Key Immune Checkpoint PD-1/PD-L1 Signaling Pathway Components in the Blood Serum from Patients with Bone Tumors

Area of Science:

• Oncology
• Immunology
• Biochemistry

Background:

• Soluble programmed death-1 (sPD-1) and soluble programmed death-ligand 1 (sPD-L1) are immune checkpoint proteins.
• Their role in primary bone tumors is not fully understood.
• Biomarkers are needed for early cancer detection and characterization.

Purpose of the Study:

• To investigate serum levels of sPD-1 and sPD-L1 in patients with various primary bone tumors.
• To compare these levels with those in healthy individuals and patients with benign neoplasms.
• To explore potential correlations between sPD-1/sPD-L1 levels and clinical parameters.

Main Methods:

• Serum samples were collected from 132 patients with primary bone tumors (osteosarcoma, chondrosarcoma, Ewing sarcoma, chordoma, giant-cell bone tumor, benign neoplasms) and 27 healthy controls.
• Levels of sPD-1 and sPD-L1 were quantified using biochemical assays.
• Statistical analyses were performed to compare levels between groups and assess correlations.

Main Results:

• sPD-L1 levels were significantly higher in all bone neoplasms compared to controls.
• sPD-1 levels were significantly elevated in giant-cell bone tumors (GCBT) compared to controls, benign neoplasms, chondrosarcoma, and chordoma.
• sPD-1 levels showed significant differences between Ewing sarcoma, chordoma, chondrosarcoma, and controls, but were not associated with clinical factors.

Conclusions:

• Elevated serum sPD-L1 is a potential biomarker for bone neoplasms.
• sPD-1 levels may help differentiate certain bone tumors like GCBT.
• These biomarkers could aid in the preliminary assessment of bone lesions, though not correlated with disease stage or grade.