BACKGROUND

Multiple myeloma (MM) remains incurable due to inevitable therapeutic resistance, and Bortezomib (BTZ ) resistance is a major challenge. The interferon-inducible protein 16 (IFI16) is implicated in oncogenesis and drug resistance, but its role in MM BTZ resistance is unknown. Here,we identified IFI16 as a key mediator of drug resistance through bioinformatic analysis and clinical validation.

METHODS

Transcriptomic profiling of bortezomib-resistant MM cells (GSE160572, GSE136337, GSE2658, GSE9782) identified IFI16 as a top resistance-associated gene (HR>1, p<0.005). Validation cohorts included 78 MM patients (newly diagnosed/remission/relapsed) a nd iron-deficiency anemia controls. Functional studies utilized IFI16-silence down/overexpression models in H929/U266 cells and murine xenografts (subcutaneous/disseminated). mechanisms were performed by RNA-seq，WB and dual-luciferase reporter assays.

KEY RESULTS

Clinical Significance:

IFI16 expression was significantly elevated in newly diagnosed (3.8-fold, p=0.002) and relapsed MM (2.9-fold, p=0.007) vs remission, correlating with bone lesions (r=0.5), renal impairment (r=0.47), and poor survival (HR=3.1, 95%CI 0.625-15.68).

Functional Validation:

IFI16 knockdown sensitized MM cells to bortezomib (IC50 decreased 2.2-fold, p<0.001), increased apoptosis (2.4-fold, p<0.001), and induced G0/G1 arrest.

IFI16 overexpression conferred resistance (IC50 increased 1.6-fold, p<0.001) and reduced drug-induced apoptosis by14% (p=0.04).

Mechanism:

IFI16 activated Wnt/β- catenin signaling, increasing β-catenin (2.1-fold), p-GSK3β (2.5-fold), and cyclin D1(1.8-fold) while suppressing p21(3.1-fold); but IWP-2 reversed changes of the above protein and function resistance in IFI16-overexpressing cells.

In Vivo Efficacy:

IFI16 knockdown synergized with bortezomib, reducing tumor volume (decreased 70%, p<0.0001) and osteolytic lesions in murine models. Immunohistochemistry confirmed pathway suppression (β-catenin downregulated 70%; Ki67downregulated 50%).

CONCLUSIONS & INNOVATION

This study identifies that IFI16 is a prognostic biomarker and predictor of treatment failure and as a novel master regulator of MM pathogenesis and BTZ resistance. We also demonstrate that IFI16 exerts its oncogenic effects primarily through constitutive activation of the Wnt/β-catenin pathway. Targeting the IFI16/Wnt/β-catenin axis represents a promising strategy to overcome BTZ resistance and restore proteasome inhibitor sensitivity in high-risk MM.

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2025
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