PD-1, PD-L1, PD-L2 expression in the chordoma microenvironment

Area of Science:

• Oncology
• Immunology
• Cancer Biology

Background:

• Chordomas are rare malignant tumors originating from notochord remnants.
• The interaction between chordomas and the immune system is not well understood.
• The PD-1/PD-L1 pathway is a key regulator of immune responses and is implicated in various cancers.

Purpose of the Study:

• To investigate the expression and localization of PD-1 pathway proteins (PD-1, PD-L1, PD-L2) in chordoma.
• To understand the potential role of this pathway in the chordoma tumor microenvironment.

Main Methods:

• Flow cytometry and RT-PCR were used on three chordoma cell lines.
• Immunohistochemical analysis was performed on chordoma tissue samples from 10 patients.

Main Results:

• PD-1 ligands were not constitutively expressed by chordoma cells but were induced by pro-inflammatory cytokines.
• Tumor-infiltrating lymphocytes expressed PD-1 in a subset of cases.
• PD-L1 was found on tumor-infiltrating macrophages and lymphocytes, but not significantly on chordoma cells.

Conclusions:

• The PD-1 pathway components are present in the microenvironment of a subset of chordomas.
• Further research is needed to determine the contribution of the PD-1 pathway to the immunosuppressive nature of chordomas.