CD73 expression and clinical significance in human metastatic melanoma

This is the first study to characterize CD73 expression in human metastatic melanomas without restriction to a specific metastatic site, also, it is the first to characterize CD73 expression in melanoma TIMC.

Dr. Laurence de Leval from the Institute of Pathology, Lausanne University Hospital, Lausanne, Switzerland said "Our study aims at characterizing CD73 expression in human metastatic melanoma, its association with clinicopathological parameters and its prognostic impact."

In physiological conditions, CD73 is expressed by stromal cells, follicular dendritic cells, and endothelial cells but also by variable proportions of adaptive immune cells.

Adenosine promotes regulatory T cell function, decreases T helper 1 and natural killer cell activity, inhibits M1 macrophage activation, promotes macrophage M2 differentiation and drives dendritic cells towards an anti-inflammatory cytokine profile.

Figure 1: Distribution of CD73 staining in tumor cells. Distribution of CD73 staining in the tumor cells of the 114 melanoma metastases according to percentage of TC staining (0 to >90%), intensity of staining (0 to 3) and H-score (0 to >37.5).

In colorectal cancer, higher tumoral CD73 and lower stromal CD73 expression significantly associated with higher TNM stage, presence of lymphatic metastasis and poor tumor differentiation.

CD73 expression on tumor cells of triple negative breast cancer was significantly associated with reduced overall survival and negatively correlated with tumor immune infiltration.

Regarding melanoma, one recent study showed that cell lines derived from metastatic melanomas express more CD73 than those derived from normal melanocytes or primary melanomas.

The Leval research team concluded "Immunohistochemistry detected CD73 expression in more than half of metastatic melanomas. While CD73 expression in TC significantly correlated with decreased OS, CD73 expression in TIMC significantly associated with improved OS. These results encourage the study of anti-CD73 therapies for metastatic melanoma patients."

Full text - https://doi.org/10.18632/oncotarget.25426

Correspondence to - Laurence de Leval - laurence.deleval@chuv.ch

Keywords - CD73, ecto-5'-nucleotidase, immunohistochemistry, melanoma, prognosis