Human bone-derived 3D ECM model induces reversible ibrutinib resistance and reshapes DLBCL cytokine milieu

Diffuse large B-cell lymphoma (DLBCL) frequently relapses due to microenvironment-mediated drug resistance, particularly with bone marrow involvement, which signals poor prognosis. Current preclinical models often fail to accurately replicate the complex extracellular matrix (ECM) of the bone marrow, hindering the investigation of how these interactions drive resistance. Understanding these mechanisms is crucial for developing strategies to overcome treatment failure in DLBCL, as standard-of-care therapies like immunochemotherapy often face limitations in this context.

Researchers utilized a decellularized human bone-derived 3D scaffold to investigate the impact of ECM interactions on four DLBCL cell lines (OCI-LY1, OCI-LY18, RIVA, NU-DUL-1). Functional assays and cytokine profiling were conducted under both 2D and 3D culture conditions. The study evaluated cell proliferation, cytokine secretion, and sensitivity to ibrutinib in both settings. Drug-induced apoptosis was a primary endpoint, with comparisons made against inert 3D scaffolds and conditions where cell-ECM interactions were disrupted.

The 3D ECM model profoundly remodeled the DLBCL secretome compared to 2D cultures, upregulating a coordinated network of pro-migratory chemokines, notably CXCL9, CCL22, CCL17, CCL4, and CXCL1/2/3. ECM engagement significantly enhanced DLBCL migration and promoted scaffold colonization, indicating a positive feedback loop. While all DLBCL cell lines were sensitive to ibrutinib in 2D, ECM-adherent OCI-LY18 and RIVA cells showed reduced drug-induced apoptosis in 3D. This effect was dependent on direct ECM contact and was not reproduced by inert 3D scaffolds. Importantly, the ibrutinib resistance was fully reversible upon disruption of cell-ECM interaction. Mechanistically, ECM adhesion was associated with activation of the AKT/mTOR pathway.

Direct tumor-matrix interactions in a human bone-derived 3D ECM model induce reversible ibrutinib resistance and significantly reshape the cytokine milieu in DLBCL.