Healthy myeloid-derived suppressor cells express the surface ectoenzyme Vanin-2 (VNN2).

Study of human monocytic Myeloid-Derived Suppressor cells Mo-MDSC (CD14 HLA-DR) has been hampered by the lack of positive cell-surface markers. In order to identify positive markers for Mo-MDSC, we performed microarray analysis comparing Mo-MDSC cells from healthy subjects versus CD14 HLA-DR monocytes. We have identified the surface ectoenzyme Vanin-2(VNN2) protein as a novel biomarker highly-enriched in healthy subjects Mo-MDSC.

A Liquid Biopsy to Assess Brain Tumor Recurrence: Presence of Circulating Mo-MDSC and CD14+ VNN2+ Myeloid Cells as Biomarkers That Distinguish Brain Metastasis From Radiation Necrosis Following Stereotactic Radiosurgery.

Background: Brain metastases (BM) are the most common type of brain tumor malignancy in the US. They are also the most common indication for stereotactic radiosurgery (SRS). However, the incidence of both local recurrence and radiation necrosis (RN) is increasing as treatments improve.

The ratio of HLA-DR and VNN2 expression on CD14 myeloid derived suppressor cells can distinguish glioblastoma from radiation necrosis patients.

Glioblastoma (GBM) is the most aggressive and lethal type of brain cancer with a median survival of less than two years even following aggressive treatment (Stupp et al., N Engl J Med 352:987-996, 2005). Among the many challenges in treating patients with this devastating disease is the ability to differentiate Magnetic Resonance Imaging (MRI) images that appear following radiation therapy, often termed "radiation necrosis" from true GBM recurrence.