niche dysfunction are not fully understood.

Purpose of the Study:

• To investigate the mechanisms of chemotherapy-induced bone marrow niche defects.
• To identify potential therapeutic targets for preserving bone marrow function post-CTX.

Main Methods:

• Utilized a murine model of doxorubicin (DOX)-based leukemia induction therapy.
• Analyzed bone marrow samples from leukemia patients before and after CTX.
• Investigated the role of interferon-gamma (IFNγ) and employed IFNγ signaling inhibition and deferoxamine mesylate (DFM) treatment.

Main Results:

• CTX induced inflammatory remodeling of the BM niche, characterized by vascular loss, impaired mesenchymal stromal cell (MSC) differentiation, and reduced hematopoietic stem cell (HSC) maintenance.
• Increased IFNγ production by CD8+ T cells was observed in the BM following CTX.
• Inhibition of IFNγ signaling partially restored vascularity and adipogenic differentiation.
• Combined IFNγ blockade and DFM attenuated chemotherapy-associated skeletal damage.
• Leukemia patient samples showed altered MSC priming, upregulated inflammatory pathways, and expanded CD8+ memory T cells post-CTX.

Conclusions:

• IFNγ-driven chronic inflammatory remodeling is a key mechanism in CTX-associated BM niche dysfunction.
• Targeting inflammatory signaling, specifically IFNγ, may preserve BM function and long-term tissue integrity after chemotherapy.