Interferon-γ Sensitises Human Osteosarcoma Cells to Trail-mediated Apoptosis

Area of Science:

• Oncology
• Molecular Biology
• Cell Death Signaling

Background:

• Osteosarcoma treatment remains challenging, with nearly half of patients not cured by current multimodal therapies.
• Novel therapeutic strategies are crucial to improve osteosarcoma patient outcomes.
• Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL) selectively induces apoptosis in cancer cells, sparing normal cells.

Purpose of the Study:

• To investigate the synergistic effects of TRAIL and Interferon-gamma (IFN-γ) on human osteosarcoma cell lines.
• To determine if IFN-γ can sensitize TRAIL-resistant osteosarcoma cells.
• To elucidate the role of caspases in TRAIL/IFN-γ-induced apoptosis in osteosarcoma.

Main Methods:

• Treatment of four human osteosarcoma cell lines (Saos-2, U2OS, KPDXM, OHS) and one normal human fibroblast cell line (MRC-5) with TRAIL and IFN-γ.
• Assessment of cell viability and apoptosis induction.
• Analysis of caspase cascade activation (caspase-8, caspase-7, PARP) and inhibition studies using caspase inhibitors (zVADfmk, zIETDfmk).

Main Results:

• IFN-γ sensitized one TRAIL-resistant osteosarcoma cell line to TRAIL-mediated apoptosis.
• IFN-γ enhanced TRAIL-induced cell death in two of three TRAIL-sensitive osteosarcoma cell lines.
• Normal fibroblasts (MRC-5) showed no adverse effects from TRAIL and IFN-γ treatment.
• Apoptosis was mediated by a caspase cascade, partly inhibited by caspase inhibitors, highlighting the role of caspases in the observed cell death.

Conclusions:

• Combined treatment with IFN-γ and TRAIL effectively induces cell death in osteosarcoma cell lines.
• This combination therapy warrants further investigation as a potential future treatment strategy for osteosarcoma.